Tips: A Case of Troubleshooting Offset Spur of Offset Press

My company has newly introduced a Heidelberg four-color offset press. Recently, when printing more high-end samples and pictures, there are often some tiny ink bars on the printed products that are difficult to eliminate. Although not very serious, they appear on this stage. Advanced machines are not normal.

After careful observation and analysis, it was found that these ink bars are separated by less than 1 cm and are very regular. They should be toothed bars. However, such a small toothed bar can only be caused by the bucket motor driving the water transfer roller. Then, after wiping the rubber roll, re-ink the pressure bar to adjust the pressure. When the water transfer roller was manually pressed onto the series water roller test pressure, the pressure between the two was found to be a bit higher, and they were all chrome-plated hard iron rollers. Excessive pressure caused the transfer roller to stand on the string. The same as on the water roller, the water transfer roller head and the bucket motor drive gear do not match, the gap is large, and there will be some vibration during operation. This kind of vibration is directly reflected on the printed product by the transmission of the water roller and the water roller, which affects the quality of the product. After finding the crux of the problem, re-adjust the pressure of the water transfer roller and the water roller, and the gear bar disappears.

It can be seen that the adjustment of the machine must be accurate and standardized, otherwise it will cause many bizarre breakdowns and even damage the machine.