Impregnation and Consolidation in Composites Made of GF/PP Powder Impregnated Bundles

Abstract

A polypropylene (PP) powder impregnated glass fiber (GF) bundle system was selected to investigate the relationships between impregnation mechanisms and pro cessing conditions during consolidation of these materials. Microscopy of cross-sections and density measurements helped to examine the quality of impregnation and consolida tion. Based on microscopic observations and previously developed processing theories, an impregnation model for the qualitative description of the consolidation behavior in lami nates made out of these materials is generated. It can be used to describe variations in void content over the laminate thickness as a function of bundle geometry and combinations of processing variables. The relationships between processing temperature, holding time and applied pressure required to reach full consolidation were evaluated. Results of transverse flexural tests are used to correlate the mechanical properties with the impregnation quality, in particular the void content in the laminates. Finally, the optimum processing window for manufacturing of laminates out of this material is suggested.