Automated 3D Skeleton Winding Process for Continuous-Fiber-Reinforcements in Structural Thermoplastic Components

Continuous fiber reinforcements can significantly improve the mechanical properties of thermoplastic injection-molded components compared to short and long fiber reinforcements. By aligning the continuous fibers in the main load paths, the reinforcement can be optimally exploited. The 3D skeleton winding process (3DSW) is a robot-based filament winding technique in which defined load application points are connected with wound closed loop structures. The introduction of thermoplastic commingled yarns in the winding process allows an efficient fiber impregnation to produce fiber skeletons that can be overmolded in an injection molding process to locally reinforce the final component. The combination of a robot-based winding process and injection molding as a process for large-scale production enables the use of thermoplastic materials for complex structural applications in higher quantities. This paper presents the 3DSW manufacturing process and introduces a simple loop and a generic 3D test specimen. Fundamental investigations into these structural components with overmolded fiber skeletons demonstrate the potential of continuous fibers in injection molded components made from PP and PPS.