The principle of roller coating and roll coating is similar, both by sucking the paint of the roller (or roller) cylinder on the surface of the coated workpiece to transfer the coating to the surface of the coated workpiece. However, the roller coating run by mechanical movement, to the roll as a poor production carrier, the coating in the roll surface to form a certain thickness of the wet film, and then the roller in the process of rotation and contact, the paint applied to the surface of the coating. Roll coating is suitable for flat coating, widely used in metal plates, plywood, artificial leather, cloth, plastic film, and paper coating, especially suitable for metal coil coating.
The coatings suitable for roller coating are solvent-based coatings, water-based coatings, and plastisol coatings. Commonly used coatings include polyester coatings, alkyd coatings, epoxy coatings, acrylic coatings, vinyl coatings, polyvinyl chloride plastisol, fluorine resin coatings, etc. Roller coating requires coatings with good leveling, wetting, and adhesion, a certain degree of hardness, flexibility, and abrasion resistance. And these coatings need to have good leveling, wetting, and adhesion, a certain hardness, flexibility and abrasion resistance, and good weather resistance and pollution resistance. You use baking type coating or normal temperature drying type coating.
The coating machine is mainly composed of a coating mechanism and steering support mechanism.
The coating machine is also known as the coating head, consisting of a feeding roller, a coating roller, and a coating disc, which is often referred to as a two-roll type. The picking roller may be a chrome plate, the role of which is to remove the paint from the coating plate and transfer the coating to the coating roller, the coating roller surface wrapped in a layer of solvent-resistant rubber. Usually, the coating scraper is set between the feeding roller and the coating roller, which can eliminate the excess coating. Each roller is equipped with a regulator that adjusts the clearance and pressure between the rollers to obtain the required amount of coating. When the shutdown and the coil seam pass, the front coated roller automatically disengages from the coil through the automatic adjustment device, protecting the coated roller from damage. Note that metal section incisions are easy to damage the rollers.
The difference between the three-roller coating head and the two-roller type is an added adjusting roller. The thickness of the wet film can be adjusted by adjusting the gap between the regulating roller and the take-up roller. The roll coater with higher production speeds are often set up with two coating heads, i.e. two coating heads on the front side of the web, which allows for a quick change of coating and coating rollers.