Could ‘polished’ wool be the answer for those with eczema and other irritable skin conditions?
Researchers at the Agricultural Research Service Eastern Regional Research Center in Wyndmoor, Pennsylvania, have developed a biopolishing method that makes scratchy wool feel silky smooth, bleaches the wool to a high level of whiteness and alters the surface of wool fibres to make them shrink-proof.
The process involves two steps. First, an activated peroxide bleach is used to whiten the wool fibers and remove the protective lipid barrier that surrounds them. This step bleaches the wool at lower temperatures and in half the time as conventional techniques, which cuts processing costs, and, because it removes the lipid layer, the peroxide treatment also makes the fibers more receptive to dye.
High-temperature dyeing is traditionally used with wool because of the lipid barrier to dye uptake and although wool has resilient properties, those high temperatures weaken the fibre. This process lets wool be dyed at lower temperatures, preserving its strength.
The second step is an enzyme treatment. The surface of a woollen fibre is covered with microscopic scales, somewhat like scales on a fish or shingles on a roof. Wool shrinks during machine-washing because the heat and pressure lock the scales in place. The enzyme treatment “digests” the scales so they can’t become locked. This controls shrinkage without loss of strength or elastic recovery.
The same lipid layer that makes wool resistant to dye uptake would usually protect the scales against such an enzyme attack. But the bleaching step removes that protection.
No damage is done to the underlying fiber structure, and the fabric’s mechanical properties are not changed, because the enzyme activity is limited to the outside layer, or cuticle. An additive is used in both the bleach pretreatment and the enzyme treatment to keep the enzymes out of the fiber’s inner structure.
The process can be applied to everything from loose fibres to yarn, fabric, or completed garments.
However, unfortunately for eczema sufferers, this wool polishing is, as yet, only in the development pahse – but, watch this space…
"Wool Biopolishing Process Scratches the Itch Factor" was published in the May 2005 issue of Agricultural Research magazine.
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