The powder coating is deposited on the workpiece in a loose structure after spraying. This loose structure causes a large amount of voids between the powder particles and the powder particles to be filled by the air. As the ambient temperature increases, the powder coating particles melt and cause this. This kind of loose structure collapses, because the thickness of the powder coating film is generally greater than 50μ (the loose structure after spraying is much larger than this thickness), the powder particles in the middle position and slower heating melt more slowly, so that the air between the particles is melted With the progress of curing, the viscosity of the system gradually increases, and the air trapped in the coating leads to the formation of pinholes in the coating film. This kind of film pinhole is necessarily possessed by the thermosetting powder coating due to its own characteristics. Therefore, strictly speaking, the pinhole is a native defect of the powder coating.

In order to eliminate the original pinholes caused by the above factors, deaerator is a raw material that must be used in the formulation of high-gloss powder coatings, and benzoin (benzoin) is a highly effective deaerator to eliminate the above-mentioned pinholes. The defoaming mechanism of benzoin is very complicated. In addition to eliminating the above-mentioned pinholes, benzoin also has a certain effect on the elimination of pinholes caused by other factors.

It should be noted that although benzoin is a very effective powder coating defoamer for powder coatings, it cannot solve all the pinhole problems of powder coatings.