Electrostatic coating equipment spray coating off yellow discoloration how is it?

Partial or large area of coating off

Main reasons: 1 There is a rust layer on the surface of the substrate, which has not been completely removed; 2 Washing is not particularly clean after phosphating; 3 Degreasing of the surface of the substrate is not complete; 4 Lubricating oil on the hanging chain drips onto the workpiece; 5 Galvanized sheet Foaming and coating shedding.

Remedy: (1) Thorough derusting; (2) Check flow rate, water quality and nozzles, check flow rate and pressure of washing; (3) Use chemical degreasing, which is more suitable for animal and vegetable oils. When it is not suitable for mineral oil, use more alkali to remove oil. Washing attention to water quality; 4 Check the quality index of the lubricant, replace the oil with higher temperature resistance if necessary, or place the groove under the easily drip place;

Yellow discoloration of the coating

The main reasons: 1 drying tunnel or oven set temperature is too high; 2 direct gas into the oven or oven; 3 workpiece in the drying tunnel or oven stay too long, or stop the operation of the conveyor chain; 4 powder quality; Bake 2 times or more; 6 paint is severely discolored.

Remedy: 1 Understand the normal curing conditions and adjust them; 2 Install heat exchangers; 3 Understand the baking conditions, pay close attention to the normal operation of the conveyor chain during production, if you want to stop production, all the workpieces should be baked and dried. Material; 4 powder factory to provide different baking conditions for the model, for reference when spraying; 5 as much as possible to complete the baking, the workpiece must be baked twice, and to determine the conditions for repeated baking; 6 check Is the baking temperature too high, such as >230 °C or higher. Check the temperature resistance of the powder.