Automated continuous fabrication of load-path adapted thermoplastic fiber prepregs

Due to the lack of suitable production processes, most up-to-date composite components show a rather simple shell design with constant laminate build-up. Such designs are also known as "black metal" and lead to high costs and incomplete material utilization. In contrast, a special load-path adapted design with a high utilization of deployed materials can increase the lightweight degree and reduce costs at the same time. This paper proposes a first practical approach to provide the automated continuous fabrication of load-path adapted thermoplastic fiber prepregs in a calendaring process. For the complete impregnation of the textile, additional matrix is added in powder form in order to ensure a homogenous fiber volume ratio. An adjustable powder application system is proposed, which can be directly integrated into the calender and is able to follow the load-path adapted design routes provided as continuous semifinished material. A sensor-driven control strategy for the application module is presented in order to cope with the challenge of synchronization of the conveyed semifinished textile with the positioning and powder dosing mechanisms of the application system.