One example of offset printing ink bars

Our factory bought a second-hand imported Heidelberg four-color monochrome offset press from a foreign country a few years ago. At that time, the printing effect was still relatively satisfactory. However, we have recently discovered that printing on-site full version with this machine will result in ink sticks, and the inconsistency of my ink. At first, it was thought that the platen was too heavy. After checking, the platen pressure of the four platen rollers was found to be appropriate (the width of the first three platens was 4mm, and the width of the fourth platen was 3mm). Then, we removed all four platen rollers and inspected the bearing at both ends of the sleeve. As a result, it was found that the bearings in the three sleeves at the end of the flywheel were worn out and almost all the needle rollers inside were missing. Only the needle roller clips and housing are left. We thought we had found the problem, but after replacing one of the three bushings, the printing effect still did not improve.

Then, for all inks in the ink, the existing two ink rollers have radial runout during operation, but after the bearing is replaced, the effect is still not improved.

The factors of the ink roller were basically eliminated, and the water roller was naturally suspected. First, remove the 2 water rollers, and then place the 4 rollers on the plate. Let the plate roller run for several weeks. At this time, we find that the plate is not only ink uniform but also has no ink. trace. After further inspection, it was found that the string of water-steel rolls had a significant radial runout. When measured with a dial gauge, the radial runout was as high as 1.02 mm. Finally, we loosened the fastening screws at both ends of the string water roller to recalibrate it. The fault was finally eliminated completely.