Hot Double-Sided Incremental Forming of Fiber-Reinforced Thermoplastics: Process Capabilities and Challenges

Fiber-reinforced thermoplastics (FRTP) offer high strength-to-weight ratios as well as weldability and recyclability, making them attractive for lightweight applications. Conventional thermoforming of continuous FRTP, however, requires part-specific molds, limiting economic viability for prototypes, individual parts, and small series. This study investigates a robotic hot double-sided incremental forming (DSIF) process developed for dieless, flexible forming of continuous FRTP sheets together with metal dummy sheets. Five different generic demonstrator parts with varying wall angles, degrees of symmetry, forming depths, and sizes were formed to assess process capability. Results demonstrate that typical defects such as fabric wrinkling and deconsolidation can be successfully avoided, and that the geometric accuracy achievable is comparable to that of metal DSIF. Challenges exist in forming larger parts due to the failure of the employed metal dummy sheets.