Ink problems in printing

When a problem occurs during printing, it is annoying. There are many causes of the problem, and often not a single factor. Ink, paper, printing plates, printing presses, and other printing conditions may be the culprits. Among them, the ink issue has the most profound impact.

There are many kinds of ink problems. The “dirty” problem often occurs in lithography; and it can be divided into “dirty” and “compacted”. "Dirty" means that the ink is difficult to clean when it is attached to a blank space on the printing plate, and "sticking" refers to a faint color that appears in a large area of ​​the blank. The former is generally related to printing plates. Therefore, when "dirty" occurs, the plate should be checked first; the reason for the latter is that the ink is mostly emulsified. Both of these problems can be temporarily erased using a cleaning solution. In addition, the use of desiccants, detackifiers, and other additives should be minimized in inks, and care should be taken when using additives.

Another common ink problem is “stacking ink,” which means that ink, paper powder, etc. accumulate on the surface of rollers, plates, and blankets. The reason is that the transferability of the ink is poor. Therefore, it can be solved by adding a varnish to improve the transferability.

The remaining ink problems also include "poorly dry" and "large dot gain." As the name implies, the former is a long time after printing, the ink is still not completely dry; the solution is very simple, it is according to the situation to add the right amount of desiccant, and maintain a good ventilation environment during printing and after printing.

"Increase in outlets" means that outlets cannot be completely reproduced. As a result, color contrasts are insufficient and outlets are connected. In response to this phenomenon, inks with higher color densities and suitable lipid sensitivities can be used, and the use of detackifiers, ink transfer inks, etc. can be reduced so that the ink inking is not excessive, and the phenomenon of dot gain can be eliminated.

Summarizing the above four major points, we can see that the use of ink additives can not completely improve the quality of printed matter; on the contrary, it is more likely to bring about different degrees of side effects. Therefore, we must also start from the basics. It is the best policy to use suitable high-quality inks.

Source: 21st Century Fine Chemicals Network