Before tinplate cans are printed in color, tin box manufacturers need to print white in the printing area, because white is the base color of all colors, and color printing after white printing can better highlight the color. Affected by the ink coverage, it is often necessary for a monochrome machine to be whitened twice, and the whiteness can reach about 80%. Moreover, it is required that the white paint and the tinplate can have a good bonding force, and can withstand high temperature baking and do not change color.
Tinplate can printing has relatively high requirements for color. In addition to the high degree of water resistance of the pigments, the requirements for the coloring power and durability of the pigments are also relatively high. In addition to the characteristics of general offset printing inks, it should also It has heat resistance. Because the surface of the tinplate can is smooth and will not penetrate water, the ink is heat-fixed and needs to be baked at a high temperature.
Since the surface of tinplate cans is impermeable to water, tin box manufacturers need to equip a drying room in the printing process. The printed ink needs to be baked at a high temperature to fully bond with the surface. It is insoluble in water and does not absorb solvents. Other offset printing has a big difference, which is also a problem that we need to pay special attention to. Therefore, the tinplate can printing line will be longer than other offset printing.
Production process requirements
1. The appearance of tinplate boxes shall not be leaked or expanded;
2. The production quality of tinplate cans is that the tin layer on the outer wall is complete, without obvious rust and scratches, and the tin cans are packaged in a smooth body without obvious edges and corners;
3. The appearance of the tinplate box is printed with main patterns and clear text, and there should be no serious scratches or damage;
4. The appearance quality of the iron can packaging production should be smooth and beautiful throughout the welding seam, the overlap is even and consistent, the welding points are evenly connected, and there should be no poor welding or breakdown;
5. The tinplate box production welding technology recoating tape should be smooth and uniform, completely covering the welding seam and the left part of the coating, curing completely, and there should be no large bubbles and iron spots
6. The body of the metal can should not be severely collapsed due to mechanical collision; the paint on the inner wall of the can should not fall off, and the quality of the inner wall of the tin can should not produce iron sulfide.
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