Why does this phenomenon occur after powder coating is applied?

Many people will ask

"Why does powder fall off after powder coating is applied?"

The general answer: "The main factor that affects the acceptance and retention of charge by powder particles is the dielectric constant

For electrostatically sprayed powder coatings, one with a high dielectric constant should be used as much as possible, which will greatly improve the powder's adsorption force

It can be known from electrostatics that the distribution of surface charges on a charged isolated conductor is related to the radius of curvature of the surface.

If it is a negative high voltage discharge, the electrons leaving the conductor will be accelerated by a strong electric field, causing them to collide with air molecules, ionizing the air molecules to generate positive ions and electrons

Most industrial powder coatings are polymer insulators with complex structures.

For the surface of the back-sprayed part has been coated with a thicker paint film, according to the resistivity and applied voltage curve, the higher resistivity is conducive to charging, but the negative effect is not easy to release the charge

It can be seen that reducing the voltage can reduce the transfer speed and charge amount of the particles, so that the powder particles will not be strongly repelled and rebound, and at the same time, the powder loading efficiency can be further improved