Coating thickness is an important factor in determining the appearance of powder coating. Thicker coating has better flow and leveling properties. Industrial aluminum electrostatic spraying is generally about 70-90μm. According to experience, when the thickness of the powder coating is 2-3 times the average particle size of the powder coating, satisfactory leveling of the coating film appearance can be obtained. However, in practical applications, not all coated objects require a thick coating film. Inappropriate thick coatings often result in excess performance and cost. Especially under environmental pressure, if powder coatings are to replace solvent-based coatings with a coating thickness of 20-30 μm, they must develop into thin films. The use of ultra-thin powder coating layer thickness can be reduced to 40-70μm (including phosphate film), and stay fat edge phenomenon, compared with the traditional powder, ultra-thin powder coating material can save about 25% of raw materials, reducing the industrial aluminum profile The scrap rate is favorable for the assembly of subsequent processes. To achieve the thin film powder coating must solve the following aspects.

1 The melt viscosity of the powder coating resin is low, but Tg can not be low;

2 The pigments used are better dispersed and stronger in hiding power;

3 The particle size of the powder coating should be small, and the distribution should be narrow;

4 powder coating dry powder mobility and electrostatic properties are better.

After the powder coating is refined, it can be combined with waxing technology to make the particle wax additive for water-based coatings, solvent-based coatings, UV-curing coatings and some active systems. It has broad development prospects in the ink industry; fine-grained powders The paint has excellent fluidity and is called "third fluid". Therefore, it can be sprayed like water, creating good conditions for the application of coating technology; a thin paint film can be obtained at the time of coating, and the coating film has no needle. Holes, orange peels and other ills laid the foundation for powder coating film. Usually solvent-based coating thickness is 20-30μm. The general powder coating film is 60-70μm. The coating film is too thick, and it is limited in construction and application. On the other hand, the film is too thick and wastes paint. Therefore, it is necessary to develop in the direction of fineness and thin film. The developed nanometer coating thickness is only 20-30 μm in fine and thin layer color powder coating, and the color change is easy. It takes only about 10 minutes, and the thermal efficiency is high, and the baking time is short and can be satisfied. For the application of aluminum with high decorative requirements.

        It is difficult to smoothen the surface of the film, the particle size of the powder is fine, and the particle size distribution is narrow. This affects the leveling property, storage stability, coating efficiency, and powder recovery efficiency of the powder coating. The thin film of powder coating is a systematic project. From the change of resin, additives, pigments and fillers, and the upgrading of processing equipment to the improvement of electrostatic spraying efficiency, we can start to achieve satisfactory results. In recent years, the thinning of powder coatings has become a hot topic of research and development.