An example of solving the paper wrinkles of a sheet-fed offset press

Wrinkling of paper is one of the problems that printers often encounter. It is caused by many factors. Machines, such as cavities, tooth pads, different lengths of dental chips, uneven, loose and inconsistent, when the crepe paper edge is not the whole, imprinting paper locally produced cattle displacement, then the paper will appear to play a light weight Wrinkles. Some people think that it is okay to swing the force of the gums. Just pick up the paper.

In actual fact, the overall swaying of the oscillating teeth is not the same as that of roller cavities, which also causes the paper to wrinkle. In addition, if the paper feeding time is inaccurate, the timing of drawing the paper is not correct, and the pressure of the paper feeding roller on the paper feeding board is different, and wrinkling occurs when the paper is pressed. Paper itself, such as uneven water content, flounces appear, the new paper contact the air quickly after the edge of the moisture deformation, after the imprint will have a certain deformation and make the paper wrinkles.

One case we encountered was wrinkled: When the J2108 machine printed 850nlm x 1168mmj paper, wrinkles appeared on both sides of the paper at about 5-Smm from the edge of the paper, causing serious dragging.

When checking that there is no problem with each part, wrinkling is still repeated, and neither the oscillating teeth nor the force on both sides of the drum teeth are effective. Again, the gap between the eraser and the impression shell and the liner were examined, and no cause of wrinkling was found. Later when cleaning the impression cylinder, it was found that the surface of the impression cylinder was not even. So we analyze the reasons, in the printing of books and more 787MM × 1092MM paper-based, often on the roller piled ink, both sides easily accumulate ink, the operator cleaning the imprint surface is not clean, two long and not rub, ink dry .

Due to the frequent use of a knife spatula, pumice stones are used to wear both ends. When replacing the large size 850mm x 1168mm paper, the large parts on both sides are just in the worn part, thus forming a certain gap in the imprinting. After confirming this reason, we first used 0.1 mm thick kraft paper on both sides of the impression cylinder to wrinkle up, and then cut a piece of kraft paper. The wrinkling disappeared completely.