Chapter 13 Yarn Structures What is the difference between staple spun yarns and filament yarns Staple spun yarns are made up of many short fibers twisted together whereas filaments are one long continuous strand What is the difference between monofilament and multifilament yarns Monofilament is one long strand by itself and multifilament is many long strands together Know what an S and a Z twist are Refers to a type of twist in a yarn Z twists also known as right twists follow the middle bar of the letter z and s twists also known as left twists follow the middle bar of the letter s What is a plied yarn Plied yarns are two separate yarns twister together If you take two or more plied yarns and ply them together again what is the new yarn structure called What would the final plying direction be The new yarn structure would be corded Know the difference between simple plain yarns and fancy novelty yarns Simple yarns are fairly smooth and uniform along their length Fancy yarns have unlike parts that are irregular and regular intervals Know the difference between these novelty yarns o o o o Corkscrew has two plies looks like a cork screw one is puffy and one is fine Boucle have closed loops Chenille looks like a caterpillar Slub has entangled tuffs throughout the yarn What is the difference between covered and core spun yarns Covered is one yarn completely covered with another yarn Core spun has the center core covered with a wrapping of a fiber instead of a yarn Know the effect of the amount of twist on yarn low high crepe Low twists are softer more textured larger and less abrasion resistance High twists are more firm smoother resilient more soil resistant and resistant to snagging and abrasion Crepes have extremely high twists and start to kink which creates a yarn without a smooth surface very wrinkle resistant and a random weave structure Know the difference between the direct and indirect methods of measuring the size of yarn What is denier What is a yarn count A direct method of measuring refers to the fixed length of yarn being weighed One method is the dernier system based on weight in grams of 9000 meters The higher the dernier numbers designate heavier thicker yarn For example 1 dernier yarn is a yarn that 9 000 meters if weighed would equal one gram Indirect methods are based on a fixed weight of yarn or how much length it would take to get that weight The higher number the finer the yarn used mainly for staple yarns The yarn count system states the number of hanks of specific length spun from a POUND of fiber Chapter 14 Manufacturing Yarns What is a texturized filament yarn A mechanical or thermomechanical process that is done to a yarn that can add bulk resiliency softness and or provides stretch How is it done Mechanically filaments are tangled into loops air jet Thermomechanically filaments are stretched twisted and heated What are the advantages of texturized yarns Adds bulk resiliency and softness and provides stress Less expensive than cutting and spinning What is the difference between carding and combing fibers Which is more expensive Why With carding drums with fine bent wires separate and align fibers Combing is a comb that arranges the fiber into parallel alignment This method is more expensive because it adds an extra step and requires special equipment but it is better quality What is drawing when it refers to preparation of staple fibers for spinning Drawing is the next step after carding combing The fibers are put through rollers which forms a long smooth strand of fibers called a sliver What is the difference between the woolen and worsted system for preparing and spinning wool What would be appropriate end uses for each of these types Worsted wool is combed whereas woolen is carded Woolen will be warmer and is better for sweaters and worsted is better for suits because it is sleek and lustrous What is the difference between ring spinning and open end spinning What are the advantages of each Ring spinning is drawn out thinner through the ring and then onto the bobbin It is higher quality but is slower and more expensive to make In open end spinning fibers are separated into a thin stream by a rotary beater Eventually drawn off to become attached to open end of already formed yarn It is faster and cheaper but is rougher and weaker What are slit film yarns They are made from films where slits are made along the length of the ribbon Chapter 15 Fabrics and Related Structures How is the weight of fabric determined Expressed as ounces per square yard 1 ounce is very sheer What constitutes light top weight medium bottom weight and heavy weight fabrics 2 4 ounces is top weight shirts blouses 5 7 ounces is bottom weight skirts slacks and 9 11 ounces is heavy weight men s jeans Chapter 16 Woven Fabrics What is a loom What does it do Device on which woven fabrics are produced What are the warp and filling weft yarns Why do the warp yarns need to be smooth and strong Warp yarns are those that you put onto the loom and must be strong to withstand high tension and abrasion Weft yarns are those interlaced with the warp What is a fabric thread count How is it measured The number of warp and filling count in a square inch What is a balanced weave structure The number of warp and filling threads is the same What are the selvages of the fabric Side edges of a fabric What is the grain of fabric Why is it important Angle of intersection between warp and weft Off grain will cause the finished textile to hang unevenly What are the different steps or motions in weaving Shedding picking beating and taking up letting off Chapter 17 Weaves Know the weave structures o o o Plain weave and variations simplest and most economical over one and under one burlap tweed crash muslin percale hopsacking batiste gingham chambray basket and rib weaves Rib weaves are unbalanced with fine yarns crossing over thicker ones Twill weaves the warp and filling yarns are interlaced so that a diagonal pattern is formed herringbone hound s tooth and denim are examples Satin weaves yarns float over a number of yarns from the opposite direction producing a smooth lustrous finish Pile weaves fabrics with cut or uncut loops which stand up densely on the surface Jacquard weaves made on jacquard looms Combines plain twill and satin weaves often in the same row Leno weave open gauzelike construction paired warp yarns twisted around a filling yarn o o Double weave uses two or more sets of yarns cloth is more