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wool,fiber made from the fleece of the domestic sheepsheep,
common name for many species of wild and domesticated ruminant mammals of the genus Ovis of the Bovidae, or cattle, family. The male is called a ram (if castrated it is a wether), the female is called a ewe, and their offspring is a lamb.
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Composition and Characteristics
Wool consists of the cortex, overlapping scales (sharper and more protruding than those of hair) that may expand at their free edges causing fibers to intermesh; elasticum, the inner layer; and a core. When soaked, the elasticum and core contract, shrinking the fiber. Elasticity resulting from the molecular structure of wool and resiliency from its crimp make wool fabrics crease resistant. Fine wool will stretch one third its length. Wool is warm because its fibers are nonconductors of heat and its crimp permits it to enmesh still air. It is highly absorbent and releases moisture slowly. Its tensile strength is one fourth greater than that of cotton. A protein compound of complex chemical composition, it is soluble in hot caustic soda.
Wool is classed as follows: fine, usually short-staple wool of Merino fineness and including Delaine Merino, combable fibers 2 in. (5.1 cm) or more in length; medium, or mutton, 2 1-2 to 6 in. (6.4–15.2 cm) long, e.g., Cheviot and Southdown; long-staple, 10 to 15 in. (25.4–38.1 cm) long, loosely crimped, e.g., the Lincoln and the Cotswold; and carpet, 1 to 15 in. (2.5–38.1 cm) long, strong, coarse, and usually blended for uniformity. For industrial purposes the fiber of the camelcamel,
ruminant mammal of the family Camelidae. The family consists of three genera, the true camels of Asia (genus Camelus); the wild guanaco and the domesticated alpaca and llama, all of South America (genus Lama
..... Click the link for more information. , Angora goat (see mohairmohair,
hair of the Angora goat or a large group of fabrics made from it, either wholly or in combination with wool, silk, or cotton. The Angora goat, native of Asia Minor for 2,000 years, is bred in other lands, e.g., the SW United States and South Africa.
..... Click the link for more information. ), Kashmir goat (cashmere or pashmina), llamallama
, South American domesticated ruminant mammal, Lama glama, of the camel family. Genetic studies indicate that it is descended from the guanaco. Smaller than the camel and lacking a hump, it somewhat resembles a large sheep with a long neck, camellike face, and long
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, partially domesticated South American mammal, Lama pacos, of the camel family. Genetic studies show that it is a descendant of the vicuña. Although the flesh is sometimes used for food, the animal is bred chiefly for its long, lustrous wool, which varies
..... Click the link for more information. , and vicuñavicuña
, wild South American hoofed mammal, Vicugna vicugna, the smallest member of the camel family. It is 30 in. (75 cm) high at the shoulder, with a long, slender neck and pale, fawn coloring.
..... Click the link for more information. is classed as wool.
Sheep are sheared with mechanical clippers. The fleece thus recovered is classed as lamb's wool, or first clip; hog wool, clipped from sheep 12 to 14 months old; wether wool, from older animals; taglocks, the ragged, discolored portion; and pulled wool, usually weakened when recovered by sweating or chemical processes from sheep slaughtered for mutton.
The wool is sorted as to fineness, crimp, length of fiber, and felting qualities. Dirt, suint (dried perspiration), and lanolin are removed by a soap-alkali scouring; by the expensive naphtha solvent method, which retains the full strength and softness of the fiber; or by freezing and shaking. Wool may be carbonized to remove vegetable matter. It is bleached and dyed as raw stock, yarn, or in the piece; it is oiled to withstand processing and is often blended.
Woolen goods are woven from carded short-staple fibers into soft yarns adapted to fulling and napping. Worsted fabrics such as whipcord, gabardine, and serge have a hard, smooth texture. Originally made only from long-staple fibers, worsted yarn is now spun also from medium or short fibers. The fibers are carded, the resulting sliver gilled to straighten the fibers and double them for uniformity; subjected to successive combings to remove nails (short ends) and lay the fibers parallel; then drawn into roving and spun, usually by the rapid, continuous ring method, and twisted. Although the twill weave is usual for worsteds, the same weaves may be used as for woolens without the pattern being obscured by the napping, fulling, and shearing processes commonly employed in finishing woolens.
History of Wool Production
No known wild sheep are wool bearing. The supposed ancestors of the domestic sheep had long hair and a soft, downy undercoat, which under domestication gradually became wool, while the long hair disappeared. In this development, breeding, feed, climate, and protection were influential, as shown by an atavistic return of neglected sheep to long hair and rudimentary wool.
In the tombs and ruins of Egypt, Nineveh, and Babylon, in the barrows of early Britons, and among the relics of the Peruvians, fragments of woolen fabrics are found. The Romans as early as 200 B.C. began to improve their flocks, which became the progenitors of the famed Spanish Merino sheepMerino sheep
, breed intermediate in body size having fine wool, developed in Spain. These sheep are noted for their hardiness and their herding instincts and have been used as parents of several other breeds, notably the Rambouillet of France. Three strains have been developed.
