An investigative study on the compression moulding process to manufacture fibre-reinforced epoxy composites using recycled carbon and glass fibres

The progress in recycling fibre-reinforced polymer (FRP) composite wastes has increased awareness among the recycling industries to realise the opportunity to convert the wastes into marketable raw materials. Especially FRP composites containing pricey carbon fibres (CFs) and glass fibres (GFs) have become the primary targets for recycling. Currently, closed-loop recycling (CLR) approaches are popularly adopted to recycle carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) composite wastes recovering the CFs and GFs. Recycling, reusing and remanufacturing are three fundamental stages involved in CLR approaches. Numerous researches have managed to recover the CFs and GFs with maximum efficiency, including the recycled fibres (rFs) strength similar to their virgin fibres. However, there are specific existing research gaps to be solved in remanufacturing and reusing stages. Often the remanufacturing process depends on the structure of the rFs. More prolonged and continuous fibres have several remanufacturing options compared to short and randomly oriented rFs. Typically for virgin CFRP and GFRP composites, compression moulding (CM), injection moulding and vacuum-based resin transfer moulding processes were used. However, taking mass manufacturing into account, a traditional process such as CM was focused. In this study, the CM process was investigated to remanufacture the recycled CFs and GFs employing commercially available laminating epoxy resin. The newly produced composites were macroscopically and microscopically examined to evaluate the CM performance. Furthermore, discussions over the pros and cons of the CM process from various point of view were included focusing on improving the mechanical properties of the new composites.