Fittings and shower manufacturer Hansgrohe from Offenburg works with Exeron eroding and milling technology. High-precision surfaces are the key task for Exeron.
The Hansgrohe Group, located in Schiltach/ Baden-Wurttemberg, is a leading company for innovation, quality and design in bathroom and kitchen applications with their Axor and Hansgrohe brands. With their fittings, showers and shower systems, the Hansgrohe Group specialises in water and its function. At the Production Center Offenburg, one of two German production sites, Robert Heeger is responsible for the technical department, together with tool technology plastics and new samples. He explains the backgrounds for the purchase: “It was necessary to replace the existing milling and eroding technology simply due to reasons of age.”
A highly precise process was demanded with the main focus on the milling side. It was important to be able to process copper as well as graphite to produce flexible 90% graphite and 10% copper electrodes. Along with that came the finishing of tool parts like, for example, hardened mould inserts and cores, the pure hardening of moulded parts as well as highly precise processing and and revision of exiting electrodes in copper. Here, too, precision is key, 2 - 5 µm is the defined demand. The requirements for the processing of moulds are also very demanding.
“We work with special, mostly through-hardened steels and also with high chromium proportions. To get an appropriate surface quality, not only high-quality tools are necessary, but also a precise positioning of the milling machine over all five axes.”
“We can start up our production very smoothly after a tool change,” Dominique Deschamps points out, “because not only in toolmaking, but also in cross-functional development, construction and production planning, our machines are connected by Hypermill and Catia. This saves time and costs. On the one hand because of the new, faster processing technology, on the other hand because of interdisciplinary internal co-operation. Thanks to our new Exeron equipment, we are today able to save around half of the processing time with higher machining dynamics and precision at the same time.”
Development and design are closely connected with other “realisation points” like simulation and toolmaking as well as part production. Tool construction is equipped with CAD/CAM for the set-up of programs and choice of work processes like wire cutting, eroding or milling. Robert Heeger says: “All these steps, including matching up to series production, the measurement and the computer tomography for quality control, are taking place in-house. This close interlinking saves time and energy. The fact that we control our technology very well is proven by the fact that our simulations represent reality to 98%.”
Design comes first
But design always has the final say at Hansgrohe. “Design always has the highest priority,” says Robert Heeger. “But this promotes our creativity. Because we always found a solution for the design specifications, even if they were enormously demanding and complex.” The requirement for Hansgrohe products is to have absolutely perfect surfaces. Robert Heeger and Dominique Deschamps have decided on EDM and milling technology from Exeron on the basis of test results and the support of a benchmarking tools, which produce between 100,000 and four million parts per year in series. Quite often, mould inserts are used that have to be changed within minutes for the different versions of one product. The key message, Dechamps says, is “One tool – one product – one series”. For this reason, there is only a low spare parts inventory, used for real problems. The toolmaking department has around 1,000 active tools weighing up to three tons; around 40 are added per year. “Surfaces – endurance – hardness” are the main factors of key significance in toolmaking at Hansgrohe, as Dominique Deschamps points out. “We need solid, sharp parting lines to produce really high-class products for processing at up to 65hc of shore hardness. We optimise our tools permanently and clean them regularly after 40,000 to 50,000 shots, depending on the construction format and plastics used. We use the HSC600 to process our mould inserts simultaneously, which saves us even more time. This is possible because of the highly precise axis and results. After the milling process, the basic process of manual high-gloss polishing takes place to make our mould inserts ready for production. In the end, we are up to ten times faster as before in processing our graphite electrodes. All in all, with the new Exeron eroding and milling technology, we found tool solutions for our highly complex tools, which proved themselves in a very short time.”
Service and co-operation
This technology is complemented by good service, according to Hansgrohe. In terms of machine settings, Robert Heeger points out, the know-how of Exeron was very important for quick success. Because here, Hansgrohe follows the rule that all plastic parts have to be processed without rework, apart from cutting off sprues. For tools, which quite often work with many core pulls, undercuts, complex cooling, slides, sensors, venting and devices for unscrewing, this is not generally possible. This makes the co-operation with Exeron even more important. Here Hansgrohe has the impression that co-operation is not just a one-way street, that developments are advanced together and that feedback from customers reaches Exeron. Not least because of that, Exeron machines are now working at the technical centre of Hansgrohe in Offenburg. In the end, Hansgrohe was satisfied with the equipment and interaction with Exeron. They managed to achieve their set goals and can now maintain the high standard the company has been known for.