Wool

The first step in the processing of wool preparatory to cloth making is the sorting of the fibers. As each fleece is pulled apart, the fibers are sorted into separate piles of similar nature and characteristics, mainly on the basis of fineness, length, and freedom from defects. After sorting, the fibers are cleaned, because wool contains an oily substance, called yolk, consisting of lanolin and suint, which is dried perspiration. The wool is scoured by a soap-alkali preparation or other detergent or solvent to remove the grease and other foreign substances.

The scoured wool fibers are disentangled and drawn straight into a continuous form in a process called carding, which employs a carding machine. In this process, the fibers are passed between pairs of rotating cylinders covered with a material called card clothing, which contains fine, pliable wire teeth. The wool emerges from the rollers in the form of a thin film known as the web. The processing of the web varies according to whether woolen or worsted yarn is to be produced.

Woolen fabrics, such as tweeds, are woven from bulky yarns containing short wool fibers arranged at random, so that the fabric is relatively thick and has a fuzzy surface. Worsted fabrics, such as gabardines, are woven from yarns composed of longer, thinner wool fibers, tightly twisted for a smooth surface.

For the production of woolen yarn, the web is split into soft, thin strands called roving, and then it is ready to be spun. For worsted yarn, the web is processed by machines that straighten the fibers, make them parallel, and remove all the short pieces. The resultant thick strand is then condensed by passing it through several machines until a very thin strand of worsted roving is obtained. From this type of roving can be spun the smooth yarn that produces firm, smooth-textured worsted fabrics. See Spinning.

See also Cashmere; Rugs and Carpets; Textiles.

Contributed by: The Wool Bureau, Inc. New York City