The characteristics and construction of powder coatings

powder coating is a new type of solvent-free 100% solid powder coatingIt has two main categories: thermoplastic powder coatings and thermoset powder coatingsCoatings are made from special resins, face fillers, curing agents and other additives, mixed in a certain proportion, and then prepared by thermo-crowding and crushing sievesThey are stable storage at room temperature, electrostatic spraying or fluidized bed immersion, reheating baking melt solidization, so that the formation of a flat and bright permanent coating film, to achieve the purpose of decoration and corrosion preventioncharacteristics
1, the product does not contain toxicity, does not contain solvents and non-volatile toxic substances, so no poisoning, no fire, no "three waste" emissions and other public hazards, in full compliance with the requirements of the national environmental protection law2, high utilization rate of raw materials, overspray powder can be recycled, the utilization rate of more than 99%3, after the pre-treatment of the coating, one-time construction, without the bottom coating, you can get enough thickness of the coating film, easy to achieve automated operation, high production efficiency, can reduce costs4, coating density, adhesion, impact strength and toughness are good, high angle coverage, with excellent resistance to chemical corrosion and electrical insulation5, powder coating storage, transport safety and conveniencepowder coating construction process and requirements
so-called powder electrostatic spray is the use of high-voltage electrostatic corona field principleIn the head of the spray gun metal guide mark is attached to the high-pressure negative pole, the sprayed workpiece ground to form a positive pole, so that the spray gun and the workpiece between the formation of a strong electrostatic electric fieldWhen the powder coating is sent from the powder supply barrel to the guide rod of the spray gun through the powder tube, due to the corona discharge generated by the high-pressure negative pole of the guide rod, a dense negative charge is generated nearit, so that the powder has a negative charge, and enters the electric field with a high electrostatic field, under the dual action of electrostatic force and carrying gas, the powder evenly flys to the surface of the grounding piece to form a thick and uniform powder coatingcoating construction process
before the treatment of a dry ingressment a dry ingressaone one inspection a baking one inspection a finished product construction requirements 1, general powder coating construction requirements (1) in order to make the characteristics of powder coating can give full play and extend the service life of the coating film, the surface of the coating first strict surface treatment (2) spray, the coating must be completely grounded to increase the efficiency of powder coating (3) for the coating with a large surface defect, should be scratched conductive putty to ensure that the film is flat and smooth
(4) after the application of the object needs to be heated and cured, curing conditions to the powder product technical indicators, but must fully guarantee its curing temperature and time, to avoid lack of curing caused by quality accidents (5) powder immediately after the inspection, if found defects should be treated in a timely manner, if the cure found that the defect, its scope is small only local and does not affect, the surface decoration of the coating, can be used the same color powder with acetone dilution after repair, if the range is large and affect the surface quality, then use sandpaper after grinding, then sprayed again or with delacoric to remove the coating, and then re-powder (6) the recycling powder must be screened to remove debris, according to a certain proportion of the new powder mixing action (7) powder supply barrels, powder booths and recycling systems should avoid contamination of other different colors of powder, so every color change must be cleaned fine-art powder coating construction requirements: fine-art powder, with beautiful, three-dimensional sense of strong, decorative effect and so on, but its construction process requirements are strict (1) when the input air pressure should not be too large, generally controlled at 0.5-1 5kg/cm2 is good Too much air pressure can cause poor clarity of the pattern or produce some hemp dots Static voltage should not be too high, generally controlled at 60-70Kv or so The voltage is too high, which causes the powder attached to the surface of the workpiece to rebound into a pothole Poor leveling and other defects (2) spray powder should pay attention to ensure the thickness of the coating film, generally controlled between 70-100 m can be conducive to the formation of a clear pattern and larger pattern, the film thin pattern is not obvious, and the pattern is also small, at the same time will appear numb ingested and other defects (3) curing must be in accordance with the prescribed temperature and time for baking If the temperature is too short, it will cause the powder to be unpatterned, and the mechanical properties of the curing is not completely reduced in addition, because of the special nature of the production process of fine-art pattern powder, with recycled powder re-sprayed, its pattern will be smaller or not significant changes, so it is generally recommended that the recycling powder of art-type powder should not be used Use must also be tested From the above point of view, although its construction requirements are more strict, but I believe that the coating process as long as a better grasp of the above factors, will certainly achieve the ideal satisfactory results the storage and use of powder coating
1, away from the source of fire, to avoid direct sunlight, should be placed in a well ventilated place, the temperature is below 35 degrees C 2, avoid storage in places prone to water, organic solvents, oil and other materials 3, powder coating safter sit not casually exposed in the air, should be at any time to cover or tighten the mouth to avoid mixing debris 4, avoid long-term contact with the skin, attached to the skin of the powder using soapy water rinse clean, do not use solvents the safety l of the coating construction site, the application equipment for the coating operation should be intact groundto eliminate static electricity 2, to avoid the phenomenon of unprovoked discharge of the machine
3, powder-spraying room, the concentration of floating dust as far as possible to control below the safety concentration, to avoid the risk of dust fire explosion