Preparation surface technology

Under the surface preparation before painting means mechanical or chemical treatment of surface to remove all types of contaminations and to give to surface roughness. Preparations quality of surface is the determining factor for adhesion coating providing. There are phisical-mechanical and chemical химические methods of surface preparation. The most prevaling are: - clearning of the surface with mechanical or manual tools or chemical preparations from rust, scale and etc. - surfaces degreasing with removal of oil, grease, contiminations with organic solvents; - degreasing with aqueous alcaline composition ( ТМС ЛН ) - application of inorganic non-metallic coatings (galvanic oxide, phosphate, etc) - application of metall coatings (zinc, cadmium and etc.); - blasting the surface with giving a certain roughness profile, etc. More detialed requirements for surface preparation are reflected in international standarts. Very promising are new processes with simultaneous degreasing and phosphating of steel surfaces with aqueous solitions. After this treatment, the surface is enough to wipe with clean dry cloth ( ТМС ДП ). Very often the method of surface preparation predetermined by technical documantation on paint-and-lacquer materials. So blast cleaning method is reqiured for special porpose coating, for example, coatings with high volume contain of zinc, coatings, immersed in water or to high temperature. This treatment is recommended for removal scale, rust, previous paint from large areas. Another method of old coatings removal from surface is the using of washing-off. Along with traditional methylen chloride washing -off, the principal new aqueous offer, wich effectively remove even epoxy and polyurethane coatings (Interplus 634).