Textile Fibers

(natural fibers), extended flexible, strong bodies of small lateral dimensions and limited length; useful in manufacturing yarn and textiles. Textile fibers that cannot be divided longitudinally are called elementary, and those consisting of several elementary fibers joined lengthwise are called industrial (conjugate) fibers. Elementary textile fibers of considerable length are called elementary filaments. Almost all textile fibers consist of high-molecular-weight substances. A characteristic feature of the structure of textile fibers is the presence of longitudinal structural elements (fibrils or layers). Some textile fibers have channels and are bent or twisted. (A classification of the main varieties of tex-tile fibers is shown in Figure 1.)

Along with natural textile fibers, which are formed in nature in various parts of plants, on animal skins, in minerals, and in other sources, chemical fibers, which are produced industrially, are also widely used.

The bulk of textile fibers is processed into yarn, which is used in the manufacture of fabrics, knitwear, spun fabrics, haberdashery articles, and other products. Felt, cotton, and a large portion of nonwoven products are made directly from textile fibers. The world production of textile fibers, including the USSR and other socialist countries, is listed in Table 1, and the production of the main types of textile fibers in the USSR is shown in Table 2.

The most important, widespread, and inexpensive textile fiber is cotton, a strong, thin, and hygroscopic fiber. It develops on the seeds of the cotton plant. Cotton yarn is used for the production of consumer fabrics for undergarments and clothing and for the production of industrial fabrics, various knitted goods, and sewing thread; cotton is used for the production of wadding and nonwoven fabrics.

Bast fibers are produced from the stems, leaves, and fruit of plants, usually in the form of industrial fibers. The thinnest stem fiber, flax, is very strong and resistant to stretching and is hygroscopic. Flax yarn is used for the production of packaging, undergarments, clothing, and indus-trial fabrics. Flax waste (short fiber) is used for the production of packaging fabrics, ropes, and other materials. Hemp, a coarse stem fiber, is obtained from the hemp plant and is used for the production of rope and coarse fabrics. The most widespread coarse stem fiber is jute, which is used for the

Figure 1. Textile fibers

preparation of bags for sugar and other materials. Kenaf has properties similar to those of jute. Hemp, manila, and sisal, which are stiff leaf fibers, are also widely used for the production of rope.

Wool, the fiber of the hairy cover of sheep, goats, camels, and other animals, is a valuable textile fiber that has high elasticity, hygroscopicity, and thermal insulation properties. Wool is used mainly for the production of yarn for suits,

dresses, coats, industrial fabrics, and knit outerwear. Wool may be felted, which makes possible its use in the production of felt goods (felts, felt boots, hats, and other articles). “Factory” wool, which is obtained from the skins of slaughtered animals, and “utility” wool, which is produced by picking apart rags, waste yarn, and other materials, are used in small quantities.

Raw silk consists of filaments obtained by unwinding co-coons and is used directly or after braiding, mainly in the production of fabrics for dresses and undergarments, as well as industrial fabrics. Picking silk waste yields silk fibers, which are processed into yarn. This yarn is used for the production of linen and pile fabrics.

Asbestos (mineral textile fibers) is used for the production of yarn for industrial fabrics (fire-resistant, filtration, and so on).

Natural textile fibers are used in pure form, as well as in blends (for example, wool-cotton)–most often with staple fibers. Blending improves the properties by combining the valuable properties of the components, reduces the mill cost, and makes it possible to achieve a variety of external effects.

The most important properties of textile fibers are summarized in Table 3.

A special place among the textile fibers is occupied by glass fibers and filaments, which are being widely used industrially as electrical, heat, sound, and other types of insulation; as filtration mediums; as fire-resistant products; and in the production of glass-fiber reinforced plastics and other materials.