Ghost shadow failure analysis and processing

Our two-color Heidelberg offset press found the first set of pattern axial ghosting when printing four-color color inserts. The preliminary analysis may be due to a printing cylinder's turbulence. After observing the machine, it was found that the first group of rubbers had no shadows on the ink, and it could be concluded that the first group of printing plates and the rubber cylinders did not move. The second group of rubbers only found the first group of ink marks in the axial direction. It was concluded that the second stage Eraser and plate cylinder were not shaken either. From this, it can be seen that the defects are in the first and second groups of impression cylinders and the intermediate transfer cylinder. These three cylinders or drum axis turbulence can cause ghosting. After using a crowbar to light, it was found that the teeth of the intermediate transfer roller were oscillated and tested with a feeler gauge. The amount of turbulence reached 0.35 mm. Remove the open-bearing bearing bracket and add a brass washer of the same thickness to the shaft. The ghosting problem is solved.