There is still a certain amount of solvent in the paint mist particles sprayed on the workpiece. The solvent should maintain a proper volatilization rate. If the volatilization rate is too slow, it will affect the formation of the coating film and may cause sagging. When volatilizing, it absorbs heat and cools down the surface of the workpiece. Too much water vapor will also cause condensation, which will affect the adhesion of the paint to the workpiece. However, if the amount of solvent is too small or the volatilization rate is too fast, it will affect the leveling of the coating film and affect the performance of the cured coating film. The factors that affect the volatilization of solvents on the workpiece are:
(1) The surface temperature of the workpiece and the temperature of the ambient air
High temperature is conducive to solvent volatilization, and vice versa.
(2) The flow velocity of the surrounding air
Fast air flow is conducive to the volatilization and diffusion of solvents, so in order to increase the air flow speed, good ventilation in the spraying environment should be maintained.
(3) Flash time
Flash time refers to the minimum time required to allow the solvent to evaporate from the previous paint layer before spraying again, including the flash time between two sprays and the flash time after the topcoat is applied. The length of the flash evaporation time is related to the characteristics of the solvent used. The flash evaporation time of fast volatile solvents is short, and the flash evaporation time of slow volatile solvents is long.