Denim Resource

Dye House Water Minimum Standards

2010-11-26T13:18:00.002+05:00

Characteristic Permissible Limit

Colour Colourless
Smell Odourless
pH value Neutral pH 7–8
Water hardness < 5 dH (6.25eH; 8.95fH; 5.2 USA)
Dissolved solids < 1 mg/l
Solid deposits < 50 mg/l
Organic substances < 20 mg/l (KMnO4 consumption)
Inorganic salts < 500 mg/l
Iron (Fe) < 0.1 mg/l
Manganese (Mn) < 0.02 mg/l
Copper (Cu) < 0.005 mg/l
Nitrate ( NO3 ) < 50 mg/l
Nitrite ( NO2 ) < 5 mg/l

Textile Dictionary

2010-11-05T12:35:00.000+05:00

A Abrasion Resistance - The degree by which a fabric is able to withstand loss of appearance through surface wear, rubbing, chafing, and other frictional actions.
Absorbency - The ability of a fabric to take in moisture. Absorbency is a very important property, which effects many other characteristics such as skin comfort, static build-up, shrinkage, stain removal, water repellency, and wrinkle recovery.
Acetate - A manufactured fiber formed by a compound of cellulose, refined from cotton linters and/or wood pulp, and acedic acid that has been extruded through a spinneret and then hardened.
Acrylic - A manufactured fiber derived from polyacrylonitrile. Its major properties include a soft, wool-like hand, machine washable and dryable, excellent color retention. Solution-dyed versions have excellent resistance to sunlight and chlorine degradation.
Air Permeability - The porosity of a fabric as estimated by the ease with which air passes through it. Air permeability measures the warmth of blankets, the air resistance of parachute cloth, the wind resistance of sailcloth, etc. as measured on standard testing equipment.
Algaecide - Kills algae.
Alpaca - A natural hair fiber obtained from the Alpaca sheep, a domesticated member of the llama family. The fiber is most commonly used in fabrics for dresses, suits, coats, and sweaters.
Angora - The hair of the Angora goat. Also known as Angora mohair. Angora may also apply to the fur of the Angora rabbit. However, according to the U.S. Federal Trade Commission, any apparel containing Angora rabbit hair must be labeled as "Angora rabbit hair" on the garment.
Anti-Bacterial (Anti-Microbial) - A fabric that has been chemically treated or a fiber that is created by incorporating the anti-bacterial chemical agent into the fiber formula, making the finished fiber or fabric resistant to, or inhibiting the growth of micro-organisms.
Antifungal - Inhibits or kills fungi.
Anti-Static - Can be either a fiber or fabric that does not allow the build-up of static electricity to occur when the fiber or fabric experiences friction or rubbing.
Aramid - A manufactured fiber in which the fiber-forming substance is a long chain of synthetic polyamide in which at least 85% of the amide linkages are attached directly to two aromatic rings. Aramid fabrics are very strong and are resistant to high temperatures and extreme external forces. Aramid fabrics are used in thermally protective clothing; (i.e. coveralls, jackets, gloves, shirts, pants). U.S. FTC Definition: A manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in that is at least 85% of the amide linkages are attached directly to two aromatic rings.
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B Back Length - The dimension on a garment taken from the center collar attaching seam to the bottom of the garment, or in the case of a coverall, to the top of the waistband.
Back Waist Length - The dimension on a body, taken from the top of the back bone at the base of the neck to the waistline.
Bactericide - Kills bacteria.
Bacteriostat - Doesn't necessarily mean that it kills bacteria. A stat means that it may simply be slowing growth or holding the death to growth rates of bacteria (same for fungal stats) more or less in equilibrium. Inhibits bacteria growth.
Ballistic - A thick woven fabric that is extremely abrasion resistant and tough; has a denier of about 2000, and is used in apparel, packs and gear.
Band (Continuous/Grown-on) - Pant panels that extend to the top of the pant and are folded over without an outside band. A separate inside band lining is sewn through the pant and has an interlining.
Band (Pasted-on/Folder-set) - A separate band sewn on the pant with stitching that shows on the outside at the top and bottom.
Band (Rocap) - A separate band of body fabric sewn on and turned down so the attaching seam is not visible. Inside the band is a separate lining---made from pcketing fabric---and interlining.
Barré - An imperfection, characterized by a ridge or mark running in the crosswise or lengthwise directions of the fabric. Barrés can be caused by tension variations in the knitting process, poor quality yarns, problems during the finishing process.
Bartack - To reinforce a seam with a bar of stitches that provides a more durable seam end. (Commonly used at points of strain.)
Base Layer - The apparel in contact with your skin. The purpose of the base layer is to keep you warm/cool and dry.
Basket Weave - A variation of the plain weave construction, formed by treating two or more warp yarns and/or two or more filling yarns as one unit in the weaving process. Yarns in a basket weave are laid into the woven construction flat, and maintain a parallel relationship. Both balanced and unbalanced basket weave fabrics can be produced. Examples of basket weave construction includes monk cloth and oxford cloth.
Bast Fiber - Strong, soft, woody fibers, such as flax, jute, hemp, and ramie, which are obtained from the inner bark in the stems of certain plants.
Batiste - A medium-weight, plain weave fabric, usually made of cotton or cotton blends. End-uses include blouses and dresses.
Bedford Cord - A cord cotton-like fabric with raised ridges in the lengthwise direction. Since the fabric has a high strength and a high durability, it is often used for upholstery and work clothes.
Beeze - Piping or cording formed at lower and inside pocket welts.
Besom - An edging or reinforcement around a pocket opening.
Bicomponent Fiber - Manufactured fiber made of continuous filaments, and made of two related components, each with different degrees of shrinkage. The result is a crimping of the filament, which makes the fiber stretchable.
Bleaching - A process of whitening fibers, yarns, or fabrics by removing the natural and artificial impurities to obtain clear whites for finished fabric, or in preparation for dyeing and finishing. The materials may be treated with chemicals or exposed to sun, air, and moisture.
Blend - A term applied to a yarn or a fabric that is made up of more than one fiber. In blended yarns, two or more different types of staple fibers are twisted or spun together to form the yarn. Examples of a typical blended yarn or fabric is polyester/cotton.
Bonding - The technique of permanently joining together two fabrics or layers of fabrics together by a bonding agent.into one package. The bonding of fibers in a single layer of material is called a web. Special adhesives, binders, or thin slices of foam may be used as the marrying agent.
Bonding - A process for adhesive laminating of two or more fabrics or fabric and a layer of plastic by means of a bonding agent (adhesives, plastics or cohesion).
Boucle - A knit or woven fabric made from a rough, curly, knotted boucle yarn. The fabric has a looped, knotted surface and is often used in sportswear and coats
Break - Point on the front edge of the garment at which the roll of the lapel begins. Usually at the same point as the lower end of the bridle.
Breathability - The movement of water or water vapor from one side of the fabric to the other, caused by capillary action, wicking, chemical, or electrostatic action. Also known as moisture transport.
Broad Spectrum Antimicrobial - An antimicrobial that effectively controls or kills at least 3 of the basic microorganism groups. This term is important to help give a specific encompassing term to technologies that offer protection from the gamut of microorganisms, without the sometimes vague nature of the term antimicrobial, which could mean kills just one type or kills many types.
Broadcloth - A plain weave tightly woven fabric, characterized by a slight ridge effect in one direction, usually the filling. The most common broadcloth is made from cotton or cotton/polyester blends.
Brocade - A heavy, exquisite jacquard type fabric with an all-over raised pattern or floral design. Common end-uses include such formal applications as upholstery, draperies, and eveningwear.
Brushing - A finishing process for knit or woven fabrics in which brushes or other abrading devices are used on a loosely constructed fabric to permit the fibers in the yarns to be raised to create a nap on fabrics or create a novelty surface texture.
Bunting - Can be either a cotton or wool fabric, woven in a plain open weave, similar to cheesecloth, and dyed in the piece. Cotton bunting is often woven with plied yarns. Wool bunting is woven with worsted worsted yarns, using strong, wiry wool.
Burlap - A loosely constructed, heavy weight, plain weave fabric used as a carpet backing, and as inexpensive packaging for sacks of grain or rice. Also, as fashion dictates, burlap may also appear as a drapery fabric.
Burn-out - A brocade-like pattern effect created on the fabric through the application of a chemical, instead of color, during the burn-out printing process. (Sulfuric acid, mixed into a colorless print paste, is the most common chemical used.) Many simulated eyelet effects can be created using this method. In these instances, the chemical destroys the fiber and creates a hole in the fabric in a specific design, where the chemical comes in contact with the fabric. The fabric is then over-printed with a simulated embroidery stitch to create the eyelet effect. However, burn-out effects can also be created on velvets made of blended fibers, in which the ground fabric is of one fiber like a polyester, and the pile may be of a cellulosic fiber like rayon or acetate. In this case, when the chemical is printed in a certain pattern, it destroys the pile in those areas where the chemical comes in contact with the fabric, but leave the ground fabric unharmed.
Buttonhole (eyelet) - Formed by a contoured patch of zig-zag stitching, followed by a cut---a portion of which is circular. Eyelet buttonholes are usually used on heavy fabrics and/or with large buttons. A gimp or cord is usually contained within the stitches to provide a reinforcement along the edge of the hole.
Buttonhole (straight) - Formed by two pairs of straight, parallel rows of zigzag stitching, followed by a single, straight knife cut. Each end of the row of stitching is secured by a bartack.
Buttons - Specified by design, size, color, and type---such as brass, melamine, or pearl, buttons are either shanked (attached by passing threads through the shank's eye) or holed (attached by passing threads through the button's holes).
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C Calendering - A process for finishing fabrics in which such special effects as high luster, glazing, embossing, and moiré are produced.
Calico - A tightly-woven cotton type fabric with an all-over print, usually a small floral pattern on a contrasting background color. Common end-uses include dresses, aprons, and quilts.
Camel's Hair - A natural fiber obtained from the hair of the Bactrian camel, a two-humped pack-carrying species. The fiber is used primarily in coats, sweaters, and suits.
Canvas - Cotton, linen, or synthetic fabric made with a basic plain weave in heavy and firm weight yarns for industrial or heavy duty purposes. Also referred to as "duck", although the term "canvas" usually relates to the heavier, coarser constructions.
Capillary Action - A process by which liquids are drawn through the fabric and into pores found between fibers and yarns.
Carding - A process which eliminates fibers too short for inclusion in the spun yarn. The process also removes dirt and foreign matter still remaining in the fiber mass, and arranges the fibers into a very thin layer.
Cashmere - A luxury fiber obtained from the soft fleecy undergrowth of the Kashmir goat of Tibet, Mongolia, China, Iran, Iraq, and India. Most commonly used in sweaters, shawls, suits, coats, and dresses.
Cellulose - A material derived from the cell walls of certain plants. Cellulose is used in the production of many vegetable fibers, as well as being the major raw material component used in the production of the manufactured fibers of acetate, rayon, and triacetate.
Challis - A lightweight, soft plain weave fabric with a slightly brushed surface. The fabric is often printed, usually in a floral pattern. Challis is most often seen in fabrics made of cotton, wool, or rayon.
Chambray - A plain woven fabric that can be made from cotton, silk, or manufactured fibers, but is most commonly cotton. It incorporates a colored warp (often blue) and white filling yarns
Chenille - 1. A specialty yarn, characterized by a pile protruding on all sides, resembling a caterpillar. The yarn is produced by first weaving a fabric with a cotton or linen warp and a silk, wool, rayon, or cotton filling. The warp yarns are taped in groups of tightly woven filling yarns, which have been beaten in very closely. After weaving, the fabric is cut into strips between the yarn groups. Each cutting produces a continuous chenille yarn, which is then twisted, creating the chenille yarn, and giving the pile appearance on all sides of the yarn. The chenille yarn is used mainly for decorative fabrics, embroidery, tassels, and rugs. 2. A fabric woven from the chenille yarn.
Chiffon - A plain woven lightweight, extremely sheer, airy, and soft silk fabric, containing highly twisted filament yarns. The fabric, used mainly in evening dresses and scarves, can also be made from rayon and other manufactured fibers.
Chino - Classic all-cotton "Army twill" fabric made of combed two-ply yarns. Usually vat dyed, mercerized, and given a compressive shrinkage finish. Used traditionally for army uniforms, chino is now finding popularity sportswear and work clothes.
Chintz - Glazed plain weave cotton fabric with a tioghtly spun fine warp and a coarser slack twist filling, often printed with brightly colored flowers or stripes. Named from Hindu word meaning spotted. Several types of glazes are used in the finishing process. Some glazes wash out in laundering, but others such as resin finishes are permanent. Unglazed chintz is called cretonne. Chintz end-uses include draperies, slipcovers, skirts, and summer dresses, and shirts.
Chintz - A plain-weave fabric, which has been glazed to produce a polished look. Usually made of cotton, this fabric is most commonly used in blouses, dresses, draperies, and slipcovers.
Chlorinated Wool - Wool in the fiber, yarn, or fabric form which are treated chemically to decrease felting shrinkage and increase ability to take dyes.
Circular Knit - Weft knit fabric made on a circular needle-bed knitting machine, which produces fabric in tubular form. Common types include single or double knits. Seamless hosiery are also made on a circular knitting machine. Although allowances are made on the machine for knitting the welt and foot. See Knitting (Circular).
Cleaning - Hand operation in which the basting threads are removed from the garment; usually done prior to the final pressing.
Clo Value - A unit of thermal resistance. The insulation required to produce the necessary heat to keep an individual comfortable at 21 degrees Centigrade with air movement at .1 m/s. One clo is about equal to the insulation value of typical indoor clothing.
Closures - Items used to close openings in apparel and other consumer textile products, i.e. buttons, buckles, hook and eye, snaps and zippers.
Coated Fabrics - Fabrics that have been coated with a lacquer, varnish, rubber, plastic resin of polyvinyl chloride or polyethylene, or other substance to make them longer lasting or impervious to water or other liquids.
Collar - Two or more thicknesses of fabric attached to the neckhole opening to provide a firm and neat-appearing finish.
Collar (Banded) - The visible or panel portion of the collar is cut separately and attached to the neckband portion. This is normal dress shirt construction.
Collar (convertible) - The panel or visible portion of the collar and the neckband portion are cut as one piece, but folded once along the length to produce the appearance of a banded collar.
Collar (Lined) - A collar made by placing a piece of interlining between the two pieces of body fabric.
Collar (one piece) - A collar constructed from a single piece of fabric with the center fold forming the outer edge.
Collar (padding) - Attaching the under-collar to canvas with several rows of blindstitching.
Collar (sandwich) - A collar which has the top-collar inserted between the canvas and the under-collar.
Collar (topstitched) - A collar with an added row of stitching along the folded edges.
Collar (two-piece) - A collar formed by joining two identical pieces, inverting and sometimes topstitching along the folded edges.
Color Abrasion - Color changes in localized areas of a garment due to differential wear, such as the knees of blue jeans. Often evident in cross-dye shades of blends where durable press treatments are applied. Color abrasion is often called "frosting".
Colorfastness - A term used to describe a dyed fabric's ability to resist fading due to washing, exposure to sunlight, and other environmental conditions.
Combing - The combing process is an additional step beyond carding. In this process the fibers are arranged in a highly parallel form, and additional short fibers are removed, producing high quality yarns with excellent strength, fineness, and uniformity.
Comfort Stretch - The term given to the freedom of movement experienced in the wearing of a garment that contains spandex, or has stretch engineered into a yarn through mechanical stretch construction.
Commercial Standards - "Recorded voluntary standards of the trade." The U.S. Bureau of Standards issues Commercial Standards which are not laws, but are important as accepted voluntary benchmarks of performance and quality by the industry. These standards are usually referred to by number, and spell out test procedures and minimum performance guidelines.
Composite Fabric - An engineered fabric made from two or more components. One component is often a strong fiber such as fiberglass, Kevlar®, or carbon fiber that gives the material its tensile strength, while another component (often called a matrix) is often a resin, such as polyester or epoxy that binds the fibers together.
Compression Fabric - A high tenacity stretch fabric which, when in a close fitting garment, provides muscles with a firm compression fit that lessons vibrations, reduces fatigue, and keeps muscles energized. The fabric is usually made in a knit construction, using a series of gradient fibers with an open knit inner surface to create a moisture transfer environment.
Compression Stretch - The name given to the expansive stretch that is created by the spandex fibers used in the development of a compression fabric.
Continuous Cure - A method of curing durable press garments which uses a moving conveyor system to carry garments into and out of the curing oven. Also known as continuous oven.
Continuous Filament - A long continuous, unbroken strand of fiber extruded from a spinneret in the form of a monofilament. Most manufactured fibers such as nylon, polyester, rayon, and acetate are made in continuous filament form.
Converter - A person or a company which buys grey goods and sells them as finished fabrics. A converter organizes and manages the process of finishing the fabric to a buyers' specifications, particularly the bleaching, dyeing, printing, etc.
Converter - A person or a company which buys grey goods and sells them as finished fabrics. A converter organizes and manages the process of finishing the fabric to a buyers' specifications, particularly the bleaching, dyeing, printing, etc.
Corduroy - A fabric, usually made of cotton, utilizing a cut-pile weave construction. Extra sets of filling yarns are woven into the fabric to form ridges of yarn on the surface. The ridges are built so that clear lines can be seen when the pile is cut
Core Yarn - A yarn in which one type of fiber is twisted or wrapped around another fiber that serves as a core. Core yarns are often used to make stretch fabrics where the core is spandex or rubber, and the outer wrapped fiber is a textured manufactured fiber such as polyester or nylon.
Core-Spun Yarns - Consist of a filament base yarn, with an exterior wrapping of loose fiber which has not been twisted into a yarn. Polyester filament is often wrapped with a cotton outer layer in order to provide the strength and resiliency of polyester, along with the moisture-absorbent aesthetics and dye affinity of cotton. Sewing thread as well as household and apparel fabrics are made from these yarns.
Cotton - A unicellular, natural fiber that grows in the seed pod of the cotton plant. Fibers are typically 1/2 inch to 2 inches long. The longest staple fibers, longer than 1 1/2 inch, including the Pima and Egyptian varieties, produce the highest quality cotton fabrics.
Count of Cloth - The number of warp ends and picks per inch in a woven fabric. If a cloth is 68 X 72, it means there are 68 ends and 72 picks per inch in a woven fabric. A cloth that has the same number of ends and picks per inch in woven goods is called a square cloth. 80-square percale, for example, has 80 warp ends and 80 picks per inch.
Course - The rows of loops or stitches running across a knitted fabric. Corresponds to the weft or filling in woven goods.
Crabbing - A treatment used to set the cloth and yarn twists permanently in woolens and worsted goods.
Crease Resistant Finish - Also referred to as CRF. Finishes used on fabrics that make them resistant to wrinkling and creasing, such as synthetic resin type finishes like durable press. Today some fabrics are made highly resistant to wrinkling through fiber blending and construction.
Crease Retention - The ability of a cloth to hold or pleat or a crease, which has been intentionally created, through the use of a heat treatment. Heat setting of thermoplastic fibers causes creases to be permanently set.
Crepe-back Satin - A satin fabric in which highly twisted yarns are used in the filling direction. The floating yarns are made with low twist and may be of either high or low luster. If the crepe effect is the right side of the fabric, the fabric is called satin-back crepe.
Crinoline - A lightweight, plain weave, stiffened fabric with a low yarn count (few yarns to the inch in each direction).
Crocking - The rubbing-off of dye from a fabric. Crocking can be the result of lack of penetration of the dyeing agent, the use of incorrect dyes or dyeing procedures, or the lack of proper washing procedures and finishing treatments after the dyeing process.
Crocking - The tendency of excess dyes to rub off. Napped and pile fabrics in deep colors are most likely to crock. Industry has set standards and tests to measure and prevent crocking.
Crotch Seam - The short seam from the back of the pants fly to the inseam.
Cuff (lined) - A cuff with interlining placed between the two pieces of body fabric.
Cuff (one-piece) - A two-ply cuff formed by folding over a single piece of fabric, usually with a lining in between.
Cuff (topstitched) - A cuff with an added row of stitching along the folded edges.
Cuff (two-piece) - A cuff in which two identical pieces of fabric, usually with a lining in between, are joined by a seam along the edge, then turned and sometimes topstitched near the folded edges.
Cuprammonium - A process of producing a type of regenerated rayon fiber. In this process, the wood pulp or cotton liners are dissolved in an ammoniac copper oxide solution. Bemberg rayon is a type of Cuprammonium rayon.
Curing - A baking process with the use of resin finishes, applying heat under carefully controlled conditions to a fabric or the garment, which cause a reaction in the finishing agents and make them work. Crease-retention, water repellency, wrinkle resistance, and durable press are examples of finishes that are cured.
Cut-on-cross - Fabric that is cut so that the warp runs horizontally across the garment piece.
Cut-on-fold - Fabric that is doubled, then cut.
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D Damask - A glossy jacquard fabric, usually made from linen, cotton, rayon, silk, or blends. The patterns are flat and reversible. The fabric is often used in napkins, tablecloths, draperies, and upholstery.
Dart (cut-in) - An open dart cut in approximately 12" under the armhole.
Dart (front or double) - An additional closed dart located toward the front edge of the garment, used to get maximum waist suppression.
Dart (panel) - A panel sewn full length to the front that is used for waist suppression.
Denier - A system of measuring the weight of a continuous filament fiber. In the United States, this measurement is used to number all manufactured fibers (both filament and staple), and silk, but excluding glass fiber. The lower the number, the finer the fiber; the higher the number, the heavier the fiber. Numerically, a denier is the equivalent to the weight in grams of 9,000 meters of continuous filament fiber.
Denier Per Filament - The size of an individual filament, or an individual staple fiber if it were continuous, The dpf is determined by dividing the yarn denier per filament by the number of filaments in the yarn.
Denim - True denim is a twill weave cotton-like fabric made with different colored yarns in the warp and the weft. Due to the twill construction, one color predominates on the fabric surface.
Dobby Weave - A decorative weave, characterized by small figures, usually geometric, that are woven into the fabric structure. Dobbies may be of any weight or compactness, with yarns ranging from very fine to coarse and fluffy. Standard dobby fabrics are usually flat and relatively fine or sheer. However, some heavyweight dobby fabrics are available for home furnishings and for heavy apparel
Doeskin - Generally used to describe a type of fabric finish in which a low nap is brushed in one direction to create a soft suede-like feel on the fabric surface. End-uses include billiard table surfaces and men's' sportswear.
Donegal Tweed - A medium to heavy, plain or twill weave fabric in which colorful yarn slubs are woven into the fabric. The name originally applied to a hand-woven woolen tweed fabric made in Donegal, Ireland. End-uses include winter coats and suits.
Dotted Swiss - A lightweight, sheer cotton or cotton blend fabric with a small dot flock-like pattern either printed on the surface of the fabric, or woven into the fabric. End-uses for this fabric include blouses, dresses, baby clothes, and curtains.
Double Cloth - A fabric construction, in which two fabrics are woven on the loom at the same time, one on top of the other. In the weaving process, the two layers of woven fabric are held together using binder threads. The woven patterns in each layer of fabric can be similar or completely different
Double Knit - A fabric knitted on a circular knitting machine using interlocking loops and a double stitch on a double needle frame to form a fabric with double thickness. It is the same on both sides. Today, most double knits are made of I5O denier polyester, although many lightweight versions are now being made using finer denier yarns and blends of filament and spun yarns.
Double Knit - A weft knit fabric in which two layers of loops are formed that cannot be separated. A double knit machine, which has two complete sets of needles, is required for this construction.
Double Weave - A woven fabric construction made by interlacing two or more sets of warp yarns with two or more sets of filling yarns. The most common double weave fabrics are made using a total of either four or five sets of yarns.
Down - The soft, fluffy fiber or underfeathers of ducks, geese, or other water fowl. Used primarily for insulation in outerwear garments.
Duck - A tightly woven, heavy, plain-weave, bottom-weight fabric with a hard, durable finish. The fabric is usually made of cotton, and is widely used in men's and women's slacks, and children's play clothes.
Durability - The ability of a fabric to resist wear through continual use.
Durable Press - A treatment applied to the fabric in the finishing process in which it maintains a smooth attractive appearance, resists wrinkling, and retains creases or pleats during laundering.
Durable Water Repellent (DWR) - Fabrics that retain their durability and their ability to repel water after wearing, washing, and cleaning. Typically involves a fabric with a coating
Dye (Piece) - Dyeing of the fabric into solid colors after weaving or knitting.
Dye (Yarn) - Dyeing of the yarn into solid colors before weaving or knitting.
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E Edge - The front margin of the garment that extends from front corner to front corner.
Edge Tape - A tape sewn along the front edge of a coat from top of the lapel to bottom of the facing. On less expensive coats, this tape starts at the bottom of the lapel (called the breakline). The tape is usually sewn with an edge-knife machine.
Elasticity - The ability of a fiber or fabric to return to its original length, shape, or size immediately after the removal of stress.
Embossing - A calendering process in which fabrics are engraved with the use of heated rollers under pressure to produce a raised design on the fabric surface.
Embroidery - An embellishment of a fabric or garment in which colored threads are sewn on to the fabric to create a design. Embroidery may be done either by hand or machine.
Encapsulation - A process in which the fibers of a fabric are coated with a filmy substance to create certain high performance qualities, such as breathability.
Ergonomic Seaming - This apparel construction technology is aimed at maximizing comfort and ease of movement. The key feature of this seaming technology is that the seams are constructed ergonomically. Therefore, the seams flow according to the body's natural movements, regardless of the type of activity engaged in by the wearer. The seams are placed away from potential pressure points, in order to maximize comfort and movement.
Ergonomics - The study of improving a garment design by enhancing the wearers' comfort, performance, or health.
Eyelet - A type of fabric which contains patterned cut-outs, around which stitching or embroidery may be applied in order to prevent the fabric from raveling.
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F Face Finished Fabrics - Fabrics which have surface treatments that provide a variety of looks and effects on the fabric surface. These include brushing, sanding, sueding, etc. The warp knit industry is specially innovative with face finishing techniques.
Facing - A piece of fabric that is sewn to the collar, front opening, cuffs, or arms eye of a garment to create a finished look.
Faille - A glossy, soft, finely-ribbed silk-like woven fabric made from cotton, silk, or manufactured fibers
Fell - To join two pieces of material with the edges folded together using double needle stitching.
Felt - A non-woven fabric made from wool, hair, or fur, and sometimes in combination with certain manufactured fibers, where the fibers are locked together in a process utilizing heat, moisture, and pressure to form a compact material.
Fiber - The basic entity, either natural or manufactured, which is twisted into yarns, and then used in the production of a fabric.
Fiberfill - Specially engineered manufactured fibers, which are used as filler material in pillows, mattresses, mattress pads, sleeping bags, comforters, quilts, and outerwear
Filament - A manufactured fiber of indefinite length (continuous), extruded from the spinneret during the fiber production process.
Filling - In a woven fabric, the yarns that run cross the fabric from selvage to selvage, and which run perpendicular to the warp or lengthwise yarns. Also referred to as the weft.
Findings - Any extra items attached to a garment during the manufacturing process. This can include trims, buttons, hooks, snaps, or embellishments.
Finished Fabric - A fabric that has gone through all the necessary finishing processes, and is ready to be used in the manufacturing of garments. These processes include bleaching, dyeing, printing, heat setting, etc.
Flame Resistant - Fabrics treated with special chemical agents or finishes to make them resistant to burning. Today many fabrics achieve this property by using fibers that have this property built directly into the polymer. A fabric is considered flame resistant if it passes federal specifications for specific end-uses.
Flame Retardant - A chemical applied to a fabric, or incorporated into the fiber at the time of production, which significantly reduces a fabric's flammability.
Flannel - A medium-weight, plain or twill weave fabric that is typically made from cotton, a cotton blend, or wool. The fabric has a very soft hand, brushed on both sides to lift the fiber ends out of the base fabric and create a soft, fuzzy surface. End-uses include shirts and pajamas.
Flannelette - A medium-weight, plain weave fabric with a soft hand, usually made from cotton. The fabric is usually brushed only on one side, and is lighter weight than flannel. End-uses include shirts and pajamas.
Flax - The plant from which cellulosic linen fiber is obtained. Linen is used in apparel, accessories, draperies, upholstery, tablecloths, and towels.
Fleece - The wool shorn from any sheep, or from any animal in the wool category.
Fleece Fabric - A lightweight fabric with a thick, heavy fleece-like surface. It may be a pile or napped fabric, or either woven or knit construction. End uses include coats, jackets, blankets, etc. Fleece fabrics are available in a variety of constuctions: 1) Polarfleece® is the original fleece fabric, developed in 1979, by Malden Mills. It is typically used for non-technical garments, and it is only available at Malden Mills®; 2) Polartec®, also developed by Malden Mills, was created for today's high-performance technical garments, which provides enhanced durability warmth, wind resistance, breathability and weather protection.
