company news about Common faults and maintenance methods in spraying equipmen

In the field of coating equipment, spraying equipment is the use of corona discharge to adsorb powder coating on the workpiece. Then in the process of work there is a fault how to repair it? The following is a small series of spray repair methods for you, I hope to help you. Common faults and maintenance methods in spraying equipment: 1) The main reasons for local uneven surface coating and unstable flow level are as follows: 1) caused by uneven film thickness; (2) The particle size changes greatly before and after the powder; ③ High voltage breakdown; ④ Venturi tube wear, uneven powder; ⑤ The powder pipe used does not adapt to the equipment; ⑥ The conveying chain has the phenomenon of squeezing, and the walking speed is uneven; The porous plate in the fluidized barrel is damaged or partially blocked. Solution: ① Strengthen the control of film thickness, check whether the powder spraying system (powder supply, recovery, spray gun voltage, etc.) is normal; ② Notify the powder factory for inspection; ③ Reduce the powder supply voltage, but must ensure the normal film thickness, can increase the powder pressure or expand the distance between the spray gun and the workpiece; ④ Check and replace; ⑤ Contact the equipment supplier, check and replace; ⑥ Repair suspension chain, make it uniform speed; ⑦ Check the fluidization condition, and repair the porous plate.
▲ Coating shrinkage, orange peel 2), the main reasons for sand: ① uniform dense appearance; ② It is a protruding circle, and the number is not much; ③ A small amount of sand, different sizes; ④ There are impurities on the surface of the workpiece, sometimes radial or slender; ⑤ A small amount of black particles. Solution: ① Determine whether the film thickness meets the process requirements; ② Check the quality of the powder, whether there are gelled particles, and check whether the surface of the workpiece is clean and free of impurities after phosphating; ③ caused by the environment is not clean, must always keep the environment clean; (4) Check the quality of the powder, and the operator should try not to wear clothes and gloves that are easy to lose fine fibers; ⑤ There are impurities in the baking path (such as colloides) falling to the clean, clean the baking path regularly. 3) The main reasons why the spray gun does not produce powder or the amount of powder is getting less and less: ① The material of the powder spray tube is poor, and the powder is easy to adhere to the inner wall of the tube; ② Insufficient air pressure or gas volume; ③ The powder pipe is heated, and the powder is caked in the pipe; ④ The powder pipe is bent and twisted; ⑤ The powder caked and could not be fluidized normally. Solution: ① Replace the high-quality powder pipe; ② Check the air source and pressure and adjust; ③ The spray room is equipped with air conditioning. Check the particle size of the powder, too thick, notify the powder factory to correct; ④ Check the powder pipe and adjust the position of the pipe; ⑤ Sieve first, if it can not be improved, change powder.
4), the main reasons for powder flow powder bar: ① When the spray gun starts to work, the powder is not uniform; ② The powder is too thick, and the powder layer falls; (3) Insufficient phosphating, there is powder rod phenomenon; ④ The output of electrostatic gun is unstable. Solution: ① Before formal spraying, let the spray gun spray empty for 3 ~ 5min, and then enter the formal spraying after the powder is stable; (2) Control the conditions of the spray gun, do not make the powder layer too thick, and control the smooth movement of the conveying chain, no shaking phenomenon; ③ Clean up the phosphating nozzle to make it smooth; ④ Ask the equipment manufacturer to adjust the test. 5), the main reasons for the secondary spraying of snow: ① the voltage is too high; ② The amount of powder is too large; ③ The distance between the spray gun and the workpiece is too close; ④ The workpiece to be sprayed is phosphating again. Solution: ① Reduce the voltage; ② Reduce the amount of powder, reduce the pressure of powder supply and increase the atomization pressure; ③ Increase the spraying distance appropriately; ④ Rework parts do not go through phosphating, just grinding, blowing the surface can be. Spray equipment (i.e. powder spraying equipment) process flow: 1, spray pretreatment: Purpose: to remove the oil, dust, rust on the surface of the workpiece, and generate a layer of corrosion resistance on the surface of the workpiece and can increase the adhesion of the spray coating "phosphating layer". Main process steps: oil removal, rust removal, phosphating, passivation. Not only is there no oil, rust, and dust on the surface of the workpiece after pre-treatment, but also a uniform and rough gray phosphating film that is not easy to rust is generated on the original silver-white glossy surface, which can both prevent rust and increase the adhesion of the spray layer.
▲ Swim immersion pretreatment
2, powder electrostatic spraying purpose: the powder coating evenly sprayed on the surface of the workpiece, special workpiece (including the position that is easy to produce electrostatic shielding) should use high-performance electrostatic spray molding machine to complete the spraying. Process steps: Using the principle of electrostatic adsorption, a layer of powder coating is sprayed uniformly on the surface of the workpiece. The powder is recovered by the recovery system and can be reused after sifting. 3, drying and curing purpose: heating the powder coating on the surface of the workpiece to the specified temperature and holding the corresponding time, so that it can melt, level and cure, so as to get the surface effect of the workpiece we want. Process steps: Push the sprayed workpiece into the curing furnace, heat it to the predetermined temperature (generally 185 degrees), and hold it for the corresponding time (15 minutes); Open the furnace and take out the cooling to get the finished product. The general workpiece is different, the heating temperature and holding time are also different; Tip: Heating and control system (including electric heating, oil, gas, coal and other heating methods)+ insulation box = curing furnace.