Common Gravure Printing Faults and Treatment Methods

Overprint fault: 

         Overprint overall fluctuation: mostly caused by unstable tension. First, it is caused by the failure of the automatic tension control system of the equipment, such as improper tension setting, damage of mechanical transmission parts, damage of PIV gearbox bearings, etc; Common Gravure Printing Faults and Treatment Methods

       Second, it is caused by unstable paper tension, such as elliptical deformation of paper roll, poor rewinding of paper or excessive difference in transverse thickness of paper web, resulting in loose and tight paper roll at the same time; Third, the first color group printing plate or cot runout is too large.Common Gravure Printing Faults and Treatment Methods

Monochrome overprint fluctuation: 

       one is caused by the damage of the support bearings at both ends of the printing plate; Common Gravure Printing Faults and Treatment Methods

       Second, the bearings at both ends of the embossing roller are damaged; Third, the runout of the embossing roller or printing plate is too large; Common Gravure Printing Faults and Treatment Methods

      Fourth, it is caused by the failure of the control system, such as the disorder of the set value of the control system parameters after a long shutdown.Common Gravure Printing Faults and Treatment Methods

      Ink blocking (paste plate): there are many reasons for the formation of ink blocking, but it is mainly caused by the poor printability of the ink, such as too fast drying, condensation reaction of the ink between the front and rear colors, mismatching of the screen angle between the ink and the printing plate, acidification and deterioration of water-based ink due to too high temperature, etc.Common Gravure Printing Faults and Treatment Methods

         In case of plate blocking, clean the printing plate in time and replace it with new ink, reduce the drying speed, reduce the pressure of the doctor blade and moderately increase the pressure of the embossing roller; Common Gravure Printing Faults and Treatment Methods

       If the blocking is caused by the reaction of the ink between the front and rear colors, the ink of the same manufacturer should be used. If the ink matches the printing plate, change the ink or change the screen angle of the printing plate.Common Gravure Printing Faults and Treatment Methods

        The transverse shrinkage of paper is too large: it is mainly because the water content of paper does not adapt to the printing environment, At this time, adjust the temperature and humidity of the environment according to the situation (the temperature is between 17c and 24C; the humidity is between 40% and 70%).Common Gravure Printing Faults and Treatment Methods       

        If there is no obvious improvement after adjusting between the upper and lower limits of the environment, modify the printing plate (according to the paper situation), gradually shorten the printing plate format from the second color group, and put forward improvement suggestions to the paper factory.Common Gravure Printing Faults and Treatment Methods

         Printing wrinkle: when the pressure of the embossing cylinder is unbalanced, the bearing of the paper feeding guide roller is worn or the locking screw is loose, and the printing plate shaft is eccentric, it is easy to produce printing wrinkle. Common Gravure Printing Faults and Treatment Methods

         At this time, the printing pressure should be corrected, and the relevant parts should be inspected. If there is wear, it should be replaced in time. Common Gravure Printing Faults and Treatment Methods

      For creases caused by paper ruffles, adding pre drying equipment before printing will have a good effect if the equipment allows folding.Common Gravure Printing Faults and Treatment Methods

          Printing leakage point (false image and text dot printing): it is mostly caused by poor paper roughness, shrinkage lines when drying the coating layer, and poor ink printability. First, adjust the ink viscosity, or change the ink and increase the embossing pressure.Common Gravure Printing Faults and Treatment Methods

        If there is no obvious improvement, you can only change the paper. Of course, adding a static ink absorption device is also a good choice.Common Gravure Printing Faults and Treatment Methods