1. Before color printing on metal, the coating process must be done on the surface of the tinplate. The production products are different, and the corresponding coating process will also be different. The most important coating is the primer and coating. Two kinds of white pigment. Most of the products produced require inner coating and outer primer coating. The biggest role of the coating is to effectively increase the adhesion between the tinplate and the ink layer. First put a layer of primer on the tinplate, and then print the ink, which can enhance the scratch resistance and firmness of the ink, so the coating plays a pivotal role in the subsequent production of digital printing on metal sheet.
2. After digital printing on metal sheet, we also need to put the printed metal plates on the coating machine and apply varnish or matte oil. Of course, we can also apply some special coatings such as pearl oil, rubber oil or explosive oil. The biggest benefit of varnish or matte oil is to protect the ink film on the tinplate and increase the gloss of the printed pattern.
3. After the varnish or matte oil is applied on the printed metal plates, it needs to be baked at high temperature, so that the scratch resistance of the ink on the surface of the tinplate can effectively meet all aspects of the production of tinplate boxes, such as stamping, welding, back cover, During the forming of the buckle bone, it will not change color and will not fall off the paint.