Matters needing attention during the process of electrostatic coating

Spray voltage

1.1 Within a certain range, the spray voltage increases and the amount of powder adhesion increases, but when the voltage exceeds 90KV, the amount of powder adhesion decreases with the increase of voltage.

1.2 When the voltage increases, the initial growth rate of the powder layer increases, but as the spraying time increases, the influence of the voltage on the thickness increase rate of the powder layer becomes smaller.

1.3 When the spray distance (the distance from the spray head to the surface of the workpiece) increases, the effect of the voltage on the thickness of the powder layer becomes smaller. The general distance should be between 150-300mm.

1.4 If the spraying voltage is too high, the powder layer will break down and affect the coating quality. Spray voltage should be controlled between 60-90KV

2. Powder pressure

The powder supply pressure refers to the air pressure of the powder feeding tube in the powder feeder. Under other conditions, 0.05 MPa (1.96 kg force) is the best.

3. The amount of dusting

The amount of powder sprayed refers to the amount of powder discharged from the gun mouth per unit time. The initial growth rate of the thickness of the powder layer is proportional to the amount of powder sprayed. However, as the spraying time increases, the effect of the amount of powder on the growth rate of the thickness of the layer is not only small, but also the deposition efficiency is reduced. 100-200g/min is more suitable.

4. Spray distance

The spraying distance refers to the distance from the gun mouth to the surface of the workpiece. When the electrostatic voltage applied by the gun is constant and the spraying distance changes, the electric field strength will also change. Therefore, the size of the spray distance directly affects the thickness of the powder layer and the deposition efficiency of the workpiece. The best distance is around 250mm.