6. Pores And Pinholes In The Coating
Causes:
1. Pores on the surface of the workpiece.
2. There is residual liquid on the surface of the workpiece, and the degreasing and rust prevention are not thorough.
3. The conductive putty is scraped too thick and not completely dry.
4. The spray gun is too close to the workpiece, and the construction voltage is too high, causing the coating to break through.
5. There is volatile gas in the drying oven.
6. The coating is too thick, or the coating is not fully cured.
7. Problems with the powder coating itself
Solutions:
1. Strengthen the processing of the workpiece.
2. Improve the pretreatment process.
3. Extend the baking time.
4. Adjust the process parameters.
5. Clean the drying oven and purify the gas in the furnace.
6. Control the coating thickness to 50-80μm and adjust the curing conditions.
7. Replace qualified powder coating
7. Poor Mechanical Properties Of Coating Film, And The Coating Falls Off In One Piece
Causes:
1. Poor quality of substrate, improper pretreatment method.
2. Improper baking conditions, incomplete curing or over-baking.
3. Poor quality of powder, or expired.
Solution:
1. Improve pretreatment.
2. Determine the appropriate baking process.
3. Select qualified powder, and conduct a comprehensive inspection if it is expired.
8. Poor Corrosion Resistance Of Coating
Cause:
1. The coating film is not fully cured.
2. The temperature of the baking oven is uneven and the temperature difference is large.
3. Improper workpiece handling.
4. Poor performance of powder coating
Solution:
1. Adjust baking conditions according to coating performance.
2. Select a suitable baking oven with a temperature difference of ±5℃.
3. Strengthen pretreatment to avoid residual treatment liquid on the surface of the workpiece.
4. Replace qualified powder coating.
9. Powder Flying And Poor Adsorption
Causes:
1. The electrostatic generator does not generate high voltage or the high voltage is insufficient.
2. The workpiece is not grounded well.
3. The air pressure is too high.
4. The air duct in the recovery device is blocked.
5. Incomplete pretreatment (rust, oil).
6. Problems with the powder coating itself
Solutions:
1. Check the electrostatic generator and adjust the voltage.
2. Clean the hanger and keep it grounded.
3. Adjust the air pressure.
4. Clean the recovery device.
5. Strengthen the pretreatment process.
6. Use qualified powder coating
10. Uneven Powder Supply And High And Low Powder Spraying
Causes:
1. The powder pipe is partially blocked and the powder fluidity is poor.
2. Insufficient air pressure and unstable pressure.
3. Oil and water are mixed in the air.
4. The fluidization of the powder feeder is unstable and the powder feeder has too little powder.
Solution:
1. Clean the debris or lumps in the powder tube, keep the powder tube unobstructed, and adjust the fluidity of the powder coating dry powder
2. Choose a suitable air compressor.
3. Regularly remove the oil and water in the air compressor.
4. Keep the fluidized bed air pressure stable and add new powder regularly.