Flocking - A type of raised decoration applied to the surface of a fabric in which an adhesive is printed on the fabric in a specific pattern, and then finely chopped fibers are applied by means of dusting, air-brushing, or electrostatic charges. The fibers adhere only to the areas where the adhesive has been applied, and the excess fibers are removed by mechanical means.
Foulard - A lightweight twill-weave fabric, made from filament yarns like silk, acetate, polyester, with a small all-over print pattern on a solid background. The fabric is often used in men's ties.
Four-way Stretch - A fabric that stretches both on the crosswise and lengthwise grains of the fabric. It is the same as two-way stretch.
Front(stitched down) - A front the has a double-turned hem that is stiched down full length of the front. The term may also refer to the shell (outside) front of self-goods.
Full-cut - Not tapered.
Fungicide - Kills fungi.
Fungistat - Inhibits fungal growth.
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G Gabardine - A tightly woven, twilled, worsted fabric with a slight diagonal line on the right side. Wool gabardine is known as a year-round fabric for business suiting. Polyester, cotton, rayon, and various blends are also used in making gabardine.
Gauge - A measurement most commonly associated with knitting equipment. It can mean the number of needles per inch in a knitting machine. However, in full fashioned hosiery and sweater machines, the number of needles per 1-1/2 inches represents the gauge.
Gauze - A thin, sheer plain-weave fabric made from cotton, wool, silk, rayon, or other manufactured fibers. End-uses include curtains, apparel, trimmings, and surgical dressings.
Georgette - A sheer lightweight fabric, often made of silk or from such manufactured fibers as polyester, with a crepe surface. End-uses include dresses and blouses.
Geotextiles - Manufactured fiber materials made into a variety of fabric constructions, and used in a variety civil engineering applications.
Gingham - A medium weight, plain weave fabric with a plaid or check pattern. End-uses include dresses, shirts, and curtains.
Glass Fiber - An inorganic fiber which is very strong, but has poor flexibility and poor abrasion resistance. Glass will not burn and will not conduct electricity. It is impervious to insects, mildew, and sunlight. Today, the primary use of glass fiber is in such industrial applications as insulation or reinforcement of composite structures.
Gorge - The break between the collar and the lapel.
Greige Goods - An unfinished fabric, just removed from a knitting machine or a loom. Also called grey goods.
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H Hand - The way the fabric feels when it is touched. Terms like softness, crispness, dryness, silkiness are all terms that describe the hand of the fabric.
Hard Shell - A high-impact, abrasion-resistant outer fabric, which provides protection from the environment.
Heat Set Finish (Heat Sealing) - A process of heat finishing that will stabilize many manufactured fiber fabrics in order that there will not be any subsequent change in shape or size. Heat setting is used to permanently impart a crease, a pleat, or durability into a fabric or garment---a finish that will remain through repeated washings and dry cleanings.
Heather - A yarn that is spun using pre-dyed fibers. These fibers are blended together to give a particular look. (For example, black and white may be blended together to create a grey heathered yarn.) The term, heather, may also be used to describe the fabric made from heathered yarns.
Heavy Weight - Also called expedition weight. Most often use din base layers. Thick and warm, it is usually brushed on the inside for warmth and wicking, and smooth on the outside to protect.
Hem (clean) - The double fold of fabric secured with a row of stitching with the raw edge of the fabric buried within the fold.
Hem (raw) - A single fold of fabric secured with a row of stitching, leaving the raw edge of the fabric exposed.
Hemp - >A coarse, durable bast fiber obtained from the inner bark of the hemp plant. Used primarily in twines and cordages, and most recently apparel.
Herringbone - A variation on the twill weave construction in which the twill is reversed, or broken, at regular intervals, producing a zig-zag effect.
High Loft - A term given to a fiber structure that contains more air then fiber. It is a lofty, low-density material that is used in such applications as fiberfill, insulation, etc.
High Visability Fabrics - Fabrics that contain fluorescent materials in order to make the wearer visible in dim and dark lights. These fabrics have the ability to reflect on-coming lights, which cause them to glow in the dark.
Hollow Fiber - Manufactured fiber made with a hollow center.
Hollow Filament Fibers - Manufactured, continuous filament fibers that have a center void, which has been created through the introduction of air or other gas in the polymer solution, or by melt spinning through specially designed spinnerets during production.
Houndstooth Check - A variation on the twill weave construction in which a broken check effect is produced by a variation in the pattern of interlacing yarns, utilizing at least two different colored yarns.
Hydrophilic Fibers - Fibers that absorb water easily, take longer to dry, and require more ironing.
Hydrophobic Fibers - Fibers that lack the ability to absorb water.
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I Infusion Technology - An infused polymer construction process that reinforces the fabric of outerwear garments in the places where they take the most abuse: zipper and pocket flaps, and other high-abrasion areas. The technology blends polymers, penetrates deep into the inner fibers, and surrounds them to form a permanent bond. this tough, resilient matrix ensures a highly wear-resistant surface while allowing the fabric to remain lightweight and flexible. The infused polymer process eliminates the need for heavier-weight abrasion overlays, tapes anhd bindings, and adds increased strength to the most crucial points on the garment, which dramatically extends the life of the garment.
Inseam - The distance from the bottom of a trouser leg to the crotch. The measurement is taken along the inside leg seam that joins the front and the back leg panels.
Insulation - With respect to a fabric, a material that protects from the loss of warmth or the penetration of cold.
Interfacing - Fabrics used to support, reinforce and give shape to fashion fabrics in sewn products. Often placed between the lining and the outer fabric., it can be made from yarns or directly from fibers, and may be either woven, nonwoven, or knitted. Some interfacings are designed to be fused (adhered with heat from an iron), while others are meant to be stitched to the fashion fabric.
Interlining - An insulation, padding, or stiffening fabric, either sewn to the wrong side of the lining or the inner side of the outer shell fabric. The interlining is used primarily to provide warmth in coats, jackets, and outerwear.
Interlock - The stitch variation of the rib stitch, which resembles two separate 1 x 1 ribbed fabrics that are interknitted. Plain (double knit) interlock stitch fabrics are thicker, heavier, and more stable than single knit constructions.
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J Jacquard - Woven fabrics manufactured by using the Jacquard attachment on the loom. This attachment provides versatility in designs and permits individual control of each of the warp yarns. Thus, fabrics of almost any type or complexity can be made. Brocade and damask are types of jacquard woven fabrics.
Jacquard Knit - A weft double knit fabric in which a Jacquard type of mechanism is used. This device individually controls needles or small groups of needles, and allows very complex and highly patterned knits to be created.
Jersey Fabric - The consistent interlooping of yarns in the jersey stitch to produces a fabric with a smooth, flat face, and a more textured, but uniform back. Jersey fabrics may be produced on either circular or flat weft knitting machines.
Jersey Stitch - A basic stitch used in weft knitting, in which each loop formed in the knit is identical. The jersey stitch is also called the plain, felt, or stockinet stitch.
Jute - A bast fiber, chiefly from India, used primarily for gunny sacks, bags, cordage, and binding threads in carpets and rugs.
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K Kapok - A short, lightweight, cotton-like, vegetable fiber found in the seed pods of the Bombocaceae tree. Because of its brittle quality, it is generally not spun. However, its buoyancy and moisture resistance makes it ideal for use in cushions, mattresses, and life jackets.
Knit Fabric - Fabrics made from only one set of yarns, all running in the same direction. Some knits have their yarns running along the length of the fabric, while others have their yarns running across the width of the fabric. Knit fabrics are held together by looping the yarns around each other. Knitting creates ridges in the resulting fabric. Wales are the ridges that run lengthwise in the fabric; courses run crosswise.
Knit-de-knit - A type of yarn texturizing in which a crimped yarn is made by knitting the yarn into a fabric, and then heat-setting the fabric. The yarn is then unraveled from the fabric and used in this permanently crinkled form.
Knitting (Circular) - A weft knitting process where the fabric is a tube,.with the threads running continuously around the fabric. Double-knit fabrics are produced on a circular knitting machine equipped with two sets of latch needles situated at right angles to each other.
Knitting (Flat or Single) - A weft knitting process where the fabric is in flat form. The threads run back and forth across the fabric. Shape can be added in the knitting process by increasing or decreasing the loops or stitches. Full-fashioned garments are made on a flat-knitting machine.
Knitting (Raschel) - A versatile warp knitting made in plain and jacquard patterns; the fabrics are coarser than other warp knits. Raschel knitting machines have one or two sets of latch needles and up to thirty sets of guides that enable them to create a wide range of fabrics.
Knitting (Warp) - A type of knitting in which the yarns generally run lengthwise in the fabric. The yarns are prepared as warps on beams. Examples of this type of knitting include tricot, Milanese, and Raschel knitting.
Knitting (Weft) - A type of knitting, in which one continuous thread runs crosswise in the fabric making all of the loops in one course. Weft knitting types are circular and flat knitting.
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L Lamb's Wool - The first clip of wool sheered from lambs up to eight months old. The wool is soft, slippery and resilient. It is used in fine grade woolen fabrics.
Lame' - A woven fabric using flat silver or gold metal threads to create either the design or the background in the fabric.
Laminated Fabric - A term used to describe fabrics which have been joined together through the use of a high-strength reinforcing scrim or base fabrics between two plies of flexible thermoplastic film.. It can a bonded utilizing either foam itself, or some other material, such as adhesives, heat, or chemical bonding agents.. See BONDING.
Lapel - The part of a garment that is turned back in the front. The front fold on a shirt that is a continuation of the collar.
Lapels (padding) - Attaching the lapel to canvas with several rows of blindstitching.
Latent Heat - The quantity of heat absorbed or released by a substance undergoing a change of state, such as ice changing to water or water to steam, at constant temperature and pressure. When a solid material is heated and reaches its melting point, it goes from solid to liquid. During this process the material absorbs a certain amount of heat, Despite the heat input, the temperature of the material stays at a relatively constant level, even though phase change is taking place. We thus speak of latent (concealed) heat having been taken up by the material.
Lawn - A light, fine cloth made using carded or combed, linen or cotton yarns. The fabric has a crease-resistant, crisp finish. Linen lawn is synonymous with handkerchief linen. Cotton lawn is a similar type of fabric, which can be white, solid colored, or printed.
Left-hand twill - Any twill weave which runs from the left. The twill or diagonal line on the face of the fabric will run from the upper left-hand corner to the lower right-hand corner of the fabric.
Leight Weight - Having an airy weave. Used as a light weight base layer in apparel for aerobic activities and cool weather.
Leno Weave - A construction of woven fabrics in which the resulting fabric is very sheer, yet durable. In this weave, two or more warp yarns are twisted around each other as they are interlaced with the filling yarns; thus securing a firm hold on the filling yarn and preventing them from slipping out of position. Also called the gauze weave. Leno weave fabrics are frequently used for window treatments, because their structure gives good durability with almost no yarn slippage, and permits the passage of light and air.
Linen - A fabric made from linen fibers obtained from inside the woody stem of the flax plant. Linen fibers are much stronger and more lustrous than cotton. Linen fabrics are very cool and absorbent, but wrinkle very easily, unless blended with manufactured fibers. Linen is one of the oldest textile fibers.
Lining - A fabric that is used to cover the inside of a garment to provide a finished look. Generally, the lining is made of a smooth lustrous fabric.
Loft - High loft is thick and fluffy, low loft is thin and dense. The higher the loft, the better the insulation characteristic.
Loom - A machine used for weaving fabrics.
Loom-Finished - Material sold in the same condition in which the goods came from the loom---duck, webbing, canvas, burlap, etc.
Lyocell Fiber - A manufactured fiber composed of regenerated cellulose. Lyocell has a similar hand and drape as rayon, but is stronger, more durable, and in many cases machine washable. It has a subtle luster and is rich in color. Lyocell possesses low shrinkage characteristics, as well as good absorbency and wrinkle resistant qualities.
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M Madras - A lightweight plain weave cotton fabric with a striped, plaid, or checked pattern. A true madras will bleed when washed. This type of fabric is usually imported from India. End-uses are men's and women's shirts and dresses.
Matelassé - A medium to heavyweight luxury fabric made in a double cloth construction to create a blistered or quilted surface. Common end-uses are upholstery, draperies, and evening dresses.
Melton - A heavyweight, dense, compacted, and tightly woven wool or wool blend fabric used mainly for coats.
Membrane - A thin, soft material made from a polymer which is laminated to the fabric to provide properties such as strength, water-proofing or wind-proofing to enhance the fabric?s performance.
Mercerization - A process of treating a cotton yarn or fabric, in which the fabric or yarn is immersed in a caustic soda solution and later neutralized in acid. The process causes a permanent swelling of the fiber, resulting in an increased luster on the surface of the fabric, an increased affinity for dyes, and increased strength.
Merino - A type of wool that originates from pure-bred Merino sheep. The best Merino wool comes from Italy.
Mesh - A type of fabric characterized by its net-like open appearance, and the spaces between the yarns. Mesh is available in a variety of constructions including wovens, knits, laces, or crocheted fabrics.
Metallic - An inorganic fiber made from minerals and metals, blended and extruded to form fibers. The fiber is formed from a flat ribbon of metal, coated with a protective layer of plastic, which reduces tarnishing. Metal used in apparel fabric is purely decorative.
Microclimate - The temperature and humidity of the space between your skin and the base layer of clothing.
Micro-encapsulation - A method of enclosing polymer additive materials in microscopic capsules, which can then be released under certain conditions to enhance performance properties.
Microfibers/Microdeniers - The name given to ultra-fine manufactured fibers and the name given to the technology of developing these fibers. Fibers made using microfiber technology, produce fibers which weigh less than 1.0 denier. The fabrics made from these extra-fine fibers provide a superior hand, a gentle drape, and incredible softness. Comparatively, microfibers are two times finer than silk, three times finer than cotton, eight times finer than wool, and one hundred times finer than a human hair. Currently, there are four types of microfibers being produced. These include acrylic microfibers, nylon microfibers, polyester microfibers, and rayon microfibers.
Microfleece - A soft, luxorous fabric with a velvety feel.
Micron - A unit of measure that describes the average staple fiber diameter in a lot of wool. Over he past 30 years, the Micron measurement has evolved to become the predominant term used commercially to describe the fineness of a wool fiber. A Micron is determined by the actual measurement when the wool lots are tested for sale during wool processing. Most wool fibers range in the area of 18-40 micron. Merino wool falls into the 18-24 micron range. The 25-32 micron, medium range wool, is usually defined by the word "Shetland", and is used in such applications as blankets and knitwear apparel. The 33-40 range Micron usually describes the wool most often used in the carpet industry.
Microporous - A coating on a fabric that breathes through microscopic pores.
Middle Weight - A weave that is tighter than lightweight, which combines warmth and wickability.
Modacrylic Fiber - A manufactured fiber similar to acrylic in characteristics and end-uses. Modacrylics have a higher resistance to chemicals and combustion than acrylic, but also have a lower safe ironing temperature and a higher specific gravity than acrylic.
Mohair - Hair fibers from the Angora goat. End-uses include sweaters, coats, suits, and scarves.
Moiré/Watermarked - A corded fabric, usually made from silk or one of the manufactured fibers, which has a distinctive water-marked wavy pattern on the face of the fabric.
Moisture Regain - The amount of water a completely dry fiber will absorb from the air at a standard condition of 70 degrees F and a relative humidity of 65%. Expressed as a % of the dry fiber weight.
Moisture Transport - The movement of water from one side of a fabric to the other, caused by capillary action, wicking, chemical or electrostatic action.
Monk's Cloth - A heavy weight cotton fabric utilizing the basket weave variation of the plain weave. Used for draperies and slip covers, monk's cloth is an example of 4 x 4 basket weave. It has poor dimensional stability and tends to snag.
Monofilament - Any single filament, generally a coarser manufactured fiber. Monofilaments are generally spun individually, rather than being extruded through the spinneret in groups of filaments. Cross-sections may be of various shapes.
Monofilament - A single filament of a manufactured fiber, usually made in a denier higher than 14. Monofilaments are usually spun singularly, rather than extruded as a group of filaments through a spinneret and spun into a yarn. End-uses include hosiery and sewing thread.
Muslin - An inexpensive, medium weight, plain weave, low count (less than 160 threads per square inch) cotton sheeting fabric. In its unfinished form, it is commonly used in fashion design to make trial garments for preliminary fit.
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N Nainsook - A lightweight plain weave cotton fabric, usually finished to create a luster and a soft hand. Common end-uses are infants' wear, blouses, and lingerie.
Nano-fiber - Nano refers to 1 billionth of a meter, or 1 x 10-8 centimeter. 150,000 strands of a nano-fiber can fit across a human hair.
Nano-technology - Complex technology that involves nano-size materials and combines science such as biology, chemistry and physics and engineering.
Nap - A fuzzy, fur-like feel created when fiber ends extend from the basic fabric structure to the fabric surface. The fabric can be napped on either one or both sides.
Napping - The raising of fibers on the face of the goods by means of teasels or rollers covered with card clothing (steel wires) that are about one inch in height. Action by either method raises the protruding fibers and causes the finished fabric to provide greater warmth to the wearer, makes the cloth more compact, causes the fabric to become softer in hand or smoother in feel, increases durability and covers the minute areas between the interlacings or the warp and the filling.
Net - An open mesh fabric of rayon, nylon, cotton, or silk; made in a variety of geometric-shaped meshes of different sizes and weights, matched to various end-uses. The net is made by knotting the intersections of thread or cord to form the mesh.
Net - An open fabric, which is created by connecting the intersections in a woven, knitted, or crocheted construction to form a mesh-like appearance that won't ravel. End-uses include veils, curtains, and fish nets.
Ninon - A lightweight, plain weave, made of silk or manufactured fibers, with an open mesh-like appearance. Since the fabric is made with high twist filament yarns, it has a crisp hand. End uses include eveningwear and curtains.
Nonwoven Fabric - A textile structure held together by interlocking of fibers in a random web, accomplished by mechanical, chemical, thermal or solvent means. Generally, crimped fibers that range in length from 0.75 to 4.5 inches are used.
Novelty Yarn - A yarn that is intentionally produced to have a special or unique effect. These effects can be produced by twisting together uneven single yarns, by using yarns that contain irregularities, or by twisting yarns that contain a color variance. A slubbed yarn is an example of a novelty yarn.
Nylon - Produced in 1938, the first completely synthetic fiber developed. Known for its high strength and excellent resilience, nylon has superior abrasion resistance and high flexibility.
Nytril - A manufactured fiber, most often used in sweaters or pile fabrics, where little or no pressing is recommended, as the fiber has a low softening or melting point. However, it has also been successfully used in blends with wool for the purpose of minimizing shrinkage and improving the shape retention in garments.
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O Off-pressing - Pressing done after the garment is completely sewn.
Olefirn (polyolefin/polypropylene) - A manufactured fiber characterized by its light weight, high strength, and abrasion resistance. Olefin is also good at transporting moisture, creating a wicking action. End-uses include activewear apparel, rope, indoor-outdoor carpets, lawn furniture, and upholstery.
Open-shoulder construction - A method used onb better coats that is characterized by hand-sewn lining shoulder seams.
Organdy - A stiffened, sheer, lightweight plain weave fabric, with a medium to high yarn count. End-uses include blouses, dresses, and curtains/draperies.
Organza - A crisp, sheer, lightweight plain weave fabric, with a medium to high yarn count, made of silk, rayon, nylon, or polyester. The fabric is used primarily in evening and wedding apparel for women.
Osnaburg - A tough medium to heavyweight coarsely woven plain weave fabric, usually made of a cotton or cotton/poly blend. Lower grades of the unfinished fabric are used for such industrial purposes as bags, sacks, pipe coverings. Higher grades of finished osnaburg can be found in mattress ticking, slipcovers, workwear, and apparel.
Ottoman - A tightly woven plain weave ribbed fabric with a hard slightly lustered surface. The ribbed effect is created by weaving a finer silk or manufactured warp yarn with a heavier filler yarn, usually made of cotton, wool, or waste yarn. In the construction, the heavier filler yarn is completely covered by the warp yarn, thus creating the ribbed effect. End uses for this fabric include coats, suits, dresses, upholstery, and draperies.
Outseam - The distance from the bottom of the trouser leg to the top of the pant at the waist. The measurement is taken along the outside leg seam that joins the front and back leg panels, and includes the width of the waistband.
Oven - Enclosed heating equipment used by garment manufacturers to apply heat for the purpose of applying heat to a garment to set, or cure (bake), a durable press finish on the article.
Oxford - A fine, soft, lightweight woven cotton or blended with manufactured fibers in a 2 x 1 basket weave variation of the plain weave construction. The fabric is used primarily in shirtings.
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P Paisley - A tear-drop shaped, fancy printed pattern, used in dresses, blouses, and men's ties.
Panné Velvet - A type of lustrous, lightweight velvet fabric, usually made of silk or a manufactured fiber, in which the pile has been flattened in one direction.
Parachute Fabric - A compactly woven, lightweight fabric comparable with airplane cloth. It is made of silk, nylon, rayon, cotton, or polyester.
Peau de Soie - A heavy twill weave drapeable satin fabric, made of silk or a manufactured fiber, and used for bridal gowns and eveningwear.
Percale - A medium weight, plain weave, low to medium count (180 to 250 threads per square inch) cotton-like fabric. End-uses include sheets, blouses, and dresses.
Performance Fabrics - Fabrics made for a variety of end-use applications, which provide functional qualitites, such as moisture management, UV protection, anti-microbial, thermo-regulation, and wind/water resistance.
Permanent Press (Durable Press) - Terms used to describe a garment which has been treated to retain its fresh appearance, crease, and shape throughout the life of the garment, Permanent press can be a misleading description, because no finish is completely permanent. Durable press or crease resistant are the more accepted terms, and are the ones approved by the Federal Trade Commission.
Permeability - A textile characteristic which allows air, water, and water vapor to penetrate and pass through it.
Perspiration Resistant - A treatment on a fabric which allows a fabric or a dye to resist perspiration.
Phase Change Materials - A hydrophilic compound applied to a fiber or fabric which results in superior breathability and a moisture management system within the fabric that helps to maintain a comfortable body temperature when the garment is worn.
Pick - A filling yarn that runs crosswise between selveges in woven goods. The pick intersects with the warp (or lengthwise yarn) to form a woven cloth.
Pile Fabric - A fabric in which certain yarns project from a foundation texture and form a pile on the surface. Pile yarns may be cut or uncut in the fabric. Corduroy and velveteen are examples of cut filling pile fabrics.
Pile Knit - A type of knit construction which utilizes a special yarn or a sliver that is interlooped into a standard knit base. This construction is used in the formation of imitation fur fabrics, in special liners for cold weather apparel such as jackets and coats, and in some floor coverings. While any basic knit stitch may be used for the base of pile knits, the most common is the jersey stitch.
Pile Weave - A type of decorative weave in which a pile is formed by additional warp or filling yarns interlaced in such a way that loops are formed on the surface or face of the fabric. The loops may be left uncut, or they may be cut to expose yarn ends and produce cut pile fabric.
Pill - A tangled ball of fibers that appears on the surface of a fabric, as a result of wear or continued friction or rubbing on the surface of the fabric.
Piping - A narrow tape used to bind seams, or used for decoration.
Pique - A knitted fabric that resembles a lightweight Bedford cord, with the wales or cords running in the warpwise or lengthwise direction.
Piqué - A medium-weight fabric, either knit or woven, with raised dobby designs including cords, wales, waffles, or patterns. Woven versions have cords running lengthwise, or in the warp direction. Knitted versions are double-knit fabric constructions, created on multi-feed circular knitting machines.
Plaid - A pattern consisting of colored bars or stripes which cross each other at right angles, comparable with a Scottish tartan.
Plain Edge (Bluff Edge) - A construction in which the edges of the garment are not stitched.
Plain Weave - A basic weave, utilizing a simple alternate interlacing of warp and filling yarns. Any type of yarn made from any type of fiber can be manufactured into a plain weave fabric.
Plaited Fabric - A narrow fabric made by crossing a number of sturdy yarns diagonally, so each strand passes alternatively over or under one or more of the other stands. Typically used in shoe laces and suspenders.
Plaited Yarn - A yarn covered by another yarn.
Pleats - A portion of the fabric folded over, and secured by stitching or pressing.
Plied Yarn - A twisting together of two or more single yarns in one operation.
Plissé - A lightweight, plain weave, fabric, made from cotton, rayon, or acetate, and characterized by a puckered striped effect, usually in the warp direction. The crinkled effect is created through the application of a caustic soda solution, which shrinks the fabric in the areas of the fabric where it is applied. Plissé is similar in appearance to seersucker. End-uses include dresses, shirtings, pajamas, and bedspreads.
Ply - Two or more yarns that have been twisted together. An automobile tire fabric yarn may be 9, 10, or 11 ply.
Pocket (patch) - A pocket attached to the outside of the garment and constructed of self-fabric.
Pocket (quarter) - The angle from the side seam.
Pocket (rule) - A patch pocket attached on the outseam, halfway betweeen the hip and the knee of the garment; usually found on coveralls.
Pocket (serged) - A pocket formed by joining two pieces of fabric and joining the edges with safety-stitching.
Pocket (slash) - A pocket that must be entered through a slash on the garment. The pocket pouch is suspended from and attached to the slash.
Pocket (stitch and turn) - Formed when two pieces of fabric are joined along the edges and turned so that the raw seam margin is inside of the finished pocket.
Pocket (stitched/topstitched) - The same as stitch and turn pocket, except with an added row of stitching along the folded edges.
Pocket (swing) - The pocket pouch is suspended from and attached to the pocket opening.
Pocket Facing - A piece of shell (outer) material super-imposed on the top of the pocket material at its opening to conceal the lining.
Polyester - A manufactured fiber introduced in the early 1950s, and is second only to cotton in worldwide use. Polyester has high strength (although somewhat lower than nylon), excellent resiliency, and high abrasion resistance. Low absorbency allows the fiber to dry quickly.
Polymer - A high molecular weight structure, which makes up the substance from which manufactured fibers are produced. The fiber is created by linking together the chain-like molecular units called monomers.
Polypropylene (Olefin or Polyolefin - A manufactured fiber characterized by its light weight, high strength, and abrasion resistance. Polypropylene is also good at transporting moisture, creating a wicking action. End-uses include activewear apparel, rope, indoor-outdoor carpets, lawn furniture, and upholstery.
Pongee - The most common form is a naturally colored lightweight, plain weave, silk-like fabric with a slubbed effect. End-uses include blouses, dresses, etc.
Poplin - A fabric made using a rib variation of the plain weave. The construction is characterized by having a slight ridge effect in one direction, usually the filling. Poplin used to be associated with casual clothing, but as the "world of work" has become more relaxed, this fabric has developed into a staple of men's wardrobes, being used frequently in casual trousers.
Post-Cure - A type of durable press finish in which the finish is applied to the fabric by the mill, but the garment manufacturer completes the cure of the finish by applying heat, using an oven, or press, or both to the completed garment.
Pre-Cure - A finishing treatment in which the durable press finish is applied to the fabric and set, or cured, through the use of heat at the mill, prior to shipment of the fabric to the garment manufacturer.
Pre-Shrunk - Fabrics which have received a treatment, which causes shrinking. Often done on cottons before cutting the fabric in order to remove the tendency for shrinkage in the finished garment. The percent of residual shrinkage must be indicated on the label of the treated goods or garments.
Press - 1. A device that uses heat and pressure to remove wrinkles and creases and smooth fabrics during garment construction. 2. A device used to press or compress raw materials. 3. To iron in the home or commercial laundry. 4. To squeeze liquid out of a fabric through the use of roller presses.
PTFE Fabric - A fabric made from Polytetrafluoroethylene, such as Gore-Tex.
Pucker - The uneven surface caused by differential shrinkage in the two layers of a bonded fabric during processing, dry cleaning, or washing.
Purl Stitch - A basic stitch used in weft knitting, which produces knit fabrics that have the same appearance on both sides. The purl stitch is frequently used in combination with the jersey and rib stitches to produce a knitted fabric design. Sweaters, knitted fabrics for infants and children's wear, knitted fabrics for specialized sportswear, and bulky knit fabrics are commonly made using the purl stitch.
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Q Quilting - A fabric construction in which a layer of down or fiberfill is placed between two layers of fabric, and then held in place by stitching or sealing in a regular, consistent, all-over pattern on the goods.
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R Ramie - A bast fiber, similar to flax, taken from the stalk of a plant grown in China.
Raschel Knit - A warp knitted fabric in which the resulting knit fabric resembles hand crocheted fabrics, lace fabrics, and nettings. Raschel warp knits contain inlaid connecting yarns in addition to columns of knit stitches.
