cotton
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cotton,
most important of the vegetable fibers, and the plant from which the fiber is harvested.The Cotton Plant
The cotton plant belongs to the genus Gossypium of the family Malvaceae (mallowmallow,
common name for members of the Malvaceae, a family of herbs and shrubs distributed over most of the world and especially abundant in the American tropics. Tropical species sometimes grow as small trees.
..... Click the link for more information. family). It is generally a shrubby plant having broad three-lobed leaves and seeds in capsules, or bolls; each seed is surrounded with downy fiber, white or creamy in color and easily spun. The fibers flatten and twist naturally as they dry.
Cotton is of tropical origin but is most successfully cultivated in temperate climates with well-distributed rainfall. All western U.S. cotton and as much as one-third of Southern cotton, however, is grown under irrigation. In the United States nearly all commercial production comes from varieties of upland cotton (G. hirsutum), but small quantities are obtained from sea-island and American-Egyptian cotton (both belonging to the species G. barbadense). G. arboreum and G. herbaceum are the chief cultivated species in Asia.
Cotton is classified in the division MagnoliophytaMagnoliophyta
, division of the plant kingdom consisting of those organisms commonly called the flowering plants, or angiosperms. The angiosperms have leaves, stems, and roots, and vascular, or conducting, tissue (xylem and phloem).
..... Click the link for more information. , class Magnoliopsida, order Malvales, family Malvaceae.
Planting and Production
Cotton is planted annually by seed in furrows; the plants are thinned and weeded during the spring growing season. Diseases and insect pests are numerous; of these the most destructive has been the boll weevilboll weevil
or cotton boll weevil
, cotton-eating weevil, or snout beetle, Anthonomus grandis. Probably of Mexican or Central American origin, it appeared in Texas about 1892 and spread to most cotton-growing regions of the United States.
..... Click the link for more information. , which has caused enormous losses. Genetically altered strains of cotton are being developed that can resist infestation by some insects and damage by application of herbicides.
Mechanical harvesting is preceded by a chemical-defoliant spray to remove the leaves, leaving only the cotton bolls. In the ginhouse the cotton is separated from the seeds by a cotton gincotton gin,
machine for separating cotton fibers from the seeds. The charkha, used in India from antiquity, consists of two revolving wooden rollers through which the fibers are drawn, leaving the seeds. A similar gin was early used in the S United States for long-staple cotton.
..... Click the link for more information. and then baled. The usual plantation bale, weighing 500 lb (227 kg), is covered with jute and bound with iron hoops. The U.S. Dept of Agriculture has established standards for grades of cotton. The manufacture of cotton cloth involves many processes—cardingcarding,
process by which fibers are opened, cleaned, and straightened in preparation for spinning. The fingers were first used, then a tool of wood or bone shaped like a hand, then two flat pieces of wood (cards) covered with skin set with thorns or teeth.
..... Click the link for more information. , combingcombing,
process that follows carding in the preparation of fibers for spinning, lays the fibers parallel, and removes noils (short fibers). The modern combing machine is a specialized carding machine.
..... Click the link for more information. , and spinningspinning,
the drawing out, twisting, and winding of fibers into a continuous thread or yarn. From antiquity until the Industrial Revolution, spinning was a household industry. The roughly carded fiber was at first held in one hand and drawn out and twisted by the other hand.
..... Click the link for more information. —which transform raw fiber into yarn or thread strong enough for weaving.
Uses of Cotton
Innumerable commodities are made from cotton. From the lint (the fiber separated from the seed) come the major products, chiefly textiletextiles,
all fabrics made by weaving, felting, knitting, braiding, or netting, from the various textile fibers (see fiber). Types of Textiles
Textiles are classified according to their component fibers into silk, wool, linen, cotton, such synthetic fibers as
..... Click the link for more information. and yarnyarn,
fibers or filaments formed into a continuous strand for use in weaving textiles or for the manufacture of thread. A staple fiber, such as cotton, linen, or wool, is made into yarn by carding, combing (for fine, long staples only), drawing out into roving, then spinning.
