Analysis of the causes and countermeasures of common problems in gravure printing from the process perspective


Published on:

2017-04-21

Common problems in the processing of printed materials are: print line marks (knife wire, knife line), poor ink adhesion, dark tone level, poor gloss, color difference, half point, leakage, blocking plate, pinhole, turtle pattern, residual solvent, etc.. In this article, we will take poor gloss and residual solvent as an example, and briefly explain the causes and solutions from the perspective of the printing process.

Analysis of the causes and countermeasures of common problems in gravure printing from the process perspective

Common problems in the processing of printed materials are: print line marks (knife wire, knife line), poor ink adhesion, dark tone level, poor gloss, color difference, half point, leakage, blocking plate, pinhole, turtle pattern, residual solvent, etc.. In this article, we will take poor gloss and residual solvent as an example, and briefly explain the causes and solutions from the perspective of the printing process.

Why does failure occur?

The drying performance of the ink and drying conditions to the combination of the decision enough to the degree of drying of the ink. The drying speed of the ink has a decisive effect on the tonal level, residual solvent and odor of the printed matter.

1, by scraping the ink retained in the gravure screen cavity in the moment of reaching the substrate, because the solvent evaporates too quickly, the viscosity rises and reduces the transfer rate of ink. This affects the color of the print, resulting in the highlight part of the ink, the dark part of the ink dispersion and other failures.

2, such as a solvent evaporates too quickly will cause the system to lose balance, the temperature of the ink layer is rapidly reduced, the moisture in the air on the ink scraper dew into the ink, causing the water of the gel "vernacular", resulting in poor ink gloss.

3, the drying speed of the ink is too slow, resulting in inadequate drying, solvent evaporation difficulties, will lead to residual solvent rise.

How to solve the problem?

1, so that the drying system to maintain the best state, drying temperature, air volume, wind speed is appropriate, and match the printing speed, fully reduce the residual solvent.

2、The solvent ratio should be correct, especially when using mixed solvents, the ink can achieve good transfer from the gravure screen cavity, and still maintain good balance of solvents and have good leveling after transfer.