Common problems of sticker printing in China printing company

Author: Meizhen Huang

Common problems of sticker printing in China printing company

1. Pressure problem printing pressure has a great influence on printing quality. Adhere to the uniform and constant printing pressure in the useful printing area, not only can make the ink color of the printed matter uniform, and the color difference is small, but also can make the printing standard stable. The flat press can obtain printing pressure. However, due to its production accuracy, printing flatness, and the thickness of the self-adhesive substrate cannot be uniform, the pressure is uneven, which affects the quality of the China sticker printing. One of the ways to deal with uneven pressure is to make cushions, and place them on the lower part of the workbench with low pressure; one is to properly reduce the hardness of the flexographic plate. But reducing the hardness of the flexographic plate is limited. Assuming that the flexibility and hardness are too low, the graphics and text geometry standards will expand outward, making small fonts a little vague. When printing a large area, the problem of printing pressure is not easy to deal with. The method that can be used when bronzing is to put a layer of 175-line mesh on the worktable, with a hardness of 90° silicone rubber plate, which can deal with the problems of exhaust and partial pressure shortage.

2. Paste small text such as fonts below No. 8 due to the small spacing of fine lines, China sticker printing often has the phenomenon of monotonous ink on it, resulting in indistinguishable adhesion between graphics and text. This is mainly due to the monotony of the ink. In this case, we must first find out the problem from the flexible resin version itself. The bottom of the resin version of the font has a smooth feel and should not be sticky, but due to lack of exposure, the bottom of the font is in a softened state, and it simply sticks to the ink. The ink accumulates more and more, and it is monotonous in the thin line. If it is discarded, it will ruin the plate. At this moment, you can choose to use a resin plate post-treatment liquid for processing. The post-treatment liquid contains sodium hypochlorite and hydrochloric acid, which can harden the bottom of the word. The basic method for sticky problems is to find out the exposure time and make a resin plate that meets the standard. Specially precise fonts are recommended to be replaced with copper-zinc plates. It is not easy to dry the ink between the copper-zinc plates, the fonts are firm, and it is easier to print clear strokes. As far as the environment is concerned, pay attention to reducing the air flow rate. If it does not work, you can add the appropriate monotonic agent in the ink to avoid the appropriate monotonic speed in the ink.

  1. Vignettes sometimes appear cloudy on the sticker printing, which is mainly caused by uneven ink distribution. The even roller for flat-pressing and sticker printing is a chrome-plated iron roller with a diameter of 150mm that can move axially. Its function is to receive ink from the ink fountain roller and the ink transfer roller, distribute the ink evenly, and then transport it to the ink. On the roller, the inking roller loses the ink to form a vignetting. In addition, the inking roller is made of vulcanized soft nitrile rubber. If you do not pay attention to maintenance, the inking effect will decrease, and it will also cause vignetting. To deal with vignetting is to deal with uneven ink distribution, and the ink supply can be increased appropriately.
  2. The synchronization problem of die-cutting and sticker printing. Sticker printing China generally needs to be cut into a certain shape for talent use. On a printing press where the die-cutting and printing are formed at one time, the synchronization of die-cutting and printing is important. The up and down movement of die-cutting and the up and down movement of the printing table are driven by the main drive shaft, so it is synchronized, but the cutting position is driven by the rotation interval of the double-crank structure. Therefore, adjust the crank radius and the pressure of the paper roller important.