wiseGEEK: What is Wool?
Wool is the dense, warm coat of sheep, also called a fleece. The hair of sheep has many unique properties that make it well suited to textile production. something humans realized approximately 8000 BCE, when sheep first began to be domesticated. Wool is used in a variety of textiles and can be found woven or knitted.
This material is highly flame resistant, and frequently used for mattresses and rugs for that reason. It is also highly durable, able to stretch up to 50% when wet and 30% when dry. In addition, wool has excellent moisture wicking properties, pulling moisture into the core of the fiber so that it doesn't feel wet or soggy to the wearer. It pulls moisture away from the skin, as well, and is worn by people in a wide variety of situations who prefer the feeling of dry air next to the skin to the clammy sense of perspiration.
Wool is favored for textile production because it is easy to work with and takes dye very well. The springy fibers remember shapes when well cared for. Furthermore, it takes to felting. a process in which fibers interlock into a tight mat, very well. Felt is used as insulation, for arts and crafts projects, and for decorative accents.
Production starts with the shearing of the sheep, which usually happens once a year. A skillful shearer can remove the entire fleece at once with long flowing strokes, keeping the fibers long. After shearing, the wool is washed to remove impurities. One of these impurities is lanolin. which is used in many cosmetics.
After washing, many producers combine wools for a specific blend and dye them together, so that the
dye will take evenly, before carding it through a set of teethed rollers. Carding pulls the fibers straight, while removing any remaining dirt or vegetable matter. The wool is pulled into slivers, long strips of fibers loosely pulled together and running in the same direction. If, after carding, the wool is under 3 inches (almost 8 centimeters), it is twisted into rovings, rope like strands that can be spun for knitting. If the strands are longer, they must be combed and drawn before spinning.
Spinning pulls the fibers tightly together and twists them so that they retain a long yarn shape. Yarn can be spun in all sorts of thicknesses and gauges, depending upon the intended use. For wool weaving. the yarn tends to be very fine. For knitting, it may be quite chunky. There are myriad uses for wool, a highly versatile textile. For example, shorter, coarse wool will turn into carpeting, while medium length material will be used in suits.
After knitting or weaving, the wool is often shrunk through a controlled process so that it won't shrink excessively for the end user. Most knits are also blocked on forms to set a shape, and many products are also brushed for a specific finish.
Proper care for wool begins with following the label directions. In general, it should be allowed to rest between wearings, to retain its shape. It should never be compressed or stored on hangers, which will stretch it. Brushing wool will remove surface soil and stains before they are ground in, and a slightly damp cloth will remove deeper stains. The material should be dried flat at room temperature, not exposed directly to heat.Source: m.wisegeek.org