When our factory used the Beiren PZ4880—01B 4-color offset printing machine to print, there was a fault in the last color of the product on the left side of the gargle that was not overprinted and wrinkled in the middle. According to the repair experience and analysis, we determined that due to the normal printing of the first three colors, the problem of paper ink was eliminated. The problem lies in the machine itself, which may appear in the following locations:
1. In the third group to the fourth group, dead teeth appeared on the left side of the mouth, and the open and close teeth were inflexible.
2. In the third to fourth groups, at least one row of teeth on the left side of the mouth was of different sizes;
3. In the 3rd to 4th group, at least one row of teeth in the row of teeth had serious wear and tear.
Based on the above points, we have gradually checked and resolved, although the phenomenon has been reduced, it cannot completely solve the problem. Finally, when the group of impression rollers was pressed to convey the paper to the rear transfer cylinder, the paper had stagnation, and the gap between the rollers of the impression cylinder was checked again. When the gap is increased, when the paper is handed over to the conventional drum, the open teeth are advanced, and the paper is printed with the first 3 colors. The adhesive force increases, and it is difficult to accurately receive the paper after the paper transfer drum. Replace the roller, the phenomenon is eliminated and the printing is normal.