Defects and Solutions of Powder Coating on Aluminum Profile

Firstly: Color Difference
Causes of defects:

Uneven coating thickness of aluminum profiles;
Not uniformtemperature distribution of theaging oven;
Simultaneous production of goods withdifferent materials, thicknesses, shapes and sizes;
Beforechanging the powder paint, the powder feeding device, spray gun, spray room and powder recovery are not be cleaned;
Color difference caused by poordistribution of powder and paint.

Solutions:

Ensure that the thickness of the coating film on the aluminum profile is uniform;
The temperature distribution of the agingovenis uniform;
Classify the goods according to the material, thickness, shape and size；
Clean all materials and devicesbeforechanging the powder paint;
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
Causes:

Impurities causedin the agingoven;
Dust in the coating room, clothing fibers, equipment abrasives and fouling of the coating system;
Too many powder additives, poor dispersionof powder paints, too high temperature of powder making resulting that some of them are fixed and solid;
Damp powder agglomerated together resulting to poor spraying effect;
Too many particles and impurities on the aluminum profiles before surface treatment;
Too much recycled powder added and not sieved;
Too thincoating sprayed onthe aluminum profiles, too hard to cover their slight defects.

Solutions:

Thoroughly clean the curing oven’s wall;
Improve the quality of powders;
Improvethe warehouse condition, not allowed forexpired plastic powder, and to transform the coating equipment;
Clean up the aluminum profilesbefore spraying to reduce the burrs;
Add light recycled andsievedpowders;
Appropriately increase the coating thickness of aluminum profiles.

Thirdly: Causes of the poor powder rate:
Causes:

Solutions:

Adjust the voltage within60-90KV;
Appropriately increase the resistance value of the resistor;
Appropriately lower the air pressure;
Regularly clean the hookfor excellentconductivity;
Properly adjust the distancebetweenspray gun and aluminum profiles; choose superior quality powders.