HP-RTM: A means, not an end
The parts running on the Mubea Carbo Tech Salzburg facility’s HP-RTM line during the CW tour were all-carbon fiber/epoxy car wheels, measuring 508 mm in diameter with a 229-mm rim, weighing in at 8 kg for a 30% saving vs. an 11 kg high-end aluminum wheel. An aluminum-spoke/CF-rim hybrid — which Siegmann says took five years to develop and uses patented technology — saves 20% at 9 kg. When multiplied by four wheels per vehicle, “no single other component on a car can deliver this much weight reduction,” says Siegmann, noting that MCT can sell these at any point in the vehicle production timeline: original model design at the OEM, mid-production retrofit and aftermarket retail. When asked about several competing CF wheels now entering the market, Siegmann replied, “We aren’t afraid of competition. It adds credibility, and OEMs don’t like single-source technology.”
The Salzburg HP-RTM machine is not as automated as the equipment under installation in Žebrák (see photos at left). When asked what size of parts the machine can make, Siegmann explains that the maximum part size is determined by the press size, injection system capability and cure time of the resin. “Our HP-RTM bed here is 2.5m by 2.5m, so we can make parts up to 2m by 2m,” he says. He notes that if it is possible to use low-pressure RTM (LP-RTM), “we can make much bigger parts on the same equipment.” This leads us back to discussing the palette of processes that MCT has at hand, and a strong statement about that palette’s relative importance at Mubea Carbo Tech. “A press or piece of equipment does not produce parts,” Siegmann points out. “It’s the engineering and design expertise and the production experience that enable a part to be made successfully. We’ve made over 1 million parts, and know where we need to add automation and where we need to improve equipment.”
“We are not waiting for suppliers to demonstrate a new press,” he adds. “They build machines. They don’t know the realities of CFRP part production.”
This article is a sidebar to a feature story. To read the main article, click on "Mubea Carbo Tech: High-quality auto composits go high-volume" under "Editor's Pick's" at top left.
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