Factors of color difference of Color-coated Steel Sheet

Color-coated Steel Sheet are widely used in daily life, but sometimes the color difference of Color-coated Steel Sheet will reduce the use of users and cause losses to manufacturers. Let us take a look at six factors that affect the color difference of Color-coated Steel Sheet. factor.
The factors that affect the chromatic aberration of color-coated boards are: coating, substrate, chemical coating treatment, film thickness, PMT and cooling water, etc. Specifically:
1. Coatings
Due to the uneven stirring of the paint or the large difference in the viscosity of the paint in different buckets, the paint extends from the side of the feed port to the direction of the return port in the tray, and a color difference band appears. In addition, changing the color of the paint, especially the two colors with a large color contrast, will cause color difference due to unclean cleaning. the
2. Substrate
The difference in the size of the spangle on the substrate will also affect the color difference. Many small pits of different sizes will be formed at the grain boundary, which will affect the color difference of the board surface. For light colors, the color difference is particularly obvious, and it is best to choose a substrate without spangles or small spangles.
3. Chemical coating treatment
Improper chemical coating process will cause the chemical coating film to be too thick, and the temperature of the board will be insufficient after drying. If the roller body of the coating roller is damaged, yellow spots will be formed after drying, resulting in color difference of the color-coated board, especially the light color is obvious.
4. Film thickness
The film thickness stability has a great influence on the chromatic aberration of the color-coated board. The adjustment methods of the film thickness mainly include: coating viscosity, adjusting the gap between the adhesive roller and the coating roller of the roller coater, changing the roll speed of the coating roller and the adhesive roller, and adjusting the gap between the coating roller and the strip steel support roller. pressure etc.
5. PMT
PMT represents the peak temperature that the strip needs to reach when the coating is fully cured. The stability of PMT has a great influence on the color difference of color-coated plates. Changes in strip specifications will cause PMT changes, local high or low temperatures will affect PMT changes, uneven substrate thickness will cause PMT changes, and seasonal changes in furnace temperature will also cause PMT changes. the
6. Cooling water
Atomization cooling, the cooling water is not replaced in time, when the volatiles of the organic solvent in the furnace gas are cooled and condensed, they are brought to the plate surface with the cooling water, and after being squeezed by the squeezing roller, color difference will be caused on the plate surface. During production, the cooling water should be properly kept overflowing, so that the condensed volatiles can be removed in a timely manner, so as to avoid color difference on the board surface.