1. The reason for the printed version: The technical level of the domestic intaglio manufacturers is very different. Due to the current shorter and shorter print delivery deadlines, the printing companies have little time for the plate-making companies, and the last part of the plate-making process. That is, the polishing process is easy to be neglected. This oversight often brings about the fog problem in printing. In addition, the printing plate undergoes long-time printing and wears through metal scrapers, and the non-graphics of the printing plate produce shallow dots. , so that the issue of the fog version was created.
2. Reasons for Printing Films: At present, there are many manufacturers of BOPP film in China. Due to the differences in the processes, formulas, and added auxiliaries produced by various manufacturers, some films are not flexible enough and will be used during long-term printing. Abrasion of the printing plate causes the printing plate to produce shallow dots, gradually causing fog plate problems.
3. Reasons for the printing environment: The printing environment has a great influence on the quality of intaglio printing products, especially in seasons where the temperature and humidity are highly variable and in bad printing environments (such as when the temperature is low and the humidity is low. Easily generate static electricity pollution).
4. The reason of the ink: other external causes are easier to solve. The problem of the ink itself is difficult to solve due to the fog printing problem. This is a problem faced by the ink industry.
II> How to Solve the Fog Problems Caused by the Cause of Gravure Ink
1. Try to design a suitable resin ratio based on the different characteristics of the raw materials:
Different varieties of raw materials, the difference between itself is very large, even if the same pigment varieties after post-processing is different, the nature of the difference is also very large, which requires the compound ink formula designer in the design of composite ink formulations, This is because of the different requirements of different colors of inks in the printing process. When designing formulations, various synthetics should be designed according to the characteristics of the pigments, ie oil absorption, tinting strength, dispersion properties, etc. The proportion of resin in the ink formulation, this can be determined by experimentation.
In general, severe fog problems can often be resolved by improving the fluidity of the ink. The reason is to improve the ink flowability, that is, low viscosity printing. Reduce the impact of the ink on the blade, so that the blade can be very clean Take a blank part of the ink.
2. Scientific application of organic pigments
Adding body pigments to the formula (such as YMT ultrafine powder, YMT ultrafine barium sulfate, CC-65 powder, FH-95 powder, etc.) is not only a problem of cost reduction in Colo. In the resin encapsulating the pigment, the body of the ink is further strengthened, the viscosity of the ink under the same printing viscosity is reduced, and the scraping performance of the scraper is improved.
3. The most current use of wax powder and OK-412 matt powder to solve fog problem
Wax powder and matte powder OK-412 is an effective additive to reduce the problem of fog plate. The particles can easily be released on the surface of the ink and enhance the scraping performance of the blade. However, many manufacturers add wax powder and OK-412 matt powder method will not be able to solve the problem of version fog, it is recommended to be made of wax powder and OK-412 matte powder into semi-finished products, the fineness of the ink grinding qualified After being added at high speed and without grinding, the effect of solving the fog plate problem will be reduced.
4... Use suitable wet dispersing aids to improve the compatibility of pigments and synthetic resins
The purpose of adding wetting and dispersing aids to the formulation is to solve the problems in the formulation system, including the poor dispersion of pigments, poor coating of pigments by various synthetic resins, and poor stability of the system itself, and these problems are solved. Inadequate results often result in fog problems. It is recommended to use L-18 dispersant and GK-208 additives to disperse black, blue and red pigments.
5... Additives to Solve Fog Problems
According to the foreign experience in solving high-speed printing fog problem, it is recommended to use AK-505 auxiliaries which is to reduce the affinity of composite ink and chromium plate layer, and the ink is not easy to adhere to the plate. At present, many domestic manufacturers have good results.
6... Designing Formulas with New Resin System
As mentioned earlier, CL-PP composite inks are more prone to fog problems. It is recommended to use BK-6380 resin system instead of CL-PP system.
Reprinted from: Huayin Media
