In electrostatic powder coating, the reasons for poor covering power of coating layer are powder coating itself and powder coating.
Considering the powder coatings powder themselves, when designing the formulation of powder coatings, the amount of pigment with covering power is insufficient, so that the coating film of powder coatings does not have enough covering power. For example, in white powder coatings, titanium dioxide is easy to occur when the amount of titanium dioxide is insufficient. For organic pigments with strong coloring power but poor shading power, the amount of other pigments with strong shading power or the amount of pigments with strong shading power is not enough, so it is easy to use organic pigments without titanium dioxide or the amount of titanium dioxide added. The problem of covering power is not good.
Considering the powder coating process, the coating thickness is the most relevant to the film covering force. If the coating thickness is too thin (40-50μm), it is easy to appear the problem of poor covering force, so the coating thickness should be sprayed to at least 60-80μm is more appropriate. If the film thickness has reached 60-80μm, but the film covering power is not very good, it shows that in the formulation design of powder coatings, the covering power is not fully considered.
For powder coating process, it can only be solved by increasing the thickness of the spraying coating. In order to make the covering power of powder coatings meet the requirements of users, powder coating plant should put forward the requirements of coating thickness to powder coatings factory, powder coatings factory should design the most reasonable formula of powder coatings according to the requirements of coating thickness, so that the covering power of powder coatings products can be satisfied by powder coatings factory, as long as the coating thickness is taken into account. To meet the requirements, there will be no problem of poor covering power.