One of the two plants was specially developed and built for the hard chrome plating of valves in the intake and exhaust tracts of internal combustion engines. Due to their special installation situation, the valves place high demands on the coating. In the operating state in the combustion engine, they move permanently to admit fresh air or allow hot combustion gases to flow out. Mechanically, they are stressed by the permanent movement and are exposed to friction. In addition, the valves are subjected to high temperatures due to the high temperatures of the combustion gases. Corrosive stress, for example from condensing exhaust gases, can also occur.
For these reasons, the valves require a high level of wear and corrosion protection, as achieved by hard chrome plating. Depending on the desired coating thickness, the Holzapfel Group's new system coats the valves in 15 to 25 seconds. A robot loads and unloads the parts directly from the customer trays. All processes within the coating system are also automated, from electrolytic degreasing, rinsing and electrolytic etching to hard chrome plating and subsequent polishing. This means that piece times of four seconds per component can be achieved with the appropriate layer thickness. One employee monitors the system and supplies it with components.
The plant uses state-of-the-art technology, including special individual part formers and robotic arms for automated loading and unloading. Since the defined conditions are exactly the same for all components from rectifier to power supply to circulation, the coating is extremely uniform and highly reproducible. Continuous monitoring of the process parameters supports the consistency of the conditions, so that n.o.k. parts do not occur in the first place. "This is also what is significantly special about the technology," explains Michael Immel, managing director of FPP Fast Plating Process S.r.l., a subsidiary of the Holzapfel Group, which co-developed the system. "With our single part plating technology, we almost always achieve the same plating result. The reproducible parameters ensure that the coating thickness and coating thickness distribution on each component are always the same."
Holzapfel Group
www.holzapfel-group.com