Scouring
Also searched as: washed wool, raw wool scouring, textile cleaning
Cleaning raw fiber or textiles to remove unwanted grease, dirt or processing residues.
In detail
Scouring is a cleaning operation whose specific purpose depends on the substrate. In raw wool, washing and rinsing remove grease and contaminants before later processing. This prepares a more usable fiber mass; it is different from aligning fibers or selecting a length distribution.
The science and numbers
Raw-wool scouring passes fleece through a series of warm aqueous bowls. Detergent emulsifies the water-insoluble wool grease while suint salts dissolve, and grease recovered from the liquor becomes lanolin. The effluent is among the more difficult industrial wastewaters: wool wax is held in a stable oil-in-water emulsion by nonionic detergent, and the stream is high in chemical oxygen demand, ammonia, salinity and potassium. CSIRO researchers showed that aerobic microbes can destabilize the emulsion, partly by cleaving wax esters and shortening the detergent's ethoxylate chains; in batch tests centrifuging then removed 97 percent of wool wax and 87 percent of COD. Tertiary oxidation with hydrogen peroxide and UV light brought total COD removal from raw effluent to about 97.5 percent, and a 2026 pilot biofilm reactor removed more than 91 percent of ammonia nitrogen. In cotton, scouring instead uses alkali to strip waxes and pectins before dyeing.
A practical example
A wool mill can receive greasy fleece and supply scoured loose wool before another facility performs top-making. The words “scoured” and “combed” therefore describe separate changes. Ask which material form is actually being supplied before comparing prices or quantities.
What to distinguish
Industrial scouring is not a home-care instruction. A finished garment may include dyes, finishes, lining and construction that require a particular wash or cleaning method. Follow the product’s label.
Origins and history
Cleaning fiber and cloth is ancient: Roman fullers used urine and absorbent clays, including the clay still called fuller's earth, to remove grease. Modern scouring shifted to detergents and multi-bowl machines, and the environmental burden moved to the effluent. Much of the treatment research came from CSIRO in Australia in the 2000s, where work on the Sirolan effluent process combined chemical flocculation, biological treatment and oxidation.
Related terms
Sources & further reading
- Woolmark: Wool processing
- Woolmark: Scouring and carbonising
- Water Research: Treatment of strongflow wool scouring effluent by biological emulsion destabilisation (2004)
- Water Research: Treatment of biorefractory organic compounds in wool scour effluent by hydroxyl radical oxidation (2004)
- Bioresource Technology: Pilot-scale treatment of wool scouring wastewater in a two-stage anoxic/oxic moving bed biofilm reactor (2026)
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.