Environment friendly finishing of sulphur, vat, direct and reactive dyed cotton fabric

Sulphur, vat, direct and reactive dyes are among the major class of dyes used to colour cotton. Cross-linkers are typically used after dyeing of the cotton to overcome the wrinkling problem. In this research performance of the toxic formaldehyde based cross-linker DMDHEU, and its alternative, non-formaldehyde based cross-linker BTCA was assessed on various dyed fabrics. Both cross-linkers impart acceptable shade change in most of the cases apart from three sulphur and five reactive dyed fabrics, where BTCA with phosphite exhibited poor results as compared to DMDHEU. However, similar shade change rating was achieved when phosphite based catalyst was replaced with phosphate based catalyst. In addition, significant increase in crease recovery angel of the dyed fabric was also achieved when any cross-linker was used. Tensile strength of the dyed and finished fabric decreased after the treatment with any cross-linker. In addition, BTCA with phosphite catalyst and DMDHEU treated fabrics exhibited similar tensile strength loss. However, BTCA and less strong reducing catalyst phosphate treated fabric demonstrated superior tensile strength retention as compared to BTCA with phosphate and, DMDHEU.