Cashmere Wool Fiber:
In parts of China, northern India, Tibet, Iran and Afghanistan, the Tibetan Cashmere goat is reared as a domestic animal. It has an outer coat of long coarse hair with an inner coat of down. This fine, soft down is the source of the fiber that is known all over the world as cashmere wool fiber.
The downy cashmere fiber is combined from the goats fleece during spring, and in the process is separated as much as possible from the coarser hair. Each animal will provide little more than 110g of cashmere fiber every year. The combined output from 30 to 4 goats provides enough fiber to make an overcoat.
Structure and Properties of Cashmere Wool Fiber:
The downy fibers are usually 2.5 to 9cm long, and the coarser hairs 5 to 12.5cm long. Like other hair fibers, cashmere fibers are covered with epidermal scales. There are about 5-7 scales per 100 micro on average. They have serrated edges and project from the fiber causing an irregular surface.
The cortical layer of the cashmere fiber consists of spindle shaped cells with occasional long narrow spaces between the cells forming striations in the fiber. The fine cashmere fiber does not have any distinct medulla.
Cashmere wool is usually grey, buff colored or white. The colored fibers are full of tiny granules of pigment. In cross section, the fiber is circular or slightly oval; the pigment granules can be seen clearly in the cortical layer.
Cashmere wool fibers are extremely fine, averaging about 15micro in diameter, which is considerably finer than the best merino wool. The coarser beard hairs which are mixed with the true wool fibers are thicker, averaging about 60micro in diameter. The latter have well marked medullae.
Chemical Properties of Cashmere Fiber:
Cashmere is chemically similar to wool fiber. It wets out with water much quicker than wool, and is more sensitive to the effect of chemicals, largely as a consequences of its greater fineness. Cashmere fiber is very easily damaged by alkalis such as washing soda. It will dissolve readily in solutions of caustic soda.
Uses of Cashmere Fiber:
The world output of cashmere wool is very small, and production is costly process. Inevitably, the fiber is expensive. Cashmere is so fine and soft, however, that it is regarded as one of the most desirable textile fibers of all. Cashmere fabrics are warm and comfortable, and have a beautiful drape. The fiber is used very largely for making high quality clothes, shawls and hosiery, either alone or mixed with other fibers.
Garments made entirely from cashmere are properly labeled “pure cashmere”. Sometimes, fabrics woven from fine botany wools are incorrectly described as cashmere.