Rayon - A manufactured fiber composed of regenerated cellulose, derived from wood pulp, cotton linters, or other vegetable matter. Today, various names for rayon fibers are taken from different manufacturing processes. The two most commonly used production methods for rayon are the cuprammonium process and the viscose process.
Repellency - The ability of a fabric to resist such things as wetting and staining by water, stains, soil, etc.
Resiliency - The ability of a fabric to spring back to its original shape after being twisted, crushed, wrinkled, or distorted in any way.
Resin - The name commonly applied to synthetic chemical compounds polymerized on the fabric or yarn to give wash-and-wear and durable press properties, crush resistance, dimentional stability, and hand to fabrics.
Resin-Treated - A finishing process associated with the application of synthetic chemical compounds to the fabric to provide wrinkle-resistance, wash-and-wear characteristics, or an improved hand.
Rib Knit - A basic stitch used in weft knitting in which the knitting machines require two sets of needles operating at right angles to each other. Rib knits have a very high degree of elasticity in the crosswise direction. This knitted fabric is used for complete garments and for such specialized uses as sleeve bands, neck bands, sweater waistbands, and special types of trims for use with other knit or woven fabrics. Lightweight sweaters in rib knits provide a close, body-hugging fit.
Rib Weave - One of the plain weave variations, which is formed by using: 1) heavy yarns in the warp or filling direction, or 2) a substantially higher number of yarns per inch in one direction than in the other, or 3) several yarns grouped together as one. Rib fabrics are all characterized by having a slight ridge effect in one direction, usually the filling. Such fabrics may have problems with yarn slippage, abrasion resistance, and tear strength. Examples of this construction include broadcloth, poplin, taffeta, faille, shantung, and cord fabric.
Ribbon - A fillet or narrow woven fabric of varying widths, commonly one-quarter to three inches, having selvage edges, chiefly or rayon, silk, or velvet, and used for braiding, decoration, trimmings, etc.
Rickrack - Flat braid in a zig-zag formation. Made from several types if fibers, it is used for many kinds of trimming on apparel.
Ring Spinning - A system of spinning, using a ring spinning frame that drafts the roving, twists the yarn, and winds it on the bobbin continuously and simultaneously on one operation. Modern ring frames are suitable for spinning all counts up to 150s.
Rip-stop Nylon - A lightweight, wind resistant, and water resistant plain weave fabric. Large rib yarns stop tears without adding excess weight to active sportswear apparel and outdoor equipment such as sleeping bags and tents.
Rise - The length of trouser from the top of the waistband at the fly opening, around the crotch, to the top of the back waistband at the center.
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S Sailcloth - Any heavy, plain-weave canvas fabric, usually made of cotton, linen, polyester, jute, nylon, etc. that is used for sails and apparel (i.e. bottomweight sportswear).
Sanforized - Registered trademark of Cluett, Peabody & Co. for fabrics processed by machine so that residual shrinkage will not exceed 1% in either direction (according to the U.S.?s standard wash test CCC-T-191a),, despite repeated washings.
Saran Fiber - A manufactured fiber which has an excellent resistance to sunlight and weathering, and is used in lawn furniture, upholstery, and carpets.
Sateen Fabric - A fabric made from yarns with low luster, such as cotton or other staple length fibers. The fabric has a soft, smooth hand and a gentle, subtle luster. Sateen fabrics are often used for draperies and upholstery.
Sateen Weave - A variation of the satin weave, produced by floating fill yarns over warp yarns.
Satin Fabric - A traditional fabric utilizing a satin weave construction to achieve a lustrous fabric surface. Satin is a traditional fabric for evening and wedding garments. Typical examples of satin weave fabrics include: slipper satin, crepe-back satin, faille satin, bridal satin, moleskin, and antique satin.
Satin Weave - A basic weave, characterized by long floats of yarn on the face of the fabric. The yarns are interlaced in such a manner that there is no definite, visible pattern of interlacing and, in this manner, a smooth and somewhat shiny surface effect is achieved. The shiny surface effect is further increased through the use of high luster filament fibers in yarns which also have a low amount of twist. A true satin weave fabric always has the warp yarns floating over filling yarns.
Saxony - Originally a high grade coating fabric made from Saxony merino wool raised in Germany.
Schiffli Embroidery - Originated in Switzerland, the word, Schiffli, means "boat", identifiable with the boat-shaped shuttle used in the frame. The lace effect is made by embroidering the motifs on a net ground.
Seam (book/booking) - The raw edge hem done on a blindstitch machine, usually sewn in the side ans back seam outlets, and on the bottom turn-up.
Seam (french) - A closure between two pieces of material, made by stitching,turning, and restitching, so as to conceal all raw edges.
Seam (open gorge) - Both the collar and the facing are turned under, basted, and then the seam is felled (edges folded together) from the outside.
Seam (raised) - A seam resulting after two pieces of fabric have been joined; one piece is folded back, and a second row of stitching is placed adjacent to the folded edge.
Seamless Knitting - A unique process of circular knitting, done on either Santoni or Sangiacomo knitting machines. This circular knitting process essentially produces finished garments with no side seams, which require only minimal sewisng to complete the garment. Seamless knitting can transform yarn into complete garments in a fraction of the time it takes for traditional garment manufacturing, by minimizing the traditional labor-intensive steps of sutting and sewing.
Seamless Technology - This term can refer to either "seamless knitting" (See Seamless Knitting), or "welding/bonding technology", which uses a bonding agent to attach two pieces of fabric together, and eliminates the need for sewing threads. (See welding.)
Seat - The circumference of a pant, measured perpendicular to the fly opening and from the base of the fly.
Seersucker - A woven fabric which incorporates modification of tension control. In the production of seersucker, some of the warp yarns are held under controlled tension at all times during the weaving, while other warp yarns are in a relaxed state and tend to pucker when the filling yarns are placed. The result produces a puckered stripe effect in the fabric. Seersucker is traditionally made into summer sportswear such as shirts, trousers, and informal suits.
Self-goods - When the same material is used as a pocket lining, or in a waistband, collar and fly construction. Also called shell.
Selvage or Selvedge - The thin compressed edge of a woven fabric which runs parallel to the warp yarns and prevents raveling. It is usually woven, utilizing tougher yarns and a tighter construction than the rest of the fabric.
Serge - A fabric with a smooth hand that is created by a two-up, two-down twill weave.
Serging - An overcasting technique done on the cut edge of a fabric to prevent raveling.
Shantung - A medium-weight, plain weave fabric, characterized by a ribbed effect, resulting from slubbed yarns used in the warp or filling direction. End-uses include dresses and suits.
Sharkskin - A hard-finished, low lustered, medium-weight fabric in a twill-weave construction. It is most commonly found in men's worsted suitings; however, it can also be found in a plain-weave construction of acetate, triacetate, and rayon for women's sportswear.
Shell - A fabric from which the garment is made.
Shuttle - The boat-like devise on weaving machines, which carries the filling yarn wound on the bobbin. The shuttle moves from the shuttle box on one side of the loom, through the shed, and onto the shuttle box at the other side of the loom.
Side Opening - An opening created by the facing tacked onto the swing pockets. It allows the wearer access to his trouser pockets. Typically found on coveralls.
Silk - A natural filament fiber produced by the silkworm in the construction of its cocoon. Most silk is collected from cultivated worms; Tussah silk, or wild silk, is a thicker, shorter fiber produced by worms in their natural habitat. All silk comes from Asia, primarily China.
Singeing - Process of burning off protruding fibers from fabrics to give the fabric a smooth surface.
Sisal - A strong bast fiber that originates from the leaves of the Agave plant, which is found in the West Indies, Central America, and Africa. End-uses include cordage and twine.
Sizing - The application of a size mixture to warp yarn. The purpose of this is to make the yarn smoother and stronger to withstand the strain of weaving, to provide an acceptable hand in the woven gray goods, and to increase fabric weight.
Sleeve Length - The sleeves measured from the center of the neckline in the back to the end of the sleeve or cuff.
Sleeve Tacking - Stitches which attach the sleeve to the lining along the sleeve inseams and elbow seams.
Sleeve Vent - A finished slit or opening in the sleeve. Vents are usually secured by snaps or buttons at the base of the cuff.
Sliver - A continuous bundle of loosely assembled untwisted fibers. These are fibers that are drawn from the card by the drawing frames, and are eventually twisted into a yarn during the sliver knitting process.
Sliver Knitting - A type of circular knitting in which a high pile fabric is knitted by the drawing-in of the sliver by the knitting needles.
Smart Textiles - Textiles that can sense and react to changes in the environment, such as changes from mechanical , thermal, chemical, magnetic and other sources.
Soft Shell - Soft shell fabrics combine the benefits of hard shell fabrics with a breathable, flexible, comfortable fabric. Stretch wovens with a DWR treatment.
Soil Release - A finish that has the purpose of increasing the absorbency of a fabric. on durable press blends. The finish allows the stain to leave the fabric faster, increases the wicking action for improved comfort, and therefore imparts greater ease in cleaning. Some soil release finishes also provide resistance to soiling as well as ease of soil removal.
Solution-dyed - A type of fiber dyeing in which colored pigments are injected into the spinning solution prior to the extrusion of the fiber through the spinneret. Fibers and yarns colored in this manner are color-fast to most destructive agents.
Spacer Fabric - Two separate fabrics faces knitted independently and then connected by a separate spacer yarn. These fabrics can be produced on both circular and flat knitting machines. Spacer fabrics have the properties of good breathability, crush resistance, and a 3D appearance.
Spandex Fiber - A manufactured elastomeric fiber that can be repeatedly stretched over 500% without breaking, and will still recover to its original length.
SPF (Sun Protection Factor) - SPF measures the effectiveness of sunscreen on the body. the test for SPF is done by using a living organism or body to measure the length of time it takes for the skin to redden without coverage or protection.
Spinneret - A metal nozzle type device with very fine holes used in the spinning process of manufactured fibers. The spinning solution is forced or extruded through the small holes to form continuous filament fibers. The holes in the spinneret can vary in diameter to produce fibers of various denier.
Spinning - This final operation in the production of a natural yarn, consists of of the drawing, twisting, and the winding of the newly spun yarn onto a device such as a bobbin, spindle, cop, tube, cheese, etc. In manufactured fibers, the spinning process is the extrusion of a spinning solution into a coagulation bath, a heated air chamber, or a cooling area in order to form a continuous filament or tow.
Sponging - A pre-shrinkage process which involves the dampening with a sponge to woolen and worsted fabrics. The process is accomplished by rolling in moist muslin, or by steaming. This procedure is performed at the fabric mill prior to cutting to insure against a contraction of the material in the garment.
Spot Weave - A woven construction in which patterns are built in at spaced intervals through the use of extra warp and/or extra fill yarns are placed in selected areas. These yarns are woven into the fabric by means of a dobby or Jacquard attachment.
Spun Yarn - A yarn made by taking a group of short staple fibers, which have been cut from the longer continuous filament fibers, and then twisting these short staple fibers together to form a single yarn, which is then used for weaving or knitting fabrics.
Stain Repellent - The ability of a fabric to resist wetting and staining by water.
Stain Resistance - A fiber or fabric property of resisting spots and stains.
Staple Fibers - Short fibers, typically ranging from 1/2 inch up to 18 inches long. Wool, cotton, and flax exist only as staple fibers. Manufactured staple fibers are cut to a specific length from the continuous filament fiber. Usually the staple fiber is cut in lengths ranging from 1-1/2 inches to 8 inches long. A group of staple fibers are twisted together to form a yarn, which is then woven or knit into fabrics.
Stay - A piece of fabric used to hold another piece of fabric in place, or to add strength to a seam or tack.
Stitch (Backstitch) - Used at the beginning and end of stitching to reinforce and prevent raveling. Also called backtack or stay-stitch.
Stitch (Baste) - A stitching which holds the fabric in place until permanent stitching has been completed.
Stitch (Blind) - A stich that is not visible on one side of the fabric.
Stitch (Chain/Class 100) - A stitch formed with one or more needle threads, the look=ps of which are passed through the material and through the loops of the preceding threads.
Stitch (Contrasting) - When the stitching thread contrasts the garment color.
Stitch (Dbl. lock/class 400 - A stitch formed with two or more groups of threads that interlace each other. The loops of needle thread are passed through the material where they are secured by looper threads; no bobbins used. This stitching ravels in one direction.
Stitch (Flat seam/class 600) - Multi-needle stitches that provide the elasticity necessary for knits.
Stitch (hand/class 200) - A stitch formed by hand with one or more needles---one thread per needle passing in and out of the material.
Stitch (Lock/class 300) - A stitch formed with two or more groups of threads that interface each other. The loops of needle threads are passed through the material where they are secured by bobbin threads.
Stitch (overedge/class 500) - A stitch formed with one or more groups of threads at least one of which passes around the edge of the material.
Stitch (safety) - A combination chain-stitch and overedge stitch made simultaneously on the same sewing machine.
Stitch (Top) - A second row of stitching close to the edge of a seam, after two or more pieces of fabric have been sewed together and turned to bury the raw seam margin side.
Stitch (Zig-zag) - A stitch made on a sewing machine in which the needle bar comes down alternately on the right and left side of an imaginary center line. Also refers to the type of machine producing this stitch.
Storm Shell - Wind proof, wind resistant outerwear.
Stretch Yarns - Continuous filament synthetic yarns that have been altered through special treatments or modification to give them elasticity. Techniques include: twisting and untwisting, use of air jets, stuffer boxes, knife blades, crimping, heat setting, curling, steaming, or looping. Use of these yarns gives fabrics a degree of elasticity and comfort.
Substrate - Fabric on which coatings or other fabrics are applied; a support.
Super Light Weight - Term used to describe a fabric used in outerwear, which allows for a minimum pack volume and weight. These lightweight, packable garments offer the most versatile weather protection. Some of these fabrics have a protection layer on the membrane, which provides durability. This means that the garments made from the extra lightweight fabrics need no separate lining.
Surah - A light weight, lustrous twill weave constructed fabric with a silk-like hand. Surah is the fabric of ties, dresses, and furnishings. It is available in silk, polyester, and rayon.
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T Taffeta - >A lustrous, medium weight, plain weave fabric with a slight ribbed appearance in the filling (crosswise) direction. For formal wear, taffeta is a favorite choice. It provides a crisp hand, with lots of body. Silk taffeta gives the ultimate rustle, but other fibers are also good choices.
Tape - Fabric sewn to a garment at the front edges, armholes, shoulder, neck, sideseams, vents, bottoms, gorge seams, etc. It is usually designed to prevent distortion of a fabric edge or seam.
Tapestry - A heavy, often hand-woven, ribbed fabric, featuring an elaborate design depicting a historical or current pictorial display. The weft-faced fabric design is made by using colored filling yarns, only in areas where needed, that are worked back and forth over spun warp yarns, which are visible on the back. End-uses include wall hangings and upholstery.
Tear Strength - The force necessary to tear a fabric, measured by the force necessary to start or continue a tear in a fabric. Expressed in pounds or in grams, the most commonly used method for determining the tear strength is the Elmendorf tear test procedure.
Tensile Strength (Breaking Stregth) - The strength shown by a fiber, yarn, or fabric to resist breaking under pressure. It is the actual number of pounds of resistance that a fabric will give before the material is broken on the testing machine.
Tension Control Weave - A type of decorative weave, characterized by a puckered effect which occurs because the tension in the warp yarns is intentionally varied before the filling yarns are placed in the fabric.
Terry Cloth - A typical uncut pile weave fabric. This fabric is formed by using two sets of warp yarns. One set of warp yarns is under very little tension; when the filling yarns are packed into place, these loose yarns are pushed backward along with the filling yarns, and loops are formed. Typical uses include towels, robes, and apparel.
Terry Velour - A pile weave cotton fabric with an uncut pile on one side and a cut pile on the reverse side. Terry velour is valued for its soft, luxurious hand. Typical uses include towels, robes, and apparel.
Textured Yarns - The yarns that result after undegoing the texturizing process, which can create crimping, looping, and otherwise modify the filament yarn for the purpose of increasing cover, abrasion resistance, insulation, warmth resilience, or moisture absorption, and to provide a different surface texture. When filament yarns are texturized, and then woven or knitted into fabrics, the result is that the finished fabric?s properties resemble a fabric that has been made from a spun yarn. Most of today's filament polyester is texturized.
Texturizing - A process performed on specialized machinery which create bulk, stretch to the yarn, and therefore creates new aesthetics to the finished fabric.
Thermal Insulation - The ability of a fabric to retain heat.
Thermoregulation - The ability to maintain a constant temperature independent of dynamic (changing) environmental conditions.
Thread Count - The number of ends and picks per inch in a woven cloth; the number of wales and courses per inch in a knit fabric. See "Count of Cloth".
Ticking - A tightly woven, very durable fabric, usually made of cotton, and used for covering mattresses, box springs, pillows, and work clothes. The fabric can be made by using a plain, satin, or twill weave construction.
Ticking - Compactly woven cotton cloth used for containers, covers for mattresses and pillows, sportswear (hickory stripes), institution fabric, and work clothes. It is striped cloth, usually white background with blue or brown stripes in the motif.
Tow - A large bundle of manufactured filament fiber as they are extruded from the spinerette, and before they have been cut into staple fibers.
Triacetate - A manufactured fiber, which like acetate, is made by modifying cellulose. However, even more acetate groups have been added to create this fiber. Triacetate is less absorbent and less sensitive to high temperatures than acetate. It can be hand or machine washed and tumble dried, with relatively good wrinkle recovery.
Tricot Knit - A warp knit fabric in which the fabric is formed by interlooping adjacent parallel yarns. The warp beam holds thousands of yards of yarns in a parallel arrangement, and these yarns are fed into the knitting area simultaneously. Sufficient yarns to produce the final fabric width and length are on the beam. Tricot knits are frequently used in women's lingerie items such as slips, bras, panties, and nightgowns.
Trim-cut - Tapered and tailored, or a form-fitting garment.
Trunk - Double the length of a coverall, from the center of the neckhole at the back to the point of the leg separation on the seat seam.
Tulle - A lightweight, extremely fine, machine-made netting, usually with a hexagon shaped mesh effect. End-uses include dance costumes and veils.
Turning - The reversing of two or more pieces of material that are seamed together for pressing or topstitching.
Tweed - A medium to heavy weight, fluffy, woolen, twill weave fabric containing colored slubbed yarns. Common end-uses include coats and suits.
Twill Weave - A basic weave in which the fabrics are constructed by interlacing warp and filling yarns in a progressive alternation which creates a diagonal effect on the face, or right side, of the fabric. In some twill weave fabrics, the diagonal effect may also be seen clearly on the back side of the fabric.
Twist - A term that applies to the number of turns and the direction that two yarns are turned during the manufacturing process. The yarn twist brings the fibers close together and makes them compact. It helps the fibers adhere to one another, increasing yarn strength. The direction and amount of yarn twist helps determine appearance, performance, durability of both yarns and the subsequent fabric or textile product. Single yarns may be twisted to the right (S twist) or to the left (Z twist). Generally, woolen and worsted yarns are S-twist, while cotton and flax yarns are typically Z-twist. Twist is generally expressed as turns per inch (tpi), turns per meter (tpm), or turns per centimeter (tpc).
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U U.L. Down - Ultra Light Down is used in women's and men's jackets. the concept is to make the lightest and warmest insulation layer available. U.L. Down jackets weigh less than a tee-shirt, blocks more wind, is warmer than even the heavist fleece jackets, and compress to the size of a water bottle. This outerwear can be used when warmth is critical, minimal weight is paramount, and space is at a premium.
Ultra-Light Weight - Term used to describe a fabric used in outerwear, which allows for a minimum pack volume and weight. Lightweight packable garments offer the most versatile weather protection. Some of these fabrics have a protective layer on the membrane, which provides durability. This means that the garments made from extra lightweight fabrics need no separate lining.
Under-press - To press the underside of a garment section during manufacturing to open the seams and give it shape.
UPF (Ultraviolet Protection Factor) - The UPF rating indicates how effective a fabric is at blocking out solar ultraviolet radiation from reaching the skin. UPF ratings range from 15 to 50 with higher ratings indicating more effective blocking and therefore better protection for the wearer of a garment. Fabrics that test higher than UPF 50 are rated as UPF50+. UPF testing involves exposing a fabric to ultraviolet radiation (UVR) and measuring how much is tranmitted through the sample. Different wave-lengths of radiation in the UVR spectrum have different effects on human skin and this is taken into consideration when calculating the UPF rating. Factors that contribute to the UPF rating of a fabric are: *Composition of the yarns (cotton, polyester, etc) *Tightness of the weave or the knit (tighter improves the rating) *Color (darket colors are generally better) *Stretch (more stretch lowers the rating) *Moisture (many fabrics have lower ratings when wet) *Condition (worn and faded garments may have reduced ratings) *Finishing (some fabrics are treated with UV absorbing chemicals)
UV Degradation - The breaking down of fibers or fabrics when exposed to ultraviolet rays.
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V Velour - A medium weight, closely woven fabric with a thick pile. It can be made using either a plain weave or a satin weave construction. It resembles velvet, but has a lower cut pile. End uses include apparel, upholstery, and drapes.
Velvet - A medium weight cut-pile constructed fabric in which the cut pile stands up very straight. It is woven using two sets of warp yarns; the extra set creates the pile. Velvet, a luxurious fabric, is commonly made with a filament fiber for high luster and smooth hand.
Velveteen - A cotton cut-pile weave fabric, utilizing extra fill yarn construction, with either a twill or a plain weave back. The fabric is woven with two sets of filling yarns; the extra set creates the pile.
Virgin Wool - New wool that has never been used before, or reclaimed from any spun, woven, knitted, felted, manufactured or used products.
Viscose - The most common type of rayon. It is produced in much greater quantity than cuprammonium rayon, the other commercial type.
Voile - A crisp, lightweight, plain weave cotton-like fabric, made with high twist yarns in a high yarn count construction. Similar in appearance to organdy and organza. Used in blouses dresses and curtains.
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W Waistband (one-piece) - A single thickness of fabric that is doubled and stitched to the top of a pant.
Waistband (Two-piece) - When two identical pieces of fabric are placed back-to-back at the top of a pant, raw edges turned inside, and joined with two widely spaced rows of stitching. the pant body is inserted betweeen and along one edge.
Warmth to Weight Ratio - A measurement used to evaluate the effectiveness of an insulated product in relation to weather conditions and the environment. The insulation with the best rating is down. Down provides the best warmth to weight ratio over almost any other insulation material, which is why you will see down garments and sleeping bags as the primary choice for use in almost every high altitude, cold weather expedition.
Warp - In woven fabric, the yarns that run lengthwise and is interwoven with the fill (weft) yarns.
Warp Knit - A type of knitted fabric construction in which the yarns are formed into stitches in a lengthwise manner. Warp knits are generally less elastic than weft knits. Common examples of warp knits are tricot knits and raschel knits.
Washable - Materials that will not fade or shrink during washing or laundering. Labels should be read by the consumer to assure proper results. Do not confuse with "wash-and-wear".
Wash-and-Wear - Ability of a garment to be washed by hand or in a washing machine and require little or no ironing. Also referred to as "easy care".
Watch Pocket - A small pocket in the garment, typically located just below the front waistband of men's trousers and used to accomodate change or a pocket watch.
Water Repellent - Fabrics that have been treated with a finish which cause them to shed water and resist water penetration, but are still air-permeable. Treatments can include wax coatings, resins, silicones, and fluorine derivatives. Such treatments do not close the pours of the fabric, while waterproof finishes do.
Water Repellent - A term applied to fabrics that have been treated with a finish which causes them to shed water, but are still air-permeable.
Water Resistant - A degree by which water is able to penetrate a fabric. Not to be confused with water-repellent. However, the terms are often used interchangeably.
Waterproof - Materials that are impermeable by water.
Waterproof - A term applied to fabrics whose pores have been closed, and therefore, will not allow water or air to pass through them.
Weaving - The process of forming a fabric on a loom by interlacing the warp (lengthwise yarns) and the filling (crosswise yarns) perpendicular to each other. Filling is fed into the goods from cones, filling bobbins or quills, which carry the filling yarns through the shed of the loom. Filling may also be inserted into the material without the use of a shuttle, as in the case of a shuttleless loom. The three basic weaves are Plain, Twill, and Satin. All other weaves, no matter how intricate, employ one or more of these basic weaves in their composition. Variations on the basic weaves make a variety of different fabric surfaces and fabric strengths.
Weft - In woven fabric, the filling yarns that run perpendicular to the warp yarns.
Weft Knit - A type of knitted fabric in which yarns are formed into stitches in widthwise manner. Common examples of weft knits are circular knits and flat knits.
Weight of Cloth - This term describes the variety of ways that fabric is sold: Ounces per linear yard, Yards per pound, and Ounces per square yard.
Welded Shell - The outer layer of a bonded wor welded garment, such as a jacket.
Welding - There are two basic methods for applying bonding or welded seams. The first method uses an adhesive film, and the application of heat to glue or laminate two substrates together. The second method involves gluing or attaching two fabrics, using ultrasonic technology. The creation and channeling of high frequency vibratory waves cause a rapid buildup of heat in synthetic fabrics to create the bonding.
Welt - 1. A strip of material seamed to a pocket opening as a finishing, as well as a strengthening device. 2. A raised or swelled lap or seam. 3. A covered cord or ornamental strip sewed on a border or along a seam. 4. In knitting, it is flat-knitted separately and then joined to the fabric by looping or hand knitting, as the heel to the stocking. 5. A ribbed piece of knit goods used in forming the end of a sleeve or sock to prevent rolling or raveling.
Welt Lining - Interlining for pocket welts.
Whipcord - A woven fabric with a very steep and compacted twill appearance on the face of the goods. End-uses for the fabric include dress woolens, worsteds, or wool blends, and many types of uniforms.
White Goods - A very broad term which implies any goods bleached and finished in the white condition. Some of the cotton white goods are muslin, cambric, dimity, lawn, longcloth, organdy, voile, etc.
White-on-White - Some fabrics, such as men's shirtings or broadcloth, poplin, madras, etc., are made on a dobby or jacquard loom so the white motifs will appear on a white background.
Wickability - The ability of a fiber or a fabric to disperse moisture and allow it to pass through to the surface of the fabric, so that evaporation can take place.
Wicking - Dispersing or spreading of moisture or liquid through a given area by capillary action in a material.
Wigwan - A converted cotton cloth, dyed black, brown or gray, and given a firm starched, plain calender finish, and used for interlinings in men's and boys's clothing to give body to the garment.
Wind Resistant - The ability of a fabric to act against or oppose the penetration of wind or air, but it is not totally windproof.
Windproof - The ability of a fabric to be nonpermeable to wind and air.
Woof - Comes from the Anglo-Saxon "owef". It is another name for the warp or warp yarn. Sometimes in advertising textiles, the word has been used to imply filling yarn, and made to interchange with the other term, weft.
Wool - Usually associated with fiber or fabric made from the fleece of sheep or lamb. However, the term "wool" can also apply to all animal hair fibers, including the hair of the Cashmere or Angora goat or the specialty hair fibers of the camel, alpaca, llama, or vicuna.
Worsted Fabric - A tightly woven fabric made by using only long staple, combed wool or wool-blend yarns. The fabric has a hard, smooth surface. Gabardine is an example of a worsted fabric. A common end use is men's tailored suits.
Worsted System - The textile process of manufacturing spun yarns from staple fibers usually over 3 inches in length. The main operations are carding, combing, drafting, and spinning.
Woven Fabric - Fabrics composed of two sets of yarns. One set of yarns, the warp, runs along the length of the fabric. The other set of yarns, the fill or weft, is perpendicular to the warp. Woven fabrics are held together by weaving the warp and the fill yarns over and under each other.
Wrinkle Free - A resistant to wrinkling created through the use of a variety of finishes and treatments.
Wrinkle Recovery - Similar to resiliency. It is the ability of a fabric to bounce back after it has been twisted, wrinkled, or distorted in any way.
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Y Yarn - A continuous strand of textile fibers created when a cluster of individual fibers are twisted together. These long yarns are used to create fabrics, either by knitting or weaving.
Yoke (self) - The entire back of a garment is one piece and has a single yoke superimposed on the outside.
Yoke (Two-pierce) - Two identical pieces of fabric are joined to a shortened back piece to produce the total back.
Yokeless Shirt - The front and backs of a shirt are joined without a yoke facing.
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Z Zipper - The physical parts of the zipper are: scoop teeth, chain, lock, pull tape, and slider. Zippers used in industrial clothing are metal or brass. Plastic zippers are used typical apparel garments. Zippers are used as a closure in pants, skirts, and dresses.

