Sustainable processes for pre-treatment of cotton fabric

Abstract

Simple and sustainable reuse and recycle strategies were investigated with the intention of assessing ways to curb water consumption in the textile wet processing. Textile pre-treatment involves desizing, scouring and bleaching processes. Each process requires a plethora of chemicals along with water, out of which the unexhausted chemicals are drained in the effluent stream. Conventionally, 7.3 % alkali and 6.9 % hydrogen peroxide are utilised in the scouring and bleaching process. Attempts were made to reutilise the unexhausted 92.7 % alkali and 93.1 % hydrogen peroxide from the scouring and bleaching process. After recycling the scouring and bleaching process bath three times, effluent still contained 55 % alkali and 67.5 % hydrogen peroxide which was reused to desize a new grey fabric. The fabric properties like Tegewa rating, absorbency and whiteness were found to be better than the conventional enzyme desized fabric. The desized fabrics were then subjected to dyeing using reactive dyes Yellow HE6G and Navy Blue HER, where analogous dyeing and fastness properties were obtained when compared with fresh water samples. Economical feasibility has been calculated considering a production of 1 ton of fabric/day. It was observed that 83 % water and 74 % energy were conserved per ton of processed fabric which contributes to a saving of around 1 lac INR/ton.