Fiber is a hairlike strand of a substance that is extremely long in relation to its width. A fiber is at least 100 times longer than it is wide. Fibers are flexible and may be spun into yarn and made into fabrics. A fiber is the smallest visible unit of any textile product. Manufacturers use fibers in clothing and in such home furnishings as carpets, drapes, and upholstery. They also use fibers in many industrial products, including parachutes, fire hoses, insulation, and tires. In medicine, fibers are used to make artificial arteries and tendons.
Some fibers occur in nature, and others are manufactured. Most natural fibers come from plants and animals. These fibers include cotton, flax, silk, and wool. There are two types of manufactured fibers. Regenerated fibers come from natural materials, but manufacturers must process the materials to form a fiber structure. Synthetic fibers are made entirely from chemicals.
No one knows when human beings learned to spin natural fibers into yarn to make fabrics. The earliest evidence of fabric is a fragment of linen found in what is now southern Turkey, dated between 8000 and 7000 B.C. Wool fabrics date from about 6000 B.C. Cotton was first used about 3000 B.C. The Chinese discovered silk about 2640 B.C. Rayon, the first practical manufactured fiber, was developed in 1884. See Textile (History).
All natural fibers except silk range from about 1/2 inch to 8 inches (1.3 to 20 centimeters) in length. A silk fiber’s length depends on the size of the silkworm’s cocoon. Fibers of limited length are called staple fibers. Textile mills spin these fibers into yarn. Manufactured fibers have no limit in length. Machines produce them in long, continuous strands called continuous filaments. Manufacturers may use a single filament to make a monofilament yarn. They may also draw (pull) many filaments together to produce one multifilament yarn. When manufacturers blend synthetic fibers with natural ones, they must first cut the synthetic fibers into staple lengths.
The properties of a particular fiber depend on its chemical composition and physical structure. Manufacturers use fibers that have properties suited to their products. For example, fibers used in clothing must feel pleasant to the touch, be water absorbent, have a good luster, and drape to fit the body. For industrial use, a fiber’s strength and durability are important. One fiber, SPECTRA-900, is 10 times stronger than steel. Another class of fibers, spandex, can stretch like rubber.
Natural fibers
Natural fibers come mainly from plants and animals. They account for more than half the fibers produced in the world yearly.
Plant fibers.
Cotton is the most widely used natural fiber. Cotton mills spin staple fibers from cotton bolls (seed pods) into yarns for clothing, and for household and industrial fabrics. Cotton cloth is absorbent, soft, and comfortable to wear. Flax, a strong fiber from the stems of flax plants, is used to make clothing and linen products. Hemp, jute, and sisal are coarse plant fibers used in cords, ropes, and rough fabrics.
Animal fibers
include fur and hair. Wool, the hair of sheep and certain other animals, is popular in clothing and home furnishings. Wool fibers have a scalelike surface that resembles shingles on a roof. Manufacturers mat wool fibers together in a process known as felting. This process produces air pockets within the matted fibers. Air trapped in these pockets acts as an insulator that helps keep the wearer warm. Silk is the strongest natural fiber. Manufacturers unwind silk filaments from silkworm cocoons and make silk yarn for clothing and decorative fabrics.
Manufactured fibers
The study of plastics has helped chemists learn how to combine chemicals to create synthetic polymers (long, chainlike molecules)with specific properties, including the ability to be shaped into fibers. The variety and qualities of manufactured fibers make them popular with consumers and manufacturers. See Textile (table: Manufactured fibers).
Machines melt synthetic polymers or mix them in solvents (substances that dissolve other substances) to create a liquid. The machines then force streams of the liquid through tiny holes in a device called a spinneret. The streams harden into filament fibers that are drawn and wound onto spools or cut into staple lengths.
Regenerated fibers
are also called cellulosics because they are derived from cellulose, a polymer found in plant cells. Manufacturers process wood pulp to make such cellulosics as rayon. Rayon has many properties that resemble those of cotton. Using a production method called acetylation, manufacturers chemically convert cellulose to produce acetate, a fiber silkier than rayon. Rayon and acetate are used in clothing. Manufacturers use industrial versions of rayon to make yarns for tires.
Synthetic fibers
are manufactured from chemicals. Most are stronger than either natural or regenerated fibers. Synthetic fibers, as well as the regenerated fiber acetate, are thermoplastic (softened by heat). Manufacturers shape these fibers at high temperatures, adding such features as pleats and creases. These fibers will melt if touched with too hot an iron. The most widely used kinds of synthetic fibers are (1) nylon fibers, (2) polyester fibers, (3) acrylic fibers, and (4) olefin fibers.
Nylon fibers,
or polyamide fibers, were the first synthetic fibers. Fabrics made from strong, lightweight nylon fibers are used in such products as windbreakers and tents. Nylon fibers are also widely used in carpets, hosiery, and ropes.
Polyester fibers
are durable and quickly regain their shape after being stretched or wrinkled. They are used in clothing and bedding. Many garments contain a blend of polyester and cotton fibers. The polyester fibers provide wash-and-wear characteristics, and the cotton fibers make the fabrics comfortable to wear. Manufacturers also use polyester fibers in filters, sails, tires, and other industrial fabrics.
Acrylic fibers
are soft and durable. A number of acrylic yarns resemble wool and are used in clothing, especially sweaters. Many artificial furs also are made from acrylic fibers.
Olefin fibers
are strong and resist stains. These properties make olefin fibers useful in carpets, upholstery, and ropes.
Other synthetic fibers.
Yarns called Lastex are made from synthetic elastic fibers wrapped in cotton, nylon, or other fibers. Lastex and spandex enable garments to hold their shape and return to their original size after being stretched. Special metal treatments produce metallic fibers, such as gold and silver filaments, that can be used to decorate fabrics.
