The Dyeing of Wool with Reactive Dyes in the Presence of Trichloroacetic Acid

Although the development of reactive dyes has been accompanied by the introduction of auxiliary products to give satisfactory dyeing quality, there are still areas where problems are encountered. A novel system, based on the use of trichloroacetic acid, is proposed, which gives improved levelness, especially when dyeing wool with mixtures of reactive dyes. Dyeing is carried out under acidic conditions where there is a slower rate of dye-fibre reaction and consequently, significant dye migration; as soon as the temperature of the bath reaches the boil, the trichloroacetic acid decomposes, the pH rises to approximately neutral and the dye is fixed