Yarn Requirements for Denim

2010-11-05T12:26:00.000+05:00

The denim units have a high production output. According to international standards a unit of 50 million metres per annum capacity is considered to be of an economic size. In India however units of 10 million metres per annum capacity have been operating.

The spinning capacity is usually determined by the performance in the dyeing range. For a 10 million metre capacity unit producing 12 ozs average fabric weight with a standard width of 150cms require denim yarn of 16 to 17 tonnes per day. Extending it further, the raw material requirement will be about 19 to 20 tonnes of cotton per day. Thus, spinning of denim yarn is really a large scale business because of heavy yarns and fabrics.

PLANT & MACHINERY

The following features in plant and machinery have become prerequisites for producing top quality denims:

A. Modern Blow room line with 4 to 5 beating points with micro dust extractor and very efficient automatic waste evacuation system.
B. Modern High Production Chute feed cards with autolevellers and efficient automatic waste evacuation system.
C. High Speed autoleveller Draw frame at finisher passage.

Open End Spinning

D. Modern Open End Spinning machine with automatic piecing and yarn monitoring devices like Corolab or Uster Polyguards.

Ring Spinning

E. High speed frames with bigger doff packages.
F. Ring Spinning machines with Longer Lift and Larger Ring dia.
G. Cone winding machines with efficient yarn clearers

COTTONS USED

Let us first start with the raw material. Cotton fibre specifications of important Indian varieties used in denim yarns are given in Table-3.1.Various cottons are used, ranging from irrigated J-34 from North, hybrid Shankar-6 from Gujarat, windy V-797 of Saurashtra, lean season rescuer NHH-44 from federation, quilty Bengal desi to cosmic bunny to name a few from the Table [Table 3.1].

Often recycled waste, purchased comber noil of other mixings is also added.

Cotton fibre specifications of some imported cottons used in denim yarns are given in Table-3.2. Here again cotton used, ranging from 32s to 36s of US upland cottons, trashy CIS cottons, to sticky Sudanese cotton.

This is because, denim fabrics that, whether we like it or not, are somehow getting close to commodity status, cannot ignore the very high raw material cost. In addition, over the years, process and technology improvements allowed the operational flexibility to use various cottons, leading to cost savings still meeting the quality standards required by customers. In addition, India has the sole distinction of producing many varieties covering all four species and their hybrids, each with limited availability. For example, V-797, [which is considered to be the seismic test for installing a wind mill, in the lighter sense] with higher Uniformity Ratio translating to better yarn, has limited availability geographically. With the increased demand from large scale denim businesses, the relative price cannot go beyond the better value cotton, say J-34. Cost, proximity and availability over-ride the variety preference.

Cotton Mixing Requirements For Denim Yarns

Cotton mixing specifications of important fibre characteristics for denim yarns engineered to meet seven major end-uses are given in Table- 3.3.

Upper Half Mean Length, Uniformity Index, Strength at 1/8” and Micronaire values as tested in HVI mode are to be maintained in a lay down. [Row 1 in Table 3.3]

Uniformity of average fibre properties in successive lay downs is far more important and desirable than a level of certain properties, that being difficult to achieve, is not easily maintained day in and day out.

Open End

Coarse count yarn in denim refers to less than 8s Ne. and fine count is 9s to 16s. Mixing requirements for rope dyed warp open end yarns are higher and normally made from “U” rotors. [Row 2 in Table 3.3]

Mock-ring yarns are made in open end by the various devices available (amsler, caipo etc). Strength variability due to character (slubs) demands slightly better mixing. [Row 3 in Table 3.3]. Strength uniformity is far more important for Weft yarns used in very high speed air jets.

For fine counts and ring spinning, no doubt a good length and appropriate micronaire are a must. [Row 4, 6 and 7 in Table 3.3]

Quality fabrics can also be produced from Value mixings. This is because of the realization that heavy denim has strength far above realistic requirements. However the denim fabrics produced out of such yarns should not be meant for elaborate destructive garment washes. [Row 5 in Table 3.3]

Ring Spun

In spite of open end yarns have lower strength than ring spun yarns it has been enjoying mass market denim products due to cost angle. The raw material costs and the cost differential between ring and open end is discussed in “Engineering of Denim Products”

For aesthetic reasons, at least in the warp, several denim products are actually ring spun. Also core-spun elastic yarns for weft will always be made in rings.

Yarn Strength from Fibre Selection

Since the yarn strength is of special significance when processing denim yarns, especially open end yarns, it is important to know the effects fibre strength, fibre length and fibre fineness have on the yarn strength.

The relationship between fibre properties and yarn strength of open end yarns for various counts are expressed in the form of equation.

The equation for calculating

CSP =735 x [UHML x Str - 3 x Str -255 -6.6 x UHML]^0.22– [72.5 x Mc/UHML + 16] x C

Where, UHML is Upper Half Mean Length in mm and
Str is Strength in grams per tex as tested using HVI Mode
Mc is Micronaire and
C is Count in Ne

The above equation which uses Fibre characteristics as tested using HVI Mode is deduced from earlier ATIRA equation for predicting CSP of Open-end yarns using Fibre characteristics using ICC Mode.

CSP =720 x [2.5% SL x S - 300]^0.22 – [72.5 x Mc/2.5% SL + 16] x C
Where, 2.5% SL is 2.5% Span Length in mm
S is Strength in grams per tex as tested using ICC mode
Mc is Micronaire and
C is Count in Ne

Cotton From Dyer’s Perspective

The colour of cotton fibre is important in gradation of cotton fibres. The calorimeter of HVI measures two colour components of cotton – lightness and yellowness. Lightness is expressed as a percent reflectance (%Rd), and yellowness is expressed in Hunter’s scale (+b) values.

These values affect dye ability of denim warp yarn. With cost savings, proximity and availability taking more focus on selection of cotton, the dyer has to leverage operational flexibility to use various cottons and still hits the target shade.

The % Rd, +b values of typical Indian and imported cottons are given in Table-3.4.

TABLE -3.4 : COLOUR COMPONENTS OF TYPICAL INDIAN AND IMPORTED COTTONS
As can be seen from the Table, that V-797 is yellowier than J-34 and necessary corrections need to be done when switching over from yarn set made from J-34 to V-797.

Norms For Yarn Realization

The percentage yarn realization depends primarily on the process waste taken out at the blow room and cards. Of these the waste taken out in the blow room depends on the trash content of the mixing, the waste in cards and on the type of cards. It is therefore, necessary to use a separate norm for yarn realization for each mixing. Over and above the type of cotton used in denim mixings range from J-34 to trashy V-797. The norms for yarn realization which depends on the trash content in the mixing is given in the Table as a guideline.

A one percent reduction in yarn realization has almost the same economic impact on the mill’s profit as an increase of one percent in the mixing cost. The control of yarn realization is thus as important to a mill as the control of cotton and mixing costs. One may find the detailed pcedures for the control of yarn realization in Chapter 3, ATIRA Silver Jubilee Monograph “Process Control in Spinning”.

TABLE - 3.5 : NORMS FOR YARN REALIZATION
Notes:

Yarn Production
1.Yarn realization (%)= -------------------------------------------------------------------- x 100
Bale Cotton +Waste of other mixings +Purchased Wastes

2. Usable wastes of the same mixing, added back are not considered while determining the yarn realization.

3. Yarn realization can also be obtained from the following formulae. These can be used for quick estimates.
Yarn Realization (%) = 93.44 – 1.30 x Trash in mixing (%)

4. The values given in the table are arrived at by considering the waste levels as follows:
Invisible loss: 1.5% on mixing fed
Sweepings : 1.5% on mixing fed
Usable Waste: (% is based on material fed at each process)
Card Sliver 0.5%,
Draw frame Sliver: 0.6%,
Speed frame: 0.5%.
Ring frame Pnemafil 1.0%,
Roving ends: 0.4%
Open End Sliver: 0.3%

5. The percentage trash in the mixing is for the mixing inclusive of usable waste and waste of other mixings added.

6. When comber noil is added to the mixing, the yarn realization will be lower than that given in the Table. For every 10% comber noil addition in the mixing, the yarn realization will come down by 1%

7. The yarn realization values given the Table are for ring doffs weighed without conditioning, wherein the time lapse between doffing and weighing is very short. If doffs are conditioned and weighed, the realization will be higher by about 1.0 to 1.5%.

Managing Waste

There was a time when blow room and carding non-re workable wastes used to be just that: non-re workable, except perhaps for surgical cotton. Attempts have always been made to re-use flat strips.

The full recycling of all opening and carding wastes, using a new line of machinery from Trutzschler and others, is attempted by few with a success . Its obvious importance in Denim manufacture lies in the overall weight on the final cost represented by the cost of cotton .Because of heavy yarns and fabrics, if one can save 3 or 4% on cotton costs, the impact on the bottom line can be remarkable.

This clean material has some residual trash in it not too different from the cotton used. Naturally there are more short fibres. The yield will be approximately 50%, in other words from each 2 kgs of raw waste we get 1 kg of clean recycled cotton. This material is baled again and fed to the mix at the lay down. Normally 10% is used. A loss of some 0.5 to 1.0 cN/tex is then unavoidable, but with 10% it will be manageable.

SPINNING PREPARATORY PROCESSES

Blow Room

The raw material for Denim yarn is cotton, the type and quality of which varies tremendously, not only from country to country but within India and even within regions. Because of this variation it is difficult to envisage a standard line to meet all cases and manufacturers of opening and cleaning machinery have to be able to configure a line to meet the requirements of each individual customer. In general, Modern Blow room line with 4 to 5 beating points with micro dust extractor and very efficient automatic waste evacuation system will be adequate to ensure satisfactory opening and cleaning.

In the case of variations within regions it is not uncommon to have fluctuation of colour from bale and therefore blending becomes very critical if shade variations from lot to lot in the finished cloth are to be kept to a minimum.

It is already mentioned in the beginning that denim units have a high production output This necessitates, the modern method of opening bales. That is to use an automatic bale plucking machine which removes small size tufts of raw material from a line of bales and feeds these pneumatically to a blending machine. This ensures a uniform tuft size being fed to the blending and cleaning machines. However, the disadvantage is that removal of foreign material. In traditional blow rooms it is the practice to pre-open the bales and create a stack mixing. This ensures easy removal of foreign matters. It is important to have both options available to maintain the ability to satisfy all the variables.

For feeding recoverable waste and small blends of fibre material it is recommendable to integrate a pre-mixer.

V-797 and CIS cottons have considerable amount of trash, as high as 15%, as a result of geographic conditions and bad picking practices. In addition to trash, the fine clay of the soil, on which the cotton grows, permeates everything. It is also important to use pre cleaners to handle trashy cottons. Tandem cards used in the past, was successful in yarn quality considerations, but cost considerations turned it into an impossible proposition. The yarn realization as well as the clean cotton cost will be impacted by the use of high trashy cottons. [See 3.2.3 Norms for Yarn Realization]

It is also possible to integrate a waste recycling line to recycle non re workable wastes from blow room line and cards to bring down cotton cost [See 3.2.4 Managing Waste]

For denim yarns produced from open end spinning systems, probably the most important characteristic of the sliver is its cleanliness with particular care to be given to dust removal.

Particularly in ring spun Denim yarn, a high incidence of nep in the yarn will cause uneven dye uptake during the warp yarn preparation. It is observed that modern blow room lines create neps, upto an increase of 100% over neps in raw cotton that will still allow the carding machine to be able to remove most of these objectionable faults.

Cards

The card is absolutely decisive for the quality of the denim yarns and for the efficiency of the production. It was possible to double the card production during the past 25 years.

The carding quality is decisively influenced in the areas of cylinder, flat. Cylinder speed, clothing fineness and distance between cylinder and flat are deciding factors.

Monitoring and controlling the carding process is critical in ensuring minimal fibre damage. Instruments such as AFIS [Advanced Fibre Information System] can be used to generate information of processes that precede yarn manufacturing. The carding process is very aggressive and, if not adjusted properly, can reduce fibre length causing short fibre. This phenomenon is especially true in the new high speed carding machines. If card flats are adjusted too close to the main cylinder, the nep and trash removal is improved, however the result can also be a reduction in fibre length and an increase in short fibre content. Replacing new cylinder wire or regrinding the wire will cause a temporary increase in short fibre content but this should return to normal in a relatively short time.

The measurement of short fibre content will have some variability due to the natural variation in raw cotton. The following guideline will give an idea on how much increase is significant.

SFC(w) SFC(n)
Significant Increase >3% >6%

Increase in short fibre content less than these values are not significant and should not be considered a processing problem.

Draw frames

The requirements of Draw Frames are as follows:

i) Drawing mixes stock coming from different cards, producing a more even sliver of a more uniform quality.

ii) The high friction between fibres, especially in modern high speed frames, tends to eliminate remaining dust adhering to fibre surfaces.

iii) The fibre parallelization induced by drawing (remember a card web has fibres randomly oriented) is essential for ring roving and spinning and is helpful in open end to achieve a combination of high draft at the opening roll and good yarn uniformity.

One or Two Process of Drawing:

No doubt, the making of ring yarn with good staple cotton needs the parallelization at two drawing passages.

Several studies have been conducted to see the effect of the number of draw frame passages on the yarn properties of rotor yarn. The original general rule suggested is

i) If you make fine counts, maintain the two processes.
ii) If you go to coarse counts, one process all you required.
iii)If you are processing very short fibre material you are better off straight from the card.

Because most cotton drawing system need a fairly uniform fibre length diagram to produce slivers of good short term evenness, it is obvious that materials with short fibre contents have little to gain from even a single passage.

On the other hand, use of draw frames is also advantageous from the point of view of blending and cleaning.

It has already been several years since cards have been offered with auto-levellers. Most of these can be classified as:

-truly short term auto-levellers
-long and short term auto-levellers

The truly short term auto-regulation, now virtually abandoned, measures the sliver thickness coming out of the card by means of short variable drafting zone which attempts to adjust sliver weight to the nominal value. But as card speeds increased, and also can sizes and weights, the increased inertia of the system made accurate corrections very difficult. Even the speed of the coiler has to follow what the correction dictates. Also even if the average sliver weight could be maintained, the short term sliver evenness does deteriorate from the lack of fibre control at the small drafting zone.

Nowadays, all long and medium term auto levelers operate by adjusting the rate of feed to the card, in fact adjusting the total draft of the machine. It is sound in principle, but does not guarantee short term uniformity and is not so easy in many cases to have every card adjusted to exactly the same average value.

This is one reason why the averaging effect of at least one passage of drawing is still necessary. The new high response short term auto-levellers provide an ideal complement and very even slivers are now possible, totally free of count drift and with very acceptable short term irregularity.

It has also been observed that the direction of majority hooks has little influence whereas the number of draw frame passage has a marked effect on yarn strength. It is also important to maintain count and strength variability to the lowest as the yarn breaks in spinning are correlated to the yarn breaks on the weaving machine.

Thus, we can modify the original rule as

i) Two passages for ring spinning and
ii)one passage for coarse count open end spinning provided, the Count CV% of yarns produced is about 1.0% [or not exceeding 1.2%] and warping breaks per million metres of warp is about 0.3 [or not exceeding 0.5]

Quality of Feed Sliver

Standards for Trash and Nep Levels

In ring spinning, trash particles are thrown harmlessly off the yarn as it balloons whereas in rotor spinning, they tend to become embedded along with dust particles in the rotor groove. The impurities and dust which accumulate in the rotor groove not only impair the operating conditions of the machine and cause rapid wear of the rotor surface but are also responsible for lower yarn quality and increased yarn breakage rate. In order to minimize end breaks, the total trash percentage of sliver fed to the rotor machine should not exceed 0.5% as tested using MDTA.

Particularly in ring spun Denim yarn, a high incidence of nep in the yarn will cause uneven dye uptake during the warp yarn preparation. It is observed that modern blow room lines create neps, upto an increase of 100% over neps in raw cotton, that will still allow the carding machine to be able to remove most of these objectionable faults. The nep content expressed in neps/gram as tested using AFIS should not exceed 150.

Mill Studies: Health Checks at Spinning Preparation Processes

In addition to level of neps at feed sliver, AFIS [Advanced Fibre Information System] can also be used as a powerful process control tool for scanning the processes that precede yarn manufacturing periodically.-
One such analysis, done Product wise and Process wise in seven different mills, four open end spinning and three ring spinning, is summarized in Table – 3.6.

TABLE - 3.6 : NEP LEVELS AT SPINNING PREPARATION AND PROCESS ANALYSIS
The product wise analysis refers to Level of neps at mixing, Blow room and Card sliver. The process wise analysis refers to nep increase at Blow room and nep reduction at card.

It is important to arrive the product standards, considering the end use requirement for card sliver. Once the level of card sliver neps required are decided, the level of neps required at blow room material and target level at mixing can be arrived. This is by working backwards with the use of process standards for nep increase in blow room and nep reduction at cards.

The standards used in the analysis are as follows:

Nep/gram at Card Sliver : 120
Card Feed : 400
Mixing : 200
Nep increase at Blowroom: 200%
Nep reduction at Card : 70%

As can be seen from the Table, the blow room nep generation was high at OE Mill1, OE Mill2 and OE Mill 4 Feeder 2. It is observed that Long and bent material transport duct lines were the reasons for nep generation in OE Mill 4 Feeder 2.

Slivers made from OE Mill1, OE Mill2, OE Mill 4 Feeders 1, 2 and , RS Mill 5 feeder1 had excessive neps. It is also observed, that the overall rep removal efficiency of cards in OE Mill 1 and 4 were very poor due to poor condition of wire points.

In addition, the cards who’s performance was too poor than the rest were identified and given in remark – though individual values could not find place in this summarized report.

SPINNING PROCESS

Denim plants have both open-end and ring denim capabilities, although a majority of the capacities are open-end, which historically cater to mass-market denim products. However, open-end plants are also able to manufacture specialty denim fabric with changes to their processes. Ring spun denim is of a higher quality and commands higher prices in the denim fabric market.

The following pages describe the merits and limitations of the systems in general, inclusive of non denim yarns, so as to understand and derive maximum benefit from both systems.

Ring Spinning: Merits and Limitations:

Ring spinning had remained unchallenged for almost 150 years, since its inception. However its limitation in regard to production speeds was well realized which made its position quite vulnerable to new spinning technologies like rotor spinning. Subsequent to this realization, renewed attempts made the maximum production speed has increased to 25000 rpm by i)by extending the maximum traveller speed to 45m/sec and using ii)smaller ring diameter and bobbin lift. However, this has not prevented rotor spinning applications in coarse denim yarns as these yarns demand higher ring diameter and bobbin lift. Today the problem of excessive knots due to smaller ring package is of little consequence due to efficient splicing systems available at winding. Another serious problem of excessive initial end breaks due to greater number of doffs has been solved by the employment of efficient automatic piecing devices. Additionally there are support systems such as automatic roving transport to the ring frame, automatic roving rupture if the yarn is not pieced in three successive attempts in order to reduce incidence of roller lapping.

The merits which makes it unique ever are i)It produces the strongest yarn, it is the bench mark among all 100% staple fibre spinning systems for various types of fibres and their blends. ii)It can produce yarns with a large range of twist, density from very low to very high. No other spinning system can match this unique capability of catering from knit to voile yarns. iii) It can be used for all types of fibres and can spin from very coarse to extremely fine yarns. iv) The desired hand, crisp or soft as per requirements can be imparted using the ring yarns.

Open End Rotor Spinning: Merits and Limitations:

The rotor spinning system has the following merits and possibilities:
As can be seen from the process sequence, i)the speed frames and cone winding machines can be dispensed with. ii)the productivity per position is 6 to 8 times that of ring spinning. iii) It is extremely amenable to automation – viz auto piecing, auto cleaning and auto doffing. Features like Online Quality Monitoring can also be opted for. iv) The rotor yarns are extremely regular and have much lower levels of imperfections and faults as compared to ring yarns.

The inherent drawbacks / limitations of the rotor spinning system are:
i)The rotor yarn strength is lower than ring yarns.
ii)Longer fibres (>32mm) offer no advantage in regards to yarn quality and /or productivity.
iii) the yarn twist required for optimum strength is higher than ring yarns.
iv)the biggest drawback of rotor yarns is the harsh feel of the fabrics made out of them.
v) The minimum number of fibres required in the cross section of rotor yarn is around 100 to 110 compared to 50 required for ring yarns. Therefore the quality of rotor yarn deteriorates when finer yarns are spun on this system.

Rotor Selection:

Rotor size, rotor groove configuration, rotor speed and rotor surface treatment all have a decisive influence on the structure and properties of a rotor yarn.

30, 33 and 36mm rotor diameters are used for finer yarns and 40 and 46mm rotors are useful for coarser yarns. A small rotor cannot accommodate the fibre mass needed for a coarse count in its narrow groove, and a possible overfeeds in case of yarn rupture would quickly choke the rotor cup.

It is a common misconception that yarn quality deteriorates with small smaller rotors and higher rotor speeds.

The grove configuration determines whether a yarn is bulky or compact, weak or strong, more or less ring-yarn-like etc. Most manufacturers of rotor spinning machines offer an array of different rotors. The grooves normally used in Denim applications are as follows:

“S” Groove Rotors produces a bulky yarn which is weaker than yarn spin in any other rotor. It yields an excellent uniformity and is suitable for cotton with above-average trash content and for all synthetic fibres.

“U” Groove Rotors possesses good self-cleaning properties as far as dust is concerned, but trash particles can still jam the groove and cause moiré. The yarn strength is higher than that from an S-rotor. For these reasons U-rotor is preferred for denim yarns.

“T” Groove furnishes the strongest yarn due to its narrow, recessed groove, especially in fine counts. It is also the leanest, most compact yarn, having a low number of hairs per yarn cross section. Yarn torques is also higher, indicating a more ring-yarn-like structure.
It is susceptible to initial deposits, but then the self cleaning effect sets in, maintaining uniform yarn properties. It is unsuitable for trashy cottons. It may also not be useful for denim warp yarns for rope dyeing where the higher yarn torque may cause problems in rebeaming.

Opening Zone

The opening roller wire specifications should be chosen as per fibre specifications, The general principle to be followed for deciding opening roller speed is that the higher the speed, the lower the yarn unevenness, the faults, the yarn strength and the breaking extension, Lower opening roller speeds should be used normally be used for the following:
i) longer, finer and crimped fibres
ii) coarser and cleaner sliver
iii) lower rotor speed

The range of speeds normally ranges from 5000 to 8000 rpm.

The influence of other machine and process parameters on rotor spinning yarn properties in general are well documented in two references given at the end which we suggest for further reading.

YARN QUALITY PROFILES

Yarn quality profiles can be presented in many different ways. E.g. in table or graphic form. One example, shown here in Tables 3.7, 3.8 and 3.9 details the properties of yarn spun on both the rotor spinning and ring spinning systems and tabulate the yarn quality levels achieved with different yarn counts. The specific information on rotor groove and end use, whether it is meant for warp/weft, rope/ slasher are provided for interesting comparisons. Each of these Tables corresponds to the Fibre characteristics of different mixings, coarse count open end, fine count open end and ring spinning mixings , as provided earlier in Table -3.3 in this treatise.

If one studies critically, the data shown in these Tables confirm many of the statements made throughout this book.

COTTON, PROCESS AND YARN TESTING

In order to monitor yarn quality consistently and efficiently, a testing laboratory equipped with modern instruments is an indispensable tool for the spinner. A good sampling plan (size and frequency of test samples) keeps track of sliver quality and yarn quality in such a way that in case of deviation from set quality standards, corrective action can be taken immediately. The sampling plan usually varies from plant to plant and should represent a careful balance between the prevailing quality requirements and the cost of testing. The Table – 3.10 lists the most commonly used testing instruments to determine specific cotton, process tests and yarn properties. These instruments are fairly well standardized throughout the world; they are not operated not only in yarn spinning plants, but also in research laboratories, textile institutes, universities and at machinery manufacturers. The following brief describes the uncommon tests – yarn torque and fancy yarn testing.

Determination of Yarn Torque

A simple and fast method to evaluate yarn kinkiness, bulk, and hand is the so-called Torque Test.

Two leas (skeins) of the same yarn are connected by slipping an O-ring in each end as the skeins are pulled off the reel. This double skein, suspended in a vertical position with the lower ring released turns due to its own torque. The number of turns reveals very useful information about the yarn structure, internal dynamics and its behavior in subsequent processes, such as kinking and snarling, as well as fabric properties such as skew, bulk and hand.

Torque measurements range from near 0 (no torque) to 6 (very high torque). Subjectively comparing the soft or harsh feel of yarn skeins provides good clues to the hand of the fabric.

