The authoritative public forum
  for Metal Finishing since 1989
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Your opinion in metallizing with silver

Can you help in metallizing with silver on plastics?

M.Pandis
- Athens, Greece
2003

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It depends on the plastic. Assuming the plastic is suitable for metallising, it is an easy process. First of all etch the plastic in a suitable etchant, such as chromic acid, or even permanganic acid, then sensitise with a solution of acidic tin (II) chloride. You do not need a precious metal here because you will get one in the silver. Rinse the tin chloride to generate the gel and then silver spray with ammoniacal silver nitrate solution and a suitable reducer such as glucose and/or formaldehyde. All in all, a very simple process, but silver is expensive. Be careful with silver spraying because in theory silver salts can form fulminates and these can be explosive, so wash everything down after doing it.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2003

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Alternatively, silver can also be sputter coated on plastics. Silver actually sputters at a fairly high deposition rate. To get good adhesion you will either need to plasma clean the plastic with something like an ion beam or deposit an adhesion layer between the plastic and silver. Titanium, chromium, tantalum or aluminum usually make decent adhesion layers.

John Davis
- Berthoud, Colorado, USA
2003