Fiber,YarnandFabric.ppt

FIBER, YARN AND FABRIC ------------ General Introduction WHAT IS A FIBER? All textiles are made up of fibers. Properties: High length to diameter ration, fineness and flexibility A certain level of strength Extensibility and elasticity Resistance to chemicals, heat and sunlight Ability to be colored COTTON kidney-bean shaped with a lumen the twists reverse in direction along the length The most outer layer of the cotton fibre is the cuticle covered with waxes and pectins and this surrounds a primary wall, built of cellulose, pectins and proteinic material. BAST AND LEAF FIBERS ramie flax linen jute HEMP longitudinal section cross section WOOL The finer the wool, the more the crimp. Wool fibres are roughly oval in cross-section and grow in a more or less wary form with a certain amount of twist. The finer the wool, the more the crimp.Keratin is a complex protein and is amphoteric in nature. so wool can be dyed with acid or reactive dyes. 羊毛纤维的横切面近似椭圆形，生长过程中形成或多或少的卷曲，带一定捻度，越细越卷曲。同时，羊毛的质量越高，卷曲度越高。 SILK silkworm moth cocoon SILK PROPERTIES Length: 1000-1300 yds (915-1190 m)/cocoon Max 3000yds (2750m)/cocoon, 1 fiber/cocoon. Fineness：2.8-3.9dtex (Bombyx mori) Absorbency: 8-9%(High heat of wetting) Medium tenacity but higher than wool High luster high crystallinity and triangular cross-sectional shape. drapability Scroop(丝鸣): rustling sound due to an acid treatment that hardens fiber surface. Lowest UV light resistance: avoid prolonged exposure to sunshine In order to prevent silk yarn from breaking up in weaving process, the silk filaments are usually produced in the form of yarn by combining reeled strands from several cocoons together by giving a certain twist to hold them and the gum existing on silk helps to hold the strands together. The degree of crystallinity of silk is about 65%-70%. The degree of polymerization of silk fibroin is uncertain, with DP of 300 to 3000 having been measured in different solvents. 为了防止蚕丝在织布过程中