A polyvinyl alcohol aftertreatment for nylon 6,6. Part 2: Complex formation

The effectiveness of a PVA aftertreatment in improving the fastness of acid dyes to repeated washing at 40, 50 and 60 °C was enhanced by the sequential application of an organic titanate, MgSO4 and a protease enzyme. This was attributed to the formation of a large molecular size, low water-solubility complex situated at the surface of the dyed substrate which physically resists diffusion of dye from the dyed fabric during washing. Although aftertreatment with each of four PVA-based aftertreatments reduced the lightness and chroma of the red and, in particular, the yellow dyeings, it had little effect on the colour of black dyeings.