Thermal reshaping as a route for reuse of end-of-life glass fibre-reinforced acrylic composites

Thermal reshaping has been employed to simulate the end-of-life reuse of liquid-resin-infused thermoplastic acrylic composite laminates, and the associated effects on matrix-dominated mechanical performance and microstructure have been studied. L-shaped laminates were infused at room temperature and subjected to 1 or 4 hot-press flattening cycles (25 min at 120 °C; 11 bar). Compared to the original references, up to 13% higher transverse flexural strengths were measured for the reprocessed laminates. Such a scheme may be readily implemented for high-value reuse without sacrificing fibre length scales, and with minimal cumulative mass loss over successive reheating cycles (10 cycles: 2% and 15 cycles: 2.6%). This study provides important insights to foster a greater understanding of the performance limits of hot-press reprocessing to inform the practical reuse and re-application of sustainable composites in a circular economy.