Spray process and requirements for general and art powder coatings
Posted by: FEIHONG Powders |on July 18, 2012
The so-called Powder coating is the use of the principle of the electric field of high voltage electrostatic corona. Connected to the high-voltage anode metal deflector standard on the gun head, spraying the workpiece ground formation of the positive, so that the formation of a strong static electric field between the gun and the workpiece. When the compressed air as a carrier gas, the barrel of powder coatings for the powder sent the pollen tube to spray gun deflector rod, guide rod connected to the corona discharge generated by the high-voltage anode, in the vicinity of dense negative charge , powder to make a negative charge, and entered the high electric field strength of the electrostatic field in the dual role of static electricity and the carrier gas, the powder toward the ground workpiece surface to form a uniform thickness of the powder layer, and then heat curing transformed into durable coating.
Coating application process :
Pretreatment – drying to remove water – spraying – Check – baking – check – Finished
Coating application requirement
Spray requirements for general type powder coatings
- the characteristics of the powder coating can give full play to extend the coating life to break the painted surface first strictly surface pre-treatment
- spray, was painted to be fully grounded in order to increase the efficiency of the powder coating of puffing.
- the larger surface defects to be painted, coated scratch conductive putty, in order to ensure the formation of the coating and smooth.
- Spray the need for heat curing, curing conditions prevail in powder product technical indicators but must be fully guaranteed cure temperature and time, to avoid curing caused by insufficient quality of the accident.
- immediately dusting after examination, if a defect is discovered should be promptly dealt, after curing a defect is discovered, its scope is only partial without affecting the painted surface decoration that can be used to repair the same color powder with acetone diluted, if the range affect the surface quality, use sandpaper, then spray once or use paint remover to remove the coating, and then re-Suona powder.
- recovery of powder to be filtered to remove debris after a certain percentage of new powder mixing.
- for the powder barrel, powder room and recovery system should avoid the pollution of a different color powder, so each time you change the color must be purged.
Spray requirements for art type powder coatings
Art powder with a beautiful, strong third dimension, and the decorative effect of rape, but its strict construction process.
- dusting the input air pressure should not be too large, the general control in the 0.5-1.5kg/cm2 as good. Pressure might cause the pattern clarity poor or have some pitting. Electrostatic voltage should not be too high, the general control of around 60-70Kv. The voltage is too high, makes the powder attached to the surface occurrence of the rebound phenomenon Ma Hang. Leveling the poor and other defects.
- to be taken to ensure that the thickness of the coating, the general control can only conducive to the formation of significant patterns and pattern between 70-100μm, coating thin the pattern is not obvious, but the pattern is also small, and it will The pitting exposed at the end defect
- curing must be baked according to the specified temperature and time. If the temperature is too low time is too short will cause the powder do not form a pattern of mechanical properties also declined significantly, while curing is not complete. In addition, due to the special nature of the art pattern powder production process, then sprayed with recycled powder, its pattern will be small or insignificant changes occurs, it is generally recommended that the recycling of the art powder powder Do not use. Use is also subject to testing. See from the above although its more stringent construction requirements, it is believed that the coating process better grasp of the above factors, will achieve the desired satisfaction.