Effect of copper treatment on the dyeability of gamma irradiated acrylic fabrics with different dyestuffs

The effect of Cu (II)/hydroxyIamine mixture on the dyeability of acrylic fa brics towards direct dyes was investigated. The effect of the different fac tors that may affect the dye affinity of acrylic fabric such as composition and concentration of copper sulphate/hydroxylamine mixture, irradiation do se, pH strength of the dye bath, dye concentration, dyeing temperature and time was studied. It was found that by using a mixture composed of 2% coppe r sulphate and 1% hydroxylamine constituting a total concentration of 3 wt. % (based on fabric weight), the dye affinity of acrylic fabric far the dire ct dye Benzamine Bordeaux FB was significantly improved. Also, it was shown that the dye affinity of the acrylic fabrics for other dyestuffs such as r eactive and acid increases with increasing concentration of such mixture. I rradiated acrylic fabric showed a higher dye affinity for the used dyes com pared to the unirradiated fabrics. Fabrics irradiated to a radiation dose o f 1 Mrad showed the highest dye affinity with high leveling of dyeing. The pH strength of the dyeing bath at which the highest colour strength obtaine d was 3. A mechanism was proposed for the dyeing of acrylic fabrics with di rect dyes in the presence of copper ions. (C) 1999 Elsevier Science S.A. Al l rights reserved.