The color difference is also affected by the different size of zinc flower on the substrate. Many small pits with different sizes will be formed at the grain boundary, which will affect the color difference of the plate surface. For the light color, the
color difference is particularly obvious, the substrate without zinc flower or small zinc flower is selected.
Due to the uneven mixing of the coating or the great difference in the viscosity of the coating in different barrels,
the coating extends from the side of the feed port to the direction of the return port in the material pan, resulting in a color difference band. In addition, changing the color of paint, especially the two colors with large color contrast, will cause
color difference due to unclean cleaning.
3. Chemical coating treatment
Improper chemical coating process leads to too thick chemical coating and insufficient plate temperature after drying. If the coating roller body is damaged, yellow patches
will be formed after drying, resulting in color difference of color aluminum coil, especially light color.
In production, the cooling water of printing plate should be kept overflow properly, and the condensed volatiles should be removed in time
to avoid color difference.