Optimization of multistep forming process for thermoplastic composite parts: Process parameters and simulation

Press forming of Fibre Reinforced Thermoplastics (FRTP) is a widely used manufacturing process. However, in order to boost innovation in FRTP production, new manufacturing strategies have to be implemented. In this context, the multistep forming process represents a promising concept for achieving a higher level of performances by means of customized fibre orientations, fibre types, fibre architecture, and thicknesses, but also higher product functionalities through the combination of different polymers in the same product. In order to improve the functional efficiency of FRTP components, this paper investigates the optimization of a multistep forming process of glass fibre fabric combined with polyetherimide (GF/PEI). The deformation mechanisms encompassing the multistep forming process is here analysed, along with the understanding of the effects of process parameters (e.g. temperature and pressure) over part quality. In particular, the feasibility of the reduction of the cycle time of the process is evaluated by means of active cooling. In addition, in order to foster future industrial application of multistep forming processes, robust and reliable process simulations are presented aiming at reducing development times and improving the overall cost-effectiveness.