Customized tinplate box brushes have special requirements for ink

Tinplate printing has special requirements for inks: (1) It requires that inks have good adhesion and mechanical properties

Because tinplate printing is made into canned food, toys, metal photo frames, and barrels and cans of chemical products, it needs to be cut, bent and stretched. Therefore, printing inks are required to have good adhesion and corresponding mechanical properties to tinplate. In order to improve the adhesion of ink, tinplate needs to be treated with white paint before printing. White is the base color of all pictures and has high brightness. After adding other high-energy tones, the brightness of each tone can be increased to form a color level.

(2) Requirements for white ink

The surface of tinplate is silver-white (or yellow) and has a metallic luster. Before printing colored graphics, the surface needs to be painted or printed with white. Due to the limitations of ink coverage, monochrome machines often need to print white twice. The whiteness can reach 75%. Whiteness is an important indicator of the quality of tinplate printing products. White ink requires good bonding with the primer, and it will not turn yellow after repeated high-temperature baking, and steam at high temperatures without fading. Bottomize the tinplate box to increase the adhesion to the tinplate and have good adhesion to the white ink. Commonly used primer is epoxy amine, which has a light color, and will not turn yellow or age after repeated baking, and has good flexibility and impact resistance.

(3) Requirements for color ink

In addition to having a certain water resistance, tinplate printing color ink also requires its special requirements. Since the surface of tinplate is impermeable to water and solvents and needs to be baked and dried, the ink should be heat-cured. High requirements for pigment coloring power and durability. In addition to the basic properties of general offset printing inks, iron printing inks should also be based on the characteristics of iron printing, heat resistance, strong ink film adhesion, impact resistance, good hardness, steaming and cooking resistance, and light resistance.

(4) Ink drying process

In tinplate printing production, ink drying is a complex physical and chemical reaction process. It is necessary to reasonably control the ink drying speed and master the physical and chemical mechanism of ink drying in order to effectively carry out rapid printing operations and ensure product quality. If the ink drying too quickly, it will reduce the normal transfer performance of the ink and affect normal production; it will cause the printing to become weaker, the color of the ink will become lighter, and the ink drying on the surface of the printing plate and ink roller will hinder the ink during the transfer process; the dry printing plate graphic layer will spread outward; excessive desiccant will increase the ink absorption, and the blank part will become dirty. If the ink is drying too slowly, it will cause difficulty in overprinting, adhesion, adhesion, etc., which will reduce the firmness; it will easily cause scratches during the transportation process. Therefore, the drying speed of the ink should be appropriate, and it is not good to be too fast or too slow.

(5) Special structure of printing equipment

Due to the different printing materials, the auxiliary mechanism of the tinplate box printing machine is also different from that of the paper offset printing machine. Iron palm is insoluble in water and does not absorb solvents, so printing inks need to be baked at high temperatures to evaporate the solvent and cure the conjunctiva. Therefore, a drying chamber is generally required in the printing processing device. The entire tinplate printing automatic line is generally more than 50 meters long, which is both precise and huge. In addition, the tinplate press is controlled by magnets for paging and double sheets. The high hardness of tinplate materials also determines that advanced continuous iron conveying structures cannot be used during printing. The structure of the push, horizontal and stacking parts is different.