Evaluating Sustainable Alternatives to Conventional Reduction Clearing in Polyester Dyeing

The increasing awareness and growing environmental consciousness have accelerated the shift toward the adoption of sustainable materials and practices across various industries, including textile wet processing. Although polyester is the most widely used fiber, its postdyeing treatments, especially reduction clearing, remain environmentally harmful. This study addresses these challenges by comparing green alternative and conventional clearing agents to reduce the ecological impact of polyester processing. This study compares the effectiveness of conventional and green alternative agents for reduction clearing (RC) of polyester fabrics, focusing on both performance and environmental impact. Filament and micro polyester fabrics were dyed at two shade levels (4 and 7%) with red dye and treated using conventional sodium hydrosulphite and green alternatives Mega Clear, Prime Cleaner, and Sera Fast. To comprehensively evaluate the efficacy and sustainability of each method color strength, color fastness to washing and rubbing, BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), and TDS (Total Dissolved Solids) were performed. Results showed the greatest color strength reduction in hydrosulphite-treated samples, with minimal loss in Mega Clear. <i>K</i>/<i>S</i> values of filament polyester were consistently lower than micro polyester. Fastness ratings were generally comparable (4 to 4-5), with wet rubbing slightly lower. Tensile strength decreased most with hydrosulphite and minimally with green agents. Environmental assessment revealed reduced BOD, COD, and TDS with green agents, except Sera Fast. Green alternatives offered comparable performance while improving effluent quality, supporting the UN sustainable development goals (SDG 9 and SDG 12) through process innovation and reduction in the environmental footprint of polyester dyeing.