Metallising and Electroplating

Surface pre-treatment by the methods mentioned in Section 8.1.2 can be applied. Chemical pretreatment by dipping in a chromosulfuric acid bath is also possible as is UV irradiation, mainly for parts with complicated shapes. Coating generally leads to a reduction in the impact strength. 

In vacuum metallising, a metal is heated in a vacuum chamber to its vaporisation point, which is lower than the melt temperature of plastics. The metal vapour deposits on the cooler plastic surface. In electroplating, an electric current is used to deposit metal from a metal salt solution onto a plastic rendered conductive by electroless plating. Arc flame, arc spraying, and sputtering are other techniques used. Metallising requires very clean surfaces, free from mould release agents. Primers or pre-cleaners can be used to improve the adhesion of the metal to the polymer surface. 

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Decoration Difficult to paint and metallise/electroplate. Surface preparation very important. 

Lancon, A.D., Katay, R., Wood, D. and Gallant, A.J. (2011) Microelectrode arrays for electroanalytical sensing comparison of electroplating and electron-beam metallisation. Electochem. Commun., 13,414. 

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