1. Main factors affecting the quality during the electrostatic spray coating process

2. Important parameters affecting the quality of the electrostatic spray coating pre-treatment process 

1. Main factors affecting the quality during the electrostatic spray coating process

* Electrostatic voltage

* Gun position

* Powder spray amount

* Compressed air pressure

* Powder material

 

1. Electrostatic voltage

Powder coating voltage has a big impact to the powder adsorption on the workpieces.In  general, voltage increasing, the amount of adhesion increases. However when the voltage exceeds a certain value, the powder adhesion will reduce and when the voltage is high enough to the breakdown the powder, the surface of the coating appears crater pinch-like eye.

Commonly spray voltage range is of 60 - 90kv

 

2. Spray gun position

The distance between the powder spray gun and the workpiece mainly affects the thickness of the coating, so the change of the distance between the spray gun and the workpiece is particularly sensitive to the influence of the film thickness limit. Usually increase the distance, the film thickness decreases. During spraying process, to adjust the distance between the spray gun and the workpieces to improve the quality of the coating surface has a great relationship.

Usually the distance between the gun and the workpiece distance is 150mm-250mm

3. Powder spray amount

The amount of powder has a certain impact on the powder layer thickness, while the amount of powder during coating also has relationship to the deposition efficiency. Under normal circumstances, a small amount of powder, sedimentation efficiency.

Powder amount is generally selected at 50-500g / min

 

Compressed air pressure

Compressed air acting as the nature gas of the powder coating, the pressure of the compressed air pressure is directly related to the coating quality. Compressed air pressure generally set at 0.1-0.4Mpa.

 

5. Powder material

Powder particle size has a big impact on the spray coating quality, fine particles (10 um below) is not easy to electrostatically charged, easily clogged or gathered in the spray gun head, so it will be sprayed raindrops powder to hit the workpiece,  cause pitting quality problems.

Powder particle size range: 64-100um <15-20%

                              16-64um 65-70%

                               0-16um <15%

2. Important parameters affecting the quality of the electrostatic spray coating pre-treatment process

*Concentration

*Temperature

*Pressure

*Time