An Efficient Thermoplastic Composite (TpC) Manufacture for High-Performance Parts: Comparison of Three Liquid Composite Moulding Processes

Abstract

[EN] Although light and performing, common thermosetting-matrix composite material cannot be recycled. Designing thermoplastic-infusion equipment is thus a technological as well as an ecological achievement. The context of the fuel-efficiency competition Eco-Marathon sponsored by Shell is perfectly suited for such an innovation. Our team is designing a process based on injecting thermoplastic monomer with initiator and activator letting the polymerization occur within the mold and thus avoiding the high viscosity of liquid thermoplastic [1]-[2]. Choosing the adequate process to produce a high performance composite part is essential. In this paper are compared three LCM processes, the classic Resin Transfer Molding (RTM), the Vacuum Assisted Resin Infusion (VARI) and Seeman¿s Composite Resin Infusion Molding Process (SCRIMP) using the example of the Shell Eco-Marathon vehicle¿s body. Our parameters of comparison are the quality of the produced part (void content) and the production time. The main issue in composite part quality is the formation of porosity. This entrapment is linked to the fiber tow impregnation and thus to the different liquid velocities within and between these fiber tows. The tow impregnation was taken in account by using an empirical model of evolution of the permeability: the more saturated the tow, the lower the permeability.