Technical requirements for electrostatic coating equipment for powder coating process: the electrostatic powder spraying process construction, often characteristic of powder coating importance, so that when the film appeared when some defects (such as bubbles, pitting, depression, shrinkage, piebald, even not coated powder etc.), unable to proceed, it is difficult to analyze. In essence, we should pay attention to the following parameters in the powder coating for electrostatic spraying to ensure the smooth implementation of the electrostatic spraying process and the high performance coating. 

1. Particle fineness of powder coatings: the notable difference between powder coatings and solvent based coatings is that the dispersing medium is different. In solvent coatings, organic solvents are used as dispersing agents; in powder coatings, purified compressed air is used as the dispersing medium. Powder coatings are dispersed in spraying and can not regulate the particle size of coatings. Therefore, the fineness of powder particles suitable for electrostatic spraying is important.

Powder coatings suitable for electrostatic spraying, preferably with a grain size between 10 and 90 microns (>170 mesh). Powder with a particle size of less than 10 microns is called ultrafine powder. It is easy to be lost in the atmosphere, and the amount of ultrafine powder can not be too much. It is worth noting here that the particle size of the powder is related to the thickness of the coating, and that the particle size of the powder coating should be distributed (Table 1) to obtain a film with uniform thickness. If the thickness of the coating is 25 microns, the maximum particle size of the powder coating shall not exceed 65 microns (200 mesh - 240 mesh), and most of the powder shall pass 35 microns (350 mesh - 400 mesh). In order to control and adjust the size of the powder particles, the crushing equipment should be adjusted. For our country's powder manufacturing plant, we can not do that at present.