The high performance discontinuous fibre (HiPerDiF) method for carbon-flax hybrid composites manufacturing

The composite material industry is not immune from growing environmental concerns. Two are the main solution that have been proposed so far: waste recycling and bio-based materials. The thermosetting-based composites recycling is a two-step processes: a fibre reclamation stage, where the fibres are retrieved by degrading the matrix, and a remanufacturing stage to produce a reusable material. However, independently from the process, reclaimed fibres are averagely fragmented in short length and a remanufacturing process able to achieve high fibre alignment is the key factor to deliver commercially valuable and high performance recycled composite materials. Natural fibres, e.g. bamboo, jute and hemp, are considered a valid structural alternative to synthetic fibres. In particular, flax fibre composites are lighter and cheaper than glass fibre composite with comparable specific tensile stiffness and strength. The possibility to use the HiPerDiF (High Performance Discontinuous Fibre) method to manufacture highly aligned discontinuous fibres intermingled hybrid composites with flax and reclaimed carbon fibres (rCF) is investigated in this paper. Intermingled flax/rCF hybrid composites are then characterised in terms of tensile and vibration damping response. It is concluded that natural/reclaimed fibre hybrid composite can be a viable solution for those applications where a reduction in primary properties is an acceptable trade-off for the enhancement of secondary properties and the reduction of costs.