Determination of Fancy Yarn Parameters:

Recently, the usage of characteristic yarns, such as slubby and multi count yarns, both in ring spinning and open end rotor spinning system in denims are on the rise. These yarns need additional monitoring of Slub parameters. Fancy yarn module of UT-5 serves this purpose with testing of Slub parameters -Slub frequency, Slub Length and Mass increase in addition to yarn diameter, yarn density and shape. The fancy yarn properties of typical characteristic yarns are given in Table-3.11
.
ON SHUTTLE LESS LOOMS

Traditional denim weaving had been done with the rapier looms and projectile looms for a long time. But with the development of the air jet weaving technology, the main flow of the denim weaving has been changed to Air Jet Loom due to its suitability to mass production.

The general guidelines in selection of various types of shuttle less weaving machines are as follows:

Rapier is known for its versatility in weaving fancy fashion materials of different constructions like suiting, upholstery, furnishing etc.

Air Jet weaving machine is most suitable for mass production.

Projectile is suited for dress material, industrial fabrics, heavy denim and geotextiles in single or multiple widths.

An evaluation on the application of various methods of weft insertion carried out by the Textile Machinery Society of Japan is given in Table 5.1

As can be seen from the Table that Air Jet Weaving scores in high productivity and labour savings however suffers in high energy costs and yarn wastage. Projectile scores well on both parameters, that is energy saving and fabric quality. More over, running cost will be the lowest for projectile during extended machine’s economic life beyond capital life. However, these ratings may be different in Indian context and for specific denim applications.

ON AIR JET LOOM

The important features of Denim weaving on Air Jet Loom are as follows:

a. High Productivity: As an actual production in the mill, 900 rpm is achieved already with the latest models of different makes.

b. Start Marks: The rush motor emits 1200% torque at the time of start and avoids start marks. Electronic let off, ensures the even warp tension from the full beam to the empty beam. Electronic let off is also equipped with the programmable kick back function which controls the cloth fell position at the start according to the loom stop duration. The second feeler is equipped to detect blow off of weft yarn.

c. Special arrangements for the Denim Weaving of Coarse Yarns:

I. Reinforced loom structure for heavy duty weaving.
II. Reinforced let-off motion for heavy warp.
III. Intermediate rocking supporter to make a strong beat without bending for heavy fabric.
IV. Positive cam motion for high speed operation for the heavy load of warp.

d. Stop Market Prevention:

i) Automatic Leveling Device: It automatically closes the shed after a loom stop by leveling all the shafts and prevents warp strain which may create corrugate marks.

ii)One Pick Insertion System: To minimize stop marks, a special weft insertion system functioning at the time of restart can be equipped with. When the loom is started first pick is automatically inserted just before the first beat. By avoiding the beat- up without yarn at reverse rotation, this system prevents the corruption of the fabric construction and prevents corrugate marks.

e. Devices for a coarse count weft:

The following are some of the arrangements equipped to use a coarse count yarn for weft.
i) Balloon Breaker reduces the weft tension due to ballooning.
ii) Auxiliary main nozzle is installed before the main nozzle to insert a coarse weft with less air pressure.
iii)Stretch nozzle is furnished to give adequate stretch to the weft for a perfect insertion of a coarse weft.

f. Labour Saving:

This is realized with a large size packages and loom automation. Automation includes automatic pick finding for easier weft repair and automatic defective pick remover.

REQUIREMENTS FOR HIGH INSERTION RATES IN AIR JET WEAVING

weaving profitability is the result of weaving productivity. The higher the weaving machine speed and efficiency the higher the productivity. As soon as speed is increased however, weaving machine efficiency, which is affected by loom down time on warp and product changing on repairs and yarn break repair times and also quit markedly by the number of warp and weft stoppages falls a rule.

The standards for loom stops per hour is given in Table-5.2

In air jet weaving, the proportion of weft stoppages to total is high, and their reduction is therefore of great importance for increased efficiency in air jet weaving processes. In addition, fewer warp yarn breaks, their faster repair and short setting times are the key for high production. It is not the speed of the machine, but the number of picks actually produced that is the deciding factor in modern weaving. The important points are i)the factors which guarantee high insertion rates ii) the humidity levels iii) the factors which lead to a high fabric quality.

Influence of Yarn:

The yarn breaks in spinning are correlated to the yarn breaks on the weaving machine. It is important to maintain count and strength variability to the lowest. The standards for Count CV% and Strength CV% is given in Table- 5.3.
The count CV% will be higher by +0.5 where auto levelers are not existing on finisher draw frame. Therefore it is necessary to use two passage draw frames where finisher draw frame is equipped with auto levelers particularly fine, ring and characteristic yarns.

In case of OE spinning there is an interesting correlation between high residual trash- content and increased yarn breaks in weaving. The norms for residual trash content at feed sliver are 0.5%.

The weft insertion performance depends to a large extent on the level of weak spots. The standards for Uster Tensojet Tensile properties are given in Table-5.4. Percentile 0.1% values given in Col 5 and 6 for Elongation% and Force in cN is a tool for identifying the weak spots in the yarn lot and estimated performance on loom.

Influence of Weaving Preparatory on the Cloth Production System:
Tight ends, lost ends, pieces of yarn or lint dragged onto the warper beam are performance killers in air jet weaving. Therefore the accurate functioning of the stop motion on the creel plays a key role.

Warper beams should not contain any grooves, high edges or crossed ends. They should be made with bobbins of adjusted length and run off the creel without crossing ends and at uniform tension. In this manner yarn breaks on the sizing machine can be almost eliminated.

During sizing, the lengths run at creep speed should present less than 4% and a moderate size application control system should be used. For air jet weaving, two size boxes and real wet splitting should be used in case of warps with more than 70% cover density, in order to reduce the hairiness of the yarn.
The use of size add on control seems to be essential when operating with two size boxes, because there are no two size boxes, because there are no two size boxes which, in spite of exactly identical setting, produce exactly the same size add on. The differences measured may reach as much as 4% in absolute figures.

Over drying, particularly when sizing cotton yarns should absolutely be avoided.

After waxing, (0.2 to 0.5%) of the warp ends generally improves its performance.

Finally the warp ends should be fixed by tapes in such a way that they can be entered into the harness without crossing.

Factors influencing the performance of the warp in the weaving machine:

The shed geometry in front of the reed is to a large extent designed by the builder of the machine. When setting the back shed and harness stroke the weaver is required to choose the proper setting, also when determining the warp tension. These settings have an important impact on the performance of the machine. It is therefore essential that these settings are optimized with utmost care and by using modern measuring instruments.

Following two factors have a particular influence on the behaviour of the warp:
i) yarn traction force
ii) yarn hairiness

A too high warp yarn traction force is leading to overloading the warp ends. As the yarn traction force is not constant during weaving, the peak tensions which generally appear in the bottom shed, particularly in the middle of the warp should be taken into consideration. These peak values should not exceed 5 to 6 cN/tex, depending on the quality of the yarn.

The importance of the setting of the warp stop motion is often under estimated. Its position has a direct influence on the back shed and thus on the yarn traction forces in the bottom and top sheds. The vertical position of the warp stop motion should therefore be set very precisely. It changes the asymmetry of the shed.

Atmospheric Conditions

Relative humidity have a great impart on the performance of the weaving machines. The optimal dissipation of temperature and humidity over the machines, that is the warp, is generally not reached, because the sources of heat within the weaving machine disturb the climatic conditions. Numerous yarn breaks are caused by dust, lint and fibre accumulations. The best experiences have been made with air conditioning systems whereby humidified air is conducted over the machine, whilst the dust – loaded exhaust air is evacuated through floor opening under the back shed, and because the descending flow of the conditioned air is assisting the sedimentation of the lint. At the same working conditions for the personnel are improved. It is surprising how much cleaner the machines and the whole weave room are, compared with systems whereby the exhaust air is evacuated in the alleys, or worse, through the outside walls.

Table -7.6: Weaving - Typical Denim Constructions

TABLE-7.7 : PRODUCTION CALCULATION

The following information is an estimated performance for weaving 14.5 ozs indigo denim.

a)Fabric : Indigo Denim 14.5 ozs/square yard
Warp Yarn : 100% Cotton Ne 7s Indigo Dyed
Weft Yarn : 100% Cotton Ne 6s Grey
Warp Density: 60 ends/inch
Weft Density : 40 picks/inch
Width : 66.5 inches
Weave : 3/1
b)Reed Space : 68.5 inches
2 Colour Weft Mixing
Positive cam shedding Motion, 4 shafts
-Denim Weaving Arrangement
c)Estimated Loom Speed : 900 rpm
d)Estimated Production Per Loom:
i)Daily Production (linear length)
= 900 rpm x 60min x 24h x 0.92 eff x 0.0254 / 40 ppi
= 757 metres/day/loom
ii)Monthly Production (linear length)
= 757 m x 30 days
=22713 metres/month/loom

The following standards for denim fabric quality in terms of inspection, packing, shade and physical requirements are of general nature considering varied requirements of end-uses / customers, however holds good for major universe.

This chapter details classifying fabrics according to color and defects so that the fabrics are made to garments at ease with defects eliminated, grouped according to shade and perform satisfactorily.

INSPECTION REQUIREMENTS

Fabric Group Classification According to Yarn Type

Group One

All Basic Denims (OE/OE)

Group Two

All Denims (RING/OE) & (RING/RING)

Group Three

Specialty Denims: Linen Denims, Vintage

Acceptable Defect Point Levels According to Yarn Type

TABLE-11.1:DEFECT POINTS PER 100 SQUARE YARDS
TABLE-11.2:DEFECT POINTS PER 100 SQUARE METRES
TABLE 11.3: QUALITY CATEGORISATION OF DENIM FABRICS

Defect Grading:

A. Point Grading System: Denim fabrics are normally graded using the “4-Point” system. This numeric grading system is endorsed by ASTM, AAMA (American Apparel Manufacturer’s Association) and ECMA (European Cloth Manufacturers Association). All defects which are clearly visible from one meter (three feet) are scored as defects and demerit points assigned according to severity.

B. Length of Defect Points: Demerit points are assigned to warp and filling defects as follows (Defects in any direction)

v 1 point - Defects 7.5 cm(3”) or less
v 2 points - Defects exceeding 7.5 cm(3”) up to 15 cm(6”)
v 3 points - Defects exceeding 15cm (6”) up to 22.5cm(9”)
v 4 points - Defects exceeding 22.5 cm(9”)

C.Counting of Lengthwise 4 Point Defects: No linear meter is penalized more than 4 points.

v Defect length 22.6cm (9”) to 100cm (40”) – 1 no of 4 point defect
v Defect length 100.1cm (40.1”) to 200cm (80”)–2 no of 4 point defects
v Defect length 200.1cm (80.1”) to 300cm (120”)–3 no of 4 point defects
v If length of defect is more than 3 meters (120”) the length containing the defect is removed.

D. Full Width Defects:

v A full width defect running over 6” in length shall be removed.
v More than four full width defects per one hundred linear meters shall not be accepted as first quality.
v A full width defect in first or last three meters of roll shall not be allowed.

E. Flagging of Defects:

v Only 4 point defects are flagged with a metallic sticker. One may find the metallic sticker at the start of the defect. Metallic flags should be a minimum of 2 cm wide and 7.5 cm length.
v Defect points 1, 2, 3 shall be counted but not flagged.
v All splices shall be flagged.
v All holes shall be removed. There must be two or more yarns broken at the same place to consider a defect as a hole.

F. Roll Length and Splicing:

v Roll length tolerance should be agreed upon the first delivery. Say maximum 135 meters and minimum 85 meters.
v No pieces shall be accepted as first quality with length less than 30 meters.
v No roll shall be accepted as first quality containing more than one splice.
v The shade continuity between parts must allow for the mixing of garment components within a garment.
v Two part rolls should be identified as such, No more than 25% two part roll should be allowed in any shipment.

G.Shading:

v No pieces shall be accepted as first quality that exhibits a noticeable degree of shading from side- to -side or side- to –centre.
v No pieces shall be accepted as first quality that exhibits a noticeable degree of shading from end– to –end.

Skew

A. All 3/1 and some 2/1 twill fabrics for bottoms require skewing. Since the optimum skew varies depending on the fabric (anywhere from 5% to 9%), this must first be determined by the supplier and agreed upon before bulk fabric orders are placed. Target for individual rolls = +/- 3%

B. No fabric shall be accepted as first quality exhibiting more than 3% skew movement.

Waviness

No roll shall be accepted as first quality exhibiting a noticeable degree of looseness (waviness) or tightness along either or both selvages.

Ripples or puckers in the body of the fabric, which prevents the fabric from lying flat when spread in a conventional manner, is unacceptable.

The woven selvage or fringe should be the same on both sides of the fabric.
Tolerance wavy selvage: 2% in length

Width

Cuttable width variations must meet the minimum fabric width specification. In addition width variation within a roll should not exceed 2 cm.

PACKING REQUIREMENTS:

Put- up- Specifications

A. Fabric shall be rolled onto a spiral-wound tube with necessary wall thickness [OD: 60 mm; ID: 45 mm] and strength [Radial Crushing Strength > 500 Kgf for 8” length] to insure it reaching to customers in good condition, provided it is handled by reasonable and acceptable methods.

B. Rolls are wrapped in such a manner that will protect the fabric from all types of damage during transportation and storage.

C. The outer edge of each roll shall be taped down to prevent unrolling during shipment and storage.

D. Roll Identification

Two stickers must be attached one to the end of the roll and another on side of the roll. The stickers shall contain the following information.
1. Roll /Bale Number.
2. Fabric Style number
3. Shade Group
4. Roll length in meters
5. Roll length in yards
6. Fabric width in inches
7. Total square meters
8. Demerit points per 100 square Yards
9. No of fabric pieces
10. Gross weight in Kg
11. Net weight in Kg
12. Quality Category
13. Total number of 4 point defects
14. Total number of Demerit points
15. Security code

COLOUR EVALUATION / SHADE GROUPING

Option 1: Instrumental Shade Evaluation Procedure of Wash Swatches

Instrumental Color Measurement: The color measurement shall be carried out using Spectrophotometer.

Master Roll: Master roll shall be established during initial stages and will remain during the entire life cycle of the product. The procedure for selecting the master roll is given under the head “Procedure for Selecting the Master Roll – Instrumental Evaluation”

Blanket Preparation: The blanket preparation procedure is given under the head “Blanket Preparation”

Shade Evaluation: The color measurement shall be carried out using Spectrophotometer and shade grouping shall be carried out according to wash color reference of master roll. Before assessment, all fabric swatches must be conditioned for at lease 1 hour in a controlled atmosphere. Samples must be conditioned from a dry state. All measurements must be done as soon as possible after conditioning.

Classifying Rolls by Color Groups: LMD grouping shall be followed. (L= Light, M = Medium, Dark = D), the taper standards are defined as color difference (dEcmc) by Standard, Average, Range and Roll to Roll. L: C [Lightness: Chroma]

The tolerance to be followed is

Average : 1.2
Standard : 2.0
Range : 1.5
Roll : 0.5
L: C Ratio : 2.0

Visual Evaluation: All roll sequences shall be evaluated visually by laying the swatches in standard lighting conditions and remove abnormal rolls.

Light Conditions: Only D65 lamps are to be used to assess color. Make sure appropriate Number of lamps is used to obtain luminosity of minimum 1500 lux.

Identifying Color Groups: To facilitate classification of rolls, the rolls shall be identified with appropriate color stickers of L, M and D and the same shade group shall be mentioned in the packing list by tracking via roll number.

Swatch Service: The system shall be to send two set of unwashed and washed swatches to customers. The washed swatches are being sent so that customer can review the shade at their end and the unwashed swatches will be used for additional use if any.

Option 2: Visual Shade Evaluation Procedure of Wash Swatches

Visual Color Assessment: Each wash swatch representing one roll in the shipment needs to be compared to the master swatch under standard light conditions.

Master Roll: Master roll shall be established during initial stages and will remain during the entire life cycle of the product. The procedure for selecting the master roll is given under the head “Procedure for Selecting the Master Roll – Visual Evaluation”

Blanket Preparation: The blanket preparation procedure is given under the head “Blanket Preparation”

Shade Evaluation: Each wash swatch shall be evaluated versus reference shade swatch on shade, color, wash-down, abrasion and overall appearance. Based on this comparison swatches representing rolls shall be accepted/ rejected.

Light Conditions: Only D65 lamps are to be used to assess color. Make sure appropriate Number of lamps is used to obtain luminosity of minimum 1500 lux. Make sure a matt grey background is used with reference of Munshell grey N5 or N7 to assess colors.

Identifying Color Groups: To facilitate classification of rolls, the rolls shall be identified with appropriate color stickers of L, M and D and the same shade group shall be mentioned in the packing list by tracking via roll number.

Swatch Service: The system shall be to send two set of unwashed and washed swatches to customers. The washed swatches are being sent so that customer can review the shade at their end and the unwashed swatches will be used for additional use if any.

Option 3: Visual Shade Evaluation Procedure of Unwashed Swatches

Visual Color Assessment: Each wash swatch representing one roll in the shipment needs to be compared to the master swatch under standard light conditions.

Master Roll: Master roll shall be established during initial stages and will remain during the entire life cycle of the product. The procedure for selecting the master roll is given under the head “Procedure for Selecting the Master Roll”

Shade Evaluation: Each unwashed swatch shall be evaluated versus reference shade swatch on shade, color and overall appearance. Based on this comparison swatches representing rolls shall be accepted/ rejected.

Light Conditions: Only D65 lamps are to be used to assess color. Make sure appropriate Number of lamps is used to obtain luminosity of minimum 1500 lux. Make sure a matt grey background is used with reference of Munshell grey N5 or N7 to assess colors.

Identifying Color Groups: To facilitate classification of rolls, the rolls shall be identified with appropriate color stickers of L, M and D or D+, D, D- and the same shade group shall be mentioned in the packing list by tracking via roll number..

Swatch Service: The system shall be to send three set of unwashed swatches to customers.

Blanket Preparation

Swatch Size: Use uniform swatch size of 8” x 6”

Preparation of Blankets: All blankets for washing shall have standard shade swatch from Master Roll. Swatch shall be cut from every roll of a shipment each 8” x 6”. Identify each roll no at the back of the swatch. In case of light weights identify by serial nos at the backside corner with indelible ink.
Waste material of same style

Wherever less number of swatches is available use dummy swatches of same style nos.

Do not use washed swatches for dummies.

v Dummy swatch size shall be of same size as that of blanket swatches.

v To make wash load if required, use dummy swatches of same style only.

v Sew the two panels together to avoid entangled panels in washing.

v All panels from one shipment to be washed in same wash load.

Washing of the Blankets: Wash blankets according to the recipe for various classes of products.

Procedure for Selecting the Master Roll

Instrumental Evaluation

v From the average of the washed lot select about five roll which are near to the average values.
v Check their UNWASHEDED L*a*b* values, these must belong to 555 block. If not then select 5 more rolls near to average values from the washed lot.
v The roll which belongs to 555 shade block, check the preceding and succeeding rolls L*a*b* values, these must also belong to 555 shade block. This will ensure that there is no shade variation within the roll.
v Now check the consistency of the complete beam. There should not be much variation within the beam.
v The dyer will use the yarn latti of this particular beam as shade reference for dyeing.

Visual Evaluation

v Select about five rolls which represent middle of the washed lot.
v Check unwashed swatches as well, for their true representation of the middle of the lot.
v Check the preceding and succeeding swatches. These must also belong to the same shade. This will ensure that there is no shade variation within the roll.
v Now check the consistency of the complete beam. There should not be much variation within the beam.
v The dyer will use the yarn latti of this particular beam as shade reference for dyeing.

TESTING REQUIREMENTS - PERFORMANCE STANDARDS

Product development concerns itself with modifications or extensions provided to ideas so as to improve the functioning, the cost, and the value-for-money of the product. Development efforts improve the performance of the product, add options and additional features and even add variants of the basic product. On the whole, development effort is innovative vis-à-vis research which is more inventive – the thrust being on developing new product ideas, technologies and processes.

The tradeoff between research and development is an important strategic decision for most organizations.

Variety or Standardization

There are two distinctly different priorities that can affect the product development.

By adding variety, an organization attempts to satisfy the varied needs and tastes of customers and competes on non-price considerations as well.

On the other hand standardization / simplification offer:
-reduction in total inventory of yarn
-reduction in extra or unutilized ends
-reduction in accessories/ reeds
-reduction in change over times
-simplifies many operational procedures
-reduces need for many controls
-lower unit costs

Now the two caveats to trade off are
# a family of similar products is much simpler to produce than a family of dissimilar products.
# it is not enough to produce a product but it has to be produced so that there is an added value as perceived by the market

Modularization: Middle Path – Buddha’s Way

One method used to obtain variety or perceived variety and yet hold down cost is through modularization. A product is deigned using modules or sub assemblies that are interchangeable and each different combination of modules gives a new variety of the product.

1 Warp sheet
X 3 Colors
X 3 Weaves
X 3 Wefts
--------------------------
1x3x3x3= 27 Products
-----------------------------
X Tints
X Garment Washes
X Blasting/Brushing
X ….
X …
X ...

For example one warp sheet, three colors, three weaves and three wefts will give
1 x 3 x 3 x 3 =27 varieties, yet making large quantities of standard modules.

This is illustrated with two typical basic denim constructions. The grey construction details are given in Table-13.1.

Volatility in Cotton prices

Denim mills are searching for ways to produce denim fabrics of the highest quality at competitive prices. The engineering from raw fiber to finished fabric results in superior denims when modern fiber and manufacturing technologies are consistently applied throughout the processing chain. However, the cost of these engineered products delivered to the market place demands, in addition the prudence in tackling the volatility associated with the raw material, mainly cotton.

The Raw Material Cost [RMC] per metre of 150 cm width basic OE denim, for various denim weights over a decade is depicted below in equation, for the sake of simplicity:

RMC/metre = 2.3 x ozs per sq.yd. + 8.4
+/-0.4

That is cotton cost per metre for a 10ozs OE denim is Rs.31.4 [Ranging 27.4 to 35.4]

The engineering of denim fabrics utilizes, ring spinning or open end rotor spinning or their differentiated innumerable characteristic yarns + modern fabric forming and finishing techniques and commonly available but selected cotton fibers. The mixing specifications for different yarns are given in Table-13.3. Cotton Mixing Specifications of Important Fibre Characteristics for Denim Yarns (HVI Mode).

The following equation depicts the cost differentials between Ring denim and Rotor denim in a simplified way:

RMC Ring per metre = RMC OE per metre x [1+ozs per sq.yd/100]

That is cotton cost for a 10 ozs ring denim is Rs.31.4 + [1+10/100] = Rs.31.4 x 1.1 = Rs34.54.

Engineering

Hence the engineering of denim fabrics begins with the selection of appropriate combination of cotton fibre characteristics for different yarn types with the aid of modern HVI instruments. The mixing specifications for different yarns are given in Table-13.3. Cotton Mixing Specifications of Important Fibre Characteristics for Denim Yarns (HVI Mode).

Once fibre characteristics are known, yarn quality and processing performance can be predicted. Last column in the Table-13.3 provides an iNDEX for various yarn types which can be used as a composite measure to arrive at a variance with respect to actual yarn quality of various yarn types including individual characteristic yarns.

The equation for calculating

iNDEX=735 x [UHML x Str - 3 x Str -255 -6.6 x UHML]^0.22

Where UHML is Upper Half Mean Length in mm and
Str is Strength in grams per tex as tested using HVI Mode

The above iNDEX which uses Fibre characteristics as tested using HVI Mode is deduced from earlier ATIRA equation for predicting CSP of Open-end yarns using Fibre characteristics using ICC Mode.

CSP =720 x [2.5% SL x S - 300]^0.22 – [72.5 x Mc/2.5% SL + 16] x C
Where 2.5% SL is 2.5% Span Length in mm
S is Strength in grams per tex as tested using ICC mode
Mc is Micronaire and
C is Count in Ne

The spinning parameter Twist Multiplier and important yarn parameters, such as strength, count and their variability’s of various yarn types are provided in Table-13.4. Spinning Parameters and Yarn Quality.
Rope dyeing technology demands less torque yarns in warp which are made from “U”rotors. The H values of Yarns made from “U” rotors as tested in Uster evenness testers are higher by 2.0 to 2.5 numbers in comparison with the yarns produced from “T” rotors

Cover Factor

To obtain better performance on the loom and fabric yield, a guideline for cover factor in developing new fabric constructions is given in Table-13.5 and classified under 3 categories for

i) Rings
ii) Bulky Open-ends and
iii) Shrinking Stretches.

B.Grey construction is used for calculations.

C.The formula used = Threads per inch
--------------------------- -------- X 100
[28 X Square root of Count]
Changing Trend in Yarn Preferences

Beginning of twenty first century saw the explorations in different yarn options. The below list is arranged by their usage in volume, starting with warp followed by their use in weft.

Crosshatch / Streak / Rain Denims

Recently, the usage of characteristic yarns, such as slubby and multi count yarns, both in ring spinning and open end rotor spinning system in denims are on the rise. These yarns need additional monitoring of Slub parameters. Fancy yarn module of UT-5 serves this purpose with testing of Slub parameters -Slub frequency, Slub Length and Mass increase in addition to yarn diameter, yarn density and shape. Aggressive slub parameters tend to lower Yarn Strength and poor performance at subsequent processes. The minimum tenacity values as tested using Uster Tensorapid for satisfactory performance level is given in Table-10.4 in Row 3 and 7. Beyond which compromise needs to be made among Slub parameters or performance levels or cotton fibre characteristics.

Chinos

Two ply chino denims in indigo dyed shade have a unique soft hand feel, Fabric cover and a luxurious appeal.

Tencel Denim

Woven century luxury cellulosic fibre made from specially grown woods and transformed in non-chemical process which give feel of silk and comfort of cotton.

Stretch Denims

For stretch denims, Core-Spun Cotton Spandex, Poly Spandex and Type -400 yarns are generally employed. Core-Spun Cotton Spandex yarns in denims range 10s to 16s Ne and uses generally 70 denier filament; though 40, 55 and 120 denier filaments are also available. The Spandex % of Core-spun cotton spandex yarn ranges from 3.5 to 5.5 %. The twist multiplier is 4.4.

Union Denims

Denims are differentiated with weft yarns to create Union Fabrics. The union denims produced in large volumes uses the following weft yarns in the same order – Polyester Texturised Filament, Stretch yarns of Poly Spandex and Type -400 yarns, and Pre-bleached Linen Yarns.

Poly Denim

Polyester Texturised Yarns in denim applications range 300 to 600 denier, with a tenacity of 4.0 g/tex and 20 to 27% extension. Bulk which is expressed in %HCC (Hot Crimp Contraction) is about 40 and nips per metre ranges from 70 to 90 for better performance.
Grey as well as dyed yarns are being used.

Poly Stretch Denim

Poly spandex yarns used in denims range 150 to 300 denier with 6 to 12 % spandex. Nips per metre for better weaving performance is 100 to 130. Type -400 yarns from Invista used in denim applications range 150 to 600 denier with a bulk of 50% HCC and nips per metre of 35 to 50.

Linen Vintages

Pre-bleached Linen yarns range 9s to 16s Ne [or 25 to 44 Lea]. Though these yarns have very high strength of over 3000 csp and 20 cN/tex, due to low elongation of 2% and the natural variation in yarn, the loom performance as well as full width defects is poor in comparison with normal denim.

Value Engineering

In accordance with the value engineering, quality fabrics can also be produced from Value mixings given in Table -11.3 Row 5. However the denim fabrics produced out of such yarns should not be meant for elaborate destructive garment washes.

Addition of 10% Recycled Waste

The full recycling of all opening and carding wastes, using a new line of machinery from Trutzschler and others, is attempted by few with a success . Its obvious importance in Denim manufacture lies in the overall weight on the final cost represented by the cost of cotton .Because of heavy yarns and fabrics, if one can save 3 or 4% on cotton costs, the impact on the bottom line can be remarkable.

