Cotton: Properties, Uses & Importance of the World's Leading Natural Fiber

Cotton

Introduction to Cotton

Cotton, a plant that yields the most important of all natural textile fibers. There are thousands of uses for cotton. A large part of the world's textile production is cloth made of cotton or blends of cotton and synthetic fibers. Cotton cloth is durable, easily laundered, and relatively inexpensive. The plant's seed provides edible vegetable oil and protein feed. Cotton also provides important raw materials for the chemical industry.

Cotton is one of the most important crops grown in the United States. Millions of people are supported directly and indirectly by the farms that grow it, the manufacturing concerns that process it, and the domestic and international marketing activities that distribute cotton products.

The world's leading cotton-producing countries and the leading cotton-producing states are shown in graphs later in this article. Most of the cotton produced in the United States comes from the Cotton Belt, a region about 2,300 miles (3,700 km) long and 700 miles (1,100 km) wide. It includes parts of North Carolina, South Carolina, Georgia, Alabama, Tennessee, Mississippi, Missouri, Arkansas, Louisiana, Oklahoma, Texas, New Mexico, Arizona, and California.

The Cotton Plant

The most common type of cultivated cotton is a woody plant that branches like a small tree and grows two to five feet (60–150 cm) high. The leaves are three to six inches (7.5–15 cm) wide, with three-pointed lobes. Cotton flowers look something like yellowish-white hollyhocks. They gradually turn red and fall off after three days, leaving the young fruit—a pointed, green capsule known as a boll ()—attached to the plant. It contains the young seeds and the valuable fiber for which the plant is grown.

The boll takes six to eight weeks to mature. It then splits into sections, opens wide, and releases a fluffy mass of fiber. In wild cotton, this mass serves as "wings" for the seeds, carrying them away on the wind. A large cotton plant may have more than 75 bolls. Each boll contains 30 to 35 brown or black seeds about the size of small peas.

Cotton fiber consists of slender, one-celled hairs that grow on the seed. The fibers vary in length from less than one inch (2.5 cm) to more than two inches (5 cm). When referring to fiber length, the term staple is used (as in "long staple" and "short staple"), the longer staples being considered the most desirable. Each mature fiber is shaped somewhat like a twisted ribbon. It is this spiral form that makes it possible to spin cotton. The spiral allows the fibers to interlock and hold the shape of the thread. The long fibers removed from the seed by the process of ginning are called lint cotton. The short, fuzzy remains that cling to the seeds after ginning are called linters.

Types of Cotton

There are more than 30 types of cotton plants, ranging from small shrubs less than one foot (30 cm) tall to trees more than 10 feet (3 m) high. Some of the better-known types are described below.

Sea Island Cotton,

with a staple of 1 3/8 to 2 1/2 inches (3.5–6.4 cm), has the highest quality fiber but its susceptibility to insect attack makes commercial production impractical. It is named for the Sea Islands (off the coast of the southeastern United States), where it was grown until the boll weevil halted production in the 1920's.

Egyptian Cotton

has yellowish fibers that are only slightly shorter than those of Sea Island cotton—1 1/2 to 1 3/4 inches (3.8–4.4 cm) long. This cotton is used in making thread, raincoats, underwear, and hosiery. An American type of Egyptian cotton, called American pima, is grown in the southwestern Cotton Belt under irrigation.

Upland Cotton

is the main type grown in the United States. It is also grown all over the rest of the cotton-producing world. The fibers are white, 3/4 to 1 1/2 inches (1.9–3.8 cm) long. The plant is 2 1/2 to 4 feet (75–120 cm) tall. It is native to Mexico and Central America.

Asiatic Cotton

has fibers less than one inch (2.5 cm) long and rather coarse in texture. It is grown mostly in India, Iran, China, and Russia.

Other Cottons of commercial importance include Peruvian cotton, with fuzzy, almost wool-like fibers, and Brazilian cotton, a perennial cotton with long, silky fibers. Levant, Mexican, and Jamaica cottons are wild varieties that may have been the early relatives of some modern varieties. Colored cotton has been produced by some agricultural experimenters, but cloth woven from it tends to fade in strong sunlight.

