Lithographic offset sheet paper discount and wrinkle causes
1. The moisture content of the paper is unevenly distributed. If the moisture content of the four sides is greater than the middle, the phenomenon of "lotus edge" will occur, and wrinkles in the trailing part will occur. If the moisture content of the four sides is less than the middle, the phenomenon of "tight edges" of the paper will occur, which will produce wrinkles in the middle.
2. The pressure of the paper pressure roller of the paper feeding table is uneven. The paper pressure wheel is a device for controlling the smoothness, constant speed and positioning of the paper when it is conveyed. Due to the unequal pressure adjustment of each wheel, the paper is affected by the axial force during the transportation process, causing the paper to swell in the middle during transportation, and the state of the middle swell is still maintained at the previous prescribed position. Eliminate, causing wrinkles in the trailing area.
3. The bite force of the impression cylinder biting the paper varies. The bite force of the roller bite should be strong and strong, and the force of each bite should be equal. If the bite force of the two sides of the bite is insufficient, the paper will produce trailing wrinkles. If the bite force of one side is insufficient, the corresponding drag The tip edge is wrinkled, and if the middle bite force is insufficient, the trailing tip in the middle is wrinkled. If the middle is seriously insufficient (bite force), and the speed difference between the printing cylinders is large, the trailing part may be crushed and damaged.
4. Improper handover of paper. If the length of the bite edge of the paper changes (becomes smaller) during the approaching process before the paper is imprinted, it is prone to wrinkle or even chip the edge.
5. The unevenness of the dental pads varies greatly. When the paper is bitten, the edges of the paper are not flat (bite) but wavy, and a short wrinkle deformation close to the bite part may occur.
6. The trace of knocking on the paper is too deep and too dense. Due to the improper force of knocking paper, the trace of knocking paper is deep and dense, so the knocking wrinkle occurs on the crease of knocking paper.
7. The corner of the paper is in the half-bite position. After the paper is positioned, the corner of the paper is bitten by the roller teeth or less than half. As a result, the corners of the paper are often uneven and the paper edges are wrinkled.
8. There are too thick deposits on the impression cylinder. The ink stained on the surface of the impression cylinder is too thick, which makes the paper impressed unevenly and produces a short-distance wrinkle deformation.
9. Paper fiber arrangement direction. When the paper enters the machine for imprinting, the fibers are arranged in straight threads, and the paper is likely to cause wrinkles.
10. The water content of the paper is too large, and the fiber of the paper itself becomes fattened. Under pressure, the fattening fiber should be narrowed from the fat, which is easy to produce wrinkle deformation extending from the bite to the trailing branch-like lines.
The above is the main reason for wrinkling and wrinkling of paper. But how to judge whether it is due to paper itself or mechanically caused by the folding and wrinkling is also very important, it determines the direction for us to deal with quality accidents.
Hot Sale Products,High Quality Hot Sale Products,Hot Sale Products Details, CN
ZHEJIANG HUZOLI METAL PRODUCTS CO.,LTD , https://www.zlplasticfurniture.com