This clean material has some residual trash in it not too different from the cotton used. Naturally there are more short fibres. The yield will be approximately 50%, in other words from each 2 kgs of raw waste we get 1 kg of clean recycled cotton. This material is baled again and fed to the mix at the lay down. Normally 10% is used. A loss of some 0.5 to 1.0 cN/tex is then unavoidable, but with 10% it will be manageable.

Control of Yarn Realization

A one percent reduction in yarn realization has almost the same economic impact on the mill’s profit as an increase of one percent in the mixing cost. The control of yarn realization is thus as important to a mill as the control of cotton and mixing costs. One may find the detailed procedures for the control of yarn realization in Chapter 3, ATIRA Silver Jubilee Monograph “Process Control in Spinning”.

Mock Rings

Various attempts to duplicate superior denims made from ring yarns with rotor yarns of mock or slubby have always failed in fabric strength properties, fabric hand and appearance due to differences in yarn structure and yarn properties. Still one wonders how much of the present so-called ring spun Denims are such and how many are mock ring made in open end.

Other Value Offerings

Cotton rich polyester denims are with superior hand feel, luster and colour contrast for fashion market. One may find a deep value in using dyed polyester texturised filament yarn in place of costly yarn dyed cotton weft for high fashion denim. Poly Spandex yarns are replacing core spun lycra yarns in the value universe. Within Poly Denims, the denier is getting coarser day by day from 300 to 450 to 600. Though, Linen Vintage denims are not in high volume, there are efforts to replace it with Jute (Indian Linen) in the value proposition.

Successful strategies in denim mean profit, often (now) even survival. Engineering the fabrics on continual basis provides a way to achieve both quality and cost benefits of substantial proportions. At the same time full manufacturing flexibility through modularization is being maintained, enabling the denim mill to meet new and changing trends in raw material and fashion.

Practical Considerations for indigo dyeing

2010-11-05T08:58:00.000+05:00

Yarn for Rope Dyeing

* Yarn faces stress and stretch at ball warping, rope dyeing, rebeaming, sizing and loom shed so elongation of yarn should be more than stretch at (ball warping + Robe Dyeing+ Rebeaming + Sizing )= (2-3%) + Loom shed (about 5%)

* Tension at Ball warping should be less by 7-8% of single yarn strength.

* Strength CV should be within limits as it may give rise to weak points

* The tendency of yarn to migrate at rope dyeing can be countered by less micronaire of yarn ( should be around 3.8-4.2)

* More dropping of short fibers at long chain beaming is good

*The sensitivity settings for neps is set at +280 for rotor spun yarn and not +200 as in case of ring spun yarn. The reason for this is that the structure of rotor spun yarn is intrinsically different from that of conventional ring spun yarn. Neps in rotor yarn tend to be spun into the solid yarn body rather than remaining on the yarn surface, which is typical of ring spun yarns. Although embedded in the yarn core, these neps still represent a short mass defect and will therefore trigger the imperfection counter upon exceeding the preset value. However, compared to neps that are attached to the yarn surface, fully embedded neps are barely perceptible for the human eye. Thus, in order to balance the typical visual appearance of rotor spun yarn with the imperfection counts, +280 sensitivity setting is a common convention for rotor spun yarns.
Comparison of Ring Yarn with OE yarn at Ne 7

1. Process of dyeing of sulphur color:

1st Wash tank: mercerisation by taking 22% NaOH ie. 250 gpl
2nd Wash Tank: Hot Wash
3rd Wash Tank: Cold Wash

2. In 1st and 2nd dye bath take sulphur color 6-8% on the weight of the yarn sheet. Temperature 90 deg. cel. The solution contains the following:

1. solubalised sulphur color: 150 gpl
2. Na2S--> reducing agent: It is added to increase its reducing power
3. Caustinc Soda --> 10 gpl--> reducing agent
4. Wetting agent--> 2gpl
5. Antioxident Sulphide ( Glucose paste--> 5gpl). This is added to prevent the oxidation of of Sulphide solution. It will always remain in reduced form
( Alos if the shade is slightly greyish, one can add tiny tinge of sulpher blue--> 20gpl)

in III, IV and V dye bath--> cold wash
in 6th dye bath. We take H2O2(30%)+Acetic Acid(2:1 by weight). H2O2 acts as an oxidising agent. But as it acts on neutral pH (=7) and after cold bath the solution is slightly alkaline, to make it neutral wil add acetic acid. Acs in alkaline pH, oxidising action of H2O2 will be similar to the bleaching action, which may cause tendering in the fabric.

7th and 8th Dye Bath: Cold Wash

Wash Box Number 4: Here washing is done with detergent and soda ash at 60-70 deg.c

5th and 6th Wash Box: Hot Wash

7th wash Box: Here softner is added at 25 gpl. It is cationic softener with pH 4.5 to 6.5. As during oxidation of sulphur, strength is reduced by 10%. On a yarn sulphur is of two types :
1. Free Sulphur
2. Reacted Sulphur.

The free sulphur will react with moisture in the atmosphere to form:
H2O + S --> H2SO4
Which tenders the yarn. Now at acidic pH reaction is much faster. So we add only a small amount of softener (25 gpl) as against that in indigo which is 100gpl.

3rd Point

Over all during sulphur dyeing and storing, the yarn strength is reduced by 15% as compared to Indigo.

4th point

If ball formation takes place of sulphur dyed warp at loom shed, then we can taken in 4th dye bath little Na2S+Caustic to reduce the free sulphur.

Practical Considerations in Rope Dyeing for Indigo dyed Denim.

The passage of yarn in rope dyeing is as follows:

Pre-scouring -->hot wash-->cold wash --> Dye baths--> hot wash-->cold wash--> application of softener

lets discuss these processes one by one:

Pre-scouring

1. The objectives of pre-scouring are the removal of wax content from cotton, removal of trapped air from cotton yarn and Making yarn wet

2. This is done at 90 o C

3. We use the following ingredients at pre-scouring stage:

Caustic Soda: Its quantity depends upon the quality of cotton fibres used in the mixing. Generally we take 2-4% of caustic soda. It removes the wax by the action of soapanification.
Wetting agent: It is anionic in nature
Sequestering Agent: Even with the use of water softening, it is very difficult to find the desired softness in water ( about 2-3 ppm) . So we use the agent to make the water soft.

4. Why Trapped Air should be removed. The reason for this can be understood as follows:
In 1 kg of yarn, there is approximately 2 litres of air. 1 litre of air decomposes 1.8 litres of Sodium Hydrosulphide. It will cause uneven dyeing and more consumption of Sodium Hydrosulphide ( hydro).

5. Absorbency of yarn may be checked after scouring.

Hot wash

As some caustic is carried by the yarn after pre-scouring, so hot water is given at 70-800C. If this is not done, this yarn will go into the dye-bath which will change the pH of the dye-bath.

Cold Wash

After hot wash, yarn temperature is more. To bring it back to its room temperature, cold wash is given to it.

INDIGO DYEING

1. Indigo is not a perfect vat color. It may be called a trash vat color. The constant of substantivity for other colors is 30, for indigo it is only 2.7. So there is a need of 5 to 6 dye baths and make the use of multi-dip and multi-nip facility to increase the penetration.
2. The dyeing is done at room temperature as indigo belongs to Ik class of vat dyes, where dyeing is done at room temperature and oxidation is done by air only and not by chemicals. If oxidizing agents are used, they will cause stripping of colors.

3. Indigo is not soluble in water. So it is reduced with Sodium Hydrosulphide. Then caustic soda is added to make sodium salt of vat colors to make it soluble. To reduce 1 kg of Indigo, 700 gms of sodium hydrosulphide is required. However some extra SHS needs to be taken to avoid some decomposition of SHS.

Practically it is prepared in the following sequence

-Take indigo
-Add caustic
-Then reducing agent

4. When caustic is added to indigo, it is an exothermic reaction. It is allowed to cool down, then before sending it to feeder, sodium hydro-sulphide is added. Reducing agent is not added first as it will be decomposed first, so consumption of it will increase. It is also not advisable to take solubalised vat, as offered by some companies due to the following reasons:

a. If it is used after 6 months, there will be a decomposition of sod. Hydrosulphide. It will become partially soluble. Then to make it soluble again, more SHS has to be added.
b. Transportation is difficult
c. Cost is more

5. Feeding System

Rat of flow of yarn is given by

((No of ropes x no of ends x speed of machine)/ count x 1.693 x 1000)

in kg of yarn / minute

So we can determine the rate of feed of indigo. It is very important that replenishment of indigo is there as any variation will result in the change of shade and also if level is more, there is a problem of over-flow.

6. If total capacity of dye bath for example is 15000 litres, then circulation must be 3 times the volume. If it is less then there are 100% chances of getting a lighter shade.

7. Core and ring dyeing effect
This effect is obtained by multidip-multinip facility

8. pH of the Dye bath should be kept in between 10.5-11.5. At this pH , sodium salt of Indigo is mono phenolic form. At this form, the strike rate of dye is very high. So after washing, there will be a better dye effect. At pH 11.5 to 11.7, at this affinity is less, so dye effect will be less prominent.

pH is controlled by the addition of caustic soda.

9. Testing of Hydro

TOTAL HYDRO
We take 10 ml of indio with SHS in 30-35 ml of water. It is set for one minute and shaken. As air will decompose SHS. So vacuum created will fetch the water from above. If 3 ml of water is required, then concentration of hydro is 3 gpl. As a thumb rule, concentration of total hydro should be min. 1.5 gpl.

REDUCED HYDRO

It is the hydro that is used for the reduction of Indigo. It should be around 0.7 ( 1000 kg of Indigo needs 700 kg of hydro to reduce it). For testing we take 10 ml of dye solution and 30 ml of water and 5-6 drops of 40% formaldehyde and shake it for one minute. The water that goes gives the readings of the reduced hydro.

Total Hydro- Reduced Hydro = free hydro

If Total hydro is min. 1.5 gm/lit. then free hydro must be min. 0.5 gms/ litre which acts as buffer

10. Also hydro reduction capacity is measured by mV meter which measures the Redox Potential.

It should be around 760-800

Through the day, the redox potential should be +- 20 mV of the norm. If it is more then the process control is a failure.

Caustic--> It is around 0.4 to 0.5 times the hydro used.

Washing
Rubbing fastness of indigo is very important. On a scale of (1-4), it is 2. Washing is done to improve the rubbing fastness.

Wash at 60 deg.--> Wash at 60 deg.--> Wash at room temperature--> wash with softener

Why Softener:

1. The rope is going to be opened at Long Chain Beamer. It the softener is not used, opening will be hampered.

2. It is generally 1.2% of the weight of the yarn. It is a cationic softener. It is always having pH in the range of 4 to 55. Softening is done at room temperature. If high temperature is used there is always some chance of tendering of yarn.

3. Concept of Buffer pH is given by Virkler USA, they say by addition of this, there is 40% less consumption of Indigo for same shade depth.

4. Metering Consumption

If solution is of 900 litres
10% Indigo-->90 litres
Hydro--> 90*.7 = 63 kg
Caustic--> 63*0.445= 28 kg.

It belongs to a VAT class of dyes. It has a dark blue color wit a bronze lustre. It belongs to KI class of dyes. In this class, dyeing is done at cold and air oxidation is done to reoxidise the dye. It can be applied on both cellulosic and protein fibres. For protein fibres, a weaker alkaline solution is used. It can be reduced by NaOH and Na2SO4 in water to give monophenolate and biphenolate ions as complete solution. Reduced form of Indigo is called leuco indigo. Leuco has got low affinity for cellulosic fibres. Dye take up can be improved by:
1. Either mercerisation of cellulosic fibres before by dyeing
2. or by adopting multidip, squeeze and airing process, so that dye is coated on the fibre layer by layer

Indigo can be further developed into Halogenated derivatives and sulphonated derivatives. Halogenated derivatives give better fastness properties and brighter shades, whereas sulphonated derivatives gives a soluble blue dye, good dye and is applicable on protein fibres.

reaction :
Image 1

Although indigo is a vat dye, it can be regarded as a 'trash' dye, the dyeing and fastness properties are in no way comparable to other class of vat dyes. It is due to these properties, that make it an excellent dye for denim. The on tone fading and the bleach down properties of indigo blue has generated a lot of denim jeans fashions like stone, ice faded looks, etc. These special effects cannot be simulated by the other classes of dyes.
During Preparatiuon of stock vat, the following points must be remembered:

1. Vatting temperture should be as close to room temperature as possible.
2. Stirring should be minumum, unnecessary stirring affects the stability of reduced vat.
3. Volume of the reduced vat should be kept constant for every stock vat batch, as the constant volume will ensure a constant replenishing amount.

For rope dyeing system, with chemical replenishment

with Stock replenishment
Indigo: NaOH: Na2SO4 :: 1:0.8:0.8

Without stock replenishment
indigo: NaOH: Na2SO4:: 1:1:1.2

Chemical Feeding
NaOH: Na2SO4: : 1: 1.2-1.6

ie. for approximately 60 gpl of NaOH--> 120 gpl of hydro is required

Indigo Dyeing process control

1. Concentration of Hydrosulphite

It is measured by vatometer. It should be from 1.5 gpl to 2.5gpl , or by redox potential of dye bath which should be from -730 mV to -860 mV.

2. Caustic Soda or pH value

Should be from 11.5-12.5

3. Dye concentration in Dye bath

it is measured by spectrophotometer. It should be in g/l

Guidelines

High Indigo Concentration --> Shade is greener and lighter
Low Indigo Concentration --> Shade is dull and Red.

High pH or Caustic Concentration --> Redder and lighter
Low pH or caustic concentration --> greener and darker

Dipping Time

Longer the dipping time, better will be the penetration and lesser will be the ring dyeing effect. It varies from 15-22 seconds.

Squeeze Pressure
High pressure will lead to lower wet pick up and result in lesser color and better penetration. At rope dyeing, squeeze pressure is 5-10 tonnes, ie. wet pick up is as low as 60%. Hardness of squeeze roller is about 70-75 deg. shores. It sqeeze rolls are too hard then there are chances of slippage and uneven yarn tension.. If squeeze rollers are too soft then shading will occur. Surface of the squeeze rolls should be ground twice a year.

Airing Time

It should be 60-75 seconds. Longer airing time results in high tension on the yarn and subsequent processes will become difficult.

Drying

Insufficient or unevenly dried yarns will result in poor rebeaming

Calculation of Replenishing Dye feed/min

Conc. of stock vat is g/l= 90
range speed in yards/min=25
count = 7s
totoal ends = 4100

Wt of yarn dyed /min= (4100*25*1000)/(7*840*202)= 7924 gms
shade desired = 2%
Amount of dye to be replenished/min= 158.5 gms

Effect of pH

At pH of 10.5 to 11.5, there will be formation of more monophenolate ions, which lead to higher color yield, as strike rate of the dye to the yarn bundle is very high, and wash down activities will be very good.

At pH higher than this, dye penetration will be less and wash down characteristics are also poor.

Testing

1. Alkalanity in Dye Bath Liquor

Pipet 10.0 ml of vat liquor into 100ml of distilled water in a 150 ml beaker. place under continuous agitation and insert the electrodes of a pH meter caliberated at pH 7.0 with standard buffer solution.

Titrate with tenth normal HCl ( 0.1 HCl) to pH 7.0 (ml = A)

calculate
g/l of NaOH = A *0.40

2. Hydro in Dye bath Liquor

Add 2 ml of 37% HCHO to 150 ml beaker. Add 2 ml of dye range liquor . Add 6 ml of 25% glacial acetic acid solution prepared by diluting 1 part acid with 3 parts water. Add 2 ml of starch/KI indicator. Add ml of water. Titrate with 0.046 N ( prepared by diluting 460 ml of 0.1 N Iodine to one liter ) solution until the color changes from emarald green to bluish purple.

G/l of hydro= mo fo 0.046N of Iodine

Importance of High Concentration of Free Hydrosulphite

The clearest shades with minimum reddish streaks are observed at by relatively high conc. of hydrosulphite. On the other side, with lack of hydrosulphite, the leuco indigo is less dissolved and thereby adheres to a greater extent to the fibres. With lack of hydrosulphite furthermore, the amount of unreduced dyestuff by oxidation at the upper level of the liquor and through activiation of unfixed dyestuff, gets separated from the fibrous material would constantly rise as the reducing agent for creating leucoform would be missing. Under these circumstances a reddish bronze like shade results due to dispersion of not reduced dyestuff in the yarn. The min. proportion of hydrosulphite should be around 1.3 to 1.5 gpl in case of rope dyeing and 3-4 gpl in case of sheet dyeing. Also to avoid the lack of hydrosulphite or Indigo at certain places in the immersion, vat, the whole quantity of the liquor should be circulated 2-3 times every hour.

Reaction Time

At very short reaction time, an adequate liquor exchange ( i.e. the amount of chemicals consumed and replaced by fresh addition of reduced indigo) is not assured. This has a negative influence on dyeing and depth of dye penetration. In addition to this the time available for diffusion of dyestuff until oxidation commences is too short. To ensure an even and good depth of dye penetration by dyeing in several passages, the reaction time should be 20-30 sec. for each vat (eg. at a speed of 20m/min for a reaciton time of 10 seconds, the immersion path should be maximum 3.3 meters).

A reaction time exceeding 60 seconds should be avoided as the amount of dyestuff again get reduced and released may again supersede that of additionally take up dye stuff, resulting in higher shades.

Softening Agent: 8 g/lit

Drying: Rest humidity should be 30% and then sized.

Addition of chemicals

1. Red Tinge: reduce addition of NaOH, increase slightly Na2S2O3
2. Darkish Red: increase Hydro
3. Light Greenish: decrease Hydro
4. Dark Green: Increase Caustic

Indigo dyeing calculations

For 12 ropes, at 24 m/min, of 344 ends of 14000 m length of 7s count.

wt of yarn = (12*344*14000*100*453.6)/(7*840*36*2.54*1000) kg= 5000 kg

at 24 m/min, a lot of 14000 m will be completed in 14000/24 = 583.3 min

at 1.8% shade
100 kg of yarn needs--> 1.8 kg of Indigo
5000 kg of yarn needs --> 90 kg of dye

at 100 gpl
100 gms of dye = 1 lit of solution
90 kg of dye = 900 litres

900 litres should be completed in 583.3 min
1 litre would be completed in = 583.3/900= 38.8 seconds

so flow rate will be 38.8 seconds / litre

Similarly flow rate of caustic and hydro can be determined

Hydro is taken around 100 gpl
caustic is taken around 90 to 100 gpl

Indigo preparation sequence

In a tank of 1000 liters:
a. take 400 litres of water (soft)
b. add setamol ws--> 4 g/l (stirring) ( dispersing solution)
c. Add 100 kg of Indigo ( at 1.8 % shade -see the indigo calculations- stirring)
d. add caustic soda --> stirring ( for solubilising and pH)
e. allow to cool it for 2/3 hours
f. Add hydrosulphide ( As reducing agent)
g. Make the solution to 1000 l by adding water.

If pH is fluctuating, if it is > 11.7 then hydro is added (2-3 kg), if (<11.2) then caustic is added.

For 100 kg of Indigo,
Caustic Required= 90 kg
Hydro Required= 80 kg

Denim Manufacturing

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Manufacturing of Denim
For manufacturing Denim and Grey Fabric, the process is same up to the level of weaving, but in case of Denim Fabric, dyeing is done at the stage of sizing where as for Grey Fabric it depends upon the finished product. The details of each process are given below:
1. Fabric Weaving
a. Grey Yarn on Cones
Normally yarns received for weaving in cone forms are either from ring spinning or from open end spinning in single or double fold as required. For weaving, yarn used is categorised into:
o Warp yarn
o Weft yarn
Normally for Weaving, yarn used as warp should be sufficiently strong to withstand stress and strains exerted during weaving operations. Hence they are having Count Strength Product(CSP) and further sized to increase its strength. The weft yarn is directly used on weaving machines and in some cases, if required, is rewound also so as to enhance its performance in weaving.
b. Warping on Sectional/ Direct Warping
The warp yarn is required to be fed into a sheet form to the weaving machines. At warping, the individual cones are put into the creel (the number of cones depends upon fabric construction) and yarn from individual cones is pulled together in sheet form, wound on a barrel called warping beams (for Direct warping) or on weaving beams (for Sectional Warping). Normally if warp sheet is with patterns of different coloured yarns it is processed on sectional warping machine.
c. Sizing of yarn in Set/ Beam to Beam Position
The object of Sizing is to improve the strength of yarn by chemically binding the fibres with each other and also improve upon its friction resistance capacity by chemically coating the surface of yarn/fibres. Further, number of threads in warpers beam sheet is very less against number of threads required in whole width of fabric. Hence multiplication of sheets by drawing yarns together from many warp beams and again making one sheet is also performed on sizing machine. On sizing, normally, 8-12 % size material on warp thread is applied. This improvement in strength and frictional resistance characteristic of warp yarn is essential because during weaving, yarn has to undergo severe strain & stress as well as frictional operations.
d. Drawing–in
Weaving is basically interlacement of two sets i.e. warp and weft threads in desired sequence and pattern. To obtain this interlacement, warp yarn sheet is bifurcated & opened in the form of two layers/ sheet and weft thread is inserted between so opened two warp sheets. This operation is called shedding. to perform shedding the warp yarn needs to be passed through heald eyes of the heald shafts, this operation is called as drawing-in.
e. Beam Gaiting or Knotting on Loom
The drawn weavers beams are fixed on weaving machines, threads are tied and heald shafts are coupled. This operation is called Beam Gaiting. If undrawn warp threads are directly knotted to the threads of finished beams, it is called Knotting. These operations are essential because normally weavers beam can carry only certain length of warp sheet on it and when so woven, whole length is converted to the fabric by weaving machine. Further warp length is required to be fed which can be done by knotting or gaiting other beams on weaving machine.
f. Weaving
As stated earlier, weaving is interlacing two sets of yarn and making fabric. One set is called warp thread which is in sheet form, the other one is called weft thread which is inserted between two layers of warp sheet by means of a suitable carrier i.e. Shuttle, Projectile, Rapier, Air current, Water current, etc. Depending upon the type of the weaving machines. The different types of technologies available for weaving machines are briefly explained as below:
o Conventional Shuttle Weaving System by Ordinary Looms or Automatic Looms.
o Shuttle less Weaving System by Airjet /Waterjet/Rapier/Projectile
Shuttle loom is a conventional Technology with much less production on account of slow speed and excessive wear and tear of machinery. This shuttle loom technology has now become obsolete. Denim is woven through Shuttle less Weaving System by using 96 ZAX-e Type Tsodakoma Corporation’s Airjet looms or rapier looms or projectile looms. These looms are distinguished by weft insertion method, which is briefly discussed hereunder.
Airjet Looms
These types of looms adopt the latest development in Weaving Technology where weft insertion is done with the help of compressed air. A very high weft insertion rate up to 1800 metre per minute is achieved. Compared to rapier and projectile looms, these looms are less versatile but are economical and are used in mass textile production unit like denim.
Finishing
a. Grey Fabric
The finally woven fabric or Grey Fabric, as it is popularly called, wound on a cloth roll is taken out from weaving machines at certain intervals and checked on inspection machines for possibilities of any weaving fault. If such faults are seen anywhere in fabric during inspection, certain corrective steps are taken at weaving, warping, sizing, etc so that they can be minimised in subsequent product. This is a quality control exercise.
b. Denim Fabric
Denim Fabrics woven of 100% cotton would be very strong and durable.
Traditionally Blue Denim is warp faced cotton fabric with 3 x 1 twill construction with warp being dyed in a solid colour and weft left un-dyed. The look and quality of the Denim Fabric shall improve after dyeing, the process of which differs from plant to plant. Normally the process of dyeing dictates the technology of Denim manufacturing.
The dyeing for Denim Fabric happens at the sizing stage. Generally there are two most popular methods of dyeing Denim Fabric. They are:
o Rope Dyeing
o Sheet Dyeing
A company can adopt any of the methods. In countries like India Sheet Dyeing Method is commonly used for manufacture of its Denim Fabrics, which has following advantages over Rope Dyeing Method:
o The technology is less capital intensive.
o The technology is a proven one.
o The cost of production is lower.
o The process time is lower.
o The Sheet Dyeing machines are very easy to operate.
The only defect in Sheet dyeing is that their is a problem of center to selvedge shade variation.
c. Sheet Dyeing Process
This process eliminates a few intermediate processes of the rope dyeing. The yarn sheet is washed with chemicals such as caustic and washing soda and after squeezing the excess water; the yarn sheet is allowed to pass through Dyeing Troughs one time for oxidation and development of dye on yarn. After dyeing, the dyed yarn is washed again with fresh water for two-three times and finalIy squeezed before allowing it to pass through six drying cylinders. The dyed yarn enters the starching device and sizing is done. After sizing, the sized warp beam goes for weaving. After weaving, the woven Denim Fabrics goes for various finishing processes consisting of brushing, singeing, washing, impregnation for dressing and drying. Brushing and singeing should eliminate impurities and help to even the surface of the fabric. Dressing regulates the hand and rigidity of the fabric while compressive shrinking regulates its dimensional stability.
Even today Denim Fabric without Indigo Dyeing is not called authentic Denim. Initially when Denim Fabric entered the fashion market, Denim manufacturers were using Natural Indigo Dye, which was costly and giving a natural finish. Though Synthetic Indigo Dye has gradually replaced Natural Indigo Dye, some unorganised manufacturers still prefer the latter and attract premium after branding them “Natural Dye Used”.
d. Making-Up
Weaving of fabrics on such multi sizes is not economical, hence a standard width fabrics is then sent to making up. Fabrics are cut into the desired width as per size required on this machine. Denim Fabric and Grey Fabric are thoroughly checked for various types of defects such as:
o Weaving Defects
• Uneven Dyeing
o Bleaching and Dyeing Defect
o Oil Stain
o Patches
Here the final product is categorised quality-wise. The products then found okay are segregated and sent to packaging department whereas defective ones are sent for correction. After inspection, the sets are wrapped with polythene covers and sent for despatch as per buyer’s specifications.
Despatch
Rolls and sets so formed and packed as per buyers’ requirements are then sent for final despatches

