The color-coated plate is referred to as a color-coated […]
The color-coated plate is referred to as a color-coated plate, which is a product made of a cold-rolled steel plate, a galvanized steel plate or an aluminum plate as a substrate, subjected to surface pretreatment, and then coated in a continuous manner, and finally baked and cooled. [1,2,3]. The color coated board has light weight, beautiful appearance and good anti-corrosion performance, and is widely used in construction, shipbuilding, vehicle manufacturing, furniture, electrical, decoration and other industries. However, from the 1940s to the present, the color-coated plate has been published for nearly 80 years, and the production method basically follows the production process of solvent coating roller coating . The biggest advantage of this production process is that it can be coated at a high speed and uniform, realizing large-scale production, so as to meet the large demand for color-coated plates for economic development. However, the use of solvent coating roller coating has serious pollution problems. Solvent coatings contain volatile toxic substances such as benzene, toluene, xylene, butyl acetate and acetone. When the traditional color coating unit is produced, the pungent smell can be heard hundreds of meters away. No matter how strict the protective measures are, the bad production environment of the unit is difficult to change. Although a very colorful coating plant has added waste gas treatment equipment to the unit, residual harmful substances are discharged into the atmosphere and soil, and the combustion exhaust gas generates a large amount of carbon dioxide. At present, as the national environmental protection inspectors become more and more strict, the restrictions on VOC emissions are becoming more and more strict, and the color coating industry is in urgent need of finding a new environmentally friendly process technology that can replace the solvent coating roller coating production.
In the 1950s, the French invented the powder electrostatic spraying process, which puts the powder coating as a film-forming substance with static electricity, and then adsorbs it on the surface of the metal plate with zero potential, eliminating the solvent as a dilution and uniformity [5, 6,7]. At present, this method is widely applied to the low-speed hanging dusting production line, which has the following advantages: