Forming strategy of CF/PPS V-shaped components using multi-point flexible molds: Relationship between process and quality

Thermoplastic composites are widely used in producing small-batch, customized aerospace components, yet their hot-stamping process still encounters challenges due to the complex fabrication and high cost of solid molds. This paper proposes a multi-point hot stamping method for thermoplastic composites, based on a reconfigurable mold and a ‘sandwich’ system comprising a flexible pad and a rigid forming plate. This method effectively addresses issues including surface indentation and uneven heating caused by multi-point molds, enabling flexible manufacturing of CF/PPS V-shaped parts. Furthermore, the effects of two key process temperatures (preheating: 300 °C–360 °C; forming surface: 130 °C–230 °C) on the geometric accuracy, internal quality, and mechanical properties were systematically investigated. The uneven confinement and compression hysteresis of the flexible pad were found to cause warpage and internal defects. However, appropriate forming surface temperature helps suppress these deficiencies caused by dynamic deformation of the flexible pad during multi-point hot stamping. The results show that at 330 °C preheating and 180 °C forming surface temperature, the V-shaped part achieved a spring-back angle of 0.37° and a normalized bending strength exceeding 94 %, demonstrating excellent stamping precision and mechanical properties. This research provides a new approach for highly flexible and low-cost manufacturing of thermoplastic composites.