Denim Finishing

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Why Is Finishing Quality Critical?
Denim finishing is critical to profits in that customers who pay the highest prices are very demanding with regard to shrinkage differences between and within fabric rolls. These customers will accept fabric that is with 0-4% shrinkage, but with no more than 0.5% difference in one shipment.
Challenges In Denim Fabric Finishing
• Control of shrinkage between fabric rolls and within rolls is more difficult than with other fabrics.
• The heavy weight, twill denim construction is dimensionally unstable after weaving.
• Denim has high shrinkage after weaving, which requires very high compression(12-15%) at Sanforizing which can be difficult .
Why Fabric Shrinks ?
• Tension that is applied to cotton yarns in weaving results in yarns being stretched beyond their “natural length”.
• When the denim garment is washed, water and agitation relax the yarns and they are returned to their minimal length.
• Variations in tension at weaving produce variations in fabric shrinkage.
Denim Finishing Process
• In basic denim finishing, fabric arrives from weaving directly, without de-sizing, and is brushed to remove contamination, singed with flame to make the fabric smoother by reducing hairiness, padded with a simple recipe, passed over a pair of skew rolls to reduce fabric torque which causes skew movement and then dried.
Finishing Recipes
The basic objectives for a denim recipe are:
• Provide lubrication for quality Sanforizing - Improve stability in garment cutting by the application of a stiffening agent.
• Including a sewing lubricant to save the customer money with sewing needles and to reduce damage from needle burn.
1. Sanforizing Lubricant
• The Sanforizer mechanically pushes weft yarns together, which reduces shrinkage.
• This mechanical shrinkage requires a high degree of friction between the rubber belt and the denim.
• A Sanforizing lubricant is necessary for the shrinkage to be consistent.
2. Sewing Lubricants
• During the garment forming, the needles used for sewing become hot because of friction.
• This heat damages the needle and can also produce holes in the garments.
• A sewing lubricant reduces needle costs and results in better garment quality.
• The garment cutting is also improved.
Stiffening Agents
• Also known as “hand-builders”, these are necessary to stabilize the fabric during fabric cutting to avoid “snapback”.
• Snapback occurs when the weft yarns are stretched during cutting, then as the cutting blade moves up, the garment panel shrinks to a width smaller than planned, which produces a distorted garment.
Finishing Chemicals
• A non-ionic, fatty-acid softener based on stearic acid produces the best Sanforizing (8 grams of 100% softener per kilogram of fabric)
• Polyethylene-based sewing lubricants are best. ( 2 grams of 100% per kilogram)
• 40 or 90 fluidity tapioca starch is the best hand-builder used for denim.
Finishing Procedure
• Basic denim finishing chemicals should provide improved fabric surface effects for Sanforizing, cutting and sewing.
• The finishing chemicals should not penetrate into the fabric, so no heat is required and no wetting agent is necessary.
• For uniformity of chemical application, a wet pick-up of at least 70% should be used.
Sanforizing Denim Fabrics
There are 4 variables that are critical for shrinkage, fabric defects and elongation:
1. Temperature
2. Moisture
3. Quantity of Pressure
4. Time of Pressure
1.Critical Temperature
There are 3 critical temperatures:
1. The temperature of the steam-heated cylinder which heats the rubber-belt.
• If this temperature is too high or too low, the surface of the rubber-belt is not able to provide consistent compression.
• Generally, cotton fabrics are processed easily between 105 and 125degrees C.
• Heavyweight denims which arrive from weaving with 12-15% potential shrinkage require about 140 degrees.
2. Temperature of the Palmer Unit for drying the denim.
3. Temperature of the fabric as it enters the rubber-belt.
Fabric that is both hot and moist is easier to compress.
• For heavyweight denim, 14% moisture and 80 degrees centrigradeprovides adequate fabric elasticity.
• For the best control, fabric moisture should be controlled by spray and cooling water at the Sanforizer, followed by heating before the rubber belt.
2.Sanforizing Moisture Control
• A general rule is that for each oz/square yard, 1% moisture should be applied. For example, for a 10 ounce fabric, 10% moisture.
• Most denim finishing is now on the “integrated range. Moisture is controlled by the drying cylinders on the finishing machine, then fabric passes directly to the Sanforizer.
• A final moisture of 4-5% is necessary in order to stabilize the fabric compression.
• If the moisture is higher, the fabric will elongate which increases final shrinkage.
• If the moisture is lower, the denim will elongate after absorbing moisture from the air.
• Sanforizers require consistent steam pressure and should be located close to the steam source.
Separate Sanforizing
• In separate Sanforizing, the denim is dried to about 6% moistureby the dyeing cylinders on the finishing range.
• Then the fabric is transported to the Sanforizer where the correct amount of moisture is applied by water sprays and by the cooling water for the rubber belt.
• This system usually provides better control.
3.Pressure (% of Compression )
• Sanforizing is a form of “mechanical shrinkage”.
• If a fabric has 12% shrinkage with 20 weft yarns/cm and 3% at 22/cm, then 10% compression by the rubber belt will result in the weft being pushed together which increases the weft yarns from 20-22/cm and reduces the shrinkage by 10 points.
4.Time Of Compression
• Denim has a very high % of shrinkage as it arrives from weaving up to 15%.
• The heat, moisture and time of pressure determine the control of shrinkage. - The time of pressure is determined by the speed of Sanforizing.
• Heavy denims should not be Sanforized at more than 35 meters/min. Slower speeds result in better control.
Conclusion
• Denim finishing is the most difficult of all apparel fabrics.
• Control of fabric quality requires a higher level of control which begins at weaving
• The moisture and temperature must be monitored and controlled at each step.
• Sanforizing is more complicated than it appears and requires the most attention

Processing parameters analysis

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1: Introduction

In most cases, an indigo dyeing is judged by the wash down effect obtained.However,if regulation of the dyeing process is based only on the shade immediately after dyeing variation in the penetration of the dyeing and thus in the effect after “ wash down “ are unavoidable . Variation in the quality can only be minimized in the long term if the control of the dyeing process is supported by the analytical data and determination of all important processing parameters. Tailing can then usually be avoided.

2: Processing parameters and analysis

Apart from the substrate and the mechanical parameters, the consumption of the liquor is the key factor where influencing the dyeing results is concerned. For the analysis, good dye bath circulation is necessary for the provision of representative liquor specimens.

2.1 PH

The ph of the dye baths is determined with ph meters that are designed for industrial use. In this procedure, the electrode is rinsed with the distilled water before it is immersed in the liquor sample and briefly agitated. The ph can be read off when the display on the meter has stabilized. Since the measuring characteristics of the electrodes fluctuate, the ph meter must be calibrated daily. For the calibration purposes, two different buffer solutions are necessary. Buffer solution 1 has a ph of 7, while buffer soln-2 should have a ph comparable to that of the dye baths.
Once the bottles in which they are stored have been opened, buffer soln have only a limited stability. Buffer soln that has been taken out is suitable for use once only.
Furthermore, the electrodes must be replaced at intervals of no longer than 2 months.

Acidimetric titration is not suitable for determining the ph of the dye bath.

We recommend checking the ph by on line measurement. A high degree of processing reliability is then achieved by controlled, metered addition of the alkali.

2.2 Hydro sulfite

In continuous dyeing processes with indigo,hydrosulphite(sodium dithionite) is used as the reducing agent .To obtain uniform dyeing results, it is important for the concentration of hydro sulfite to be kept constant.
With a low hydro sulfite to be kept constant with a low hydro sulfite concentration, the dye has less time to diffuse in the air passage and a more pronounced ring dyeing effect is obtained. If dyeing is carried out with two little reducing agent, this will lead to an accumulation of indigo pigment in the dye bath.

Measuring the redox potential is a simple method of determining whether hydro sulfite is present, but the potential can provide no indication of concentration. Since the redox potential depends on the type of electrode employed there is no point in providing absolute measuring data.
For a quantitative determination of hydro sulfite, volumetric analysis with atmospheric oxygen is not recommended. In the titration of indigo dye baths with iodine, the accuracy of the method is not guaranteed. Titration with hexacyanoferrate offers significant advantages over other methods of analysis for the quantitative determination of hydrosulfite.Furthurmore in addition to the reducing agent; it allows simultaneous determination of the indigo content.

2.3 Indigo

Indigo can be determined by spectronic and volumetric methods of analysis.Since Indigo, in its oxidized form, is not sufficiently soluble in any solvent,photometric determination of the indigo concentration must be carried out with the indigo in its reduced state. For this purpose , the indigo or dye liquor is reduced completely with an alkaline hydrosulphite solution ( Sodium dithionate) ; this vatted indigo solution is then diluted and measured photometrically .If this test is carried out with only an aqueous hydrosulphite solution,without an inorganic solvent,the measurement can be hindered by the formation of vat skin.this can be prevented by stabilizing the solution with the 1-methyl-2-pyrrolidinone.
Titration with hexacyanoferrate(111) has proved very suitable for determining the concentration of indigo in the dyebath.this method allows determination of both the hydrosulfite and the indigo.

2. 4Temperature

The rate at which the dye diffuses increases with the temperature.This leads to a deterrioration in the ring dyeing affect. In addition ,the temperature affects the ph and the hydrosulphite consumption . If the bath temperature fluctuates it is not possible to obtain constant dyeing results.For his reason it has proved advisable to dye at a constant temperature. To achieve this ,the dyebath temperature in the hot season of the year can serve as the controlled parameter for the dyehouse concerned . In this case the dyebaths are heated in the cold season of the year.In principle ,it is also possible to use cooling units to compensate for extreme temperature in the summer months , but this would be a more expensive option.

2. Salt
With freshly prepared dyebaths , tailing can also be due to the continuity rising salt concentration , before a constant concentration is established after some hours . As the concentration rises, the substantivity of the dye increases and shade shifts towards the redder side . With new baths , this tailing can be minimised by making appropriate addition of salt( Common or Glauber's salt) . For this purpose , it is necessary to know the composition of the liquor during steady-state operation of the dyeing range .Analytical determination of the different salts in the baths is not practicable procedure for the dyehouse. To largely restrict tailing it is sufficient to use methods that provides a summary value.

3: Description of the methods employed

3.1: The hexacyanoferrate(111) method is a redox titration , which allows the concentration of the hydrosulfite and indigo to be determining simultaneously , in the presense of excess reducing agent, two end points are observed with redox electrodes . The hydrosulfite content is shown by the first end point while the indigo end point can be calculated from the difference between the two end points. It must be insured that oxygen is quantitatively excluded, when the liquor specimen is taken and during any intermediate storage period.

Description of the method Employed

Titration with hexacyanoferrate(111)

The hexacyanoferrate(111) method is a redox titration , which allows the concentration of
the hydrosulfite and indigo to be determined simultaneously in the presense of excess reducing agent , two end points are observed with redox electrodes.
The hydrosulfite content is shown by the first end point , while the indigo content can be calculated from the difference between the two end points.it must be insured that oxygen is quantitatively excluded when the liquor specimen is taken and during any intermediate storage period.
If the only hydrosulfite is to be titrated , the end point can also be detected visually without a redox electrode , with an excess of reducing agent present, the liquor is yellow to greenish brown color.In the drop wise addition of cyanoferrate during the titration, the liquor ius seen too briefly turn blue.within a matter of seconds the excess hydrosulfite then reduces the dye back agin to the lecuo compound.
The end point is reached when the specimen remains blue.

Chemicals

0.05 mol/l Hexacyanoferrate(111)
(16.46 g/l k3(Fe(CN)6
5% Setamol WS Soln
(dispersing agent)
0.10 mol/l NaoH
Distiiled Water
Pure Nitrogen or Light oil.

The normal solutions used for the redox titrations have only a limited shelf life.We recmmond the use of cyanoferrate in p.a quality.The soln should be kept in brown bottles and a fresh soln prepared weekly.

Apparatus

Automatic titrator with megnatic stirrer, Vessel(approx.100 ml) that can be sealed air-tight,fittted with inlet and outlet points, redx electrodes.

Or ,alternatively,
Magnetic stirrer, redox electode with measuring device and stand ,glass beaker(100 ml)
and burette with stand.
● Place 50 ml NaoH(0.1 mol/l) and 1 ml Setamol WS Soln in the titration vessel.
● Close the titration vessel.
● Fluh the soln with nitrogen for 5 min( Volume flow rate>200 ml/min)
● Pass nitrogen over the soln ( to the end of the titration)
● Add, with the pipette,10 ml dye liquor(5 ml if the indigo content is expected to be > 2 g/l)
● Titration
● Evaluation

Procedure with automatic titrator without nitrogen
● place 50ml NaoH(0.1 MOL/L) and 1 ml Setamol WS Soln in the titration vessel.
● Cover the soln with light oil.
● Immerse the titration-Soln outlet below the layer of light oil.
● Add , with a pipette,10 ml dye liquor below the layer of light oil
● (5 ml if the indigo content is expected to be >2 g/l)
● Titrations
● Evaluation
Procedure without titrator and without Nitrogen
● Place 50 ml NaoH (0.1 MOL/L) and 1 ml Setamol WS Soln in the titration vessel.
● Cover the soln with light oil.
● Immerse the redox electrode in the soln.
● Add with a pippette , 10 ml dye liquor below the layer of light oil(5 ml if the indigo content is expected to be >2 g/l)
● Immerse the outlet of the burette below the layer of light oil
● Titrations
● Evaluation

Evaluation
● 1 ml/l 0.05 mol/l titration solution corresponds to 4.9 mg hydro sulfite conc.BASF OR 6.8 mg Indigo Pure BASF.

5 ml liquor Specimen 10 ml liquor Specimen

1 ml 0.05 mol/L k3 Fe(CN)6 0.98 g/l hydro sulfite Conc. 0.49 G/L hydrosulfite
BASF ;1.36 G/L Indigo Pure BASF Conc.BASF
Soln Corresponds to 0.68 g/l Indigo Pure
BASF

Notes

Sulfide and Sulfur dyes interfere with this method of determination , whereas sulfite and thiosulfate dont affect the result.
If the dye liquor contains no hydro sulfite , it is blue in color. Titration is then not possible owing to the precipitated indigo pigment.

3. Spectroscopic determination of the indigo concentration

Solution

11.4 ml/l NaoH(50%)

10.0 G/L Hydrosulphite Conc.BASF
300.0 ML/L 1-methyl-2-pyrrolidinone(NMP)

Preparation of the Solvent
● Place 300 ml/l 1-methyl-2-pyrrolidinone in the measuring flask
● Add 550 ml/l distilled water
● Add 11.4 ml/l NaoH 50%
● Add 10 g/l hydro sulfite Conc.BASF and shake occasionally until dissolved
● Close the measuring flask and cool to room temperature.
● Fill with distilled water to the calibration mark.

Procedure

● Pipette 10 ml dye liquor into a 100 ml measduring flask
● Add 90 ml solvent
● Vat for 15 min
● Spectroscpy
● Evaluation
The calibration curve was produced with a high-resolution spectrometer. The absorption measured cann be affected if another filter system isused.we therefore recommend checking the calibration curve.

For this purpose , solutions containing 0.5 to 5 g/l dye are prepared .the dye is weighed out, transferred to a measuring flask with the solvent described and the flask made up to the volume . The dye is dispersed after which the soln is heated upto 60c. And the dye vatted within a period 15 min within the occasional shaking. The liquor is then allowed to cool.when 0.1 cm cells are used , the soln should be diluted with the solvent to a concentration range of 20-~100 mg/l. For the linear calibration curve, at least three separate weighings-out should be used.

Notes

In all procedures the vessels should be kept closed. Opening them brieflyand careful decanting does not harm the determination.The formation of the vat skin is prevented by using 1-methyl -2-pyrrolidinone.The presense of hydrosul;fite in the solutionb can be checked with vat yellow paper.Provided that air is excluded, the solvent is is stable for several days.If it is to be used constantly, it should be prepared fresh daily.
The method is also suitable for determining the dye content of stock vats of the retained matter from the ultrafilteration, and the dye present on the textile substrate.

Conductivity measurement and density

An assessment of the salt present in the dyebath can be made from the conductivity measurement or by checking the density.both the conductivity and density are temerature dependent.the conductivity should be determined in the ph range of 11.5~12.
the density as a function of the salt concentration.
These values for conductivity or density can vary by up to 20% from the actual value between the calibration curves and a dyebath.

Denim Dictionary

2010-11-03T14:49:00.001+05:00

A guide to denim terminology at Lands’ End

B
Boot Cut: Jean leg that tapers to the knee, then flares slightly at the hem for a wider leg opening.
Busted Seams: Seams that are pressed open so that they lie flat and smooth for a better appearance. Lands’ End ensures its seams are busted. (Available in 47IndigoTM and Hand-crafted Denim).
C
City Waist: This is the lowest jean waist Lands’ End offers.
Classic Waist: Jeans that sit slightly below the natural waist.
Curvy Fit: A new fit in Lands’ End women’s denim designed specifically for women with waists significantly smaller than hips. It prevents the waistband from gapping in the back on curvy women.
Crocking: The process of removing dyes by rubbing the fabric. Crocking can occur under dry or wet conditions. Denim is notorious for crocking, which is very hard to control due to indigo’s dye properties.
D
Denim: Highly durable, typically all-cotton, fabric with a twill weave. Just as Lands’ End travels to Inner Mongolia to find the finest cashmere, Lands’ End knows the best sources and suppliers of denim.
Details: Jean elements that create a unique look such as molded buttons on Hand-crafted Denim, thread color and stitching width.
Dips: Immersing fabric yarns into dye vats. When denim warp threads are dipped in
indigo-and then emerge to oxidize, the shade darkens achieving deeper degrees
of depth.
F
47IndigoTM: 47Indigo Denim is named for the way the yarns get their color: they’re dipped in indigo dye 46 times and then washed in one of four ways. The finished washes range from Indigo Rinse (the darkest), to one year, three year and five year (the most faded).
Fit Labels: The inside label on jeans with fit information and size. Lands’ End features
easy-to-read labels so reordering your favorite jeans is a snap.
H
Hand Crafted: Intricate detailing on high-quality denim products. Application whiskering and sanding details by hand to each jean, giving an individualized uniqueness to each pair made. This is the epitome of high-end denim.
Hand Sanding: A special process of carefully running sandpaper across denim to create a naturally worn look.
Hang Tag: The exterior tags on jeans with product and fit information.
-more-

The Denim Dictionary from Lands’ End / Page Two

I
Indigo: The blue to violet pigment in which cotton fibers are dyed to give denim its “blue” color. Indigo was originally extracted from the Indigofera tinctoria plant. Most indigos today are man made. Generally, yarns are dipped in indigo anywhere from 8 to 16 times, but can be more or less depending on final shade and wash desired. For example the Lands’ End 47Indigo™ jeans are dipped 46 times and rinsed once.
Indigo Rinse: A rinse following dying that helps retain the indigo pigment. Lands’ End Indigo Rinse jeans are dark.
Inseam: Length of inside leg seam.
M
Mercerization: Fabric or yarn is immersed in a caustic soda solution and later neutralized in acid.
The process causes a permanent swelling of the fiber, resulting in an increased luster on the surface of the fabric, an increased ability to absorb dyes, and greater strength.
Modern Waist: For women, these jeans sit below the waist.
N
No-waist
Waistband: The waistband is cut “all in one” with the pants for a smoother fit and feel.
P
Premium: Usually refers to high-end denim used to make jeans. Lands’ End uses premium denim from sources in places such as Italy and Japan. Or, it may have high-quality spandex woven with the cotton fibers.
R
Relaxed Fit: A more generous fit with more room at the thigh and knee and a tapered leg.
Ringspun Denim: Ringspun refers to denim cotton threads on ringspun jeans. Ringspun yarns are stronger because they are drawn and spun the old-fashioned way, rather than ‘blown together’ like open- end yarns. They exhibit greater character because of natural variations called slubs that occur during spinning.
Riser: Often referred to as a “yoke” on pants, this is the piece of fabric above the back pockets that is sewn in to create a rise below the waistband. It is typically triangular and adds shape to the jeans.
S
Selvage: This term derives from “self-edge.” It’s a highly durable edging on a fabric bolt
so that the fiber won’t fray. Lands’ End incorporates selvage seams into its men’s
Hand-crafted Denim to create an authentic look and wear.
Selvage
Denim: Denim made on narrow-gauge looms – the very same American looms used before the 1970’s which are now in Japan.
Shanks/Tacks: Metal buttons used on waistband closures. The shank is the front piece and the tack is the back. Lands’ End uses high-quality shanks and tacks that are either stamped with the Lands’ End logo or form molded such as in our Hand-crafted Denim.
-more-

The Denim Dictionary from Lands’ End / Page Three

T
Tapered Leg: Jeans that narrow gently from thigh to ankle.
Trouser Leg: A straighter, slightly fuller leg.
Traditional
Waist: Jeans that sit at the natural waist.
W
Weathered
Edges: Slight wear-like nicks along the edges of pockets, waistlines and hems. Usually, these weathered edges occur after extended wash and wear or may be created on new jeans.
Whiskering: The lighter-colored lines of “whiskers” that occur as jeans naturally wear. These typically appear as creases at the pockets or behind the knees. Lands’ End creates whiskering for a more natural, lived-in look.
Workwear Fit: A new men’s jean fit that is similar to the Relaxed Fit, but sits a bit lower on the waist, more eased in seat with a straight leg and wider leg opening.

Spinning Notes

2010-02-22T13:23:00.001+05:00

Spinning
Calculations

Count:-

Count is the measure of fineness or coarseness of yarn.

Systems of Count Measurement

There are two systems for the measurement of count.

1) Direct System
2) Indirect System

1) Direct System

It is used for the measurement of weight per unit length of yarn.
When count increases, fineness decreases. ( count↑ fineness↓ )

Commonly used units in this system of measurement are:-

1) Tex ( 1 Tex = 1g/ 1000m )
2) Grex ( 1 Grex = 1g/ 10,000m )
3) Denier ( 1 Denier = 1g/ 9000m )

2) Indirect System:-

It is used for the measurement of length per unit weight of yarn.
When count increases, fineness increases. ( count↑ fineness↑ )

Commonly used subsystems of indirect system are:-

1) English System ( 1 Ne = 1 Hank/ lb )
2) Metric System ( 1 Nm = 1 Km/ kg )

For cotton yarn, length of 1 Hank = 840 yards.

Whenever the type of count is not mentioned with the count, it is understood that it is the English count.

Basic Conversions

No
Length
Weight
Time
1.
1 in = 2.54 cm
1 lb = 7000 gr
1 min = 60 sec
2.
1 yd = 36 in
1 lb = 16 oz
1 hr = 60 min
3.
1 m = 1.0936 yd
1 oz = 437.5 gr
1 shift = 8 hr
4.
1 Hk = 840 yd
1 kg = 2.2046 lb
1 day = 24 hr
5.
1 Hk = 7 leas
1 bag = 100 lb
1 day = 3 shifts

Abbreviations:

In [inch(es)], yd [yard(s)], kg [kilogram(s)], m [meter(s)], Hk [hank(s)], lb [pound(s)], oz [ounce(s)], gr [grain(s)] , sec [second(s)], min [minute(s)], [hour(s)].

Count Conversion Table

Ne
Nm
Tex
Grex
Denier
Ne=
1 xNe
0.5905 xNm
590.5 /Tex
5905 /Grex
5315 /Den
Nm=
1.693xNe
1 xNm
1000 /Tex
10,000/Grex
9000 /Den
Tex=
590.5 /Ne
1000 /Nm
1 xTex
0.1 xGrex
0.111 xDen
Grex=
5905 /Ne
10,000 /Nm
10 xTex
1 xGrex
1.111 xDen
Denier=
5315 /Ne
9000 /Nm
9 xTex
0.9 xGrex
1 xDen

Derivation:-

Ne = 0.5905 Nm

Let us suppose we have,

Total Ne = x Ne
Ne = x Hanks/ lb

This means that,

x Hanks are in ------------------ 1 lb

840x yards in ------------------ 1 lb

840x m in ------------------- 1 lb
1.0936

840x x 2.2046 m in---------- 1 lb
1.0936 x 1000
( We know that, Nm= km/ kg = m/ g.
840x x 2.2046 m/ g Since this value has the units of Nm
1.0936 x 1000 so it equals Nm.)

Nm = 840 x 2.2046 x
1.0936 x 1000

Nm = 1.693 x ( as x = Ne, )

Nm = 1.693 Ne

Ne = 0.5905 Nm

Yarn Classification
(on the basis of no. of plies)

1) Single yarn
e.g 80/1 (read as 80 single) means 80 fibres twisted to form a single yarn.

2) Plied yarn
e.g. 80/2 (read as 80 double) means 80 fibres twisted to form two individual yarns.
The number of plied yarns may exceed two.
Draft & TPI Formulas

Surface speed = DN / min

D = dia. of rotating element
N = rpm (no. of revolutions/min)

Mechanical Draft = S.S of Front roller ( D N ) > 1
S.S of Back roller ( D N )

Actual Draft = count delivered
count fed
Indirect system
A. D. = l / w delivered
l / w fed

Actual Draft = count fed
count delivered
Direct system
A.D. = w / l fed .
w / l delivered

No. of Twists Per Inch, TPI = rpm of flyer simplex
S.S of F.R

Numerical Problems

1) Calculate the length of a package of 80/1 and cone weight 2.083 lb.
(Note:- English count is represented as C/N i-e, yarn count/ no. of yarn plies)

Yarn type = 80/1
Cone wt. = 2.083 lb
Cone length = ?

Solution:-

length = Ne x lb x 840 yards

= 80 x 2.083 x 840 yards

= 139977.6 m
1.0936

= 127997.07 m ------------Ans.

2) Calculate the length of yarn with Ne (80/2) and weight 4.166 lb :-

Yarn type = 80/2
Cone weight = 4.166 lb
Cone length = ?

Solution:-

length = Ne x lb x 840 yards

= 80 x 4.166 x 840 yards
2
= 139977.6 m
1.0936

= 127997.07 m ---------------Ans.

3) Calculate the draft at drawing frame if the feeding sliver is 68 grains/ yard, delivered sliver is 48 grains/ yard and the number of doublings is 8 :-

Count of feeding sliver = 68 gr/ yd
Count of delivered sliver = 48 gr/ yd
Doubling = 8 (8 sliver cans used)
Draft = ?

Solution:-
Actual draft = count fed x doubling (direct system)
count delivered

= 68 x 8
48

= 11.33-------------Ans.

4) Calculate the grains/ yard of delivered sliver if feeding sliver is 68, doubling is 6 and the draft is 7 :-

Count of F.S = 68
Count of D.S = ?
Doubling = 6
Draft = 7

Solution :-
A.D = F.S x D
D.S

7 = 68 x 6
D.S
D.S = 68 x 6 = 58.28 grains/ yard ----------Ans.
7

5) Calculate the draft if feeding sliver is 60 gr/ yd, delivered sliver is 1 HS and doubling is 6 :-

Count of F.S = 60 gr/yd
Count of D.S = 1 HS
Doubling, D = 6
Draft = ?

Solution :-
60 gr in-------------------- 1 yd

60 lb in-------------------- 1 yd
7000
60 x 840 lb in----------- 840 yd
7000

60 x 840 lb/ Hank (direct count)
7000

7000 x 1 Hank/ lb (indirect count)
60 840

= 0.139 Hank/ lb

= 0.139 Ne

Actual Draft = count del. = 1 . = 43.6 ----------Ans.
count fed 0.139/ 6

6) Calculate the English count of delivered sliver on drawing frame when doubling is 6, count of feeding sliver is 70 gr/ yd, diameter of front roller is 30 mm and its rpm is 100, whereas the diameter of back roller is 15 mm and its rpm is 10 :-

Count of D.S = ?
Count of F.S = 70 gr/ yd
Doubling, D = 6
Dia. of F.R, DF = 30 mm
Dia. of B.R, DB = 15 mm
Rpm of F.R, NF = 100
Rpm of B.R, NB = 10

Solution :-

F.S. = 70 gr/ yd = 70 grains in--------------- 1 yd

= 70 lb in------------------ 1 yd
7000

= 0.01 lb in------------------ 1 yd

= (0.01 x 840) lb in---------- 840 yd

= 8.4 lb in--------------------- 840 yd

= 8.4 lb in--------------------- 1 Hank
= 1/ 8.4 Hanks/ lb

= 0.119 Hanks/ lb = 0.119 H.S (Ne).

Mechanical Draft = S.S of F.R = π DF NF = 30 x 100 = 20
S.S of B.R π DB NB 15 x 10

On drawing frame, neither twist is inserted nor the waste is produced so we have;
Mechanical draft = Actual draft = 20

Now in case of indirect count, A.D = count delivered
count fed

A.D = D.S .
F.S/ D

20 = D.S .
0.119 / 6

D.S = 20 x 0.119
6

= 0.396 H.S (Ne)---------------Ans.

7) Calculate the TPI (twists per inch) produced on a simplex with diameter of front roller 28 mm and its rpm be 30. The rpm of flyer is 1000.

TPI on simplex = ?
Dia. of F.R = 28 mm = 2.8 cm
Rpm of F.R = 30
Rpm of flyer = 1000

Solution :-
Dia. of Front roller = 2.8 cm / 2.54 (1 in= 2.54 cm)

= 1.1023 inch

Surface speed of F.R, ^DN = π x dia. of F.R x rpm of F.R

= π x 1.1023 x 30
= 103.88 “/ min.

