Impact of Chemicals and Processing Treatments on Thermo-Mechanical Recycling of Polyester Textiles

The textile industry is among the world’s largest, producing an estimated 124 million tonnes of fibres in 2023, with more than half of these being made from virgin polyester. Less than 0.1% of polyester fibres are recycled into new textiles at the end of their lives. Mechanical, thermo-mechanical, and chemical textile-to-textile polyester recycling are all technically possible, but thermo-mechanical recycling is reported to provide the most promising compromise between cost and quality. Myriad chemicals are used in polyester production, and this paper is the first to review the related academic literature to better understand their impact on recyclability. It has been demonstrated that chemicals used during the production and processing of polyester textiles can either provide resistance to, or catalyse, the degradation of polyester during thermo-mechanical recycling processes. However, the effect of combinations of these chemicals on recycling is largely unknown. Limiting, standardising, and transparently reporting the chemicals used during textile production would simplify research and could lead to better quality products after recycling.