Textiles section

National Safety Council, Textile Section. C. J. Hyslup, chairman, Elkin, N. C. 

This chapter wUl be presented in two sections plasma technologies for textile applications (Section 2.2) and laser technologies for textiles (Section 2.4). 

Cross-sectional area or fiber fineness also affects textile processing efficiency and the quatity of the end product. The number of fibers in a cross section of yam of a given size is related to fiber fineness, that is, the smaller the fiber cross section the more fibers will be needed in the yam. Other factors being equal, yam strength increases as the number of fibers in the yam cross section increases. However, fibers with too small a cross section caimot be processed efficiently. 

Gut Rubber. To produce cut mbber thread, smoked mbber sheet or crepe mbber is milled with vulcanizing agents, stabilizers, and pigments. This milled stock is calendered into sheets 0.3—1.3 mm thickness, depending on the final size of the mbber thread desired. Multiple sheets are layered, heat-treated to vulcanize, then sHt into threads for textile uses (Fig. 2). Individual threads have either square or rectangular cross-sections. 

In the Philippines, the principal suppHer of abaca fiber, the fibrous layer ia the sheath is separated with a knife between the layers, and the strips of fiber-containing layers, called tuxies, are pulled off and cleaned by hand to remove the pulp. In Indonesia and Central America these operations are performed mechanically. Hand- and spiadle-stripped fiber is graded for braids, fine textiles, and cordage decorticated fiber is another class. A cross-sectional view is shown ia Figure 4a. The abaca fiber has a large lumen and the presence of siUcified plates is not unusual. 

Transverse Dimensions or Fineness. Historically, the quantity used to describe the fineness or coarseness of a fiber was the diameter. Eor fibers that have irregular cross-sections or that taper along their lengths, the term diameter has no useful meaning. Eor cylindrical fibers, however, diameter is an accurate measurement of the transverse dimension. Though textile fibers can be purchased in a variety of cross-sectional shapes, diameter is stiU a useful descriptor of the transverse dimension. Eiber diameter is important in determining not only the ease with which fibers can be twisted in converting them to yams, but also fiber stiffness, ie, fabric stiffness, and, alternatively, fabric softness and drapeabiHty. 

Textile fibers must be flexible to be useful. The flexural rigidity or stiffness of a fiber is defined as the couple required to bend the fiber to unit curvature (3). The stiffness of an ideal cylindrical rod is proportional to the square of the linear density. Because the linear density is proportional to the square of the diameter, stiffness increases in proportion to the fourth power of the filament diameter. In addition, the shape of the filament cross-section must be considered also. For textile purposes and when flexibiUty is requisite, shear and torsional stresses are relatively minor factors compared to tensile stresses. Techniques for measuring flexural rigidity of fibers have been given in the Hterature (67—73). 

In fine wool such as that obtained from merino sheep, the cuticle is normally one cell thick (20 x 30 x 0.5 mm, approximate dimensions) and usually constitutes about 10% by weight of the total fiber. Sections of cuticle cells show an internal series of laminations (Figs. 1 and 2) comprising outer sulfur-rich bands known as the exocuticle and inner regions of lower sulfur content called the endocuticle (13). On the exposed surface of cuticle cells, a membrane-like proteinaceous band (epicuticle) and a unique hpid component form a hydrophobic resistant barrier (14). These hpid and protein components are the functional moieties of the fiber surface and are important in fiber protection and textile processing (15). 

Poly(vinyl acetate) is too soft and shows excessive cold flow for use in moulded plastics. This is no doubt associated with the fact that the glass transition temperature of 28°C is little above the usual ambient temperatures and in fact in many places at various times the glass temperature may be the lower. It has a density of 1.19 g/cm and a refractive index of 1.47. Commercial polymers are atactic and, since they do not crystallise, transparent (if free from emulsifier). They are successfully used in emulsion paints, as adhesives for textiles, paper and wood, as a sizing material and as a permanent starch . A number of grades are supplied by manufacturers which differ in molecular weight and in the nature of comonomers (e.g. vinyl maleate) which are commonly used (see Section 14.4.4)... 

In 1997 it was estimated that global production of PET was about 16.7 X 10 t.p.a., of which 12 million tonnes was used in textiles, 2 million tonnes for audio and video film (with a small quantity for technical mouldings) and 3 million tonnes for packaging, particularly bottles. The tremendous growth in the bottles market from zero in the late 1970s to 1.5 million tonnes in the USA alone in 1998 is, in consumption terms, one of the most spectacular examples of growth in plastics materials in recent times and will be considered later in this section. 

This section provides an overview of the synthesis of dyes and pigments used in textiles and related industries. Dyes are soluble at some stage of the application process, whereas pigments, in general, retain essentially their particulate or crystalline form during application. A dye is used to impart color to materials of... 

A common supply air unit used as an air shower has a flat underside covering an area over rhc workplace with a typical size approximately 1 m (Fig. 10.49). Another type of unit is shaped as a half sphere, distributing the air over an area much bi er then the cross-section of the unit (Fig. 10.490L Other iype,s of supply air units such as a textile tube may be used for the same purpose. 

Azo-coupled products are widely used as dyes for textiles because their extended conjugated tt electron system causes them to absorb in the visible region of the electromagnetic spectrum (Section 14.9). / -(Dimethylamino)azobenzene, for instance, is a bright yellow compound that was at one time used as a coloring agent in margarine. 

Carbon-Fiber Electrodes The growing interest in ultramicroelectrodes (Section 4-5.4) has led to widespread use of carbon fibers in electroanalysis. Such materials are produced, mainly in connection with the preparation of high-strength composites, by high-temperature pyrolysis of polymer textiles or via... 

This chapter will cover sulfosuccinate monoesters and diesters. The monoesters are best used in cosmetics and toiletries the diesters—especially those based on 2-ethylhexanol—play an important role in, for example, the textile industry due to their outstanding wetting activities [5]. Sulfosuccinamates and sulfosuccinamides are consumed in technical fields like emulsion polymerization. The next section discusses the historical development of the sulfosuccinates. 

Polonium is a radioactive, low-melting metalloid. It is a useful source of a particles (helium-4 nuclei they are described in more detail in Section 15.11) and is used in antistatic devices in textile mills the a particles reduce static by counteracting the negative charges that tend to build up on the fast-moving fabric. 

Chlorine is used in a number of industrial processes, including the manufacture of plastics, solvents, and pesticides. It is used as a bleach in the paper and textile industries and as a disinfectant in water treatment (Section 15.6). 

There are various textbooks available on the calendering process,which is referred for an extensive explanation. In this section the impact of the presented theory on the general layout of a dual-purpose calendering line for textile cord and steel cord coating is considered. 

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