Visual accuracy of powder output from powder coating gun
When we visually evaluate the powder output of the spray gun, we often unconsciously judge that the powder sprayed by the spray gun has low transparency (intuitive feeling of high concentration), and the powder is flying violently during spraying (intuitive feeling of large residual powder) is the powder output of the spray gun The amount of powder is large, and the spray gun with high powder transparency and less flying powder is judged to have a small amount of powder, but the actual situation is not the case. The principle is as follows:
1. Mistakenly believe that the powder sprayed by the powder spray gun has low transparency, and intuitively feel that the spray gun with high concentration has a large powder output. Practice has proved that when the same powder supply amount (same powder supply equipment, same air pressure conditions, and same powder box) is used to supply powder to powder spray guns with different charging properties, the transparency of the side of the powder spray gun sprayed by the spray gun with poor charge Low and intuitive. It feels that the powder concentration is high; while the powder sprayed by the powder spray gun with excellent electrification performance has high transparency when viewed from the side, but low intuitive feeling.
Reason: The powder spray gun with good electrification performance can fill the sprayed powder particles with sufficient electrostatic charge, so that the powder particles can obtain sufficient mutual electrostatic repulsion. There is no adhesion between them, showing a very good atomization state. Viewed from the side, you will feel that the powder is even and transparent, creating the illusion of "less powder".
However, the electrostatic repulsion force between the powder particles of the powder sprayed by the spray gun with poor charging performance is not enough, and the powder particles form adhesions, and the atomization effect is not good. Viewed from the side of the gun, the sprayed powder is less transparent. Often cause the illusion of "more powder".
Conclusion: For two spraying powder guns with the same powder output, the better the charging performance, the better the powder atomization, and the higher the side-view transparency, rather than the gun with low powder transparency and high visual concentration.
2. When spraying a workpiece with a powder gun, it is often mistaken for a spray gun with a strong powder spraying power, which produces a large amount of powder. Practice has proved that when the same powder supply (same powder supply equipment, same air pressure conditions, and same powder box) is used to supply powder to two different spray guns (with obvious differences in powder loading), the recovery in the same powder When spraying the same workpiece, most of the powder sprayed by the spray gun with good performance will be adsorbed on the surface of the target workpiece to be sprayed after flying away from the spray gun, and very little powder will bounce back from the spray gun to the workpiece and Flying around; on the other hand, a poorly performing gun will have a lot of kickback and a lot of powder flying around.
Reason: The gun with good performance has a high powder output rate and less dust from the workpiece, while the gun with poor performance has a low powder output rate and more powder from the workpiece. Therefore, when spraying with a powder spray gun with poor performance, it is often easy to have a large amount of powder sprayed, resulting in the illusion of "large powder output" from the spray gun (actually it is a waste).
Conclusion: Two powder spraying guns with the same powder output rate have a low powder spray rate when spraying, but it is easy to cause the illusion of large powder output; when using a powder spray gun with excellent performance and high powder output rate, a large amount The powder is attached to the workpiece, and the scattered powder is very small, which is easy to cause the illusion of "low powder output".
