The power supply for electrostatic powder spraying is supplied by a high-voltage electrostatic generator. It is connected to the electrostatic spray gun through a high-voltage cable. The spray gun is connected to the air source at the same time, and is connected to the powder supply pipe and the powder feeder. The powder is mixed with the air flow in the powder feeder and sent to the spray gun. The high voltage generated by the high-voltage electrostatic generator is connected to the inside or front end of the spray gun. The powder particles in the mixture of powder and air are charged inside the spray gun or at the spray gun outlet (determined by the structure of the spray gun). Under the action of the electrostatic field, the powder particles fly to the grounded workpiece to be coated. Therefore, it can not only be sprayed on the front of the workpiece, but also on the back of the workpiece. The powder adheres to the coated object. When it exceeds a certain thickness, like charges repel each other, and the subsequent powder is not easy to be adsorbed, so that it can achieve a uniform film thickness. The powder is generally negatively charged, and the voltage is between 30 kV and 100 kV. The workpiece after spraying melts, leveling, and solidifies the powder layer in the curing furnace to form a uniform film layer.

Powder electrostatic spraying equipment consists of the following equipment: high-voltage electrostatic generator, electrostatic spray gun, powder feeder, powder spraying room, powder recovery device (with mechanical ventilation), compressed air and oil-water separator, etc. For easy operation, an additional control console can be added.

In order to make the powder-water electrostatic spraying form a thin and uniform coating, the following process parameters should be referred to.

The output voltage of the high-voltage electrostatic generator should be 80-100 kV. In order to improve the embracing effect of the electrostatic field force, the output voltage can be increased to 20-110 kV. The compressed air pressure supplied to the spray gun should be 1.5 kg/cm2. The powder output range of the powder feeder through the spray gun is generally 3-18 kg/hour. The distance between the end of the powder electrostatic spray gun and the workpiece is about 200 mm. In order to ensure that the powder coating is not contaminated, the oil-water separation requirement of the compressed air oil-water separator is that the air dew point temperature should be below -3 degrees Celsius. Some powder coatings require that the hot air temperature of the compressed air used to transport the powder be 10 degrees Celsius.