Mechanical recycling process: An alternative for a viable disposal of carbon fiber‐reinforced thermoplastic waste

Abstract

AbstractConcern for the environment has increased the interest of the automotive and aerospace industries in evaluating the feasibility of mechanical recycling of waste carbon‐fiber‐reinforced polymer composites (CFRP) and waste from protective films used during the transport and storage of thermosetting composites, which are removed and discarded during manufacturing. Therefore, this work aimed to develop a recyclable composite from protective film waste by incorporating carbon fiber/poly(aryl ether ketone) (CF/PAEK) composite particles obtained through grinding in knife mills, followed by an analysis of the particle size distribution. Protective film residues (PEres) were cut to facilitate processing. A mixture of low‐density polyethylene and PEres (50/50) was used as the composite matrix, and 5, 10, 15, and 20 wt% CF/PAEK composite particles were added as the reinforcing agents. Then, these recycled composites were prepared by melt mixing using a twin‐screw extruder and injection molding to obtain standardized samples. Mechanical, thermal, electrical, and electromagnetic properties were evaluated. It was possible to observe that the increase in the addition of CF/PAEK composite particles contributed to a 290% increase in elastic modulus values and a 9.1% increase in Shore D hardness, electrical conductivity, and attenuation of the electromagnetic wave. Furthermore, satisfactory adhesion between filler and matrix contributed to a good interface and reinforcement of the final material.Highlights Mechanical recycling by extrusion of waste from the automotive and aerospace sectors Grinding of carbon fiber/poly(aryl ether ketone) composite waste to be used as filler Protective film waste used as matrix Composites developed with waste with good electrical and electromagnetic properties The addition of thermoplastic composite residues does not affect thermal and mechanical properties