Increasing the recycling rates of post-use fishing ropes: the role of cleaning processes and the possibilities of a systematic Individual-Producer-Responsibility implementation

Abstract

Plastics from fishing gear represent a significant source of marine pollution, with post-use fishing ropes made of high-density polyethylene (HDPE) and polypropylene (PP) posing both environmental challenges and recycling opportunities. This study investigates the mechanical recyclability of post-use fishing ropes and the effect of washing processes on material recovery. Used ropes collected from Vietnamese fisheries were sorted, subjected to up to five washing cycles, and analyzed through FTIR spectroscopy, differential scanning calorimetry (DSC), and mechanical testing. Results indicate that washing significantly reduces surface impurities, leading to improved flexural modulus and yield strength of the recyclates, while impact strength remains largely unaffected. Both old bright (OBR) and old dark ropes (ODR) retain accessible crystallinity and mechanical properties comparable to virgin material when optimally washed. The study demonstrates that the mechanical properties of recycled material are sufficient for reintegration as up to 25 % recyclate in new fishing ropes, supporting circular economy goals and forthcoming EU requirements for recycled content. Our findings underscore the feasibility of closed-loop recycling for fishing gear polymers and advocate for integrating washing steps and producer responsibility schemes to improve material circularity and reduce marine plastic pollution.