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Parts are failing nickel emission test

September 14, 2011

We are doing PVD coating on brass and SS components. Over Brass our plating specs are as under -
by Electroplating
Nickel - 15 to 20 micron
chrome - 0.2 to 0.3 micron
by PVD
Titanium Nitride - 0.5+ micron
Gold - 0.05 micron
we are facing a problem that components fail in Nickel Emission Test. can anybody suggest the cause of failure and how to avoid the same.

Robin Madhiyan
director - India

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September 14, 2011

Hi, Robin.

I'm not sure that I understand the question, but it sounds like you are offering jewelry which must pass a nickel leaching test. If so, I think the right answer is to make the jewelry nickel-free by plating it with white bronze instead of nickel.

I also think you should evaluate the actual need for chrome plating, as it doesn't sound like a good idea to chrome plate jewelry. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Hi Ted,
Thanks for your response. I'm sorry that my question is not clear enough. We are actually doing plating on brass watch cases. Before doing PVD coating we are doing nickel-chrome plating by electroplating process. After that we are doing PVD coating of TiN (0.5+ micron) and Au (0.05 to 0.1 micron). These plated cases are failing in nickel emission test (required level is less than 0.5 ppm)

We are not sure why our component is failing in nickel emission test? How can we avoid the same ?

We have already done different trials with different layer thickness but of no use.

kindly suggest how can we avoid this problem.

Robin Madhiyan
director - India
September 17, 2011

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September 18, 2011

Hi, Robin.

Your question was clear enough, but I guess my answer wasn't :-)

The way to achieve nickel compliance on jewelry such as watch cases is to not do nickel plating, and instead do white bronze plating. Then you will easily pass the nickel emission test because the watchcase will contain no nickel.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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September 20, 2011

Hi Ted,
Is by any chance there is way we can avoid the problem without avoiding nickel plating.

secondly I would like to know what plating specifications are been followed by branded watch manufacturer in Europe.

thanks and regards

Robin Madhiyan
director - India

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Sorry, Robin, I can't in good conscience recommend that. Nickel allergy is a serious, miserable, problem for tens of millions of people, and plating or sealing the nickel in is a temporary measure that may reduce the nickel emissions long enough to pass a screening, only to afflict the consumer with the problem later. Do the best thing: get rid of the nickel.

White bronze plating is a three-metal alloy, which almost demands a proprietary solution. So I would suggest you find a vendor of the white bronze process, and they can guide you in exactly how to apply it, and how the branded manufacturers in Europe apply it. Best of luck!

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 20, 2011

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September 28, 2011

In Europe, and I believe in the USA, it is illegal to sell any jewellery or other components that come into prolonged and intimate contact with human skin. For further details, consult both the Nickel Regulations and REACH. There are very tight limits set on the rate of nickel release and indeed the nickel content of the component. Articles that release more than 0.5 micrograms of nickel per square centimeter per week are prohibited. Testing is by using the dimethyl glyoxime test.
Any products found not complying are impounded and the seller, manufacturer or importer will be prosecuted. As Ted says, nickel allergies are a major health issue and its effects are being taken very seriously. The only sensible way to comply with the regulations is to avoid using nickel releasing systems.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK