Carbon fibre reinforced plastic (CFRP) is increasingly being used in the automotive industry. Overall it makes for lighter and therefore more fuel-efficient vehicles. Even complex components like side panel frames, for example, are now made of CFRP. But how can you guarantee the efficient and high-quality mass production of these elements?
When it comes to the finishing of complex geometries, the specialists in automotive component systems (ACS) at KraussMaffei Technologies in Viersen have found an interesting solution. Among other things, the experts in toolmaking and trimming systems are developing robot systems for the serial finishing of CFRP components. The composites experts at LMT TOOL SYSTEMS are also involved as tool partners. Joint pilot projects for automotive OEMs and suppliers are currently being carried out with considerable success.
In order to be able to manufacture composite components in high-volume production processes, the machines used must guarantee a high degree of quality and process reliability on a sustainable basis. One of the key processes here is final trimming. “Essentially there are two competing techniques. While waterjet technology has clear advantages when applied to thin-walled components with simple shapes, machining become more interesting as the complexity of components increases,” explains Jörg Rommelfanger, the engineer who is in charge of robot systems at KraussMaffei Technologies.
Advantage robot technology
The company develops robot systems for use in the final machining of CFRP components. One of the many advantages of this technology is its flexibility in the production process. Several components can be processed simultaneously in one robot cell. Tool changes for different machining operations are possible within the processing cycle. As a result, the machining of the components is completed in one cycle – from roughening and finishing through edging and grooving to drilling and other applications.
Technology partner LMT
LMT ONSRUD and LMT BELIN are important technology partners for KraussMaffei. As part of LMT Technology Group, both develop precision tools for the machining of plastic and composite materials. Attention here focuses especially on high-speed machining, as Martin Danielczick, manager of the Plastics and Composites Segment within LMT, emphasizes: “Ultimately, it is important to produce smooth, straight and burr-free cut edges using high feed rates. Cutters, drills, reamers and specialized tools that have been developed by LMT for specific applications are precisely tailored to the requirements of composite materials. Their cutting geometry, the coating and the tool substrate ensure that delamination cannot occur and perfect cut edges are produced.
Successful pilot projects
By working together, KraussMaffei and LMT are improving the final machining of CFRP components. Various pilot projects are currently running with automotive OEMs, supplier companies and other industrial partners. “We can already look back on initial successes. The robot technology used is realizing improvements in all important parameters – for example, cycle time, component quality and cost per piece – compared to water jet technology,” says Rommelfanger. For example, there are no abrasion residues or delamination on the component and the overall surface quality is very high. Long tool life and low maintenance costs improve the cost-effectiveness of the process and, last but not least, the investment costs for equipment are significantly lower than when compared to water jet technology or to NC tool machines.