Raising and Harvesting Cotton

Climate and Soil

Cotton is a warm-weather crop that grows in the region between 40° north and 30° south of the equator. It requires moderate rainfall—a minimum of six to seven inches (150–175 mm) during the growing season. While the bolls are ripening, the climate should be drier. Six frost-free months are required for cotton growing. In tropical countries, cotton is a perennial. It grows to the height of 10 feet (3 m) and can be harvested all year round. In the far-western United States, cotton is grown on irrigated land.

The plant grows best in a fertile soil that contains some sand or clay. (Such soil is often found in valleys or near rivers.) Commercial fertilizers are applied to the soil in many areas to improve plant growth and increase yields.

Soil Preparation and Planting

In areas where cotton is an annual, rather than a perennial, stalks of the previous year's crop are cut up and plowed under before planting. Then the fields may be further prepared with a disk harrow. A bedding machine, usually drawn by a tractor, prepares the seedbed, and planting is done by machine. One, two, or four rows are planted at a time. In the southernmost United States, cotton is planted in March. Farther north, it is planted as late as May.

Cultivation

In some areas seeds are planted in continuous bands that must be thinned out when the plants spring up. However, most of the crop is planted in such a way that thinning, or "chopping," is not required. The young plants are cultivated by machine to kill weeds. Chemicals are also used, to prevent the growth of weeds.

Insect Enemies and Diseases

Cotton is subject to the attacks of many kinds of insects. Among these are the boll weevil, bollworm, pink bollworm, cotton fleahopper, red spider (spider mite), cotton aphid, and cotton stainer. The plants are dusted with insecticides several times during the season to kill pests. Rigid quarantines are used to prevent spread of the pink bollworm.

The fungus and bacterial diseases of cotton include root rot, fusarium wilt, bacterial blight, root knot, and anthracnose. These diseases are prevented by crop rotation, by use of fertilizers, by treating soil and seed with chemicals, and by planting varieties of cotton that resist disease.

Cotton Harvesting

Cotton requires about 200 days to mature. In much of the Cotton Belt the bulls begin opening in August and September. Although most of the cotton is harvested by machine, some is still gathered by hand. The most common method of hand harvesting is for workers to pick the lint from the open bolls. Since the bolls do not all mature at the same time, the fields must be gone over two or three times by the pickers. Another method of hand picking, called snapping, is to take the entire boll from the plant. It is faster than the common picking method, but can be used only with special varieties of cotton, and special gins are required to process the cotton.

The use of mechanical harvesters in the United States increased greatly after the end of World War II. The spindle-type mechanical picker uses vertical drums with revolving spindles to engage and pull the cotton from the open bolls. Since it does little injury to plants or unopened bolls, picking may be repeated as the younger bolls open. One machine can do the work of 30 to 40 hand pickers.

The stripper is used for mechanical snapping. These machines pull the boll from the plant with rollers, steel fingers, brushes, or other devices. A stripper harvests as much cotton as 20 laborers can by hand snapping.

Ginning Cotton

Lint cotton is separated from the seeds by a machine called a gin. A large pipe sucks freshly picked cotton from trucks or wagons into a tower, where it is dried if necessary. The dried cotton is fed through a series of rollers and toothed wheels that remove trash. The cotton is then conveyed to the gin stand, which removes the lint from the seed.

A typical gin stand consists of a gang of fine-toothed circular saws mounted on a revolving shaft and stationary bars placed between the saw blades. The saw teeth take the seed cotton up to the bars. The lint sticks to the teeth and passes through the bars. The seeds, too large to pass through, are separated from the lint and fall onto a conveyor belt. The lint is removed from the saw teeth by revolving brushes or by air pressure. It is then taken by pipe to be cleaned further, if necessary, and baled.

In a roller gin, used for some long-fiber cottons (such as Sea Island), the lint adheres to rollers and the seeds are separated from the lint by vibrating blades.

Ordinarily, lint cotton remains the property of the grower, while the seeds are purchased by the gin operator.

