1, Good bottom coating. Bottom coating is an essential coating in the tinplate surface printing process. It is mainly used to improve the adhesion of tinplate surface, so that the ink can be firmly adsorbed on the iron surface, so that the ink coating is not easily damaged when the tinplate is processed by bending, impact, stretching, crimping and other processing. Therefore, as a coating, it is required to have good wetting and adsorption properties on the metal surface, and high mechanical strength after drying into a film. And resins such as alkyd and epoxy have good adsorption and impact resistance due to their molecular structure.
2,Advanced coating process. In order to obtain a high-quality primer coating layer, in addition to having a good-performance primer, a technologically advanced coating process is also essential. High-quality coating refers to the coating of tinplate with a thick and uniform coating, good spreadability, and a smooth surface. The thickness of the coating film should be controlled at about 1.5 to 2 g / m2. If the coating is too thin, the hiding power, abrasion resistance, adsorption, gloss, etc. cannot meet the requirements. If the coating is too thick, it will cause shrinkage stress, affect adhesion, and increase cost, which may cause incomplete hardening. quality.
The control of the coating process is mainly to control the coating speed and stability of the coating machine, the uniformity of the coating supply and the baking temperature, which depends to a large extent on the advanced nature of the coating process. Equipment accuracy and automation.