TAM 2200 Notes Ch. 10 - Kerri McBee-Black PDF

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Kerri McBee-Black...

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Ch. 10: Yarn Processing Intro ● Most apparel and interior fabric are produced from yarns ● Yarn is continuous strand of textile fibers, filaments, or materials in a form suitable for knitting, weaving, or otherwise intertwining to form a textile fabric ● Yarn type and quality affect product cost, quality, and performance Filament Yarns ● Made from manufactured fibers, except for small % that is filament silk ● Manufactured filament yarns are made by extruding polymer solution through spinneret and solidifying it in fiberform; individual filaments are brought together w/ or w/o twist ● Grouping of filaments w/ addition of twist create filament yarn ● Throwing is twisting of manufactured fibers and then into texturing Smooth-Filament Yarn ● Uniform and come from spinneret ● Smooth nature gives them luster, but luster varies w/ amt. Of delusterant in fiber and amt. Of twist in yarn ● Max. luster obtained w/ bright filaments w/ little or no twist ● Very-high-twist yarns, like crepe, reduce filament luster ● Have no protruding ends, so they don’t lint; fibers very parallel; resist pilling; fabrics made from them shed soil ● Compact w/ little bulk, loft or cover and used in wind and water resistant fabrics ● Yarn strength depends on strength of individual fibers and # of filaments in yarn ● Strength of filament yarns is usually greater than staple Monofilament Yarn ● Fishing line- #N30 ● Single coarse filament fiber ● Used for industrial purposes: sewing thread, fishing line, and vegetable bags ● Metallic fibers used monofilament for their sparkle

Bulk Yarns ● Made to have greater covering power or volume than conventional

● Referred to as bulk-continuous-filament yarns ● Bulking the yarn gives filaments the aesthetic properties of spun yarns by altering surface and creating space b/t fibers ● Irregular surface, soft twist, and continuous nonparallel fibers that resist being pulled apart ● More absorbent, more breathable, better bulk, cover and elasticity ● Static buildup is lower, no pill or shed ● Three classifications: ○ Bulky yarns ○ Stretch yarns ○ Textured yarns Spun Yarns ● Continuous strands of staple fibers held together by twisting ● Have fuzzy surface, more twist w/ filament yarns, short fibers that pull apart and partially parallel fibers ● Fabric made w/ spun yarn is more comfortable next to skin than one made from smooth-filament yarn ● Most insulating properties due to structure of yarn ● More space b/t fibers in spun yarn and spaces trap air and insulate better ● Spun yarn w/ low twist has more air spaces then spun yarn w/ high twist and has better insulating properties ● If wind-resistance is desired, fabrics w/ high-twist compact yarns and high count are more desireable ● Protruding ends in spun yarns contribute to greater comfort and warmth and are dull, fuzzy and shed w/ surface that pills (carded-short, combedlong) ● Strength of individual staple fiber is less important in strength of spun yarns than filament ● Strength depends on fiber’s cohesiveness of twist ● Spinning of staple fibers is one of oldest manufacturing arts ● Spinning yarn consists of drawing out fibers, twisting them by rotating until creating a yarn length

Processing Staple Yarns Opening

● Loosens, cleans, and blends fibers from cotton bale that has been compacted and stored ● Blending fibers from several bales achieves more uniform quality in finished yarn Carding ● Partially aligns fibers and forms into thin web that is brought together as soft rope called a silver Drawing ● Combines several carded silvers’ together into thinner drawn silver Combing ● Used when long-staple fibers are spun ● Used to produce high-quality fibers ● Removes short fibers and increases parallelism of fibers ● Combed yarns are more expensive than carded yarns Other Systems ● Woolen: oil is added to wool fibers to facilitate processing ● Ring Spinning: used to produce bulky, soft, fuzzy yarns ● Worsted: longer wool and manufactured fibers are passed through gill boxes to ensure fiber distribution of silver and makes fibers more parallel ● Roving: reduces drawn silver, increase parallel alignment of fibers, and inserts small amount of twist in strand

Inserting Yarn Twist ● Made using ring (conventional) or open-end spinning ● Conventional Spinning (ring): consists of series of operations designed to clean and parallel staple fibers, draw them into a fine strand, and twist them to keep them together and give them strength ○ Most important method for short staple fibers ○ Finer, smoother, better quality, more uniform and fewer problems ● Spinning adds yarn twist ● Ring Spinning: draws, twists, and winds in one continuous operation ○ Slow process ○ Preferred for knits of fine blends of polyester and cotton due to hand ● Blending occurs ● Ring-frame spinning is used for woolen yarns ● Open-end Rotor Spinning: eliminates formation of roving

○ Knots eliminated, larger packages of yarn are formed, less operator supervision, production speeds 4x ring ○ Harsher hand and weaker and more sensitive to abrasion, but more uniform and more opaque ○ Preferred for toweling and other pile yarn fabrics ● Friction spinning: combines rotor and air techniques ○ More even, free of lint, loftier, but weaker than open-end yarns ● Air-jet spinning: narrow silver is fed into machine with 2 nozzles facing in opposite directions ○ Nozzle blows air against silver forcing outermost fibers to wrap around silver, which produces a yarn ○ Elastic, weaker and rougher than ring-spun or rotor-spun yarns

Alternate Spun-Yarn Processes ● Compact Spinning: variation of ring spinning that condenses roving b/f final insertion and creates smoother compact or condensed yarn ● Vortex Spinning: produces yarn that has an outer layer of fibers wrapped around center of parallel fibers ● Twistless Spinning: eliminates twisting process and creates yarns that are easy to dye and good durability but not suitable for open fabric structures ● Self-Twist Spinning: creates yarns w/ areas of both S and Z twist Comparing Twists ● Ring spun has higher fiber parallelism ● Ring spun has high yarn hairiness ● Air jet spun has best thermal retention and best hand ● Air jet spun has highest abrasion resistance

Fiber Blends ● Blend is intimate mixture of fibers of different generic type, composition, length, diameter or color spun together into one yarn ● Fiber types cannot be separated and when untwisted and examined through a microscope, both fibers are visible ● Mixture refers to yarns of different generic types w/i a fabric ● One type of yarn used in one fabric place and another type is used in another fabric place ● In a combination, ply yarns are used ● At least one strand of ply yarn is of diff. generic fiber type from other strands of ply yarn ● Blends, mixtures, and combos produce fabrics w/ properties that are different

from those obtained w/ one fiber only ● Blends improve processing and uniformity ● You can achieve better hand, texture and appearance ● To gain cross-dyeable effects...