Dow Automotive Systems (Horgen, Switzerland) made big news at JEC Europe 2014 with the introduction of VORAFORCE, its ultralow-viscosity, fast-cure epoxy for automotive molding. Since then, says Peter Cate, global strategic marketing manager, composite structures, the company has made much progress evaluating processing of the material. Particularly promising, he says, is the wet, or liquid, compression molding (LCM) process, whereby a dry fiber reinforcement is placed in a mold, resin is applied atop the fiber, the mold is transferred to a compression machine, and then the resin is infused into the fabric via the compres- sion process. Working with KraussMaffei (Munich, Germany) and Cannon SpA (Peschiera, Italy), Dow has developed a process that, Cate says, takes 15-20 seconds for resin application and only 30 seconds for cure, for a total manu- facturing time of less than 60 seconds.
Further, says Cate, use of multiple molds in coordina- tion with one compression machine would enable the molder to dispense resin onto one mold while another is in the press, increasing throughput considerably.
A limiting factor of the technology, Cate admits, is part complexity. It’s most suitable for relatively flat or slightly contoured parts. Complex parts, Cate says, might not provide a tooling surface suitable for containment of the applied resin. In such cases, Cate says, RTM is the next best alternative. Dow is working with DowAksa (Istanbul, Turkey) fabrics and hopes, he says, to implement the tech- nology for a Tier 1 automaker before 2020.