FOR AUTO RTM

Mubea Carbo NEWS Tech
automotive customers, as well as room to
expand. A Mubea production site for more
than 20 years, it also has the necessary
infrastructure in place — human resources,
a skilled work force and logistics, including
material handling and shipping.
“After prototyping is completed in
Salzburg, production is installed here,”
explains Karas. Salzburg still handles all
motorsports production, while Žebrák
is focused on higher volumes, already
producing thousands of parts each week,
including side sills, front and rear spoilers
for Bentley (Crewe, UK), visual carbon
rear wing and blades (air intakes) for the
Audi (Ingolstadt, Germany) R8 carbon
option, visual carbon seats for Volkswagen,
rear sills and other body parts for General
Motors (Detroit, MI, US) and LEAR seats
as well as structural parts for Porsche
(Stuttgart, Germany). An example of the
latter is the Spyder 918 front subframe,
which supports the electric motor and
wheels and integrates the air filter box.
Much lighter in weight than the previous
steel parts, this subframe and the car’s
monocoque tub (built in Salzburg) help
to deliver the highest power output per
liter for a naturally aspirated (not turbocharged)
Porsche engine.
This facility is also ISO/TS 16959 and
ISO 14001 certified. The former, an automotive
supply standard, isn’t typical for
CFRP parts producers, but in the auto
industry, “it means we are serious about
serial production,” says Karas. The whole
building is climate-controlled to room
temperature (21°C) and 50% relative
humidity. Its ventilation and dust-extraction
system is equipped with special filters
in areas exposed to carbon dust.
CW’s tour begins in the LP-RTM production
area (see Fig. 3, p. 55), which contains
six machines equipped with separate mix,
meter and dispense (MMD) equipment for
mixing and injecting the resin (see “Learn
More”). LP-RTM presses are sourced from
Langzauner (Lambrechten, Austria) and
Hidroliksan Halim Usta (Konya, Turkey),
while MMD units are from a variety of
suppliers, including DOPAG (Cham,
Switzerland).
“We can process preforms up to 10 mm
thick,” notes Karas, “but the standard
SIDE STORY
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 aluminumspoke/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.
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 lowpressure
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 HP-RTM: 3-minute cycle
out. “It’s the engineering and
MCT’s latest HP-RTM installation in Žebrák features automated
preforming (top) and injection and a 2,500-ton press
design expertise and the production
experience that enable a for serial production of parts with cycle times of less than 3
part to be made successfully. minutes. Source | Mubea Carbo Tech
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.”
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