Coating process: powder electrostatic spraying process

Core tip: powder electrostatic spraying is to use the principle of high voltage electrostatic corona electric field A high voltage negative electrode is connected to the metal guide sign at the head of the spray gun, and the sprayed workpiece is grounded to form a positive electrode, so as to form a strong electrostatic field between the spray gun and the workpiece When the powder coating is sent from the powder supply barrel to the guide rod of the spray gun by the compressed air as the carrier gas, because the guide rod is connected with the corona discharge generated by the high-voltage negative pole, a dense negative charge is generated near the guide rod, which causes the powder to carry the negative charge and enter the electrostatic field with high electric field strength Under the double action of electrostatic power and carrier gas, the powder flies to the ground evenly land Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Coating home news: powder electrostatic spraying is the use of high-voltage electrostatic corona electric field principle A high voltage negative electrode is connected to the metal guide sign at the head of the spray gun, and the sprayed workpiece is grounded to form a positive electrode, so as to form a strong electrostatic field between the spray gun and the workpiece When the powder coating is sent from the powder supply barrel to the guide rod of the spray gun by the compressed air as the carrier gas, because the guide rod is connected with the corona discharge generated by the high-voltage negative pole, a dense negative charge is generated near the guide rod, which causes the powder to carry the negative charge and enter the electrostatic field with high electric field strength Under the double action of electrostatic power and carrier gas, the powder flies to the ground evenly A thick and even powder layer is formed on the surface of the workpiece, and then heated and solidified to form a durable coating The following is the construction process and requirements of electrostatic powder spraying 1、 Pretreatment of coating construction process - drying and removing water - spraying - Inspection - baking - Inspection - finished products - Requirements for electrostatic powder spraying construction 1 General requirements for powder spraying construction (1) in order to make full use of the characteristics of powder coating and extend the service life of the coating film, the surface of the damaged coating shall be strictly pretreated first; (2) When spraying, the coating shall be completely grounded to increase the spray efficiency of powder coating; (3) for the coating with large surface defects, conductive putty shall be applied to ensure the smoothness and smoothness of the coating; (4) After spraying, the objects need to be heated and solidified The curing conditions are subject to the technical specifications of powder products, but the curing temperature and time must be fully guaranteed to avoid quality accidents caused by insufficient curing; (5) Check immediately after powder spraying If any defect is found, it shall be handled in time If any defect is found after curing, the scope is small and only local, and it will not affect the surface decoration of the coated object It can be repaired after diluting with the same color powder and acetone If the scope is large and it also affects the surface quality, it shall be polished with sandpaper, sprayed once again or removed with paint remover, and then Suo powder shall be re applied; (6) The recycled powder shall be screened to remove the sundries and mixed with the new powder in a certain proportion; (7) the powder supply barrel, powder spraying room and recycling system shall avoid the pollution of other powder of different colors, so each time the color is changed, it must be purged 2 The construction of fine arts powder spraying requires fine arts powder, which has the characteristics of beauty, strong three-dimensional sense, decorative effect, etc., but the construction process is strictly required (1) When spraying powder, the input air pressure should not be too large Generally, it is better to control it at 0.5-1.5kg/cm2 Too much air pressure will cause poor pattern definition or some pockmarks The static voltage should not be too high, generally controlled at about 60-70 kV If the voltage is too high, the powder attached to the surface of the workpiece will rebound and appear pockmarks Defects such as poor leveling; (2) pay attention to ensure the thickness of the coating film when spraying powder Generally, 70-100 μ M can help to form obvious pattern and larger pattern If the coating film is thin, the pattern is not obvious, and the pattern is also small, and at the same time, there will be defects such as pitting and exposed bottom; (3) baking must be carried out according to the specified temperature and time when curing If the temperature is too low and the time is too short, the powder will not form a pattern, and the mechanical properties will be greatly reduced due to incomplete curing In addition, due to the particularity of the production process of art pattern powder, the pattern will be smaller or not obvious change after re spraying with recycled powder, so it is generally recommended not to use recycled powder of art pattern powder It has to be tested if it is to be used From the above point of view, although the construction requirements are strict, it is believed that as long as the above factors are well grasped in the coating process, the ideal satisfactory effect will be achieved 3、 The storage and use of powder coating 1 Keep away from the fire source and avoid direct sunlight It should be placed in a well ventilated place with a temperature below 35 ℃ 2 Avoid storage in places susceptible to contamination by water, organic solvents, oil and other materials 3 Powder coating shall not be exposed in the air at will after use, and the bag mouth shall be capped or screwed tightly at any time to avoid sundries mixing 4 Avoid long-term contact with the skin The powder attached to the skin should be washed with soapy water Do not use solvent 4、 The safety of the coating construction site 1 The equipment used in the coating operation shall be well grounded to eliminate static electricity 2 Avoid the phenomenon of no end discharge of coating machine 3 In the powder spraying room, the concentration of floating dust shall be controlled below the safe concentration as far as possible to avoid the risk of dust ignition and explosion Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,