How to solve the problem of poor printing ink? It can easily let the printing staff overcome the problem of ink drying in the process of pad printing or screen printing. So how does the screen printing machine control the printing ink? The following is an introduction to you by the editor of Yinyouyou:
1. Try not to use soybean oil-based ink in the printing process, because soybean oil is a semi-drying (slow) oil, so it is not easy to dry when printing on paper with a dense surface.
2. The best solution to the drying problem is prevention. Before printing, you need to communicate clearly with the ink supplier. The ink supplier of the screen printing machine understands their products better than the printing master. What kind of printed matter does the ink work on? For example, the trademark nameplate, printing on paper. Even the inks used for printing on different papers are not the same. For example, the drying of ink on newsprint is quite different from that on a paper like this.
3. The printing environment should control the pH value of the fountain solution within the range of 4.0 to 5.0. The higher the acidity (the lower the pH), the slower the drying process of the ink.
4. Mixing an additional drying agent in the fountain solution can improve the drying performance of the ink. GrafOSiec is an example of an additional desiccant, which can be added at 1% to 3%.
5. Use a large particle powder to help separate the printed paper and allow more oxygen to enter and react with the oil and resin.
6. Ask the supplier to increase the strength of the ink so that it can be printed with a thinner layer of ink that can be set and dried more easily.
7. Because the temperature of the printing press or the paper may be too low and will delay the drying of the ink, pretreat the paper before printing.
8. When printing a large solid area, overprint with a varnish containing a desiccant or use a clear size.
9. Use the recommended amount of desiccant for the ink being used. Too much desiccant will plasticize the ink, preventing it from drying.
In short, to control the drying speed of the pad printing ink, the best solution is to reach an agreement with the ink supplier about what you want to print and what kind of ink the other party needs to provide. After choosing the right ink, master the areas that should be paid attention to from the details to prevent micro-duplication. The rate of oxidation can be increased by incorporating more oil or alkyd in the catalyst, or by the use of completely dry materials, such as linseed or tung oil, instead of semi-dry oils, such as soybean oil. Some ink drying problems are the result of an improper carrier, which results in a low oxidation process or a lack of available catalysts.