Abstract:

In order to reduce the serious reactive dye hydrolysis ascribed to high pick-up and slowly heating of the wet fabric in the conventional pad-steam (P-S) dyeing process, a vacuum-dehydration procedure was employed for the padded cotton fabric prior to steaming (low-water content-wet steaming (L-W-S) dyeing process). Reactive blue 19 was adopted as an example to investigate the influences of fabric water content, steaming time and Na2CO3 concentration on the steaming fixation of padded fabrics with low water content. Comparisons of the color strength ( K/S value) and dye fixation rate (F) of the cotton fabrics dyed with the L-W-S dyeing process and the conventional pad-(dry)-steam [P-(D)-S] dyeing process was made. The results show that both K/S value and F of the dyed cotton fabrics obtained from the former process are higher than those from the later process. Incorporating vacuuum-dehydration procedure in the P-S dyeing process offers a potential way to improve reactive dye fixation.

Key words: reactive blue 19, cotton fabric, wet-steaming fixation, low water content, color strength