Recycling concepts for short-fiber-reinforced and particle-filled thermoplastic composites: A review

Short-fiber-reinforced thermoplastic composites (SFRTCs) and particle-filled thermoplastic composites (PFTCs) are widely used in various industrial sectors, from automotive to electronic appliances, from building constructions to domestic equipment. Their environmental impact could be significantly reduced through both open and closed loop recycling, which allows a reduction of the usage of new resources and limit the energy consumption and CO2 release associated to their production. The main challenges and opportunities in the recycling of SFRTCs and PFTCs are currently represented by i) reprocessing (also called mechanical recycling), use of recycled matrices ii) use of recycled fibers, iii) use of waste composites, iv) chemical recycling. Opportunities and current limitations in the recycling strategies and technologies for SFRTCs and PFTCs are here reviewed.