Dyeing of gamma irradiated cotton using Direct Yellow 12 and Direct Yellow 27: improvement in colour strength and fastness properties

Present study is concerned with the dyeing behavior of gamma irradiated cotton using direct dyes. The fabric and dye powder was exposed to absorbed doses of Cs-137 gamma irradiator between 14 and 26 kGy. It was found that 18 kGy is the optimal absorbed dose for tuning the surface of fabric to get colour strength using Direct Yellow 12, whereas good colour strength was obtained by dyeing irradiated fabric at 70 °C for 70 min by keeping M:L of 1:30 using dyeing bath of pH 10 in the presence of 2 g/L of table salt. While 14 kGy is the most effective absorbed dose for Direct Yellow 27 where good colour strength was obtained at 80 °C for 60 min keeping M:L of 1:70 in presence of 10 g/L of salt using neutral dyeing bath. At these conditions not only leveled dyeing was achieved but the colourfastness was also improved.