COLUMBUS, Ohio—A unique, automated production platform developed by a French industry consortium—and utilizing an epoxy resin system from Hexion Inc.—is reported to have demonstrated the feasibility of manufacturing large, net-shape composite parts at industrial scale. It is said to offer a model for automotive manufacturers seeking to integrate weight-saving structural composites into their mass production vehicles.
The fully automated manufacturing platform, developed by the French FastRTM consortium led by the Institut de Recherche Technologique – Materiaux, Metallurgie, et Procedes (IRT M2P), consists of a press, modular tooling, high pressure injection machines, and temperature-controlled flow tube technology. It also includes two 6-axis robots, online monitoring and control, and a fast-cure resin system from Hexion (www.hexion.com/en-US). Together, the equipment and materials enable an innovative process called compression resin transfer molding (C-RTM).
In this two-step process, Hexion’s resin system—Epikote™ Resin Trac 06170 / Epikure™ Curing Agent Trac 06170 /Heloxy Additive Trac 06805—is injected into a mold with a preform, a preliminary fiber shape, when the press is slightly open, allowing for partial impregnation. Then, a compression stroke presses the resin through the preform for complete impregnation. This allows for very fast resin injection and curing—from 15 seconds to one minute—and less than two-minute part-to-part production.
“Hexion is proud of the contribution we have made to the success of the FastRTM project, which closed in December,” said Ann Frederix, Hexion’s senior vice president, epoxy specialties, in a press release. “In its last year, the consortium achieved some major milestones, including a final, successful mass production session.”
This final manufacturing session is reported to have demonstrated automated production of 100 large (1m²), complex, net shape glass-fiber reinforced plastic structural parts in two-minute part-to-part cycle times. It reportedly demonstrated curing times as short as one minute per part with no need for machining or trimming post-production. It also simulated “start and stop” with no adverse reactions in the process, and produced consistently high-quality parts with excellent mechanical performance and uniform impregnation (no fiber distortion, dry spots, or unfilled resin at ends), according to the release.
The epoxy thermoset composite parts made with the Hexion resin system can also be recycled or recovered at the end of their useful life via mechanical recycling, thermal recycling, and chemical recycling.
The FastRTM project was led by the IRT M2P, a research center that brings together industrial and public research entities to accelerate innovation and develop key technologies, based on public-private co-investment and partnership.