Theme: digital textile

Treatment of wool products

Wool products also have to undergo a series of pre-treatments prior to carrying out the dyeing step. The basic processes to prepare them are carbonization, pre-washing and bleaching.

Carbonization aims to completely remove plant impurities. This process involves treating the wool fibers with a solution of sulfuric acid and then heating them to a temperature above 100°C. Damaged fibers are mechanically removed and the whole is neutralized with sodium acetate. After the carbonization is completed, a washing step follows in order to remove the substances from the fibers applied during spinning. Prewashing results in a high degree of wettability and absorbency of bleaching agents and dyes. The last stage is bleaching of the wool. Hydrogen peroxide is most commonly used in this process.