Regarding environmental protection metal coating, I believe that everyone is not very familiar with it. How much do you know about the common problems in the use of environmental protection metal coating? What are the characteristics of coating?
The environmental protection metal coating process is to make raw materials into water-soluble coating solution, and then directly coat it on the surface of the workpiece after activation treatment, after drying, sintering to form an inorganic film layer. Do you know the common problems in the environmental protection metal coating process? ?
1. The instability of the coating solution: due to the relatively high density of zinc powder, it is easy to precipitate when the coating is prepared, which makes the coating solution layered. Therefore, a high-efficiency thickener must be selected. Sodium polyacrylate is used to thicken the coating solution. When adding When the amount is excessive, the coating liquid is very easy to gel, thereby shortening the service life. It is not suitable from the perspective of the service life of the coating liquid and production efficiency;
2. Surface color of coated parts: The surface color of the workpiece coated with advanced raw materials is silvery white after treatment. It is found in the production process that the ratio of zinc powder and aluminum powder has a great influence on the color, and increasing the amount of aluminum powder can Increase the silver-white luster of the workpiece. After the amount of aluminum powder increases, it will have a certain impact on the corrosion resistance of the workpiece;
3. The influence of the pH value of chromic acid: In Dacromet coating solution, there is a component that must be considered, that is, chromic acid solution. In the actual preparation process, if the pH value of chromic acid is high, the reaction between chromic acid and the slurry is very Vigorous, a large amount of heat is released, and finally the entire solution system is agglomerated and invalid. If it is diluted with water and then coated, the surface adhesion of the workpiece will decrease, and it is easy to peel;
4. The influence of stirring time on the quality of the zinc-chromium film layer: Dacromet coating liquid must be stirred after mixing, so that the slurry is mixed with chromic acid and other components and reacted and matured. The prepared coating liquid has a service life Store in an airtight container and keep stirring, it can be used for 3 days;
5. The influence of wetting agent: Dacromet-coated workpieces are all steel parts. The coating liquid wets on the surface of the workpiece and spreads, which directly affects the quality of the layer. If it is wet and spreads poorly, it will make the workpiece The surface is leaked, and it takes multiple coatings to cover the surface of the workpiece, resulting in uneven coating. Dacromet coating, do you know the common problems in the dacromet coating process? The corrosion resistance is reduced.
The above is the whole content of environmentally friendly metal coating. If you want to know more information, please call us for details.
