What are the characteristics of powder electrostatic coating and its application in automobile coating?

In order to solve the problem of pollution in painting, in addition to the waterborne coating materials, another solution is to use solvent-free powder coating In the automobile industry, at present, in addition to the powder coating of some parts, BMW adopts powder coating to cover the car body Chrysler has applied powder coating to the body chassis parts of two factories in the United States; Ford and general motors have applied powder coating to the parts with low appearance performance requirements, such as cylinder, chassis parts, wheels, etc Now the three major American automobile companies (Ford, general motors and Chrysler) have decided to jointly develop the powder antirust coating and powder finish coating for automobiles The new technology after development is ready to be used in about 50 car and light vehicle factories in the United States The basic principle of powder electrostatic spraying method which can be used for automobile coating is the same as that of electrostatic spraying solvent coating, and the coated part is grounded as the positive pole The coating thickness of powder coating can reach more than 60-100um, and the coating formed by one baking is uniform, with strong adhesion and high protection and decoration performance The powder can be recycled and reused If the powder is recycled through screening, it can reach about 95% Because of the solvent-free and flying powder can be recycled, the environmental pollution is smaller than other coating methods, and it is easy to form mechanized and automatic assembly line coating production It is suitable for coating of various metal parts, one-time coating, one-time baking and film-forming, and the coating production cycle is short This coating method needs to be studied and solved, such as the difficulty of thin coating and color change, the complex shape of the coated workpiece (due to electrostatic shielding phenomenon at the inner cavity and sharp edges and corners, the coating effect is not good), and the structure of the complete set of equipment and other problems need to be further improved.