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The surface treatment of plastic products mainly includes coating treatment and coating treatment. Generally, the crystallinity of plastics is large, the polarity is small or non-polar, and the surface energy is low, which will affect the adhesion of coating. As plastic is a kind of non-conductive insulator, it can not be directly coated on the plastic surface according to a electroplating process specification. Therefore, before surface treatment, necessary pretreatment should be carried out to improve the adhesion of the coating and provide a conductive bottom layer with good adhesion for the coating.