EXAM II STUDY GUIDE CHAPTERS 13 20 Chapter 13 Yarn Structures What is the difference between staple spun yarns and filament yarns Spun yarns are made from small staple length fibers Twisting them is the most common way of holding them Filament yarns are long continuous strands of fibers made from manufactured fibers or silk filament the only natural filament What is the difference between monofilament and multifilament yarns Monofilament single strand ex Fishing line artificial hair Multifilament many fine filament yarns join together Know what an S and a Z twist are S twist left clockwise Z twist right counterclockwise What is a plied yarn If the original single yarns are spun Z what direction does the ply twist need to be If you take two or more plied yarns and ply them together again what is the new yarn structure called Plied yarn Twisting together two or more single yarns how many are being twisted together The ply twist needs to be to the left if the yarns are spun Z If you take two or more plied yarns and ply them together it is called a cord yarn What would the final plying direction be The final plying direction would be to the left Know the difference between simple plain yarns and fancy novelty yarns Simple yarns are fairly smooth and uniform along their length regular surface Not much is done to them and they re not always one yarn They have varying degrees of twist ranging from loose to moderate tight or hard twist Single ply and cord yarns can all be simple yarns Novelty yarns are made to create interesting decorative effects in the fabrics Novelty yarns are single ply or cord staple or filament They are weaker than simple ones and usually placed in the cross wise direction of woven fabrics and can be knitted too Know the difference between these novelty yarns corkscrew boucle chenille slub Corkscrew made of two plies one soft and heavy the other fine The heavy yarn winds around the fine yarn Also called a spiral yarn Boucle aka loop yarns Multi ply yarns that is used to create decorative effects and forms irregular loops around a base yarn Another yarn binds or ties the effect yarn to the base The loops are visible in the yarn and in fabrics made from those yarns Chenille Require steps in their preparation First leno weave fabric is woven Then it is cut into strips which have soft pile on all sides are used as yarns They are not yarns in the traditional sense of a twisted fiber but have been taken through a series of stages before being readied for use Slub May be either ply or single yarns of staple fibers The slub effect is created by varying the twist in the yarn allowing areas of looser twist to be created This produces a long thick soft area in the fabric called a slub creating an irregular diameter along the yarn The surface of fabrics woven w these yarns shows these irregularities Have varying twist Slubs are the same color as the rest of the yarn and cannot be pulled out r Know the effect of the amount of twist on yarn low high crepe Low yarn twist softer larger in diameter more textured fiber ends not held in place low abrasion resistance They are hairier too many fibers protrude from yarn surface High yarn twist More firm more fibers packed in a smaller area smaller in diameter smoother more resilient twist adds bounce more soil resistant and resistant to snagging and abrasion Crepe Twist Crepe yarns have an extremely high twist and usually start to kink thus creating a yarn that does not have a smooth surface They have a random weave structure comes from kinkling of the yarns but technically it s a plain weave and are very wrinkle resistant Know the difference between the direct and indirect methods of measuring the size of yarn What is denier Direct Method The higher the number the bigger thicker heavier the yarn Used for filament yarns Tex weight in grams of 1000 meters of Fixed length of yarn is weighted Denier weight in grams of 9000 meters yarn of a yarn Indirect Method The higher the number the finer the yarn Used for staple yarns Denier is the weight in grams of 9000 meters of yarn The Denier System is direct and the simpler of the two systems Yarn Count system is indirect and used for all spun fibers and states the number of hanks of specific length spun from a pound of fiber natural fibers hanks how much in fiber Yarn count number is inversely proportional to the weight Cotton 840 yd hank Linen 300 yard hank Wool 1600 yard hank Linen is the biggest wool is thin Chapter 14 Manufacturing Yarns What is a texturized filament yarn How is it done What are the advantages of texturized yarns A texturized filament yarn is a filament yarn in which the smooth straight form of the fibers has been altered They are smooth and slippery to the touch and lack comfort bulk and feel of yarns spun from staple fibers Cannot be treated w heat substances It is done in two methods mechanical and thermo mechanical Only mechanical action is usd to entangle the fibers in the yarn They are produced through air jet texturing where the texture is produced not by heat but by feeding yarns into a system where slack filaments are formed into loops by jets of air These yarns resemble staple yarns Thermo mechanical method if fibers in a yarn are deformed under heat the resulting yarns have not only increased bulk but greater stretch False twist texturizing yarn is twisted in a heated zone and allowed to untwist as it cools Hot fluid jet texturizing the bulk continuous filament BCF yarns used in carpets are made using this process Fibers are fed into a chamber and subjected to hot air or stream Advantages it is less expensive than spinning staple yarns consumer friendly increase bulk for comfort resiliency or feel and provide the yarn stretch What is the difference between carding and combing fibers Which is more expensive Why Carding a process step in making spun yarns in which fibers are passed through intermeshing wires like drums that separate and pull them into somewhat a parallel form It is most commonly used in the industry Combing A process step following carding in making spun yarns in which the fibers are pulled through a comblike device into a more parallel alignment Combing is more expensive because an additional step is required in specialized equipment Some of the cotton fiber is removed and will usually be indicated on the label as a sign of quality What is the difference between the woolen and worsted system for preparing and spinning wool What would be