The application of heterobifunctional reactive dyes to nylon 6,6: process modifications to achieve high efficiencies

A heterobifunctional monochlorotriazine/vinyl sulphone (MCT/VS) reactive dye was applied to nylon 6,6 using various pH and temperature conditions. Optimum dye exhaustion and fixation were achieved at pH 4 and 98°C. The form in which the VS moiety was present during dyeing was examined by capillary electrophoresis. Preconversion of the dye to its VS form gave improved fixation and modified dyeing methods in which alkali additions were made at various points during the dyeing were used to achieve high dye fixation.