TPI = rpm of flyer = 1000 = 9.63 -----------------Ans.
S.S of F.R 103.88

8) Calculate the TPI on simplex if the diameter of back roller is 15/16”, rpm of B.R is 10, rpm of flyer is 1000 and draft is 6 :-

TPI on simplex = ?
Dia. of B.R = 15/16”
Dia. of F.R = ?
Rpm of B.R = 10
Rpm of flyer = 1000 rpm
Draft, D = 6

Solution :-
S.S of B.R = πDN = π x 15/16” x 10 = 29.45”/ min

D = S.S of F.R => 6 = S.S of F.R
S.S of B.R 29.45

S.S of F.R = 6 x 29.45 = 176.71”/ min

TPI = rpm of flyer = 1000 . = 5.66 -----------------Ans.
S.S of F.R 176.71

Production calculations

§ Production

The output of a m/c per unit time is called its production. The production is usually calculated in the units of weight/time or length/time e.g, oz/hr, lb/shift, yd/hr, Hk/day etc.

The most commonly used unit of time for production calculation is hour. So if the unit is not mentioned, it is understood to be a production/hr.
§ Efficiency

It is the ability of a material to perform its task.
In other words, it is the ratio of the output of a m/c to the input of that m/c.

Mathematically,

Efficiency = output
Input

Its value ranges from 0→1. it has no units.

§ Efficiency Percentage

It is the %age performance of a m/c.
Mathematically,
Efficiency = output x 100
Input
Its value ranges from 0→100.

If the efficiency of a m/c is 0.8, its percentage efficiency 80. The word ‘percent’ means ‘per 100’ which suggests that the efficiency is 80 .
100

§ Cleaning Efficiency (%)

It is the ratio of the trash extracted to the total trash content in a material.
For any m/c, mathematically,

Cleaning eff. = trash in fed material - trash in del. material
trash in fed material

§ Beating action

The regular hard hits or strikes made by a rotating beater through a material (for its opening or cleaning) are known as beating action.

§ Beats per inch

The no. of beats made by a beater per inch of a material surface is known as beating action.
Mathematically,

Beats/inch = beater rpm x no. of arms .
π x feed roller dia” x feed roller rpm

§ Twists per inch

Twist insertion & draft in a sliver gives roving and further twisting and drafting of roving gives yarn.
So the no. of twists in one inch of yarn (or roving) is known as TPI (twists per inch).

Mathematically,

TPI = spindle speed (rpm) .
Front roller delivery (in/min)

Also,
TPI √count
TPI = TM x √count

Hank:

The word ‘Hank’ is used in two ways. Literally, it is a unit of length, i-e;
1 Hank = 840 yard but practically, we take it as a unit of English count, i-e;
1 Hank = 840 yd/lb
2 Hank = 1680 yd/lb

Roller Speeds:

In spinning calculations, we deal in two kinds of roller speeds, i-e; surface speed and rotating speed (rpm). So when the speed of a roller is mentioned without any units, this means that it is the rpm of the roller, e-g;
speed = 20 means
speed = 20 rpm

Production Formulas

1. Production of Scutcher

P = πDN x 60 x lap ct.(oz/yd) x η [oz/hr]
36

2. Production of Card m/c

P = πDN x 60 x sliver ct.(gr/yd) x η x tension draft [lb/hr]
36 7000

3. Production of Draw frame

P = πDN x 60 x del. sliver ct.(gr/yd) x η x no. of x no. of [lb/hr]
36 7000 heads m/c

4. Production of Lap Former

P = πDN x 60 x lap ct.(gr/yd) x η x no. of m/c [lb/hr]
36 7000

5. Production of Comber

P = f (πDN) x 60 x sliver ct.(gr/yd) x η x N x no. of x no. of x 1 - w .
36 7000 heads m/c 100

[ lb/hr]
6. Production of Simplex

P = πDN x 60 x roving ct.(gr/yd) x η x no. of spindles [lb/hr]
36 7000

7. Production of Ring frame

P = πDN x 60 x 16 x 8 x η [oz/shift/spindle]
TPI x 36 840 x ct.

P = P [oz/shift/spindle] x no. of spindles x no. of frames [oz/shift]

Details of production formulas
derivations & Problems

1. Production of Scutcher

P = πDN x 60 x lap ct.(oz/yd) x η [oz/hr]
36

Derivation:

Let D = dia. of lap roller (in inches)
N = rpm of lap roller
η = efficiency of m/c
P = production

Production = surface speed of lap roller x lap ct. (wt/l)

= πDN (in/min) x lap (oz/yd)

= πDN (yd/min) x lap (oz/yd)
36

= πDN x 60 (yd/hr) x lap (oz/yd)
36

Since the efficiency of a m/c is always less than 1 so,

= πDN x 60 (yd/hr) x lap (oz/yd) x η
36

= πDN x 60 (yd/hr) x lap (oz/yd) x η [oz/hr]
36

The value (πDN/36) x 60 may be taken as a production constant when working on a m/c with a fixed dia. and rpm of delivery roller.
The delivery speed of a pair of rollers is the same as its surface speed. So the value πDN can also be mentioned as delivery speed.

P = P [oz/hr] [lb/hr]
16
P = P [lb/hr] x 8 [lb/shift]
P = P [lb/hr] x 24 [lb/day]

P = P [oz/hr] [kg/hr]
16 x 2.2046

Also,
P = πDN x 60 x 1 x η [lb/hr]
36 840 Ne
but let us not use this formula to avoid confusions.

Q:1—Calculate the production of scutcher if the lap wt. is 13 oz/yd, and the dia and speed of shell roller are 11 rpm and 240 mm respectively. Furnish the production in lb/hr, kg/hr, lb/shift, kg/shift and bag/day when the efficiency of the m/c is 75%:-

Lap wt/l = 13 oz/yd
Shell roller speed, N = 11 rpm
Shell roller dia., D = 240 mm = 9.5”
Efficiency, η = 75% = 75/100 = 0.75
P [lb/hr], P [kg/hr] , P [lb/shift], P [kg/shift] & P[bag/day] = ?

Solution:-

P [oz/hr] = πDN x 60 x lap ct.(oz/yd) x η [oz/hr]
36
= π x 9.5 x 11 x 60 x 13 (oz/yd) x 0.75 [oz/hr]
36
= 9.12 x 60 x 13 (oz/yd) x 0.75 [oz/hr]

= 5334.82 [oz/hr]

P [lb/hr] = P [oz/hr] = 5334.82 = 333.43 [lb/hr] -----Ans
16 16

P [kg/hr] = P [lb/hr] = 333.43 = 151.24 [kg/hr] -----Ans
2.2046 2.2046

P [lb/shift] = P [lb/hr] x 8 = 333.43 x 8 = 2667.44 [lb/shift] -----Ans

P [kg/shift] = P [kg/hr] x 8 = 151.24 x 8 = 1209.92 [kg/shift] -----Ans

P [bag/day] = P [lb/hr] x 24 = 333.43 x 24 = 80.02 [bag/day]
100 100 Ans

Q:2—The fluted lap roller of a scutcher of 9” dia. makes 10 revolutions per minute. If the lap count is 0.00136 Hk, calculate the production of scutcher in one shift at 80% efficiency:-

Lap count = 0.00136 Hk
= 0.00136 x 840 (yd/lb)
= 1 (lb/yd) x 16 = 14 (oz/yd)
0.00136 x 840

Lap roller speed, N = 10 rpm
Lap roller dia., D = 9”
Efficiency, η = 80/100 = 0.8
P [lb/shift] = ?

Solution:-

P [oz/hr] = πDN x 60 x lap ct.(oz/yd) x η [oz/hr]
36
= π x 9”x 10 x 60 x 14 x 0.8 [oz/hr]
36

= 5277.88 [oz/hr]

P [lb/shift] = P [oz/hr] x 8 = 2639 [lb/shift] -------Ans
16

2. Production of Card m/c

P = πDN x 60 x sliver ct.(gr/yd) x η x tension draft [lb/hr]
36 7000

Derivation:

Let D = dia. of coiler calendar rollers (in inches)
N = rpm of coiler calendar rollers
η = efficiency of m/c

Production = surface speed of doffer x carded sliver ct. (wt/l)

As the sliver has a lesser wt/l than a lap it is
easier to observe its gr/yd rather than its lb/yd.

= πDN (in/min) x sliver (gr/yd)

= πDN (yd/min) x sliver (gr/yd)
36

= πDN x 60 (yd/hr) x sliver (gr/yd)
36

Since the efficiency of a m/c is always less than 1
and 1lb = 7000 gr so,

= πDN x 60 (yd/hr) x sliver (gr/yd) (lb/yd) x η [lb/hr]
36 7000

P [lb/hr] = πDN x 60 x sliver ct.(gr/yd) x η [lb/hr]
36 7000

Although mainly dispersion drafting takes place on card m/c but there is a very small tension draft b/w calendar rollers and coiler calendar rollers. Theoretically, this is ignored but is included in mathematical calculations.
In a case when the dia. and speed (rpm) of coiler calendar rollers are given instead of doffer or calendar rollers, then the tension draft is already included in those values and we need not include that in our formula. So,

P [lb/hr] = πD’N’ x 60 x sliver ct.(gr/yd) x η x tension draft [lb/hr]
36 7000

Here D’ & N’ are assumed to be the dia. & rpm (respectively) of doffer or calendar rollers.

Q:3—What will be the production of a carding engine in 8 hours at 84% efficiency and 5% waste, if the speed of 2” coiler calendar rollers is 125 rpm with the carded sliver weighing 58 gr/yd ?

Carded sliver wt/l = 58 gr/yd
Coiler calendar rollers speed, N = 125 rpm
Coiler calendar rollers dia., D = 2”
Efficiency, η = 84% = 0.84
Waste %age = 5%
P [lb/shift] = ?
Solution:-

P [lb/hr] = πD’N’ x 60 x sliver ct.(gr/yd) x η [lb/hr]
36 7000

= π x 2” x 125 x 60 x 58(gr/yd) x 0.84 [lb/hr]
36 7000

= 9.11 [lb/hr]

P [lb/shift] = P [lb/hr] x 8 = 72.9 [lb/shift] -------Ans

Here the waste percentage is not concerned as the given count is of carded (cleaned) sliver and not of lap. Hence it was just a value given to create confusion.

3. Production of Draw frame

P = πDN x 60 x del. sliver ct.(gr/yd) x η x no. of heads [lb/hr]
36 7000

Derivation:

Let D = dia. of calendar rollers (in inches)
N = rpm of calendar rollers
η = efficiency of m/c

Production = surface speed of calendar rollers x drawn sliver ct. (wt/l)

= πDN (in/min) x sliver (gr/yd)

= πDN (yd/min) x sliver (gr/yd)
36

= πDN x 60 (yd/hr) x sliver (gr/yd)
36

= πDN x 60 (yd/hr) x sliver (gr/yd) (lb/yd) x η [lb/hr]
36 7000

= πDN x 60 x sliver ct.(gr/yd) x η [lb/hr]
36 7000
Since a drawing frame may have more than one delivery ends or heads and also we may use one or more m/cs at a time for drawing the same kinds of slivers, so to calculate the total production,

P = πDN x 60 x del. sliver ct.(gr/yd) x η x no. of x no. of [lb/hr]
36 7000 heads m/c

Q:4—The 3” diameter calendar rollers of a 6 delivery drawing frame revolves 125 rpm. Calculate the production in pounds if the drawn sliver is 60 gr/yd and the m/c works for 8 hrs at 70% efficiency:-

Drawn sliver wt/l = 60 gr/yd
Calendar rollers speed, N = 125 rpm
Calendar rollers dia., D = 3”
Efficiency, η = 70% = 0.7
P [lb/shift] = ?

Solution:-

P = πDN x 60 x del. sliver ct.(gr/yd) x η x no. of x no. of [lb/hr]
36 7000 heads m/c

= π x 3”x 125 x 60 x 60 (gr/yd) x 0.7 x 6 x 1 [lb/hr]
36 7000

= 32.725 x 2.16 [lb/hr]

= 70.69 [lb/hr]

P [lb/shift] = P [lb/hr] x 8 = 565.52 [lb/shift] -------Ans

4. Production of Lap Former

P = πDN x 60 x lap ct.(gr/yd) x η x no. of m/c [lb/hr]
36 7000

1—Sliver Lap M/c

Q:5—The speed and dia. of the fluted lap drum of a sliver lap m/c are 30 rpm and 16” respectively. If 24 card cans having 0.15 Hk sliver are fed to the m/c, what will be the production in one shift at 70% efficiency?

Feeding sliver count = 0.15 Hk
Lap roller speed, N = 30 rpm
Lap roller dia., D = 16”
Efficiency, η = 70% = 0.7
P [lb/shift] = ?

Solution:-

No. of yards of each sliver delivered in 1 shift at 70% efficiency

= πDN x 60 x 8 hr x η [yd/shift]
36
= π x 16” x 30 x 60 x 8 hr x 0.7 [yd/shift]
36

= 14074.34 [yd/shift]

No. of pounds of each sliver delivered in 1 shift at 70% efficiency

= [yd/shift] = 14074.34 yd x lb = 111.7 [lb/shift]
sliver count shift 0.15 x 840 yd

No. of pounds/yard of each sliver delivered

= [lb/shift] = 111.7 = 0.00794 [lb/yd]
[yd/shift] 14074.34

No. of [gr/yd] of each sliver = [lb/yd] x 7000 = 55.55 [gr/yd]

No. of [gr/yd] of 24 slivers = 55.55 x 24 = 1333.33 [gr/yd]

Now total production;

P = πDN x 60 x lap ct.(gr/yd) x η x no. of m/c [lb/hr]
36 7000

P = π x 16” x 30 x 60 x 1333.33 (gr/yd) x 8 x 0.7 x 1 [lb/shift]
36 7000

= 2680 [lb/shift] ------Ans

2—Ribbon Lap M/c

Q:6—Calculate the production of a ribbon lap m/c in 8 hours at 70% efficiency if the speed of 16” dia. lap drum is 48 rpm and hank of ribbon lap is 0.0119.

Feeding sliver count = 0.0119 Hk
Lap roller speed, N = 48 rpm
Lap roller dia., D = 16”
Efficiency, η = 70% = 0.7
P [lb/shift] = ?

Solution:-

No. of yards of lap delivered in 1 shift at 70% efficiency

= πDN x 60 x 8 hr x η [yd/shift]
36
= π x 16” x 48 x 60 x 8 hr x 0.7 [yd/shift]
36

= 22519 [yd/shift]

No. of pounds of lap delivered in 1 shift at 70% efficiency

= [yd/shift] = 22519 yd x lb = 2253.7 [lb/shift]
sliver count shift 0.0119 x 840 yd
Ans

5. Production of Comber

P = f (πDN) x 60 x sliver ct.(gr/yd) x η x N x no. of x no. of x 1 - w
36 7000 heads m/c 100

[lb/hr]
Here,
f = feeding rate
N = nips/ min of m/c
w = waste %age

Q:7—The cylinder of a 6 head comber is running at a speed of 100 nips per minute and each nip feeds 0.25” lap. The hank of lap is 0.0166. calculate the production of comber in 8 hours at 70% efficiency and 12% waste:-

Feeding rate = 0.25”/min
Count of lap = 0.0166 Hk
= 0.0166 x 840 (yd/lb)
= 1 / 13.94 (lb/yd) = 0.0717 (lb/yd)

No. of heads = 6
Nips/min = 100
No. of m/c = 1
Efficiency = 70% = 0.7
Waste %age = 12%

Solution:-

P = f (πDN) x 60 x sliver ct.(gr/yd) x η x N x no. of x no. of x 1 - w .
36 7000 heads m/c 100
[lb/hr]

P = 0.25 x 60 x 0.0717 (lb/yd) x 0.7 x 100 x 6 x 1 x 1 - 12 .
36 100
[lb/hr]
= 11.04 [lb/hr]

= 88.33 [lb/shift] ------Ans

6. Production of Simplex

P = πDN x 60 x roving ct.(gr/yd) x η x no. of spindles [lb/hr]
36 7000

Also,
P = πDN x 60 x roving ct.(gr/yd) x η [lb/hr/spindle]
36 7000

This formula is used when the production of a single spindle is concerned.

Q:8—A simplex frame working at 80% efficiency prepares a full doff in 3½ hours. The wt. of roving on full bobbin is 3 lb and 4 oz. The hank of roving is 1.0. Calculate the production of a frame of two doffs in hanks and the speed of the front roller of 1⅛ “ diameter:-

(When the required production of a m/c on its output package is complete, it is said to be one doff and the process of replacing these full packages with the empty ones to get further output is known as doffing)

Efficiency, η = 80% = 80/100 = 0.8
Time to complete one doff = 3½ hr
Wt. of roving on full bobbin = 3 lb + 4 oz
= 3 lb + 4/16 lb
= 3.25 lb
Hank of roving = 1.0
Dia. of Front Roller, D = 1⅛ “ = 1.125”
Production of a frame of two doffs, P2 = ?
Speed (rpm) of Front Roller, N = ?

Solution:-

1 doff (3½ hr) makes a bobbin of roving wt--------------------------------3.25 lb
2 doffs (7 hr) make a bobbin of roving wt----------------------------------3.25 x 2
= 6.5 lb

Production, P2 (Hk/ 2 doffs) = wt. of 2 doffs (lb) x Hk of roving
= 6.5 x 1
= 6.5 Hk in 7 hr---------Ans

Production, P (Hk/hr) = 6.5 / 7 = 0.93 Hk / hr

On simplex we have,

P (Hk/hr) =  DN x 60 x no. of spindles x η
36 840 roving Hk

N = P x 36 x 840 x 1 x 1
D 60 η 1

= 0.93 x 36 x 840 x 1 .
1.125  60 0.8

= 165.4 rpm------Ans

7. Production of Ring frame

P = πDN x 60 x 16 x 8 x η [oz/shift/spindle]
TPI x 36 840 x ct.

P = P [oz/shift/spindle] x no. of spindles x no. of frames [oz/shift]

DERIVATION

Let D = dia. of front rollers (in inches)
N = rpm of front rollers
η = efficiency of m/c

Production = surface speed of front rollers x yarn ct. (wt/l) or,

= delivery speed of F.R. x yarn (oz/yard) [oz/hr]

Now let us calculate the delivery speed of F.R.

On a ring frame,
TPI = spindle speed (rpm)
F.R. delivery (in/min)

F.R. delivery = spindle speed (rpm) [in/min]
TPI

F.R. delivery = sp. speed x 60 [yd/hr]
TPI x 36

Now substituting this value in the production formula,

P [oz/yd] = sp. speed x 60 [yd/hr] x yarn ct. [oz/yd]
TPI x 36

= sp. speed x 60 [yd/hr] x yarn ct. [oz/yd] x η [oz/yd]
TPI x 36

As 1 shift = 8hr and this is the calculation for a single spindle so,

P [OPS] = sp. speed x 60 x 8 x yarn ct. [oz/yd] x η [oz/shift/spindle]
TPI x 36

However, in some cases the English count is given instead of oz/yd of yarn. For that purpose, let us make some changes in the above formula,

= sp. speed x 60 x 8 x η [lb/shift/spindle]
TPI x 36 840 x ct.

= sp. speed x 60 x 8 x 16 x η [oz/shift/spindle]
TPI x 36 840 x ct.

This formula helps to calculate the production of one spindle. For the production of a full ring frame,

P [oz/shift] = P [oz/shift/spindle] x no. of spindles [oz/shift]

The no. of spindles in one ring frame is 480. This is a fixed value and can be used when spindle capacity of the ring frame is not mentioned. Also, if the production of more than one ring frames is to be calculated, then

P [oz/shift] = P [oz/shift/spindle] x 480 x no. of frames [oz/shift]

As 1 day = 3 shifts and 1 bag = 100 lb,

P [bag/day] = P [oz/shift/spindle] x 480 x 3 x no. of [bag/day]
16 x 100 frames

= 0.9 x P [oz/shift/spindle] x no. of frames [bags/day]

Q:9—Calculate the production of yarn in oz/spindle/shift on a ring frame if the spindle speed is 16000”/min, TM is 3.8, yarn is 30/1 and efficiency of the m/c is 93%:-

Yarn count = 30/1
Efficiency = 93% = 0.93
No. of spindles = 480
TM = 3.8

Solution:-
TPI = TM √ ct.
= 3.8 √ 30
= 20.78
Now,

P [OPS] = sp. speed x 60 x 8 x 16 x η [oz/shift/spindle]
TPI x 36 840 x ct.

= 16000 x 60 x 8 x 16 x 0.93 [oz/shift/spindle]
20.78 x 36 840 x 30

= 6.06 [oz/shift/spindle]

P [bag/day] = P [oz/shift/spindle] x 480 x 3 x no. of [bag/day]
16 x 100 frames

= 6.06 x 480 x 3 x 1 [bag/day]
16 x 100

= 5.45 [bag/day] --------Ans
THE PROCESS FLOW OF
YARN MANUFACTURING

Axi-flow Cleaner Step Cleaner Multi-mixer

Scutcher
Card Machine

Sanforizing/Shrinkage recommendations 5

2009-09-13T09:45:00.000+06:00

Large deep cracks on the belt interior with no signs of general surface roughness on the belt interior, are usually the result of insufficient belt tension. When adjusting belt tension, always start by relaxing all tension on the rubber belt. Always place new marks 12 inches (305 mm) apart on the edge of the relaxed belt. For belts thicker than 2 inches (51 mm) stretch the belt until the marks are 12-1/4 inches (311 mm) apart. For belts less than 2 inches (51 mm) thick, stretch the belt until the marks are 12-1/2 (318 mm) apart. After stretching the belt always rotate the belt several revolutions and again measure the distance between marks again. Re-adjust the tension to the correct amount and again rotate the belt several revolutions followed by re-measuring the marks. Continue to repeat these operations until the marks remain stable at the desired distance apart

To eliminate these edge pleats, which are the result of overfeed of the cloth edges into the rubber belt nip, increase tension on the cloth entering the rubber belt. Most machines are equipped with a variable speed control roll. Slowing down the speed of this roll will apply greater tension on the cloth. It is not recommended to increase compression of the rubber belt to eliminate selvage creases, although this will often serve to eliminate the selvage creases, it will also reduce rubber belt useful life.

It is not always possible to eliminate this high pitched sound. In some cases increasing the temperature of the steam heated cylinder or pre-heating the cloth using the hated can located between the fabric skyer and the rubber belt unit will reduce or eliminate the noise. Increasing rubber belt heated cylinder temperature may also reduce rubber belt useful life.

Some success has been reported in eliminating the noise by hanging a heavy cotton cloth over the emergency cooling water spray pipe and allowing the cloth to just drape onto the top of the steam heated cylinder. Water from the emergency cooling spray is allowed to lightly drip onto the cloth so that very light moisture wicks down the cloth and onto the heated cylinder. This reportedly sometimes solves the problem.

This is usually a problem of cloth elongation after shrinking. The cause may be insufficient moisture in the cloth being pre-shrunk or too much or too little moisture in the cloth coming from the palmer. Cotton fabrics usually require about 1% of moisture for each one ounce per square yard of cloth weight prior to entering the rubber belt. Too little moisture in the cloth being pre-shrunk does not permit the cloth to take on a stable new dimensional memory. Yarns may tend to push out or elongate and the cloth will again shrink when washed.

Too much or too little moisture in pre-shrunk cloth coming from the palmer will also result in elongation of the cloth during relaxation. Ideally cloth coming from the palmer should have 4% residual moisture content. Less than 4% moisture content will usually result in relax elongation of the cloth, while more than 4% residual moisture content will result in less stable cloth which can be stretched with slight tension such as is normal during inspection and rolling of the cloth.

Parallel of the pressure roll and the steam heated rubber belt cylinder is extremely important. If this adjustment is not made precisely, fabric shrinkage will vary from side to side causing a slack selvage on one side of the cloth coming out of the rubber belt. This may also cause the rubber belt to track forcibly to one side, resulting in belt edge cracks.

Cracks forming on the side edge of a rubber belt may be the result of several conditions. Failure to grind a radius on the rubber belt outer edge, as the original radius disappears with repeated surface grinding of the rubber belt, is a common cause of cracks on the outer belt edge. A sharp angle on the belt outer edge causes a focus of mechanical stress which promotes the formation of cracks in this area.
Poor rubber belt tracking adjustment can result in belt edge cracks caused by the excessive force of the belt edge working against the limit roller.
Limit rollers set tight up against both belt edges or rollers set at an improper angle are a leading cause of belt edge cracks. Limit rollers which do not turn due to defective bearings or peeling chrome plating on roller surfaces can lead to belt edge cracking.
Rubber belt edge cracks often are the result of damage to the belt edge by lifting straps etc, during installation of the rubber belt on the shrinking machine

Sanforizing/Shrinkage recommendation 4

2009-09-13T09:44:00.000+06:00

When rubber belts reach a thickness of 2 inches (51 mm) or for rubber belts ordered at 2 inches (51 mm) thick, the amount of lengthwise tension required to insure best performance is ½ inch (13 mm) of stretch of the 12 inch (305 mm) marks placed on the belt edge. Failure to apply sufficient lengthwise tension to a rubber belt will often greatly reduce the capacity of the belt to shrink, cause generalized light corrugations in some shrunk fabrics and may result in the occurrence of cracks on the belt interior.

Sanforizing/Shrinkage recommendation 3

2009-09-13T09:43:00.000+06:00

Most rubber belt shrinking machines have the internal water spray installed in the wrong location. The internal water spray is used to lubricate the belt interior. Lubrication is important so that, as the rubber belt elongates and becomes wider as it is squeezed at the nip point, it can slip easily against the surface of the pressure roll. Otherwise, elongation of the belt will be restrained and the capacity of the rubber belt to recoil, elongate and compact the cloth will be reduced. Severe abrasion to the rubber belt interior may also occur.

Therefore, the internal water spray should be located just below the pressure roll and after the water removal roll. Water sprays located at the back side of the rubber belt are very much less effective, since most water applied to the belt inner surface at this location, will be removed by the wiping action of the belt idler roll and the water removal roll (s), by the time it arrives at the pressure roll.

Sanforizing/Shrinkage recommendation 2

2009-09-13T09:40:00.000+06:00

Most rubber belts are not taken out of service because they no longer perform. Many rubber belts are removed from machines because they have reached a certain thickness such as 50 mm or 45 mm, but are often capable of continued performance if rubber belt tension is simply increased.

Most rubber belts are removed from service because of damage to the rubber belt resulting from accidents, poor machine operator practices, poor maintenance, etc.
Good quality rubber belts used to pre-shrink 14-3/4 oz. (500 gr/m2) denim, if properly maintained by well trained shrinking machine operators, should last between 11 and 14 million yards (10 and 13 million meters). Some users have even reported greater useful life.

Rubber belts used for lightweight goods or cotton blends, as well as belts used to improve cloth hand only, may last between 20 and 25 million yards (18.3 and 22.9 million meters).

Unfortunately, many users of good quality rubber belts who shrink heavy weight denim fabric regularly obtain only 7 to 9 million yards (6.4 to 8.2 million meters) of useful life. This may be due to poor operator skills, poor preparation of cloth to be pre-shrunk, and poor rubber belt and shrinking machine maintenance.

Sanforizing/Shrinkage recommendation 1

2009-09-13T09:29:00.000+06:00

When a rubber belt is thinner than 2 inches (51mm), belt lengthwise tension must be doubled to avoid loss of pre-shrinking capability and occurrence of corrugations in the pre-shrunk cloth.

Correct tension adjustment is:

For rubber belts thicker than 2" (51mm): 1/4" (6mm) of stretch for 12" (305mm) marks placed on the belt edge.
For rubber belts thinner than 2" (51mm): 1/2" (13mm) of stretch for 12" (305mm) marks placed on the belt edge