Powder coating treatment on the surface of workpieces
Powder coating is a very new type of material product that is very suitable for today's society. Has good utility, such as solvent-free, pollution-free, etc. There are many places in life where we need to use coatings, and powder coatings can ensure the integrity of coatings very well. This is something that many other application devices do not have. Today, the plastic powder manufacturer talked about the treatment of powder coatings on the surface of workpieces.
Generally, powder coating workpieces need to undergo surface treatment processes such as degreasing, rust removal, degreasing, water washing, phosphating, water washing (passivation), deionized water washing, and drying. Impurities such as rust removal and phosphating residue may adhere to the workpiece, resulting in the presence of particles after film formation.
In the pre-treatment process, before phosphating, one or a combination of methods should be used to remove scale, rust, grease, fingerprints, and foreign substances on the surface to be phosphated, mainly to ensure that no coarse grains are produced. To avoid the formation of coarse crystalline phosphating films or films with excessive mass per unit area, strong acid or alkali cleaning should be minimized or avoided as much as possible. Processed workpieces should be thoroughly cleaned in cold or hot water to remove residue. Otherwise, if the residue is brought into the phosphating tank, it will damage the quality of the tank solution and directly affect the phosphating effect.
During the phosphating process, attention should be paid to the acidity of the phosphating solution, including total acidity and free acidity. Total acidity refers to the total concentration of various ions such as Zn2+, Fe2+, H+, H2PO4-, HPO42-, etc. in phosphating (such as zinc based). The total acidity is too low, the phosphating reaction rate is slow, and the phosphating film layer is thick and rough. Free acidity refers to the concentration of free H+in the phosphating tank solution. When the free acidity is too high, the phosphating reaction rate is slow, the film formation time is prolonged, and the phosphating film crystals are coarse and porous, resulting in more precipitation in the solution.
There are many areas that need to be noted when applying powder coatings. More often than not, we need to process and organize. We should also pay more attention to the chemical reactions of powder coatings when we are not using them. In daily life, there are always many places where we need to use powder coating. Only with a better understanding of powder coatings can we use them more effectively.
Zhejiang Xingshun New Material Technology Co., Ltd. sells high-quality plastic powder, steel wooden door plastic powder, and powder coating. Welcome to call for consultation.
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