The setting was well-chosen: The Leading-Edge Cluster MAI Carbon organized its accompanying conference on industrialized Composite production (ICPC) parallel to this year’s Automatica in the beginning of June. Around 50 participants – mostly from southern Germany but also from the rest of Europe and overseas – had the opportunity to learn about the highlights of carbon research, development and production in 18 presentations over the course of two days and optionally visit the stands and exhibits of the Automatica as well.
“The conference is supposed to present the latest developments and encourage discussions”, explained Rainer Kehrle, manager of the Leading-Edge Cluster MAI Carbon and facilitator of the event. For Kehrle the conference is an important step towards further strengthening the network of carbon developers. The need for exchange and collaborative development is considerable. The new material system Carbon has yet to be explored and optimized in many ways – from material understanding to simulation and production.
An important aspect of the conference was the exchange amongst the research-intensive regions, where research initiatives will examine the promising composites and make them ready for the market. These are, for example, the CFK-Valley in Stade and the research campus ARENA2036 in Stuttgart next to the Leading-Edge Cluster in the Munich-Augsburg-Ingolstadt region. At the research campus, industrial developers work together with university researchers on manufacturing processes for automotive lightweight structures, said Peter Middendorf, Chair of the Institute of Aircraft Design at the University of Stuttgart. Arena has already started with two projects. Amongst other things, the researchers are developing a vehicle ground module made from composites. The demonstrator should be crash-resistant and include a variety of functions in the composite: heating, sensors and electrics. Inductive charging will also be installed right away by the researchers, the Daimler Research Officer Thomas Weber explained.
Additionally, the researchers want to develop a so-called digital prototype that includes all the necessary modeling and simulation tools for the component design and for manufacturing. This is in line with the motto: “What cannot be simulated will not be part of the vehicle,” explain Middendorf.
New manufacturing processes are intended to reduce the process costs. “The decisive factor for the use of CFRP is the price," says Mark Thiessen, Head of Sales at Compositence in Leonberg. The company has developed a method to lay the carbon fiber bundle (rovings) in a three-dimensional way with a robot arm. The robot adjusts 16 rovings simultaneously in one operating step. The endings of the fiber bundles are fixed. “The waste is low and the laying speed is high,” said Thiessen. Compositence has already integrated three applications in the portfolio: a carbon table top, an acoustic seat and a vehicle body part. There is three to seven percent waste. However, the more complex the geometry, the larger the amount of waste will be. In the next step, these preforms are then further processed into carbon parts.
The Broetje Automation from Wiefelstede has recognized CFRP as a technology of the future as well. Broetje builds facilities for the assembly of aircraft components. The product manager Raphael Reinhold introduced a production cell in which automated preforms are being brought into shape. After a technology screening, Broetje decided in favour of the RTM process. The automation specialist develops facilities for draping, part handling and trimming. A robot arm is at the center of the cell and hands the components from one production step to the next. Large quantities should not be a problem, according to Reinhold.
High quantities, low cycle times with stable and robust processes – this is what Jaromir Ufer is in charge of at Voith Composites. In the Voith process, a robot arm places the rovings on a board, which is then converted similar to a deep drawing process in the near net shape geometry. First forming tests with rectangular and hemispherical geometries went well. Currently, the laying speed of the fiber rovings is 6 kg/h. In the future, the method should be able to reach up to 80 kg/h.
Frieder Heieck from the Institute of Aircraft Design in Stuttgart and Olaf Rüger from Munich Composites presented interesting work examples. A four-meter-long CFRP tipper wall reduces the curb weight of a truck by 330 kilograms when compared to the steel version. Thus, the payload gain is at around 2 percent for light bulk material such as grain reported Heieck. The notorious braiding bike from Ottobrunn (weight below 5 kg, estimated price 11,000 euros) demonstrates the light weight potential of CFRP according to the manager Rüger. Munich Composites is a specialist for the braiding of hollow bodies. So far, the core which needs to be braided can only be used once. To reduce the material costs, engineers have developed an inflatable core comprised of elastomer, which can be removed and reused prior to infiltration of the wattle work. Rüger's exhibits are lightweight: the Carbon bicycle saddle weighs only 99 grams. The crash box of a car for energy absorption ifworstcomes to theworse, is 60 percent lighter than the original aluminum component.
Johannes Graf of Fraunhofer Institute for Machine Tools and Forming Technology and Elisabeth Ladstätter from the Chair of the Institute of Carbon Composites at the Technical University Munich reported progress in the MAI-Carbon leading project MAI Plast. It's about continuous process chains for thermoplastic CFRP in large-scale production. The goals: lower costs, higher quantities. Various approaches and technologies should be considered and evaluated. The initial situation describes Ladstätter as follows: So far, it takes around 12 minutes to cure a carbon car roof. In the future, this should be possible in 1 to 3 minutes.
Further presentations demonstrated examples from the aircraft industry, discussed possibilities of quality assurance in automation as well as the state of the modeling and simulation of CFRP components. “There is a lot happening rapidly” summarizes a conference participant his impressions.
Attentive participant sat the ICPC of MAI Carbon