1. Distance between spray gun and workpiece

According to years of experience of hardware spraying plants, the most suitable average electric field strength for electrostatic spraying is 30-40KV/cm, so when the electrostatic voltage is below 80-100KV, the distance between the spray gun and the workpiece is actually between the positive and negative poles of the high-voltage electric field. Distance. Under a certain voltage, the electric field strength is inversely proportional to the distance between the two poles. Within a certain range of electric field strength, the stronger the electric field strength is, the more the charge is, the stronger the electrostatic attraction is, the better the atomization effect is, and the higher the coating efficiency is. High.

However, when the spray gun is too close to the workpiece, the electric field intensity is too high, which will cause spark discharge. If the distance is too far, the adhesion rate of paint mist will be reduced. Therefore, during electrostatic hardware spraying, the distance between the spray gun and the workpiece shall be controlled within 250~350mm. When spraying small pieces of hardware, the distance should be low, and when spraying large pieces of hardware, the distance should be high.

2. Injection quantity

Different types of electrostatic spray guns specify a certain amount of hardware spraying. Too much spraying will lead to insufficient charging of paint and poor atomization effect, affecting the coating effect, but too low spray amount will affect the production efficiency. Therefore, the amount of spray should be kept on the premise of maintaining the charging effect. In order to improve production efficiency, the method of installing multiple spray guns for metal spraying at the same time is often adopted.

3. Layout of spray gun

When arranging the spray gun in the electrostatic hardware spraying assembly line of the hardware spraying factory, in addition to keeping a proper distance from the object to be coated, attention should also be paid to the adjacent spray gun and other objects in contact (including the ground, hardware spraying support, paint booth wallboard, etc.). The distance from the adjacent electrostatic spray gun is based on the principle that the hardware spraying of the two electrostatic spray guns and their patterns do not interfere with each other. Paint particles will collide with each other due to improper location. Splash back. When two electric spray guns cannot be on the same plane due to the limitation of the workpiece, the gun spacing shall be at least 1m.

4. Suspension of workpiece

Whether the suspension of workpieces in the production line is reasonable has a great influence on the effect of electrostatic coating. Suspension is based on the principle that the workpieces do not collide with each other In the process of electrostatic hardware spraying, it is better for the workpiece to rotate to ensure uniform film thickness, and the rotating speed should be 3-4r/min. At the same time, pay attention to the cleaning and maintenance of the hanger, remove the residual paint in time, ensure that the workpiece is well grounded, and prevent electric shock during unloading after the hardware of the workpiece is sprayed. It is better to prepare two sets of fixtures and hangers. When one is used, the other is sent for cleaning to ensure that the hanger is always in a clean state.