Water stickers appear ink, flying oil sand hole problem

The problems of ink dirt, flying oil sand hole and sticking on the water sticker are as follows:
(1) Ink scum is a problem of four-color inking in offset printing. It will not appear in solid color printing. Offset printing is fast. This phenomenon is a common phenomenon, and it is also caused by the irresistible factors of technology and manpower. When it is found that there is ink excrement, it will disappear after shutdown for cleaning. However, during the process of discovery and shutdown, many sheets of paper will be printed with ink excrement on them. In addition, after shutdown for cleaning, some water paper will have color difference.
(2) Flying oil is the phenomenon of oil scattering in the process of solid color printing. Sand hole is the phenomenon that the high concentration of oil blocks the mesh so that the ink is not printed on the water paper, and some ink voids appear, which shows that the pattern is broken, mainly on some smaller patterns.