Lint Cotton

Marketing

After being ginned, lint cotton is pressed and baled at the gin in a continuous operation. A standard bale measures 28 by 56 by 45 inches (71 X 142 X 114 cm) and weighs 500 pounds (227 kg). It is wrapped in burlap and bound with metal bands.

There are more than 300 distinct qualities of cotton and the quality of a particular bale is a big factor in determining its value. Samples are drawn from bales and classed on the basis of grade (color, foreign matter content, and smoothness), fiber length, and character (fiber strength, fineness, pliability). About two-thirds of the United States cotton crop is classed by the U.S. Department of Agriculture through regional boards of cotton examiners. Much of the classing is done by comparing samples submitted by growers with official cotton standards.

Cotton may pass through the hands of several buyers before it reaches the mills. Some growers, however, sell directly to mills through cooperative associations.

Manufacturing Cotton Textiles

Raw lint cotton is made into yarn at a spinning mill and woven into fabric at a weaving mill; often, a single mill handles both processes. Originally, most textile mills were in New England. Today, the textile industry is centered in the Southeast.

Lint cotton goes through 4 to 16 separate manufacturing processes at the spinning mill. Those most commonly used are:

Opening and Cleaning

A single machine opens the bales and cleans, fluffs, loosens, and blends the compressed fibers. Another machine, called a picker, beats the fluffy cotton to loosen the fibers and force out impurities. The cotton leaves the picker in a soft, loose roll called a lap.

Carding or Carding and Combing

The short fibers are removed and the long fibers are made to lie parallel to each other. The cotton becomes a soft, untwisted rope called a sliver ().

Drawing

The slivers are run through rollers, making them longer and thinner.

Roving

A machine called a roving frame further thins and lengthens the slivers and twists them slightly until they become slender strings called roving.

Spinning

The roving is further thinned and twisted until it becomes yarn.

Warping, or Beaming

Hundreds of spools of yarn are wound into a single spool called a section beam. These spools are shipped to the weaving mill.

The weaving process is described in the article Weaving Woven fabrics are usually shipped to finishing mills in rolls or bales. The processing at the finishing mill may include bleaching, dyeing (some textiles, however, are dyed in the yarn), mercerizing, calendering, preshrinking, and printing. The textiles are then ready to be made into finished products.

The products made from cotton textiles are of three classes: (1) clothing; (2) household items, such as draperies, towels, tablecloths, and sheets; and (3) industrial products, such as machinery belts, tarpaulins, bags, upholsteries, thread, footwear, linings.

Cottonseed

Processing

Cottonseed is sold by the gin operator to a cottonseed oil mill. Here the seed is cleaned, then the linters are removed through further ginning. The seed is then sent to machines that separate the hulls from the kernel, or meat. The hulls are sacked for shipment and the meats are pressed or dissolved in chemicals to extract the oil.

Uses

The linters, hulls, and kernels each provide important products.

The Oil is the most valuable. It is used almost entirely as food, being processed into such products as shortening, cooking oils, salad dressings and oils, margarine, and high-protein flour, tn addition, cottonseed oil is used in making such non-food products as soap, paint, artificial leather, oilcloth, roofing, and candles.

Meal or Cake,

obtained from the kernels after the oil is extracted, is used primarily as livestock feed.

The Hulls

are also used as feed.

The Linters

have a number of uses. Made into a cellulose pulp, they are used in rayon, plastics, photographic film, explosives, paper, and lacquers. The better fibers are spun into coarse yarns. Others serve as filler in bedding and furniture.

History of Cotton

Archeologists digging in ruins in Pakistan have found traces of cotton fabrics and cotton string dating back to 3000 B.C. Excavations in Peru have uncovered cotton cloth dating back to 2500 B.C. Cotton fabrics were described by the Greek historian Herodotus in 500 B.C.

Cotton cultivation was brought from North Africa to Spain in 712 A.D. by the Moors. There, cotton manufacture in Europe began and gradually spread northward. By 1400, central Europe and the Low Countries were making fine fabrics with cotton imported mainly from the Middle East, where the best cotton was grown.

