Problems Often Encountered In The Printing Process Of The Printing Plate Roll

1. Printing plate surface crystallization, calcification

The surface of the high-quality printing plate roller should be fine and smooth, the hand feels slightly sticky, and has good ink transfer performance. However, since the printing plate roller is affected by factors such as dampening solution, ink, paper and the like for a long time, and each cleaning cannot be completely thorough, various substances are stacked on the surface of the printing plate layer layer by layer, and the printing plate is closed for a long time. The original capillary pores on the surface of the roller form a smooth crystalline layer similar to calcium, which seriously affects the ink transfer and water transfer performance, and cannot stably control the ink color of the print. In order to solve this problem, it was originally cleaned with a special starting paste and water, but it was time consuming and laborious, and invisibly increased the production cost. Later, after each wash, try to wash it with some citric acid water to chemically react some calcium impurities on the surface of the printing plate to form a soluble substance for cleaning. Practice has proved that this method works well and saves money and effort.

2. The surface of the printing plate is easy to have scratches and numbness

Since the printing plate roller is relatively soft, a slight hard object will be scratched during high-speed operation. In particular, the alcohol dampening solution relies on the plate water roller, and once scratched, it can no longer be used. There are two main reasons: one is that the plate is not tight or the clip is not tight, the plate has cracks and cracks at the tip of the plate, scratches against the plate water and ink roller; second, the ink roller is not maintained in time. There are many impurities such as ink and ink residue on the printing plate roller, which accelerates the friction, heat generation and aging of the printing plate roller, and makes the surface of the printing plate roll full of numbness. Generally, the printing plate roller is more serious at both ends.

3. Printing plate roll prematurely cracks and ages

There are many reasons for this problem, such as excessive dry oil in the ink, so that the ink is dry on the rubber roller; the cleaning agent used for cleaning the rubber roller is improperly selected, the cleaning time is too rushed, and the impurities on the printing plate roll are made. It can not be thoroughly cleaned; the ambient temperature of the workshop is high, and the dampening cooling system works poorly, so that the large amount of heat generated during the operation of the printing plate roller cannot be dissipated in time, and the cohesive temperature of the printing plate roller is very high: the performance of the printing plate roller bearing is not good. It is rotated by the squeezing roller to generate jumping friction, extrusion, and the like. All of these factors will accelerate the early cracking and aging of the printing plate roll.