Effects of automated patch placement on the mechanical performance of reformed NCF carbon fibre

Whilst there have been efforts into recycling processes for end of life composites, a waste stream that is largely ignored to date is the scrap produced by kit cutting. The few solutions that are available produce a short, randomly aligned reinforcement that cannot be used for structural applications. An approach has been developed that aims to retain the feedstock properties by cutting the scrap into patches and reforming it using the Fibre Patch Placement (F.P.P.) process. F.P.P. utilises binder applied to the fabric to place the patches on a tool. The binder already applied to the fabric is insufficient for the process to work, therefore more must be added. This work investigates the effect of additional thermoplastic polyester resin on the flexural properties and the manufacturing efficiency of the reforming process with varying binder content. Biaxial samples made up of 60mm x 30mm patches were created for three point bend tests. It was found that the addition of binder has little effect on the flexural strength of the material but a large quantity of binder will reduce the stiffness with the possible addition of "pseudo-ductile" behaviour. In terms of manufacturing efficiency, the increased quantity of binder creates a more aligned preform, which is favourable for high performance laminates.