Paint Film Discoloration
Causes:
1. There is residual treatment liquid on the surface of the coating.
2. Over-baking, or volatile gas in the furnace.
3. Powders of other colors are mixed in during construction.
4. The pigment of the powder itself is not resistant to high temperature or the resin is prone to yellowing.
Solutions:
1. Improve the pre-treatment method.
2. Establish appropriate baking conditions and purify the baking furnace.
3. Strengthen the cleaning before construction.
4. Replace qualified powder coatings.
There Are Particles And Lumps On The Surface Of The Coating
Causes:
1. The surface of the coated workpiece is not clean
2. Uneven powder supply and poor spray gun atomization.
3. The powder is too fine or the powder is damp and agglomerated, causing powder accumulation in the spray gun.
4. The coating site is not clean or there is powder dripping in the spray room.
5. The recycled powder or the powder itself is of poor quality.
Solution:
1. Improve the quality of the workpiece substrate and strengthen pre-treatment.
2. Adjust the air pressure, check the deflector, and adjust it to the best point.
3. Control the powder particle size distribution, properly store the powder, and strictly prevent moisture.
4. Clean the site and purify the air.
5. After sieving the recycled powder, mix it with the new powder and replace it with qualified powder.
Shrinkage Holes
Causes:
1. There is oil on the surface of the workpiece.
2. The compressed air contains water, oil, etc., causing the powder to be contaminated.
3. Contaminated by dust or other impurities
4. The powder coating itself is contaminated
Solution:
1. Strengthen pre-treatment.
2. Strengthen the purification of compressed air before painting.
3. Thoroughly clean the environment and replace qualified powder.
Poor Leveling Or Serious Orange Peel
Causes:
1. The surface of the workpiece is rough.
2. The powder particles are coarse, damp or the powder leveling itself is poor
3. The curing temperature is too high or too low
4. The coating is too thin or too thick.
5. The workpiece is poorly grounded.
Different Powders Are Mixed
Solution:
1. Improve the finish of the workpiece.
2. Select high-quality powders with uniform particle size distribution and good leveling and strictly prevent the powder from getting damp.
3. Adjust the appropriate curing conditions.
4. Control the powder thickness at 60-80μm.
5. Clean the hanger regularly.
6. Strictly clean the powder spraying system and site before construction to avoid mixing powders of different types or manufacturers.
The Coating Surface Loses Gloss
Causes:
1. The quality of substrate pretreatment is poor.
2. The baking time is too long or the temperature is too high.
3. There are volatile gases in the furnace.
4. The proportion of recycled powder is too large.
5. Two powders of different properties are mixed.
6. The quality of powder coating is poor.
Solution:
1. Choose a suitable pre-treatment process.
2. Adjust the appropriate curing conditions.
3. Purify the oven.
4. Filter the recycled powder and mix it with the new powder, preferably <30%.
5. Clean the powder spraying system thoroughly before changing the powder.
6. Replace the powder with good quality.
