Textile materials yarn processing

Wool fibres may be subjected to fullering - the fibres are treated with an appropriate agent (traditionally mercury compounds were used), which causes the individual scales on the fibre to stand proud of the surface, causing adjacent fibres to become entangled, and increasing the bulk of the material. The process can be employed to make non-woven woollen textiles (i.e. felt), but is also employed to modify the properties of fibres used for yarns and fabrics, and can give a durability to wool fabrics that is not found in the individual fibres. 

Fibers, yarns, threads, cords, rope, cloth and other fabricated textile materials and the methods of test, terminology, and definitions relating thereto Textile industry raw materials, auxiliaries and chemical products required for processing and testing... 

Textile materials can be produced by a whole series of processes, for example, by weaving, knitting, or by fleece formation. Knitted fabrics have stronger elasticity than weaves and this was first used in the manufacture of wool jerseys and later found extensive application in what are known as double knits from polyester yarns. Fibers and filaments can also be made more elastic by a whole series of mechanical procedures such as, for example, crimping or giving a false twist to the yarn. 

Conditioners n. A process of allowing textile materials (staple, tow, yarns, and fabrics) to reach hygroscopic equilibrium with the surrounding atmosphere. Materials may be conditioned in a standard atmosphere (65% RH, 70°F) for testing purposes or in... 

Multiple production stages are necessary for the manufacture of fibers, yarns, and textiles. Figure 1.5 gives an overview of raw materials and processing steps. 

The natural fibers obtained from cotton, wood, flax, hemp, and jute all are cellulose fibers and serve as raw materials for the textile and paper industries. In addition to its use as a natural fiber and in those industries that depend on wood as a construction material, cellulose is used to make cellulose acetate (for making rayon acetate yarn, photographic film, and cellulose acetate butyrate plastics), nitric acid esters (gun cotton and celluloid7), and cellulose xanthate (for making viscose rayon fibers). The process by which viscose rayon is manufactured involves converting wood pulp or cotton Iinters into cellulose xanthate by reaction with carbon disulfide and sodium hydroxide ... 

While some of the Mississippian textiles are of similar structure to the Middle Woodland textiles, others are very complex materials and are lace-like in appearance. Many of the materials from Etowah are preserved by mineralization, and display green-colored deposits on their surfaces. Bast fiber, rabbit hair, and feathers have been identified (2, 11). The textiles from these two sites selected for analysis are representative of the complexity of structure and fineness of yarns seen in the materials they provide evidence of the sophisticated technology of prehistoric people in all phases of fiber collection, processing, yarn spinning, fabric manufacture and, when present, coloration. 

Functional fibres, filaments and yams are the basic building blocks of electrotextiles. The textile industry has demonstrated a remarkable capability to incorporate both natural and man-made filaments into yarns and fabrics to satisfy a wide range of physical parameters which survive the manufacturing process and are tailored to specific application environments. Electronic components can be fabricated within and/or on the surface of filaments and can subsequently be processed into functional yams and woven into fabrics. Passive components such as resistors, capacitors and inductors can be fabricated in several different manners. Diodes and transistors can be made on long, thin, flat strands of silicon or formed in a coaxial way. Progress has been made in the development of fibre batteries and fibre-based solar cells. In addition, a variety of actuated materials (piezoelectric, etc.) can be made into multiple long strands (filaments) and subsequently be woven into fabric. 

PAN, a synthetic fiber, is a polymer of acrylonitrile monomers. Worldwide, 2.73 million tons of PAN are produced per year, of which over 98% are processed as filament yarn serving as material in the textile industry (Tauber et al., 2000). PAN usually has a molecular weight of 55,000-70,000 g mol and is most commonly a copolymer produced by radical polymerization from acrylonitrile, 5-10 mol% vinyl acetate (or similar nonionic comonomers) to disrupt the regularity and crystallinity, and ionic comonomers, such as sulfuric or sulfonic acid salts. PAN is a hydrophobic polymer that affects the processability of the fibers. The surface is not easily wetted. 

The paper and textile industries have been concerned about the aging, deterioration, and degradation of cellulosic materials at elevated temperatures for practical reasons, such as the performance of tire yarn and electrical insulation paper, and the problems involved in drying or processing the cellulosic materials in general. However, due to the practical nature of these problems, the reactions involved have often been measured in terms of loss of strength and other physical properties. 

The fibers or the yarn or rovings made therefrom can be processed to fleeces or mats (non-oriented semi-finished product) and textiles, lattices or meshes (oriented semifinished products) and can be utilized as such e.g. for thermal insulation or as filter materials, or in composites with other materials e.g. for fiber-reinforced polymers, metals or ceramics. Fibers are generally marketed after surface treatment (chemical modification, annealing, smoothing) to optimize their application and processing properties. 

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