An engineered enzyme called DAM-2-MULTI can break down mixed nylon textiles from post-consumer waste into their original chemical building blocks, ready to be spun into new fibres with no quality loss. The problem is that nylon clothing is nearly impossible to recycle. Current methods require meticulous sorting, high temperatures and pressures, and cannot tolerate even small amounts of common co-materials like elastane. Chemical recycling often uses rare metal catalysts and generates problematic waste. As a result, most nylon textiles end up in landfill, while manufacturing virgin nylon releases substantial greenhouse gases and other pollutants. If this enzyme technology succeeds, it could enable perpetual fibre-to-fibre recycling of both Nylon-6 and Nylon-6,6 without introducing impurities. That would reduce the demand for virgin polymer production and the associated environmental damage from monomer manufacturing. The project aims to mature the enzyme from a laboratory concept to a pilot-scale industrial process, supporting the fashion industry’s shift toward circular practices.
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**Problems:** Globally, 2.145 million tonnes of Nylon-6 and Nylon-6,6 polymers are used for fashion clothing and other clothes textiles each year. The manufacturing processes used to generate Nylon-6 and Nylon-6,6 polymers cause significant environmental harm, from both polymer production, as well as creation of the constituent monomers: * Nylon-6 manufacturing requires heating cyclic caprolactam (260°C in atmospheric nitrogen for 4-5 hours) to generate linear 6-Aminohexanoic acid (6-AHA), which then polymerises to form Nylon-6\. Global caprolactam manufacturing releases 10 million tonnes CO2 equivalent annually. * Nylon-6,6 manufacturing requires esterification of adipic acid (ADP) and hexamethylenediamine (HMDA) monomers. Nylon-6,6 manufacturing consumes 60-80 MJ energy/tonne, and its manufacturing releases ~12 million tonnes of CO2 and ~2 million tonnes of NOx annually. ADP manufacturing is responsible for ~15% of global nitric oxide (N2O) and 0.2% CO2 emissions. Both Nylon-6/Nylon-6,6 face significant thermomechanical recycling challenges. First, the materials needs to be meticulously separated into waste streams with no contaminants. The waste feedstock is then subjected to high temperatures/pressures, requiring significant energy expenditure, causing high CO2 release. Co-materials, such as elastane, are not tolerated over 1% in this process, yet are very commonly used with Nylon-6 and Nylon-6,6 in fashion applications. Chemical depolymerisation methods exist, but these frequently require rare metal catalysts, and consumer excess reagents. They can generate problematic waste streams, and again struggle to process Nylon blended with co-materials. There is an **unmet need** for Nylon fibre-to-fibre recycling methods to improve the circularity of Nylon-6 and Nylon-6,6 containing clothing textiles. **OPPORTUNITY:** In 2023 Epoch Biodesign received funding to engineer the 'DAM-2' to depolymerise Nylon-6,6\. Through that research, they created a variant (DAM-2-MULTI) that can partially depolymerise Nylon-6\. This project enables focussed development and optimisation of DAM-2-MULTI as an industrial enzyme for depolymerising mixed Nylon-6/Nylon-6,6 feedstocks from post-consumer wastes, maturing DAM-2-MULTI technology from TRL-3 to TRL-6\. **IMPROVEMENT:** DAM-2-MULTI technology enables perpetual recycling of both Nylon-6/Nylon-6,6 with no quality loss, or introduction of impurities. This will significantly reduce waste textiles sent to landfill, and lower demand for virgin ADP/HDMA/6-AHA monomers and virgin polymer production. In turn, this will significantly lower the environmental damage associated with current manufacturing processes for the monomers, Nylon-6/Nylon-6,6 polymers, and end-of-life textiles. **TIMELINESS:** Epoch technology supports the Textiles 2030 initiative supporting the fashion/textiles industry to transition to circular practices by the end of the decade (Epoch is a member of their Close the Loop and Design for Circularity working groups).
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