Aligned virgin and recycled short carbon fibre hybrid composites

One of the main problems in industrial applications of carbon composite materials is recycling end of life products. Usually chopped recycled fibres are randomly dispersed in materials as low-grade additives for non-structural applications; however, in order to maximize economic and functional viability, these fibres should be reused as reinforcement for high performance structural composites. The fibre alignment level is the key factor to increase the fibre volume fraction, and consequently the performance of recycled composites. Another important factor is the impact of the fibre recovery process on the mechanical properties of carbon fibres. Carbon fibres can be damaged during the fibre recovery process leading to a significant loss of strength, but the modulus is almost the same as that of virgin carbon fibres. The aim of this research is to manufacture intermingled hybrid composites using highly aligned new and recycled discontinuous carbon fibres with the HiPerDiF (High Performance Discontinuous Fibres) method to increase the availability of recycled carbon fibres. This method enables manufacturing of discontinuous fibre hybrid composites with different fibre mixing ratios; the constituents are intimately mixed and the hybridisation is achieved within the ply. In this work, the stiffness and the failure properties of aligned short fibre composites, as a function of the recycled to virgin carbon fibres ratio, are investigated. The HiPerDiF method proved to be a valuable remanufacturing method to achieve high performance short fibre composite from end of life recycled composites.