Wool

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  • Publicado : 26 de noviembre de 2011
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Production of Wool:
There are 8 major steps necessary to process wool from the sheep to the fabric. These are: shearing, cleaning and scouring, grading and sorting, carding, spinning, weaving, and finishing.
Shearing
In most parts of the world sheep are sheared once a year, usually in the springtime. A veteran shearer can shear up to two hundred sheep per day. The fleece recovered from asheep can weigh between 6 and 18 pounds (2.7 and 8.1 kilograms); as much as possible, the fleece is kept in one piece. While most sheep are still sheared by hand, new technologies have been developed that use computers and sensitive, robot-controlled arms to do the clipping.
Different types of fleece are used in producing wool. Lambs' wool is fleece that is taken from young sheep before the age ofeight months. Because the fiber has not been cut, it has a natural, tapered end that gives it a softer feel. Pulled wool is taken from animals originally slaughtered for meat and is pulled from the pelt using various chemicals. The fibers of pulled wool are of low quality and produce a low-grade cloth. Virgin wool is wool that has never been processed in any manner before it goes into themanufacturing phase. This term is often misunderstood to mean higher quality, which is not necessarily the case.

Grading and sorting
Grading is the breaking up of the fleece to remove any stained, damaged or inferior wool. In sorting, the wool is divided into sections of different quality fibers, from different parts of the body. The best quality of wool comes from the shoulders and sides of thesheep and is used for clothing; the lesser quality comes from the lower legs and is used to make rugs. In wool grading, high quality does not always mean high durability. Wool fibers are judged not only on the basis of their strength but also by their fineness (diameter), length, crimp (waviness) and color.
Cleaning and scouring
When wool is taken directly from the sheep it contains sand, dirt,grease, and dried sweat (called suint); this wool is called "raw" or "grease wool." the weight of contaminants accounts for about 30 to 70 percent of the total weight of the fibers. To remove these contaminants, the wool is scoured in a series of alkaline baths containing water, soap, and soda ash or a similar alkali. The byproducts from this process such as lanolin (Lanolin is grease that is inthe water where the wool was scoured) are saved and used in a variety of household products including shampoo, makeup, and hand lotion. Rollers in the scouring machines squeeze excess water from the fleece, but the fleece is not allowed to dry completely. Following this process, the wool is often treated with oil to give it increased manageability.
Carding
After the wool dries, it is carded.The carding process involves passing the wool through rollers that have thin wire teeth. The teeth untangle the fibers and arrange them into a flat sheet called a web. The web is then formed into narrow ropes known as slivers. Carding also removes residual dirt and other matter left in the fibers. After carding, the processes used in making yarn vary slightly, depending on the length of thefibers. Carding length fibers are used to make woolen yarn. Combing length fibers and French combing length fibers are made into worsted yarn. Carded wool intended for worsted yarn is put through gilling and combing, two procedures that remove short fibers and place the longer fibers parallel to each other. From there, the sleeker slivers are compacted and thinned through a process called drawing.Carded wool to be used for woolen yarn is sent directly for spinning.
Spinning
Thread is formed by spinning the fibers together to form one strand of yarn; the strand is spun with two, three, or four other strands. Since the fibers cling and stick to one another, it is fairly easy to join, extend, and spin wool into yarn. Spinning for woolen yarns is typically done on a mule spinning machine,...
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