Compression molding of reused in-process waste – effects of material and process factors

Effective strategies for the reuse and recycling of in-process prepreg waste are needed to reduce economic and environmental costs. In this paper, we investigate the compression molding of prepreg waste converted into scrap “chips” (or strands). Material is randomly distributed within a lab-scale closed mold and cured with control of temperature and pressure. Material properties and process parameters such as chip geometry, fiber bed reinforcement, resin state, and cure cycle are varied and shown to influence porosity and thickness. These experiments clarify the phenomena governing microstructural quality and identify manufacturing pathways for high-quality parts. In addition, mechanical properties are measured for laminates with high and low defect levels. The study demonstrates the viability of prepreg reuse. Furthermore, the resulting insights provide a basis for practical science-based optimization of the reuse of production prepreg waste.