Considering initial part quality and injection molding parameters in optimizing the reconsolidation of thermoplastic composite plates

In the production of thermoplastic composite parts, preheating consolidated laminates is crucial to enhancing formability and bonding during subsequent forming or overmolding in an injection molding machine. However, depending on their initial quality, preheating may cause deconsolidation of the laminate layers. This study evaluated final part quality after reconsolidation, focusing on two primary factors: (i) the consolidation quality before preheating and (ii) the effects of injection molding settings, such as clamping force and mold temperature. Consolidated polycarbonate/carbon fiber plates that differed in their properties were preheated in an infrared oven and then reconsolidated in an injection molding machine. The reconsolidated plates were assessed based on (i) thickness, (ii) warpage, (iii) apparent shear strength and (iv) void content. Our findings indicate that high press temperatures and low press pressures during initial consolidation lead to strong bonding and reduce residual stresses, which minimizes deconsolidation after preheating. Consequently, these reconsolidated plates exhibit levels of quality that are comparable to those achieved after consolidation.