The object of metal printing is a non-absorbent material, a low-carbon tinplate, commonly known as tinplate. The printing principle of tinplate is similar to that of lithographic offset printing, but there is a special aspect in the process, such as:
1. After the tinplate is printed, the ink stays on the surface and must be dried and solidified by some form of heat energy;
2. The tin layer on the surface of the tinplate is bright and shiny, and its spectral characteristics are considered as the black phase. Therefore, before the color printing, the surface of tinplate must be coated with white paint. Of course, depending on the special artistic effect of the product pattern, it may be partially coated with white paint or directly using the tinplate surface of the tinplate itself;
3. Tinplate after printing the finished product. Need to go to the next process for machining, made into a variety of shapes of containers or other packaging. In the machining process, the ink coating on the tinplate surface must be resistant to mechanical impact and extension. For special products such as canned containers, the ink coating also has the physical properties of autoclaving. This requires excellent adhesion between the ink coating and the tinplate surface.
The quality of the ink coating on the surface of tinplate has always been a long-term discussion and careful study by professionals in practice. It is related to the surface properties of tinplate itself, the types of ink used in the printing process, the type of coating, the baking temperature, and the thickness of the ink coating. Now on how to enhance the adhesion between ink coating and tinplate, talk about personal superficial views.