Powder coating defects and countermeasures
Name of defects: impurities, particles
The reason:
1. Curing furnace impurities;
2. The powder spraying indoor dust, clothing fibers, equipment of abrasive powder spraying system and fouling;
3. Too much powder additives, pigment dispersion uneven or powder when the temperature is too high, part of the powder has crosslinking curing;
4. The powder coating accumulation of be affected with damp be affected with damp agglomerate, jet atomization is bad;
5. Profiles before spraying the surface of particles of sundry;
6. Add recycling powder too much and not sieving;
7. Spray coating is too thin, base slightly chi disease is difficult to cover.
The solution:
1. With a damp cloth and vacuum cleaner thoroughly clean curing furnace lining, with a focus on the hanging chain and duct gaps;
2. The purge gas powder before start working, every day with a damp cloth and vacuum cleaner thoroughly clean powder spraying equipment and spray chamber;
3. Improve the quality of powder;
4. Change the warehouse conditions, do not use expired molding powder, modified coating equipment;
5. Clean up before spraying, reduce profiles of burr, etc.;
6. Add recycling powder is suitable and sieving
7. Appropriate increase the coating thickness.
Defect name: bubble, shrinkage cavity, pinhole
The reason:
1. Pretreatment in addition to the oil not clean, or surfactant oil removal after washing is not net residual;
2. Use compressed air medium oil, water levels;
3. The water cut of overweight or raw material powder coating itself is unqualified, volatile paint or powder be affected with damp be affected with damp;
4. On oil pollution and so on all sorts of fall in powder spraying room or in the oven will be powder coating, spray powder room and baked way;
5. By blending caused by shrinkage cavity;
6. Too close to spray gun from the workpiece, causing electric shocks perforation
The solution:
1. In addition to the oil tank . Good control of the concentration, reduce profiles with oil, and strengthen the washing effect;
2. Increase the oil-water separator, dry compressed air;
3. Choose the high quality powder coating or improve powder storage and transportation conditions, recycling powder dehumidifier to ensure timely use;
4. Clean up in time, all sorts of ensure no oil fell into;
5. Clean up when in powder spray system;
6. Adopt the appropriate distance (preferably 150-300 – mm) to spray powder.