Manufacturing Multi-Matrix Composites: Out-of-Vacuum Bag Consolidation

The formation of porosity is a major challenge in any composite manufacturing process, particularly in the absence of vacuum assistance. Highly localised injection of polymer matrix into regions of interest in a dry preform is a route to manufacturing multi-matrix fibre-reinforced composites with high filler concentrations, which are otherwise difficult to achieve. Unlike traditional composites, such multi-matrix fibre-reinforced composite systems, which combine multiple resins in continuous form, offer improved structural performance around stress concentrators and multifunctional capabilities. As the process lacks vacuum assistance, porosity becomes a primary issue to be addressed. This paper presents a rheo-kinetic coupled rapid consolidation procedure for optimising the quality of localised matrix patches. The procedure involves manufacturing trials and analytical consolidation models to determine the best processing program for minimal voidage in the patch. The results provide a step towards an efficient manufacturing process for the optimal design of multi-matrix composites without the need for complex vacuum bag arrangements, thus reducing cost and time while opening avenues to improve overall composite performance.