Professional guide

Wool in production

In the "olden days" wool was a major textile resource. In Noway, up until the 1950's, it was forbidden to import cotton in order to protect the wool industry. No more. Wool today is almost a non-player on the textile market. Considering all the eco-benefits from wool, this is really a sad state of affairs.

Wool comes primarily from sheep. The raw wool is full of natural impurities and grease which will be removed during the washing process.Wool straight off a sheep, known as "grease wool" or "wool in the grease", contains a high level of valuable lanolin, as well as dirt, dead skin, sweat residue, and vegetable matter. Before the wool can be used for commercial purposes, it must be scoured, or cleaned. Scouring may be as simple as a bath in warm water, or as complicated as an industrial process using detergent and alkali, and specialized equipment. In commercial wool, vegetable matter is often removed by chemical carbonization.

The waste water from the washing process contains large amounts of grease which, when discharged into the wastewater, is favourable to the growth of algae which may cause oxygen depletion and kill off fish. When the wastewater has a large content of grease (organic substance) it is known as having a high COD/BOD level. Conventional wool processing traditionally uses many products derived from petrochemical bases. Organic wool processors replace these with plant-based alternatives. To lubricate fibres during spinning, one uses coconut oil instead of petroleum-derived products.

Comparing the energy used in production of textiles, wool comes out using at least a third less than polyester, and at least a fifth less than nylon.

Superwash wool (or washable wool) technology first appeared in the early 1970s to produce wool that has been specially treated so that it is machine washable and may be tumble-dried. This wool is produced using an acid bath that removes the "scales" from the fiber, or by coating the fiber with a polymer that prevents the scales from attaching to each other and causing shrinkage. This process results in a fiber that holds longevity and durability over synthetic materials, while retaining its shape. The process does however, release organohalogens in the waste-water, and constitutes an environmental problem. 

Dyeing
Chrome-dyes have generally been used to attain dark shades like black and navy in wool dyeing, and have been used because of their high standard of fastness and low prices. But the risks associated with chrome dyes have resulted in many leading EU retailers banning them.

Chrome-free colours
Huntsman Textile Effects has launched Lanasol Blacks range of chrome-free dyes for wool and other fine animal fibres. This disproves, according to the company, the argument that deep black shades are not achievable with metal free dyes. Complementing the black dyes is Miralan, the first low temperature dyeing auxiliary which facilitates the application of Lanasol Black dyes for the deepest black shades at reduced temperature and shorter dyeing times with minimal fibre damage. (Source: EcoTextileNews)
 
Finishing
Under a microscope raw wool fiber appears covered in scales. Those scales make raw wool itchy and also cause the fiber to shrink when wet. Most washable wool is scoured with chlorine to remove the scales and coated with synthetic resins (making the wool softer and preventing shrinkage). Chlorine from the washing process can create chlorinated hydrocarbons, harmful toxins that accumulate in the environment. The company O-Wool Washable starts with high-quality low-micron merino wool from sheep raised organically by their farm partners. They gently remove scales through a process that uses non-toxic hydrogen peroxide. They don't coat their fiber in resins, the process leaves the wool as soft, strong, and shrink resistant -- naturally. They also claim that since they're gentler on the fiber, their yarns and fabrics pill far less than others.

Because wool is basically a by-product of the sheep industry, it will demand a surge in demand for organic sheep to galvanize the domestic organic wool production base. There is discussion whether organic wool has any big advantages over conventional wool production. The sports company Nau has been looking at other ways of classifying more environmentally sound methods to ensure wool production, but this work was hindered when the company ran into financial problems.