On many surfaces lacquer adherence is not sufficient. A vital requirement for a perfect adherence is complete wetting of the surface by the lacquer or varnish. An untreated surface usually carries unvisible deposites of substances preventing proper wetting. Either these deposites are residuals caused by the manufacturing process or organic contamnation deposited from the enviroment. Intensive cleaning of a surface to be painted therefore is indispensable independent from the character of the substrate, even if the surface appears to be completely clean. Plasma Cleaning is a superior method to high-puridity cleaning even of complex surfaces with undercuts, cavities and narrow slits.
Adhesion of lacquer
Surfaces with a small surface energy additionally need to be activated. In general this is necessary for any kind of plastic surface. Low pressure plasma activation by oxygene plasma very often is an appropriate methode, so that plasma cleaning and plasma activation can be a combined one-step process.