PRECARBIProject ID: 30848
Materials, Process and CAE Tools Developments for Pre-impregnated Carbon Binder Yarn Preform Composites
Composites are the material of choice for many advanced aircraft structural applications (A380 28% and Boeing 787 50% content) and have proven weight/performance superiority over metals. The critical issues today are performance improvements, development of faster, more cost effective manufacturing and simulation tools to optimise their manufacture and design. Today manufacture of advanced composites uses either layers of pre-impregnated plies (prepregs) to form a laminate, or resin infusion of dry textiles (Liquid Composite Moulding LCM). Prepreg composites give superior mechanical properties due to toughened resins well dispersed in a carefully controlled fabric architecture, but suffer from high material costs, limited shapeability, complex/expensive manufacturing and limited shelf life. LCM technologies can overcome many limitations, but must use low viscosity resins for infusion and suffer from fiber misalignments due to textile patterns, both of which lead to poorer mechanical performance intolerable for many structural aircraft applications. The PreCarBi project will develop new materials (carbon fibers and liquid resins) as well as supporting technologies, already proven on a laboratory scale, that bring together prepreg and LCM technologies to combine the advantages of each. Essentially pre-impregnated carbon fibers with a polymer binder formulation are developed for LCM and tow placement processes. Activation (e.g. heat, microwave, ultrasound) allows binder yarns to be (repeatedly) shaped prior to resin infusion. The binder yarns enhance mechanical properties, due to their formulation and ability to eliminate fibre waviness; also, they have indefinite shelf life, improve pre-form handling/trimming and drapeability. The combination of superior performance and cost effective manufacture will ensure composites growth in future aircrafts leading to improved performance, greater payloads and fuel/emissions reductions.