Due to the advantages of in-line processing, combination of various printing methods, and use of environmentally friendly water-based inks, flexo presses have occupied a certain market in the high-end packaging and printing industry in China, especially in the printing of beer labels and soft packs. China has a great advantage. However, compared with offset printing and gravure printing, flexo printing also has some disadvantages, such as the large amount of deformation of the printing plate. These are specifically shown as misprints and stencil printing defects during the printing operation. Imprinting is not allowed 1. Tension control In the printing process, because the tension is not stable, a large amount of waste products are likely to occur, so the tension of the tape must be strictly controlled. In general, there is a magnetic powder tension controller and a tension driving roller at the unwinding and winding positions of the machine, and each has a tension display. Because the paper has joints, the tension will always fluctuate each time the joint comes. It will be possible to advance the rules and reduce the amount of waste. If you want to replace the printing job, if the newly replaced tape is wider, the tension roller will often be worn due to the narrower tape on the front, and the wide paper will cause bridging effect in the middle of the roller. The two sides of the belt are tight and the middle is loose, which has a great influence on the rear slitting unit. At this time, it is necessary to replace the rubber roller, or to smooth the surface of the old rubber roller and continue to use it. In addition, the gas lifted spindle will become loose after a long time. 2. Ensure the accuracy of the printing plate, accurate alignment of the plate At the time of loading, manual paste is generally used, which requires a high degree of proficiency. The edge of the plate must be parallel to the axis of the plate cylinder, and the seam should be as close as possible. Otherwise, it is easy to cause the plate at the seam. Roll beat. If a single printing plate is replaced separately, the overprinting of the printing plate is often inaccurate because of different plate-making time. At this time, the plate can be blown with a hair dryer, and then stretched longitudinally or laterally to keep the same with other printing plates. 3. Fixed speed printing For large-volume prints, it is advisable to use constant-speed printing under conditions where the process is relatively mature, so that the effect of the drying device on paper deformation is relatively uniform and overprinting is easy. Other process parameters such as ink viscosity and tension settings can have a fixed range so that the quality can be guaranteed.