Color coated board has been widely used in our life, this product operation, but in the process of use, sometimes appear the phenomenon of paint explosion, what are the reasons for this phenomenon? When No. 2 water quenched cover plate slot was coated on the surface of color coating machine, silt and dust were found, dust was found on the exit inspection mirror, and floating dust was also found on the surface of some rollers. Dust will affect the surface quality of Shandong color coated sheet, especially the quality defects of aging paint explosion. The production process of passivation plate temperature is regulated to check every 2 hours, and the passivation plate temperature is not tracked in real time.When the ambient temperature is 10 ℃ in winter, the temperature change of ring 2122112 may cause the temperature change after passivation within 2 hours, which eventually leads to the aging of Shandong color coated plate and the scratch of paint during the molding. Add passivation solution before adding water. When the density of passivation solution is higher than that of water, it will cause uneven mixing, poor adhesion between passivation layer and substrate, and easy to cause quality defects of top coat.