六个影响彩涂板色差的因素

影响彩涂板色差的因素有：涂层、基材、化学涂层处理、膜厚、PMT、冷却水等，具体为：
一、涂层
彩涂板由于涂层的不均匀混合或涂层在不同桶中粘度的大差异，涂层从进料口的一侧延伸到进料盘中的回流口的方向，并且存在色差带。另外，改变油漆颜色，特别是颜色对比度大的两种颜色，由于清洗不干净，会造成色差

二。底板
彩涂板锌花在基体上的大小也会影响其色差，晶界处会形成许多大小不一的小坑，从而影响基体表面的色差。对于浅色，色差特别明显。宜选用非锌花或小锌花基质。
三、化学涂层处理
彩涂板化学镀膜工艺不当，导致化学镀膜过厚，干燥后板温不足。如果涂布辊体损坏，干燥后会形成黄色斑块，造成彩涂板色差，特别是浅色。
四、膜厚
膜厚的稳定性对彩涂板的色差有很大影响。涂膜厚度的调整方法主要有：涂膜粘度、调整粘辊与涂膜辊的间隙、改变涂膜辊与粘辊的辊速、调整涂膜辊与托带辊的压力等。
五，PMT
彩涂板PMT表示涂层固化良好时带钢所需的最高温度。pmt的稳定性对彩涂板的色差有很大影响。带钢规格的变化会导致pmt的变化，局部温度的高低会影响pmt的变化，基板厚度的不均匀会导致pmt的变化，炉内温度的变化也会导致pmt的变化。
六、冷却水
雾化冷却，冷却水不及时更换。当炉气中有机溶剂挥发物冷却冷凝时，冷却水被带到板面上，由挤压辊挤压后板面产生色差。在生产过程中，冷却水应保持适当的溢流，并及时清除冷凝挥发物，避免板上色差。

The factors that affect the color difference of color coated plate are: coating, substrate, chemical coating treatment, film thickness, PMT and cooling water, etc. Specifically:

I. coating
Becaue of the uneven mixing of the coating or the big difference of the viscosity of the coating in different barrels, the coating extends from one side of the feed port to the direction of the reflux port in the feed tray, and there is a color difference band. In addition, changing the paint color, especially the two colors with large color contrast, will cause color difference due to unclean cleaning
II. Base plate
The color difference is also affected by the size of the zinc flower on the substrate, and many small pits with different sizes will be formed at the grain boundary, which will affect the color difference on the surface of the substrate. For light color, the color difference is particularly obvious. It's better to choose non zinc flower or small zinc flower substrate.
III. chemical coating treatment
Improper chemical coating process results in 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 coating plate, especially light color.
IV. film thickness
The stability of film thickness has great influence on the color difference of color coated plate. The adjustment methods of film thickness mainly include: coating viscosity, adjusting the gap between the sticking roller and the coating roller, changing the roller speed of the coating roller and the sticking roller, adjusting the pressure between the coating roller and the strip supporting roller, etc.
Five, PMT
PMT indicates the peak temperature required for the strip steel when the coating is well cured. The stability of PMT has a great influence on the color difference of color coated plate. The change of strip specification will result in the change of PMT, the high or low local temperature will affect the change of PMT, the uneven thickness of substrate will result in the change of PMT, and the change of temperature in the furnace will also result in the change of PMT.
Vi. cooling water
Atomization cooling, cooling water is not replaced in time. When the volatiles of organic solvent in the furnace gas are cooled and condensed, the cooling water is brought to the plate surface, and the color difference is caused on the plate surface after extrusion by the extrusion roller. In production, the cooling water should be kept overflowing properly, and the condensed volatiles should be removed in time to avoid the color difference on the board.