Effect of tool temperature on dimensional fidelity and strength of thermoformed polyetheretherketone composites

This article presents an experimental study of the effect of tool/consolidation temperature on dimensional fidelity and curved beam strength of thermoformed carbon/PEEK composites made of continuous fibers and random oriented strands (ROS). When processing continuous fiber carbon/PEEK composites, higher tool/consolidation temperatures give higher curved beam and inter-ply strength and more repeatable process induced deformations. Spring-in increases with tool temperature but the spring-in is repeatable and flange warpage is reduced because of lower resin viscosity and increased material flow during consolidation. For the ROS material form, no increase in curved beam strength was observed with higher consolidation temperatures and failure was not governed by the inter-ply strength of the laminate because of the shorter fibers. Lower tool/consolidation temperatures gave less spring-in and flange warpage was not dependent on consolidation temperature. Spring-in for both material forms was found to be thermo-elastic with no effects from crystallization shrinkage.