Integration of Thermoplastic Films into the Compression Resin Transfer Molding Process
Themes: Leichtbau, Thermoplastics, Thermoplastics
The Compression Resin Transfer Molding (CRTM) process is increasingly used in the automotive industry. For instance, the rear wall of the Audi A8 is manufactured in series using CRTM (process naming: ultra-RTM). By including the tool position in the process control, cycle times and process pressures can be minimized. In recent years, the Chair of Carbon Composites at the Technical University of Munich has been carring out various research projects to integrate thermoplastic films in Liquid Composite Molding (LCM) processes. Films can be used for various purposes, i.e. as surface finishing, separating layer or sealing. In this context, the Film-Sealed Compression Resin Transfer Molding (FS-CRTM) process was developed, which integrates thermoplastic films as a process aid material into CRTM. By encapsulating the preform in-between films, the resin does not come into contact with the mold during preform impregnation. This eliminates the need for conventional sealing concepts and opens up new design space for LCM-molds. Tools with slider technology can now be increasingly used for automated composite production of complex part geometries with e.g. undercuts, as it is already standard in other industries such as injection moulding. Proof of concept of the FS-CRTM process has already been shown an a process-specific test stand and the novel process is currently being further researched at the TUM.