Coating Thickness Selection Color-Coated Plates

Microscopically, the coating is a long empty tissue. Water in the air, corrosive media (chloride ions, etc.) will invade through the weak part of the coating, causing corrosion under the film, and the coating will foam and flake off. In addition, even with the same coating thickness, the secondary coating is denser than the primary coating. According to foreign reports and related corrosion test results, the front coating can effectively prevent the intrusion of corrosive media by more than 20μm. Due to the different corrosion protection mechanisms of the primer and the topcoat, it is necessary to specify not only the total film thickness but also the thickness of the primer (“5 μm” and the topcoat (“15 μm”). Only in this way can the different parts of the painted steel plate be ensured. Corrosion resistance is balanced. PVDF products require a thicker coating film. Because of the longer lifespan guarantee. The requirements for the backside coating depend on the application, and the sandwich panel requires only a layer of bondable primer. The formed steel sheet is also required to be coated with two layers due to the indoor corrosive environment. The thickness is at least 10 μm or more.