The common problems with electrostatic coating spraying process mainly come from particles in the spraying environment and impurities caused by various other factors, roughly as follows:

Coating impurities

(1) Impurities in the solidification furnace. The solution is to thoroughly clean the inner wall of the curing oven with a damp cloth and a vacuum cleaner, with a focus on the suspension chain and air duct gaps. If it is a black large particle impurity, it is necessary to check whether there is any damage to the air supply duct filter screen, and replace it in a timely manner.

(2) Impurities in the powder spraying room. Mainly dust, clothing fibers, equipment abrasives, and powder coating system fouling. The solution is to use compressed air to blow the powder spraying system before starting work every day, and thoroughly clean the powder spraying equipment and powder spraying room with a damp cloth and vacuum cleaner.

(3) Hanging chain impurities. The main product is the corrosion of the suspension chain oil baffle and the primary hoist water pan (made of hot-dip galvanized sheet) by pre-treatment acid and alkali vapor. The solution is to regularly clean these facilities

(4) Metal impurities. Mainly due to excessive metal additives, uneven pigment dispersion, and powder spots caused by metal compression. The solution is to improve the quality of metal and improve the way metal is stored and transported.

(5) Pre processing impurities. The main causes are large particle impurities caused by phosphating slag and scattered small impurities caused by yellow rust on the phosphating film. The solution is to promptly clean the slag accumulation in the phosphating tank and spray pipeline, and control the concentration and proportion of the phosphating tank solution.

(6) Impurities in water quality. Mainly due to impurities caused by excessive sand and salt content in the water used for pre-treatment. The solution is to add a water filter and use pure water as the cleaning water for the last two stages.

Coating shrinkage

(1) Shrinkage caused by incomplete oil removal during pre-treatment or incomplete water washing after oil removal, resulting in residual surfactants. The solution is to control the concentration and proportion of the pre degreasing tank and degreasing tank solution, reduce the amount of oil on the workpiece, and enhance the water washing effect.

(2) Shrinkage caused by excessive oil content in water quality. The solution is to add a water inlet filter to prevent oil leakage from the water supply pump.

(3) Shrinkage caused by excessive water content in compressed air. The solution is to promptly discharge the compressed air condensate.

(4) Shrinkage caused by metal moisture. The solution is to improve the storage and transportation conditions of metals, increase dehumidifiers to ensure timely use of recycled metals

(5) Shrinkage caused by oil stains on the suspension chain being blown onto the workpiece by air conditioning. The solution is to change the position and direction of the air conditioning air outlet.

(6) Shrinkage caused by mixing powder. The solution is to thoroughly clean the powder spraying system when changing the powder

Coating color difference

(1) Color difference caused by uneven distribution of metallic pigments. The solution is to improve the quality of the metal, ensuring that the L, a, and b values of the metal are not significantly different and are uniformly positive and negative.

(2) Color difference caused by different curing temperatures. The solution is to control the set temperature and conveyor chain speed to maintain consistency and stability in the curing temperature and time of the workpiece.

(3) Color difference caused by uneven coating thickness. The solution is to adjust the powder spraying process parameters and ensure that the powder spraying equipment operates well to ensure uniform coating thickness.

In short, there are still many metal electrostatic spraying technologies and their application methods that need to be flexibly applied in practice.