There are three main coating processes of color coated sheet: roll coating, laminating film coating and powder coating.
Roller coating process: The liquid coating is uniformly and continuously applied on the upper surface, the surface and the lower surface of the base plate by rotating adhesive rollers and coating rollers, and cured by baking. In the world, the number of units using this type of technology is the largest, and the production capacity is the largest, and the wax temperature is difficult to accumulate a large number of mature production and operation experience. Product applications are also the most common, and its products are widely used in outdoor buildings, but also in the field of indoor decoration, household appliances, furniture and other areas. This kind of unit has high running speed and large single unit capacity.
Roller coating process has the advantages of flexible production, strong adaptability of coatings and wide thickness range of coatings. By using roll coating process, laminating and embossing products can be produced by configuring special equipment (such as laminator and embossing machine) after coating.
Laminating process: the plastic film is pressed on the surface of steel plate with thermosetting binder. The product can maintain the original color of the plastic film. The film and the base plate are not easy to peel off. It is suitable for reprocessing. The product has a striking appearance, fire resistance, corrosion resistance, acid resistance and other properties, and good fire resistance and pollution resistance. The products are mainly used in household appliances, furniture, interior decoration and interior decoration of vehicles and ships. At present, although its products have a momentum of growth, but the production scale of the unit using this process is small, which is generally selected by professional household appliances board manufacturers. There are also some color coating units which are roll coating and laminating film dual-purpose units.
Powder coating process: is a new process developed in recent years, which is divided into powder gun and powder cloud technology. A few years ago, a number of color coating units using powder gun technology were put into operation in the world, but their speed is low and their production capacity is small. The recent development of MSC powder cloud technology has greatly improved the efficiency of powder coating unit. The deposition rate of powder coating is up to 90%. The speed of the unit put into operation has reached 100 mw/min, and the width of steel band has reached 1300 mm. Powder coating is used in this technology. Powder rotating brush produces powder cloud under strong electrostatic field, and charges fly to the substrate, deposit on the surface of steel strip, and then solidify by induction heating to produce powder coated plate.
At present, most of the domestic units adopt roll coating process. There are three main production processes of roll coating type units, one coat one drying, two coat two drying and three coat three drying. Among them, the two coat two drying process is the most widely used. It has the characteristics of flexible production, wide product range, strong adaptability and moderate investment.