Dehairing
Also searched as: dehaired, undercoat separation
Separating fine undercoat from coarser guard hair.
In detail
Dehairing separates the fine undercoat sought for textiles from the coarser outer hairs present in some animal fleeces. Cashmere is associated with the fine, dehaired undercoat of the cashmere goat. Separation matters because an average description of a fleece can conceal very different fiber populations.
The science and numbers
Dehairing works because down and guard hair differ in diameter, stiffness, length and mass. In one study of Changthangi goats, down averaged about 13 microns and 48 mm long while guard hair averaged about 68 microns and 81 mm; in coarser Bakerwal and Kargil goats guard hair exceeded 100 microns. Fleece composition varies too: Raeini cashmere goats in Iran averaged about 66 percent cashmere and 34 percent guard hair. Machines exploit these contrasts with repeated opening and carding-type actions in which heavier, stiffer hairs are thrown out while fine down is carried forward, and several passes may be needed. The US statutory test shows what counts as success: a cashmere product must have a mean diameter not over 19 microns, a coefficient of variation not over 24 percent and no more than 3 percent by weight of fibers over 30 microns.
A practical example
When discussing a cashmere lot, ask whether measurements describe the raw mixed fleece or the prepared textile fiber. A soft-looking photograph cannot establish how effectively coarse hairs were removed. Composition and diameter information provide different pieces of evidence.
What to distinguish
Dehairing is not simply another name for washing, nor does it mean that every remaining fiber has an identical diameter. Avoid judging finished comfort from a process name alone; yarn construction and surface finishing also matter.
Origins and history
Kashmir shawls woven from fine goat down were luxury goods in Mughal and later courts, and nineteenth-century European mills copied their buta motif so extensively that it took the name of Paisley. European industry then shifted from importing finished shawls to importing raw down, and Bradford firms such as Joseph Dawson Ltd of Cashmere Works industrialized mechanical dehairing in the late nineteenth century. A 1996 review noted that the absence of acceptable small-scale dehairing equipment limited cottage-scale cashmere processing in the United States.
Related terms
Sources & further reading
- Cashmere and Camel Hair Manufacturers Institute: Fiber definitions
- GovInfo: 15 U.S.C. 68b, Misbranded wool products
- Gene: Characterization and polymorphism of keratin associated protein 1.4 gene in goats (2012)
- Journal of Animal Science and Biotechnology: Effect of sex and rearing system on the quality and mineral content of fiber from Raeini cashmere goats (2012)
- Journal of Animal Science: Prospects for expanded mohair and cashmere production and processing in the United States (1996)
Technical references reviewed 2026-09-22. Examples are illustrative. Industry organizations and manufacturers describe their own fields; their references are not independent product endorsements. Figures are approximate and depend on the stated test conditions.