A case of misregistration

Our factory PZ4880—01B sheetfed offset press (manufactured by Beijing People’s Machine Factory) had such problems in use: When the paper advances to the lower gauge plate contacting the former rule on the transport plate, it appears slightly skewed. The phenomenon. The paper feed nozzle conveys skewed paper to the platen roller, resulting in overprinting failure.

It is not uncommon for paper to be skewed in the process of paper feeding. Based on past experience, we have conducted detailed inspections and adjustments of the pressure of each platen and the pressure of the suction nozzles, but with little success. Through careful observation (observed during operation), it was found that the paper is generally skewed when it hits the platen end and the regular gauge plate. Based on this, the previous rules were removed and examined, and it was found that the pin joints of the two preceding rules with one end (spare part number: N126-70216) and the joint plate (part number: N126-70217) had a large wear and tear. Loosening. Therefore, the lower gauges of the two rules cannot run at the same time as the other lower gauges at the other end to the front surface of the paper and the platen, causing a lag. Thus, the conveyed paper loses its balance and naturally generates a skew. We changed the pin and connecting plate and the fault was eliminated.