The Hong Kong Research Institute of Textiles and Apparel (HKRITA) developed two recycling solutions for Polyester and Cotton (and its blends) textiles: enzymatic recycling and hydrothermal treatment. Enzymatic recycling enables capturing the embodied value of the synthetic fibre. The bio-based products derived from textile waste can replace fossil fuel resources and eventually lead to the establishment of a sustainable and circular economy. Hydrothermal treatment allows for selectively decomposing cotton into cellulose powders, thereby enabling the separation of the polyester fibres from the blends. The whole process uses only heat, water and less than 5% of a biodegradable green chemical to achieve a recovery rate of over 98% for polyester fibres in 0.5-2 hours.

The fast cycle of buying and disposing of clothes drives demand for nonstop manufacturing and contributes to the fashion industries wastefulness and polluting impact. According to a waste statistics from Greenpeace in 2015, people in Hong Kong throw away 110,000 tonnes of textile products annually. Among these textiles wastes, there is a substantial amount made from blended materials. However, no commercially viable separation, sorting, and recycling technologies are currently available for materials such as cotton and polyester blends.

The Hong Kong Research Institute of Textiles and Apparel (HKRITA) has partnered H&M Foundation to develop practical solutions to recycle blended textiles into new fabrics and yarns. The objective of the collaboration is to facilitate the development of a closed loop textiles industry. The technology will be licensed widely to ensure broad market access and maximum impact. The ultimate goal is to develop a multi-discipline research platform that engages in innovative, impactful, and long term research efforts to improve closed loop recycling, and reduce damage to the environment.

At present, two directions are identified: biological and chemical. The chemical method is to recycle PET/cellulose from cotton and PET blends through hydrothermal treatment and dissolution treatment. No harmful chemicals are involved, and no sorting is needed which means energy consumption is low. The biological way is to recover glucose and synthetic fibre from textile wastes. Enzymes like cellulose and β-glucosidase are used to degrade bio-degradable textiles such as cottons and wools into glucose, while the non-biodegradable textiles such as polyester and polyamide, are recovered for textile application after the enzymatic hydrolysis.