Variable cavity volume tooling for high-performance resin infusion moulding

Abstract

This article describes the research carried out by Warwick under the BAE Systems/EPSRC programme 'Flapless Aerial Vehicles Integrated Interdisciplinary Research -FLAVIIR'. Warwick's aim in FLAVIIR was to develop low-cost innovative tooling technologies to enable the affordable manufacture of complex composite aerospace structures and to help realize the aim of the Grand Challenge of maintenance-free, low-cost unmanned aerial vehicle manufacture. This article focuses on the evaluation of a novel tooling process (variable cavity tooling) to enable the complete infusion of resin throughout non-crimp fabric within a mould cavity under low (0.1 MPa) injection pressure. The contribution of the primary processing parameters to the mechanical properties of a carbon composite component (bulk-head lug section), and the interactions between parameters, was determined. The initial mould gap (d i ) was identified as having the most significant effect on all measured mechanical properties, but complex interactions between d i , n (number of fabric layers), and v c (mould closure rate) were observed. The process capability was low due to the manual processing, but was improved through process optimization, and delivered properties comparable to high-pressure resin transfer moulding.