It is not uncommon for quality defects to occur during the gravure printing process. The main reasons for this failure from production practices are the following: First, the ink is dried and solidified; second, impurities are mixed in the ink; There is a problem with platemaking.
1. Ink dried on the layout
Electric gravure gravure printing roller nets are fine and rich in layers, and the ratio of layout inks varies depending on the ink type, viscosity, and printing speed. In general, the ink in the cells is only transferred to the printed substrate. If the remaining part is dry, the scraper will come into contact with the scraper before the drum is turned into the ink tank again before it is dissolved by the solvent, and the ink transfer rate will gradually decrease, eventually resulting in jamming. This type of failure is particularly prone to occur during the summer heat season. Because of the high temperature, the solvent volatilization speed is increased and the viscosity of the ink is increased. The ink is easily dried in the network. If the solvent is not cleaned in time, it will also cause blockage. In addition, if the squeegee is not properly angled, the squeegee is too far from the drum, the roller diameter is too large, and the printing speed is too slow, it will cause blocking.
The usual response measures are as follows:
1. Increase the printing speed as much as possible, or use a slow-drying solvent;
2, to strengthen the circulation of ink;
3. Clean the layout with solvent in time;
4, to maintain a certain concentration of ink and viscosity, long time printing, pay attention to add solvent;
5. When a serious blockage occurs, use slick to clean the layout after shutdown;
6, control to maintain a good workshop temperature and humidity, and to do this, the workshop is necessary to install the air conditioner.
2. Ink mixed with impurities
In the printing process, the ink is mixed with impurities. For example, the chips of the substrate, the sand particles of the scraper, the dust absorbed by the static electricity, or the moisture in the air, will make the gravure plate blocked, and the ink can be filtered by the circulation pump.
It is worth noting that some of the ink itself may also cause a chemical reaction for some reason, resulting in a blockage phenomenon.
3. Problems with platemaking
The electric carving gravure is first carved on the copper surface, followed by chrome plating and then ground. In these processes, the defects created by the inner walls of the cells and the surface defects caused by the chrome plating during the process of electric engraving will cause burrs during grinding, which will affect the transfer of the ink. This is also the reason for blockage, especially in the high gloss of the printed products. Departments or small words are particularly prone to blockages.
Author: Putian County, Fujian Province, Chen Jin as printing
