Defects and Solutions of Powder Coating on Aluminum Profile

Firstly: Color Difference
Causes of defects:
  1. Uneven coating thickness of aluminum profiles;
  2. Not uniformtemperature distribution of theaging oven;
  3. Simultaneous production of goods withdifferent materials, thicknesses, shapes and sizes;
  4. Beforechanging the powder paint, the powder feeding device, spray gun, spray room and powder recovery are not be cleaned;
  5. Color difference caused by poordistribution of powder and paint.
  1. Ensure that the thickness of the coating film on the aluminum profile is uniform;
  2. The temperature distribution of the agingovenis uniform;
  3. Classify the goods according to the material, thickness, shape and size;
  4. Clean all materials and devicesbeforechanging the powder paint;
  5. Improve the quality of the powder and ensure that the L, a, and b of the powder are not much different and theirpositive and negative are uniform.
Secondly: The causes of impurities and particles
  1. Impurities causedin the agingoven;
  2. Dust in the coating room, clothing fibers, equipment abrasives and fouling of the coating system;
  3. Too many powder additives, poor dispersionof powder paints, too high temperature of powder making resulting that some of them are fixed and solid;
  4. Damp powder agglomerated together resulting to poor spraying effect;
  5. Too many particles and impurities on the aluminum profiles before surface treatment;
  6. Too much recycled powder added and not sieved;
  7. Too thincoating sprayed onthe aluminum profiles, too hard to cover their slight defects.
  1. Thoroughly clean the curing oven’s wall;
  2. Improve the quality of powders;
  3. Improvethe warehouse condition, not allowed forexpired plastic powder, and to transform the coating equipment;
  4. Clean up the aluminum profilesbefore spraying to reduce the burrs;
  5. Add light recycled andsievedpowders;
  6. Appropriately increase the coating thickness of aluminum profiles.
Thirdly: Causes of the poor powder rate:
  1. Too smallvoltage when spraying;
  2. Too small resistance of the high-voltage generator and too largeoutput current;
  3. Too largepowder coatingpressure;
  4. Insulatedhook and too poor electrical conductivity;
  5. Longdistance between the spray gun and the aluminum profiles;
  6. Poorpowder performance.
  1. Adjust the voltage within60-90KV;
  2. Appropriately increase the resistance value of the resistor;
  3. Appropriately lower the air pressure;
  4. Regularly clean the hookfor excellentconductivity;
  5. Properly adjust the distancebetweenspray gun and aluminum profiles; choose superior quality powders.