Researchers from Fraunhofer Institute for Manufacturing Engineering and Automation IPA have, together with industry, developed a high-precision processing machine that not only shapes carbon fiber reinforced polymers (CFRP), but also handles post-processing in its entirety. CFRP parts can therefore be processed up to 50% more economically.
Irrespective of whether trucks, buses, automobiles, bicycles or scooters, in future, a common feature of all these modes of transport is that they will be powered by electric drive systems. Another feature in common is the lighter the vehicle, the longer the battery service life. Carbon fiber reinforced polymers (CFRP) are well suited as chassis material for all these vehicles. CFRP offers a similar level of stability to steel, but is approximately eight times lighter. Even aluminum weighs around three times more than CFRP. However, the manufacturing and processing costs for CFRP components remain high.
Many of the tasks are still currently handled manually. Workers take freshly milled components from the machine, remove any remaining fibers and clean up the part before the edges can be sealed. Philipp Esch of the Department for Lightweight Construction Technologies at Fraunhofer IPA takes a critical view here: “This is not a reliable process, as individual workers may assess an edge differently on a subjective basis”. In addition, the fine CFRP dust generated during the milling process is harmful to health and abrasive, and if the dust settles on machine components, it also increases the degree of wear and tear.
Producing CFRP components would be up to 50% more cost-effective if there were a machine that could not only process these parts, but was also able to handle automated measuring and sealing. Esch and other researchers at Fraunhofer IPA have now developed just such a machine in conjunction with Homag Holzbearbeitungssysteme GmbH and other partners from industry. An operational demo prototype of this processing machine is located in a production hall at Fraunhofer IPA.
When an NSC (near-net-shape) produced CFRP component is fed into the machine, high precision milling will shape it into the desired form. An abrasive brush is then used to remove any remaining loose fibers and extraction jets blast away the fine CFRP dust, which is filtered off before being expelled into surrounding air. This also avoids premature wear and tear of the machine.
A sensor scans the CFRP part using strip light projection technology to generate a point cloud. This enables special algorithms to detect any variation from the ideal contouring for the component concerned. If the variations are within the defined tolerance range, the processing machine will subsequently seal the edges using a liquid paint. The part is then irradiated with UV light and hardened immediately – the component is ready.
“We have developed a modular, fully integrated machine concept”, Esch explains. The individual process steps can therefore be carried out in any order, combined with others and adapted to components of other shapes and sizes. CFKComplete does not have to be predefined for the component, either: “Irrespective of whether we are dealing with wood, aluminum or other metal components, our machine is able to mill, post-process and finish the parts equally effectively”, Esch adds.
The researchers and project partners are keen to underline that they can easily adapt the processing machine to the needs of prospective users.
Fraunhofer Institute for Manufacturing Engineering and Automation IPA