The initial step in the metal pre-treatment process is the removal of oils, dirt, and other soils that will interfere with the development of a superior quality phosphate coating, good coating adhesion, or cause surface defects. Chemical cleaning can be accomplished by subjecting a part to an aqueous spray or dip cleaner. The degreasing chemicalwill be alkaline, acidic, neutral, solvent, or emulsion depends upon the type of surface to be treated and as per customer need.
More preferable product is alkaline degreaser, which is very effective in removing all oil contents on the metal surface. Alkaline degreaser able to convert insoluble fatty acid to soluble fatty acids and hence it is more effective than other type of degreaser