Flexo printing machine has many advantages such as in-line post-processing, the combination of multiple printing methods, and the use of environmentally friendly water-based inks. China has a great advantage. However, compared with offset and gravure printing processes, flexo printing also has some shortcomings, such as large deformation of the printing plate, which are specifically manifested as faults such as inaccurate overprinting and pasting in the printing operation. The following is a brief explanation of the problem of overprinting. â’ˆ Tension control In the printing process, due to unstable tension, a large number of waste products are prone to occur, so the tension of the paper tape should be strictly controlled. Generally, there is a magnetic powder tension controller and a tension drive roller at the unwinding and rewinding positions of the machine, and the tension display is provided. Because the paper has a joint, every time the joint comes over, there will always be fluctuations in the tension, which can be gauged in advance to reduce the amount of waste. If the printing job is to be replaced, if the newly replaced paper tape is wider, it is often due to the abrasion of the tension drive roller due to the narrower paper tape in front, and the replaced wide paper will form a bridge effect in the middle of the rubber roller. The two sides of the belt are tight, and the middle is loose, which has a great impact on the subsequent slitting unit. At this time, the rubber roller needs to be replaced, or the surface of the old rubber roller can be continued to be used. In addition, the gas-expanding mandrel will become loose after a long time. When installing the plate, 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 the plate may be caused at the seam. Roll beating. If a certain printing plate is replaced alone, the printing plate is often inaccurate due to different plate-making time. At this time, the plate can be blown soft with an electric hair dryer, and then stretched in the longitudinal or horizontal direction to keep it consistent with other printing plates. â’Š Fixed speed printing For large batches of prints, under the conditions of relatively mature technology, it is advisable to adopt fixed-speed printing, so that the drying device has a more consistent effect on paper deformation and is easy to overprint. Other process parameters such as ink viscosity and tension setting can have a fixed range, so that the quality can be guaranteed. Foshan Liqia Hardware Products Co., Ltd. , https://www.liqiahardware.com
â’‰ Ensure the accuracy of the printing plate, and install the plate accurately