Polyvinyl alcohol as an aftertreatment. Part 1: Initial studies

The fastness, to repeated washing at 50 °C, of three acid dyes on nylon 6,6 was improved by an aftertreatment with polyvinyl alcohol. Whilst aftertreatment reduced the lightness and chroma of red and, in particular, yellow dyeings, it had little effect on the colour of black dyeings; the extent of this shade change did not increase significantly with increasing amounts of PVA used. PVA imparted a yellow colouration to undyed fabric but the extent of this shade change was much lower than that imparted by the same concentration of tannic acid.