A variety of solutions for gravure blockage failures

The transfer rate of ink in gravure printing is usually between 50% and 70%, and the remaining ink remains in the cells. If the residual rate of the ink is always maintained at a certain value, there will be no problem, but in the actual printing process, the residual rate of ink in the cell site is often increased due to several reasons, resulting in blockage. After the blockage phenomenon occurs, the printed images will be blurred, the small prints will not be printed, and the colors of the printed products will change. In severe cases, printing cannot continue.

Blocking fault solution:

Through the analysis of the cause of gravure blocking, the author summarized the following solutions.

(1) The temperature and humidity of the printing shop should be appropriate, and the drying speed of the solvent must be compatible with the printing speed and the printing environment.

(2) Keep the distance between the doctor blade and the impression cylinder as short as possible, and prevent the hot air from the dryer box from directly blowing the plate layout.

(3) Use a slow-drying solvent in combination to appropriately increase the printing speed.

(4) Replace the ink when it is blocked due to defects in ink properties. When replacing the ink, first wash the ink tank and the circulation pump thoroughly, then pour in new ink and try to avoid mixing the ink with a significant difference in density.

(5) Always mix the ink in the ink tank so that the ink in each part is in a flowing state. New inks should also be added or replaced in time to avoid ink filming.

(6) Wipe the plate cylinder with solvent before or just after starting the machine. During the printing process, midway parking should be avoided as much as possible. For long-term parking, it is necessary to first clean the plate or immerse the plate cylinder in the ink tank and keep it idle continuously.

(7) When using a new ink, due to temperature differences and other reasons, the phenomenon of crystal precipitation of additives, waxes, etc. in the ink may occur. Therefore, the new ink should be heated to 40 to 50°C until the crystals are dissolved. use.

(8) Use a regular special dilution solvent.