..... Click the link for more information. . The Britons kept sheep and wove wool long before the Roman invasion, but the establishment by the Romans of a factory at Winchester probably improved their methods. William the Conqueror brought into England skilled Flemish weavers. Henry II encouraged wool industries by laws, cloth fairs, and guilds of weavers. Edward III brought weavers, dyers, and fullers from Flanders. England became the great wool-producing country of Europe, and wool was the staple of its industry until cotton began to overshadow it in the 18th cent.
In the American colonies, sheep raising started in Jamestown. Stringent English laws against exporting wool passed in an attempt to force the use of English cloth on the colonies, early drove the settlers to the raising of sheep. George Washington imported sheep and brought spinners and weavers from England. Early in the 19th cent., imported Merinos greatly improved the existing stock. Spinning and weaving were early established in New England, at first in homes, later in small factories. The first factory in America using water power to weave wool was established (1788) at Hartford, Conn., and was encouraged by tax exemption and a bounty on each yard woven.
In the United States, by the Wool Products Labeling Act of 1939, the term wool may be applied only to fabrics made entirely of new wool; the term reprocessed wool, to wool recovered from unused articles and waste; and reused wool, to wool reclaimed from used articles. The trade designates fleece wool as virgin wool, salvaged wool as shoddy. Salvaged wool may legitimately be used to add strength to soft new wool or to produce a cheaper product. Numerous synthetic fibers have been developed as wool imitations and for blending with wool.
The United States now produces a substantial amount of the world's wool, chiefly in Texas, Montana, Wyoming, Utah, Oregon, Idaho, New Mexico, Colorado, California, and Ohio. Woolen cloth manufacture is largely centered in New England. Other important wool producers include Australia, Argentina, New Zealand, Russia, the Republic of South Africa, Uruguay, Great Britain, China, and India.
See W. J. Onions, Wool: An Introduction to Its Properties, Varieties, Uses, and Production (1962); W. von Bergen, ed., Wool Handbook (2 vol., 3d ed. 1963–70); H. S. Bell, Wool: An Introduction to Wool Production and Marketing (1970).
one of the primary natural textile fibers, the raw material of the wool-processing industry. Most of the wool processed industrially comes from sheep; considerably smaller quantities of similar fibers are obtained from goats, camels, yaks, hares, rabbits, horses, cows, deer, dogs, and other animals. Possessed of useful qualities, such as low heat conduction and high moisture absorption, wool is a valuable material for the manufacture of fabrics, knitwear, carpets, and other articles. The world production of wool from sheep totaled 2.6 million tons in 1976. Most was produced by Australia (747,000 tons), New Zealand (311,000 tons), and Argentina (160,000 tons). The USSR produced 432,800 tons in 1976.
Grease, or fleece, wool is obtained from live animals by shearing (sheep, goats, and others), combing (camels, yaks, dogs, goats, and rabbits), or gathering during molting (cows, horses, and yaks). Wool removed from the hides of slaughtered animals is called pulled wool. Wool is a keratinized filament produced by the animal’s skin. Animals produce a hairy outer coat and a downy undercoat. In sheep the outer coat consists of guard, transitional, and surface hairs; the downy undercoat is homogeneous. Fibers from the outer coat have a cuticle, a cortex, and usually a medulla; undercoat fibers have a cuticle and a cortex. The cuticle is a thin (0.5–2 micrometers) protective fiber casing. It accounts for the wool’s spinning and felting properties. Damage to the cuticle leads to deterioration of the cortical layer and lessens the usefulness of the wool. The condition of the cortical layer, located underneath the cuticle, affects the strength, elasticity, resiliency, and other properties of the wool. The medulla may be solid or porous (with air cavities) and is situated along the fiber axis. Increased medullation lessens the usefulness of the wool.
The guard hairs consist of coarse, usually longer fibers of low crimp whose cuticle scales are not ring-shaped. Their use characteristics are inferior to those of undercoat and transitional hairs. The transitional hairs have a length, thickness, and structure intermediate between guard hairs and fibers from the undercoat. The medullary layer is poorly developed or absent. Transitional hairs have better use characteristics than guard hairs. The undercoat consists of the finest fibers, which are usually shorter than those of the guard and transitional hairs.
Sheep’s wool may be classified as uniform or nonuniform depending on the composition of the fibers. In uniform wool the undercoat and transitional fibers are grouped together to form staple fibers (the transitional fibers of wool from long-wool breeds form uniform locks). In nonuniform wool the undercoat, transitional, and guard hairs are formed into locks. Staple fibers and locks are the elements of the fleece—the wool covering of sheep that is removed in one piece by shearing.
