A Review on Circular Economy Approaches for Pre-impregnated Carbon Composites Mould Remanufacturing

With approximately 40% of virgin pre-impregnated (prepreg) composite waste generated during manufacturing, the need to integrate circular economy approaches into prepreg manufacturing has become increasingly urgent. This study investigates evaluates the current recycling, remanufacturing, and additive manufacturing pathways to achieve circular economy for prepregs. A characterisation of prepreg composite moulds is presented, along with an overview of carbon fibre recycling processes. This study places a specific focus on the integration of reclaimed carbon fibres into fused deposition modelling (FDM) based moulds, highlighting its potential as a Sustainable, near-net-shape Manufacturing route for prepreg moulds. A Life cycle assessment Analysis is also conducted to evaluate the environmental impact of FDM-based moulds compared to tradition materials Such as aluminium or carbon, noting that at their current technology readiness level they emit 33% more CO2 than aluminium but 27% less than carbon moulds. For low-production applications, FDM moulds demonstrate up to 50% And 21% lower environmental impact compared to aluminium and carbon mould alternatives, respectively. These findings underscore the the viability of FDM as a Sustainable tooling solution, particularly in low-volume and high-complexity applications. While FDM-based moulds offer significant advantages in design freedom, material efficiency, and sustainability, challenges such as surface roughness, limited durability, and inter-bead porosity remain barriers to widespread adoption. The study concludes that with continued innovation in Post-processing, Material selection, 4D printing, and process optimisation, FDM-based moulds have a promising potential in closing the loop on composite waste and advancing sustainable prepreg manufacturing.