Study of the deepdrawing process of technical textile reinforced thermoplastics

Technical textile reinforced thermoplastics have recently emerged as promising engineering materials for shell-like structures. They combine the load bearing capacity of technical textiles with the damage tolerance and thermoformability of thermoplastic matrices. Thermoforming processes like matched-metal die forming, rubber stamping and diaphragm forming are typical production processes to form 3D shell structures. This research focuses on deepdrawing as an alternative to thermoforming. It is a feasibility study of the deepdrawing process for Twintex woven fabrics. During deepdrawing, undesired wrinkling can occur. To investigate the mechanism of wrinkle formation, an experimental process parameter study has been run. Throughout the experimentation, visual inspection is used as quality evaluator for the deepdrawn cups.Wrinkle formation during fabric shear has shown to be strongly dependent on drawing velocity, temperature of the sheet and blankholder forces. Maintained product quality up to a high deepdrawing velocity (200 300 mm/s) opens perspectives with respect to short cycle times.