The German Aerospace Center reports progress in cutting production times of aerospace composite components with RTM 6 epoxy resin, which has a curing time of 90 minutes or more.
About 30 to 40 minutes of cycle time have been cut by splitting cure time between a heated mold and an oven. The current production rate in the test production system is 10,000 to 20,000 parts per year.
“The next step is to optimize or replace sub processes,” project leader Sven Torstrick told The Molding Blog. “We are working on different sensors to make the whole process more transparent and efficient or integrate different technologies of gripping, draping and cutting. We can now test different textiles and examine how they behave during the process while keeping all parameters in an automated and reproducible environment.”
The production line was set up to have an infrastructure for doing research. “Our goal is a better understanding of the whole process in matters of production rate, quality and cost.”
The parts in the first approach are typical frames of a short range aircraft fuselage. “Our current part is not a real part of an existing plane, but more like a ‘franken-frame’ that includes difficulties that can occur in real parts.”
It is a curved Z-shaped profile with varying radius and width. Also local reinforcement patches and different NCF-materials (UD, Biax, Triax) are used. The line is able to produce part sizes up to 2m by 2.5m and about 0.4m height.
The German Aerospace center awarded a contract called EvoRTM to Global RTM in 2011 to design and manufacture the automated RTM line with the goal to manufacture 100,000 primary carbon parts. The line was installed in 2012,
“If the requirements and the resin system were different, higher rates would be possible,” says Torstrick.
Other research groups around the world are looking at the potential for thermoplastic composites in an effort to speed cycle times and make for complex shapes.