Theoretical and practical aspects of the Tactel Coloursafe reactive dyeing system for modified nylon 6,6

Three, commercial Stanalan reactive dyes were applied to Tactel Coloursafe knitted fabric at different pH values and the extents of dye exhaustion and fixation were determined. The three dyes displayed similar characteristics in terms of dye exhaustion and dye fixation. High exhaustion was achieved and this reached a maximum in the region pH 5¯6; dye fixation (%F) increased with increasing pH of application over the pH region used (pH 3¯8). The extent of total fixation (%T) followed the same pattern as that of dye fixation (%F) in the pH region 3¯6 whereas at pH values 7 and 8, total fixation decreased owing to a lowering of dye exhaustion in the same pH region. While unfixed dye was removed from dyeings as a result of a recommended wash-off and syntan aftertreatment, the extent of dye removed was small. Wash-off and syntanning did not markedly alter the colour of the dyeings. The wash fastness of 2% omf dyeings was found to be very good.