Reasons of Poor Powder Coating Layer.

In electrostatic powder coating, the reasons for poor covering power of coating layer are powder coating itself and powder coating.    

从粉末涂料本身考虑，在设计粉末涂料配方时，对有遮盖力的颜料用量不够，使粉末涂料的涂膜没有足够的遮盖力，例如在白色粉末涂料中，钛白粉的用量不够时容易出现这种问题。对于使用着色力强，但是遮盖力差的有机颜料时，没有配合使用遮盖力强的其他颜料或者添加遮盖力强的颜料量不够，便如不配制红色粉末涂料时，在使用有机颜料的同时，没有配合使用钛白粉或添加钛白粉的量不够，就容易出现遮盖力不好的问题。     

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.     

从粉末涂装考虑，与涂膜遮盖力最有关的是涂膜的厚度问题，如果涂膜厚度太薄（40-50μm）就容易出现遮盖力不好的问题，所以涂膜厚度至少应喷涂到60-80μm是比较合适的。如果涂膜厚度已达到60-80μm，但涂膜遮盖力还不太好，那就说明在粉末涂料的配方设计上，对遮盖力的考虑不充分。    

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.     

从粉末涂装来说，只能通过采取增加喷涂涂膜厚度的措施来解决。为了使粉末涂料的遮盖力达到用户要求，粉末喷涂厂应向粉末涂料厂提出涂膜厚度的要求，粉末涂料厂再根据涂膜厚度的要求设计最合理的粉末涂料配方，这样就能使粉末涂料产品的遮盖力令粉末涂装厂满意，只要把涂膜厚度达到要求，就不会存在涂膜遮盖力不好的问题。

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.