Abstract:

In order to enhance the fixation rate and color build-up property of reactive dyes in the conventional pad-steam (P-S) dyeing process, a vacuum-dewatering  procedure was incorporated. Factors influencing the wet -steaming dyeing of reactive golden yellow SRE, such as the water content of the padded cotton fabric, the steaming time and sodium carbonate dosage were investigated. The color build-up property and rubbing fastness of the cotton fabrics dyed using the pad vacuum-dehydration steam (P-Vac-S) process and the P-S process were compared as well. The results show that cotton fabrics padded with 25 g/L dye liquor exhibited higher K/S value and dye fixation rate by reducing the fabric water content down to 20% ~ 30% by vacuum-dehydration prior to the steaming stage. The steaming time of 5 min and sodium carbonate concentration of 25 g/L were appropriate for dyeing of padded cotton fabrics with (25 ± 2)% water content. The K/S value of the cotton fabric is impeoved by 15% ~ 30% when dyed by the P-Vac-S process, compared with that by the P-S process, however, the rubbing fastness of the cotton fabric obtained by the former process was a bit poorer than that by the later process.

Key words: reactive golden yellow SRE, cotton fabric, vacuum-dewatering, wet-steaming dyeing, color build-up property