Media Based Forming and Injection Molding Based on Fiber Reinforced Plastic Tubes

Research and development for industrial applications forces Fraunhofer IWU to explore new fields of technology. The combination of Media Based Forming and Injection Molding (MBF-IM) in a single process is such a new development to meet the requirements on lightweight design and resource efficiency. Based on over 20 years of Fraunhofer IWU experience in hydroforming, this technology development started with the usage of metal tubes and PA6 with glass fiber to produce metal-plastic-hybrid-components the structural strength of the component is realized by the formed metal tube while the molded attachment allows for easy functionalization. Cockpit cross beams (CQB) are known state of the art components produced this way. In a first development step the conventional hydroforming process was replaced by media based forming (MBF) using nitrogen as a pressure medium. With this process the tool can always be kept dry for the injection molding (IM) process without any additional effort, and no subsequent part cleaning is necessary. Together with TU Chemnitz and industrial partners further developments are continuously carried out and still under research. The focus of this strategic cooperation is the development and the usage of plastic tubes for the structural function of the component. The paper shows the development path from the state of the art for the MBF-IM from metal-plastic hybrid components to the replacement of the liquid active medium for the MBF by gaseous nitrogen, the use of endless fiber-reinforced plastic tubes as semi-finished products to the MBF-IM of short-fiber-reinforced plastic tubes.