Robert Bosch Corporation

Cassette Chrome Plating Process

When Bosch was evaluating design alternatives for its new EV14 fuel injector, they wanted to improve the precision of fuel injection over a 100,000 mile lifetime. The critical component in reaching such an objective was the inlet tube, which opens and closes to admit fuel, and which would need to sustain uncompromised performance for 5x108 closures. A thin coating of chrome was the only material of reasonable cost having the durability to sustain a precision inlet tube impact surface. But besides all the other environmental hazards of plating, chrome baths emit hexachrome, toxic to workers. As a result, chrome plating is usually avoided because of these environmental and health dangers or problems. Bosch looked for a supplier that could develop a high precision, high volume, environmentally safe chrome plating process. None could be found – anywhere – so they began to develop what became their Cassette Chrome Plating internally. Their team came up with a dramatic success, an innovative process achievement in itself.

After startup in April 2002, the first Cassette Chrome Plating unit ramped up very rapidly to a volume of 100,000 per day. This fully automated system has high uptime, and sets several new benchmarks in volume plating production. First, no other high volume system achieves the same precision in both depth and uniformity of coating. Second, this “process in a box” sets new benchmarks for emission of hexachrome; so safe and reliable that people can work in its proximity safely. Third, because of this, Cassette Chrome Plating is the only system known to be installed in the flow layout of component fabrication directly feeding assembly in a plant where cleanliness is vital to quality. Fourth, Cassette Chrome Plating was a necessary and critical element for the design of Bosch’s new EV 14 fuel injector. Additional Cassette Chrome Plating systems are being installed at other Bosch factories for similar applications.