..... Click the link for more information. goods, cordage, automobile-tire cord, and plastic reinforcing. The linters (short, cut ends removed from the seed after ginning) are a valuable source of cellulosecellulose,
chief constituent of the cell walls of plants. Chemically, it is a carbohydrate that is a high molecular weight polysaccharide. Raw cotton is composed of 91% pure cellulose; other important natural sources are flax, hemp, jute, straw, and wood.
..... Click the link for more information. . Cotton hulls are used for fertilizer, fuel, and packing; fiber from the stalk is used for pressed paper and cardboard.
Production of the chief byproduct, cottonseed oil, has grown into a separate industry since its establishment in the late 19th cent. The oil content of cotton seeds is about 20%. After being freed from the linters, the seeds are shelled and then crushed and pressed or treated with solvents to obtain the crude oil. In its highly refined state, cottonseed oil is employed as salad and cooking oil, for cosmetics, and especially in the manufacture of margarine and shortenings. Paint makers use it to some extent as a semidrying oil. Less refined grades are used in the manufacture of soap, candles, detergents, artificial leather, oilcloth, and many other commodities. Cottonseed oil is increasingly important to cotton growers as cotton fiber meets competition from cheaper and stronger synthetic fibers.
History
Early History
Cotton has been spun, woven, and dyed since prehistoric times. It clothed the people of ancient India, Egypt, and China. Hundreds of years before the Christian era cotton textiles were woven in India with matchless skill, and their use spread to the Mediterranean countries. In the 1st cent. Arab traders brought fine muslinmuslin,
general name for plain woven fine white cottons for domestic use. It is believed that muslins were first made at Mosul (now a city of Iraq). They were widely made in India, from where they were first imported to England in the late 17th cent.
..... Click the link for more information. and calicocalico,
plain weave cotton fabric in one or more colors. Calico, named for Calicut, India, where the fabric originated, was mentioned by historians before the Christian era and praised by early travelers for its fine texture and beautiful colors.
..... Click the link for more information. to Italy and Spain. The Moors introduced the cultivation of cotton into Spain in the 9th cent. Fustians and dimities were woven there and in the 14th cent. in Venice and Milan, at first with a linen warp. Little cotton cloth was imported to England before the 15th cent., although small amounts were obtained chiefly for candlewicks. By the 17th cent. the East India Company was bringing rare fabrics from India. Native Americans skillfully spun and wove cotton into fine garments and dyed tapestries. Cotton fabrics found in Peruvian tombs are said to belong to a pre-Inca culture. In color and texture the ancient Peruvian and Mexican textiles resemble those found in Egyptian tombs.
Effect of the Cotton Gin
The invention (1793) of the cotton gin, a machine for separating seeds from fiber, and the mechanization of textile production in the Industrial Revolution enabled cotton to supersede flax and wool textiles. Cotton has played a significant role in history. Britain's need for imported cotton fiber encouraged its accession to the Monroe Doctrine; Britain's need for vast African and Indian markets for its cotton manufactures influenced its role as an imperial sea power. Beginning in North America in the Jamestown colony (1607), cotton cultivation became the basis of the one-crop, slave-labor economy of the Deep South and a principal economic cause of the Civil War. The end of slavery and the exhaustion of the soil pushed the Cotton Belt to the west. The demand for and production of cotton in the 19th cent. also provided impetus for the development of global capitalism.
Cotton Production Today
Today the leading cotton states are Texas, Georgia, Mississippi, Arkansas, North Carolina, and Louisiana. From the early days of the republic until recent years the United States was the world's leading cotton producer and second only to Great Britain in the manufacture of cotton goods. China now is the leading cotton-producing country, followed by the United States and India. Other important cotton producers are Pakistan, Brazil, Uzbekistan, and Turkey. China and India are the leading cotton manufacturers, followed by the United States, where cotton mills have relocated from New England to the Southern cotton-producing states. Historically, all cotton-producing nations have depended on cheap labor; although mechanical cultivating and picking devices have long been known, they have been widely used (especially in the United States) only since World War II.