The physical properties of wool that determine its use characteristics and market qualities include fineness, crimp, length, strength, elasticity, resiliency, stiffness, flexibility, extensibility, hygroscopicity, color, and luster. The average thickness is 10–25 micrometers (μm) for undercoat fibers, 30–50 μm for transitional fibers, and more than 50 μm for guard hairs. According to the Soviet scale, uniform wool is divided into 13 classes of thickness: from class 32 (55.1–67 μm average thickness) to class 80 (14.5–18.0 μm). Guard hairs usually have little crimp; undercoat fibers of uniform wool have normal crimp, and transitional fibers of uniform wool are flat. Crimp gives fibers additional resiliency. The longest wool—40 cm and longer—is found in sheep of the long-wool meat breeds (Lincoln and others) and some coarse-wool breeds (Highland Carpathian and others). Short wool—4 cm to 7 cm—is found in fine-wool and some coarse-wool breeds (Gissar and others).
The color of wool is determined by the presence of the pigment melanin in the cortex along the entire length or in part of the fiber. The principal colors of wool are white, black, and red-yellow. White wool is the most highly valued because it can be dyed any color. The wool of Lincoln sheep and Angora goats is especially lustrous. The production uses of wool depend to a certain degree on the luster, which affects the external appearance of the article. The yolk, suint, and foreign mineral matter in wool covers and mats the fibers. Washed wool is usually required for commercial processing, with the exception of some types of felting. The ratio in percent of the weight of washed wool, with correction for conditioning moisture, to the original weight of unwashed wool is called the yield.
The production use of wool is determined by the complex of properties inherent in the type of wool. Fine wool is uniform and consists of medium-fine (18–23 μm) and fine undercoat fibers. The staple is of uniform fineness and length, has uniform crimp along the entire length of the fiber, and possesses good physicomechanical properties and use characteristics. Semifine wool is uniform, consisting of coarsened undercoat fibers or transitional hair (average fineness up to 25 μm). It has a larger but less uniform crimp in the staple and lock and sometimes less uniformity of length. This group also includes crossbred and crossbredlike wools, which have good use characteristics, and yak wool, which has poor felting properties and good resiliency. Semicoarse wool is nonuniform and consists of undercoat fibers, transitional hairs, and a small quantity of fine guard hairs. Its fibers are of irregular fineness and length. Coarse wool is nonuniform and consists of undercoat fibers, transitional hairs, and, frequently, dry and dead hair. The nonuniformity of fiber fineness and length is greater than is the case with semicoarse wool. Sheep’s wool is used for the production of various fabrics, knitwear, carpets, and felted articles.
Goat’s wool is primarily nonuniform. It is characterized by poor use characteristics and spinning and felting properties. Consequently, in goats with nonuniform wool, it is the undercoat that is primarily used, principally for knitted articles. Goats of the Angora and Soviet wool breeds yield uniform semifine wool (mohair) consisting of transitional hairs; such wool is characterized by its luster and strength.
Camel hair is nonuniform. Its color ranges from white to dark brown. It is characterized by great strength and resiliency, good luster, and poor felting properties. It is used to produce high-quality beaver cloth, blankets, rugs, and knitwear. The mane is used to make drive belts and filter cloth used in the extraction of vegetable oils.
Yak wool is nonuniform and is used in cloth manufacture. The coat fibers of hares and rabbits are characterized by fineness, high extensibility, and good felting properties. They are a valuable raw material for the felting industry. Knitwear and felt are manufactured from the undercoats of certain rabbit breeds. Horsehair is a low-quality raw material used for the production of coarse felts. Cow hairs have good felting properties and are used mainly in the felting industry. Deer also provide fibers, large quantities of which consist of dead hair; the fibers are used in the saddle-making, mattress, and furniture industries and as an insulation material. The hair of some breeds of dogs is used for handmade knitted goods. The wool of llamas, guanacos, alpacas, and other animals is used in small quantities.
REFERENCESAlexander, P., and R. F. Hudson. Fizika i khimiia shersti. Moscow, 1958. (Translated from English.)
Gusev, V. E. Syr’e i pervichnaia obrabotka shersti. Moscow, 1960.
Kukin, G. N., and A. N. Solov’ev. Tekstil’noe materialovedenie, part 1. Moscow, 1961.
Ovtsevodstvo, vol. 1. Edited by G. R. Litovchenko and P. A. Esaulov. Moscow, 1972.
Povyshenie sherstnoi produktivnosti ovets. Moscow, 1976.
V. V. KALININ
What does it mean when you dream about wool?
As a symbol, wool often represents nurturing warmth. A dream that emphasizes wool could also be alluding to certain common expressions, such as to “pull the wool over someone’s eyes” or to be “dyed-in-the-wool.”