- This article is about wool, the fiber. For alternative meanings see Wool (disambiguation).
Long and short hair wool at the South Central Family Farm Research Center in Boonesville, AR
Wool is the fiber derived from the hair of domesticated animals, usually sheep.
Properties
Wool is the fibre produced as the outer coat of sheep. Most of the fiber from domestic sheep has two qualities that distinguish it from hair or fur: it has scales which overlap like shingles on a roof and it is crimped, in some fleeces more than 20 bends per inch.
Both the scaling and the crimp make it possible to spin and felt the fleece. They help the individual fibers "grab" each other so that they stay together. Because of the crimp, wool fabrics have a greater bulk than other textiles and retain air, which causes the product to retain heat. Insulation also works both ways; bedouins and tuaregs use wool clothes to keep the heat out.
The amount of crimp corresponds with the fineness of the wool fibers. A fine wool like merino may have up to a hundred crimps per inch, where the coarser wools like karakul may have as few as one to two crimps per inch.
Hair, by contrast, has little if any scale and no crimp and little ability to bind into yarn. On sheep, the hair part of the fleece is called kemp. The relative amounts of kemp to wool vary from breed to breed, and make some fleeces more desirable for spinning, felting or carding into batts for quilts or other insulating products.
Wool is generally a creamy white colour, although some breeds of sheep produce natural colors such as black, brown (also called moorit) and grey.
Wool straight off a sheep contains a high level of grease which contains the valuable lanolin, in this state it can be worked into yarn or knitted into water-resistant mittens, as did the Aran Island fishermen. The grease is generally removed for processing by scouring with detergent and alkali.
The quality of wool is determined by the technique known as wool classing, whereby a qualified woolclasser might group wools of similar gradings together to maximise the return for a farmer wishing to yield the most from the sheep's fleeces.
The fibre diameter of wool varies from 15 micrometres (superfine merino) up to 30 or more micrometres for the coarser wool breeds. The finer diameters are generally more valuable.
History
As the raw material has been readily available since the widespread domestication of sheep and similar animals, the use of wool for clothing and other fabrics dates back to some of the earliest civilizations. Prior to invention of shears - probably in the Iron Age - they probably plucked the wool out by hand or by bronze combs.
In medieval times, the wool trade was serious business. English wool exports - which bordered on European monopoly - were a significant source of income to the crown. Over the centuries, various British laws controlled the wool trade or required the use of wool even in burials. In 1699 English crown forbade its American colonies to trade wool with anyone else but England itself.
In the Renaissance, Medicis of Florence built their wealth and banking system on wool trade with the aid of the Arte della Lana, the wool guild. Spain allowed export of Merino lambs only with royal permission. German wool - based on sheep of Spanish origin - begun to overtake British one only at the end of 19th century. Australia's colonial economy was based on sheep raising and Australian wool trade overtook Germans by 1845.
Production
Global wool production is approximately 1.3 million tonnes per annum of which 60% goes into apparel. Australia and New Zealand are leading commercial producers of wool. Most Australian wool comes from the Merino breed of sheep, and breeds such as Lincoln and Romney produce coarser fibers that are usually used for making carpets.
In the United States, Texas, New Mexico and Colorado also have large commercial sheep flocks and their mainstay is the Rambouillet, or French Merino. There is also a thriving 'home flock' contingent of small scale farmers who raise small hobby flocks of specialty sheep for the handspinning market. These small scale farmers may raise any type of sheep they wish, so the selection of fleeces is quite wide.
Uses
In addition to clothing, wool has been used for carpeting, felt, and upholstery. Wool felt covers piano hammers and it is used to absorb odors and noise in heavy machinery and stereo speakers. Ancient Greeks lined their helmets with felt and Roman legionnaires used breastplates made of wool felt.
Shoddy is recycled or remanufactured wool. To make shoddy, existing wool fabric is cut or torn apart and respun. As this process makes the wool fibers shorter, the remanufactured fabric is inferior to the original. The recycled wool may be mixed with raw wool, wool noil, or another fiber such as cotton to increase the average fiber length. Such yarns are typically used as weft yarns with a cotton warp.
Ragg is a sturdy wool fiber made into yarn and used in rugged application like gloves.
See also
External Links
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