Bibliography
See J. M. Munro, Cotton (2d ed. 1987); C. W. Smith and J. T. Cothren, ed., Cotton (1999); G. Riello, Cotton (2013); S. Beckert, Empire of Cotton (2014).
Cotton
Cotton
the fibers that cover the seeds of the cotton plant (Gossypium). When the plant matures, the fiber is harvested without removing the seeds; the harvested product is called seed cotton. During initial processing at gins, the seeds are separated to produce successively fibers mostly longer than 20 mm, fibers less than 20 mm long, and short fibers less than 5 mm long. The first category accounts for about one-third of the total mass of the seed cotton. Cotton is the most inexpensive and common type of textile fiber. It accounts for approximately 50 percent of the world production of textile fibers.
In Russian technical literature until the second half of the 19th century, the term khlopchataia bumaga (literally “cotton paper”) was used for cotton fiber instead of the current term khlopok. The adjectival derivative khlopchatobumazhnyi is still used, for example, in reference to the cotton industry and cotton fabric. In modern technical literature, the terms khlopok-volokno (“lint cotton”) and khlopok-syrets (“seed cotton”) are usually used instead of khlopok.
Cotton pressed into prism-shaped bales is delivered to spinning mills. In addition to fiber suitable for processing, the bale cotton contains various defective cotton fibers and contaminants, which reduce the quality of the cotton because they make the spinning process more difficult, decrease the output of yarn, and spoil the yarn’s appearance. The amount of waste material in cotton fiber depends primarily on the methods used for harvesting the seed cotton and for primary processing, but also on the cotton plant variety and the conditions of growth.
Cotton defects differ in degree of harmfulness and may be classified in three groups. First are fiber defects—tangles (packed and intertwined bundles of fibers) and flattened clusters of immature fibers. Such defects are broken into fiber by opening and carding machines during spinning. Most of the defective pieces are converted to yarn, and the rest become waste material. The second group of defects includes immature and crushed seeds and contaminants (parts of leaves, bolls, and branches of the cotton plant). During the spinning process they are separated into waste, which reduces the yarn output and makes the yarn more expensive. The third group includes the particularly undesirable defects—parts of seed husks with fibers and linters as well as very small clusters of tangled fibers. They are difficult to separate from the cotton, but they increase the thread breakage on the spinning machines and spoil the appearance of the articles produced.
Cotton is subdivided into two types, depending on the type of plant from which it is obtained and the most important qualitative characteristic, the fineness, or smallness of the cross section, of the fiber. The two classes are medium-fine and fine cotton; the latter has a longer and finer fiber. In the USSR fine cotton accounted for approximately 10 percent of the total production volume in 1976. It is produced from Soviet strains of fine-fiber cotton plants. All Soviet cottons are divided into seven grades, depending on breaking strength and degree of maturity: select (0), 1st, 2nd, 3rd, 4th, 5th, and 6th grades. In turn the cottons of grades 0 through 4 are subdivided into eight-types, depending on relative breaking strength and length. Cotton fiber of grades 5 and 6 is not subdivided into types.
Most cotton is processed for yarn; only a small portion of the cotton and linters is used to make medical garments, everyday apparel, furniture padding, and such products as packing and filters. Fibers shorter than 20 mm are also used in the chemical industry as a raw material from which synthetic fibers and yarns, films, lacquers, plastics, explosives, and other products are made.
Various textile products are made from cotton yarn, including fabrics, knitwear, nonwoven materials, sewing threads, twine, rope, and netting. Some textile goods are also produced from a blend of cotton with chemical and natural fibers.
REFERENCES
Osnovnye napravleniia razvitiia narodnogo khoziaistva SSSR na 1976–1980goda. Moscow, 1975.Kukin, G. N., and A. N. Solov’ev. Tekstil’noe materialovedenie, parts 1–2. Moscow, 1961–64.
Khafizov, I. K., and G. A. Tikhomirov. “Mirovoe proizvodstvo i potreblenie khlopka.” Tekstil’naia promyshlennost’. 1974, no 9.
A. N. SOLOV’EV