In April 2022, five companies, including Japan-based Teijin Ltd., collaborated on the development of a breakthrough solution addressing the problem of disposing of discarded polyester fishing nets.
While the process for recycling nylon fishing nets is a well-established one, polyester fishing nets still present a challenge. Lacking a dedicated process, it is expensive to recycle these and technically more difficult. So in Japan, polyester fishing nets have, over the past years, accounted for about 1,300 metric tons of landfill waste annually.
The process launched by Teijin and its partners is a game changer, a mechanical recycling solution that covers the trajectory from collection of the fishing nets to their reprocessing into resin suitable for converting into commercially marketable trays and stationery.
The three-step process is relatively straightforward: first, the used fishing nets are collected; then they are cleaned, then pelletized and made into a resin product.
Initially, the partners faced two major tasks. First was the challenge of developing a technology capable of cleaning smelly, waterlogged fishing nets and stripping the polyester of the coatings applied to improve durability. Teijin and the other partners eventually identified organic solvents that can be used in an environmentally friendly cleaning process to produce virtually odorless resin that can be recycled repeatedly.
The second big challenge was profitability. The low cost of virgin PET meant that the recycled resin would not be price competitive if cleaning and drying it raised the costs too high. To improve durability and heat resistance, the companies mix virgin ABS into the recycled PET.
The result is a commercially viable resin recycled from fishing nets that is now being used, for example to produce food trays for a restaurant chain in Japan. The trays are not in direct contact with the food, and are therefore not required to comply with the Food Sanitation Act.