KraussMaffei: Lightweight hydrogen tanks of the future

Short cycle times support series production

The specific defining features of the KraussMaffei RimStar series mixing and metering systems are their flexibility and high product quality with low scrap rates. One example of where these advantages shine is in conjunction with HP-RTM (high pressure resin transfer molding) processes. “High-pressure injection using the RimStar series enables the processing of fast-reacting resin systems. This makes it possible to quickly fill the mold for fiber-reinforced components to the benefit of shorter cycle times,” explains Steffen Bauer, the sales manager for reaction process machinery in Germany at KraussMaffei.

Rehau is using the process at its Viechtach location to research new methods for developing thick-walled hollow components in lightweight design, such as hydrogen pressure tanks for vehicle manufacturing. The goal is to achieve process control capable of supporting large-scale series production for these kinds of components. Collaboration with KraussMaffei began back in the prototype development phase. As a result, initial component tests regarding the mold concept and high pressure resin transfer molding technology in the technical center for lightweight construction took place at KraussMaffei’s facilities. The results this provided were successively integrated into ongoing development and formed the basis for the design of the high pressure RTM system for Rehau’s new technical center for lightweight construction.

Perfect premixing

Rehau’s RimStar-Compact 8/4 HP-RTM is equipped with a MJH 10P-2KV-HM mixing head. This ensures perfect premixing of resin and hardener and works according to the self-cleaning principle. Release-agent metering at the mixing head, including the corresponding release agent station, complete the efficient mixing head system. Systems with demanding processing temperature requirements can be metered to perfection with RimStar high pressure RTM metering machines. High-pressure engineering ensures that the components are thoroughly mixed in the mixing head.

Investment in the future

The technology developed in-house at Rehau for manufacturing hydrogen tanks is to transition from the laboratory to production scale at the Viechtach production location. To accomplish this goal, the company invested 3.4 million euros in special systems engineering within the plant. “This decision is a significant step towards the future for us—to drive the development of new technologies and to make an important contribution to maintaining job security at the plant location,” says Martin Wippermann, Member of the Executive Board for Rehau Automotive. “Our customers demand that we lead the way with new ideas and efficient solutions, that we support them in engineering mobility fit for the future, that we develop environmentally friendly systems that reduce resource usage and grow those systems to support series production for the market.”