Pultrusion and compression molding are combined in the PullPress process developed by Secar Technologie and Evonik to produce complex carbon composite parts that include light weight rigid foam structural cores.
Potential applications range from automotive chassis parts to aircraft components. Evonik says the material has excellent mechanical properties, even at higher temperatures.
The process is said to be about 30 to 60 percent more cost-effective compared to resin transfer molding. Foam cores are produced by LiteCon GmbH (Austria), a joint venture between Evonik and Secar Technologie GmbH. PullPress uses a proprietary pultrusion technology developed by Secar, which was founded in Austria in 1988.
The LiteCon Advanced Composite Products joint venture was established in Hönigsberg, Austria two years ago to mass-produce fiber-reinforced composite components for the automotive and aviation industries. Evonik supports the JV with its materials development expertise, particularly Rohacell structural foam.
Evonik developed a new in-mold foaming process (IMF) for its rigid foam for manufacturing complex geometries. For Rohacell Triple F, PMI granules in the desired density are foamed into a finished foam core in a mold. Metallic parts such as threaded inserts can be directly integrated during the foaming process. Rohacell Triple F is compatible with conventional resins such as epoxy. Thermoplastic materials can also be set directly in the mold as a cover layer.
Previously, it had been necessary to produce blocks that were subsequently machined in order to make complex shapes from hard plastic foams for sandwich components. The high waste rate combined with manual work made the process cost prohibitive.