Process technology for Net-Shape-Conversion of thermoplastic tapes - stacking and consolidation
Themes: Process-Tech Forum
Partner: VDMA-Arbeitsgemeinschaft Hybride Leichtbau Technologien
Composite tapes made out of thermoplastic polymer and unidirectional fibers offer superior opportunities for lightweight design. From these, it is possible to produce load optimized blanks that are adjusted perfectly to the specific application. The blanks have areas with different thickness and the fibers are locally aligned in different fashion according to the loading conditions in service. Ideally, already during the manufacturing of the blanks, an outer shape is brought into being, that can become draped towards the composite parts without projecting edges. Then, there is no cutting of the 3D part necessary. For the production of such a net-shape blank from composite tapes, the two process steps tape stacking and consolidation are necessary. Attention must be paid to high efficiency, precision, repeatability and productivity. In the case of the tape stacking, high-precision camera measurement technology is used to obtain correction data for the robots during the ongoing stacking procedure. The robots carry out the actual stacking operations. In the case of the consolidation, where the heating-and-cooling approach is employed, a shuttle concept used in the system enables the required high production rates. The essential guiding value is the cycle time of the injection molding machine. The processing units for the tape stacking and for the consolidation must achieve comparable output as the subsequent processing, where the blanks are heated, shaped and functionalized by means of injection molding.