Problems and environmental question about Chrome Plating on Plastics

A. Hi Thirumeni.

Automotive quality plating on plastics is a very involved process. I'm sure you are not going to find the detail you are looking for on the internet, and that nobody is going to write a web-based book about plating on plastics.

Although this book is very difficult to find, look for ASEP's "Standards and Guidelines for Electroplated Plastics", as it will have everything you need. Inquire of friends in the industry, the Indian Association of Metal Finishing, and local libraries to see if anyone has it. Best of luck.

A. Please contact some suppliers / manufacturers of Metal finishing chemicals in your area (Pune) for details.

A. Hi Mohammad.

In the decorative plating of nickel-chrome, whether it is done on on metals or whether on plastics, the chrome plating step is the last step, and it can be either hexavalent chrome or trivalent chrome regardless of whether the substrate is metal or plastic.

You are correct that the hexavalent chromium is an issue of concern, but only for the plating shop. Once the chrome plating is on the plastic, it is metallic chrome of valence 0; there is no trivalent chromium on the part, and no hexavalent chromium. So there is no reason to be concerned about which bath it was deposited from, and indeed no way to even know (except for the fact that trivalent chrome plating is not quite the full equal of hexavalent chrome plating yet, and tends to leave a deposit that is slightly darker).

Within the plating shop, however, hexavalent chromium is toxic and carcinogenic, so both the waste water and the fumes must be environmentally managed. Good luck.

Regards,