1. Working principle of powder coating in the painting production line:

Powder coating is achieved by utilizing the phenomenon of corona discharge to adsorb powder coating onto the workpiece. The process of powder spraying is as follows: the powder gun is connected to the negative electrode, the workpiece is grounded (positive electrode), the powder coating is sent to the spray gun by the powder supply system through compressed air gas, and a high-voltage electrostatic generator is added at the front end of the spray gun. Due to corona discharge, dense charges are generated near it. When the powder is sprayed from the nozzle, a circuit is formed to form charged coating particles, which are attracted to the workpiece with the opposite polarity by electrostatic force. As the amount of powder sprayed increases, the charge accumulates more. When it reaches a certain thickness, due to the electrostatic repulsion effect, it stops adsorbing, so that the entire workpiece obtains a certain thickness of powder coating. Then, through heat, the powder melts, flattens, and solidifies, forming a hard coating on the surface of the workpiece.

2. Composition of powder coating equipment in the painting production line:

The powder electrostatic spraying equipment mainly includes: powder spraying room, high-voltage electrostatic generator, electrostatic spraying gun, powder supplier, powder recovery device, workpiece rotation mechanism, etc.

(1.) Powder spraying room

The powder spraying room is one of the main equipment for powder electrostatic coating. Maintaining a smooth airflow is essential for maintaining cleanliness in the powder room and providing a clean working environment for operators. Control the dust content in the spray booth to below the explosion limit (generally set at 10g/m3). In addition, the powder spraying room should be easy to clean, so that the powder is not easily deposited in the room, in order to change the color of the powder. There should be sufficient light inside the room to facilitate the coating work.

(2.) Electrostatic spray gun