Early Spanish explorers in the New World found widely scattered native cultures using cotton cloth. The first cultivation of cotton by Europeans in the New World was by the Spanish in Florida.

Edward III of England brought Flemish weavers to Manchester in the 14th century. Their cloth soon became famous. Before 1700, most weaving was done in the home. In the mid-18th century, the Industrial Revolution contributed many inventions to the cloth manufacturing trade, and factory production of cotton goods developed.

Cotton In Early America

British colonists found that the climate of the southern American colonies was ideal for cotton growing. But because there were no mills in America, the raw cotton was sent to England. Cloth was woven there and resold in the colonies. The secrets of cotton manufacturing machinery were carefully guarded by the British to preserve this monopoly.

The cotton textile industry began in the United States in 1790, when Samuel Slater, who had worked in English mills, was able to reconstruct from memory the cotton-manufacturing machinery, at Pawtucket, Rhode Island. The growth of American mills, mostly run by water power, was rapid. Eli Whitney invented the cotton gin in 1793. Before the invention of this machine, cottonseed was separated from the lint by hand—a very slow process. One person could clean only about one pound (0.45 kg) of cotton a day. Whitney's gin could clean 50 pounds (23 kg) a day, making possible the widespread use of cotton cloth.

King Cotton

The South, with its slave labor, produced cotton cheaply and came to be called the Cotton Kingdom. Huge plantations of 2,000 acres (800 hectares) or more were the basis for the cotton economy. Most of the people of the South depended, either directly or indirectly, upon cotton for their living.

Cotton was one of the contributing factors leading to the Civil War. Plantation owners bitterly opposed a high tariff that protected the products of northern factories but not the raw materials exported from the South. "Cotton is king" became a Southern slogan, the planters erroneously believing that the North could not carry on a war without Southern cotton.

After the Civil War

Few plantations could survive without slave labor and many were broken up into small farms. They were worked by sharecroppers, or share tenants. The tenant paid the landlord a portion, usually a half, of the value of the crop for use of his land. The tenant supplied his labor and sometimes half the fertilizer, and generally received half the crop. This system was inefficient and the sharecroppers were often extremely poor. Nonetheless, it survived until the South began to become industrialized, during and after World War II. Since then, most of the former sharecroppers have left the farms to work in factories.

There have been two other major changes in the cotton industry since World War II. One is the greatly increased use of mechanical planting and harvesting equipment, resulting in greater efficiency. The second is the decline in the total acreage devoted to cotton. One reason for this decline is that synthetic fibers, paper, and other cotton substitutes have come into wide use. Another is that foreign production has increased greatly. A third reason is that many farmers have found it more profitable to diversify their crops. Instead of devoting all their land to cotton—which is subject to wide variations in price—they also raise other crops as well.

Aid to Cotton Farmers

Since about 1920 the cotton farmer has been receiving increasing attention from the federal government and private organizations. Agricultural colleges and the U.S. Department of Agriculture have developed better varieties of cotton and are constantly seeking better ways to grow and market the product. The National Cotton Council of America was organized in 1938 for the purpose of increasing consumption of cotton, cottonseed, and their products. Its program of research and promotion is financed by all branches of the cotton industry.

Federal agencies offer various types of financial aid. The Commodity Credit Corporation (organized in 1933) uses facilities of the Agricultural Stabilization and Conservation Service (1961) to support cotton prices through loans and purchases. Various federal programs of acreage control have also been used since the early 1930's in efforts to keep supply in line with demand. The Farmers Home Administration (1946) offers long-term, low-interest loans to farmers unable to secure private credit for operating expenses, farm ownership, housing, improvements, and other purposes. The Federal Crop Insurance Corporation (1938) insures crops against loss from causes beyond the farmer's control, such as weather, insects, and disease.

The cotton plant belongs to the genus Gossypium of the mallow family (Malvaceae). Upland cotton is G. hirsutum; Sea Island and Egyptian cottons are G. barbadense; Asiatic cottons are G. arboreum and G. herbaceum; Peruvian cotton is G. peruvium; Mexican cotton is G. mexicanum; Jamaica cotton is G. punctatum.