A collaboration between researchers from Cardiff University and Haydale conducted a study focused on component-scale hierarchical composites using nanocarbons, mainly graphene and CNTs. The team's main aim was to explore techniques for component-scale manufacture of hierarchical composites by liquid infusion.
A plasma process, developed by Haydale, was adopted for controllable functionalization of large batches of nanocarbons (100s of grams) prior to mixing with epoxy resin. A rheological study indicated that filler morphology, functionalization and fill weight all have an effect on epoxy resin viscosity. Using these developed nanocomposite resins, a resin infusion under flexible tooling (RIFT) technique was developed. Resin flow studies informed an optimum setup that facilitated full wet-out of large area UD carbon fibre laminates and the resulting materials showed significant improvements in mechanical properties, demonstrating up to ~50% increase in compression after impact (CAI) properties.
The RIFT process and tooling were further developed to enable the manufacture of I-section stiffeners and the production of component-scale (0.9x0.55m) stiffened panels was demonstrated. The scalability of the Haydale graphene plasma functionalization technique, resin mixing and resin infusion processes has been demonstrated by the manufacture of component-scale stiffened composite panels. The advances in composite material strength and stiffness should be of considerable interest to the aerospace and automotive industry in particular.