Test of film thickness of workshop primer

Regarding the quality of the film thickness of the shop primer, in addition to the fact that the average film thickness can meet the requirements of the specified film thickness, that is, 10-15µm, the film thickness should also be uniform, and there should be no structural points, so that the shop bottom method can truly play a role. The anti-rust effect of the process interval.

When testing the film thickness of the shop primer, the dry film thickness of the shop primer cannot be directly measured with a magnetic paint Film Thickness Gauge , because after the container copper plate is approved, the surface group roughness value is 35-50 microns, while the shop primer It is only 10~15μm, and the measured value is not the true thickness of the shop primer. In actual production, the "test small pull method" should be used, that is, take a few steel plates that have not been shot and painted, and measure them with a magnetic paint film. The thickness meter first measures the thickness of the degree of oxidation, etc., and then puts it into the pretreatment line, let it be coated with the shop primer, and after 1000 minutes. The measured thickness minus the thickness of the degree of oxidation, etc., is the approximate thickness of the shop primer. thickness.

In particular, it should be pointed out that the shop primer of the container is zinc-rich ring shop primer, and the volume powder content is relatively high. If the car bottom method exceeds 20µm, a large amount of zinc oxide fumes will be formed during cutting and electric welding. The physical health of workers is detrimental. In production, the film thickness of the shop primer is generally controlled by adjusting the dilution ratio, the size of the nozzle aperture and the transmission speed of the collar plate.