Analysis Of Dirt On Both Sides Of Offset Printing Plate

Uneven water roller

        When adjusting the contact pressure between the water supply roller and the water channeling roller, we must pay attention to the symmetry of the direction of the eccentric bearing, Analysis Of Dirt On Both Sides Of Offset Printing Plate

       otherwise it will lead to the non parallelism of the water roller with the printing plate roller and the water channeling roller, Analysis Of Dirt On Both Sides Of Offset Printing Plate

       The flannelette of the water channeling roller is easy to be pushed into a spiral shape by the axial force, and the water delivery will not be uniform. Analysis Of Dirt On Both Sides Of Offset Printing Plate

       If the eccentric adjustment at both ends of the water roller is asymmetric, the pressure of the water roller will be uneven and the side of the printing plate will be easy to get dirty. Analysis Of Dirt On Both Sides Of Offset Printing Plate

      Therefore, when testing the water roll pressure, you can measure several places, not only at both ends, but also in the middle.Analysis Of Dirt On Both Sides Of Offset Printing Plate

      In addition to accurately adjusting the contact pressure of the water roller, the daily reasonable maintenance of the water roller is also very important.Analysis Of Dirt On Both Sides Of Offset Printing Plate

1. During normal offset printing operation, the water roller shall be kept clean and free from oil stain.Analysis Of Dirt On Both Sides Of Offset Printing Plate

2. The water roller fleece shall be kept moist and have certain moisture.Analysis Of Dirt On Both Sides Of Offset Printing Plate

3. Clean the water roller regularly. If the water rubber roller can be cleaned, it shall be washed. If there is too much oil stain and it is impossible to clean, Analysis Of Dirt On Both Sides Of Offset Printing Plate

       it shall be replaced with a new water wool sleeve in time to avoid the printing plate from getting dirty. Analysis Of Dirt On Both Sides Of Offset Printing Plate

        Another method can effectively prevent ink sticking on the water roller, that is, when printing, a small amount of hydrophilic colloidal substance Arabic gum is added to the water bucket solution,Analysis Of Dirt On Both Sides Of Offset Printing Plate

      which can effectively increase the hydrophilicity of the water roller. Analysis Of Dirt On Both Sides Of Offset Printing Plate

       Wipe the emulsified oil stain in the water bucket solution with hydrophilic materials such as sponge, and adsorb the dirty ink on the surface of the water roller.Analysis Of Dirt On Both Sides Of Offset Printing Plate

The water roller is thin at both ends and thick in the middle   Analysis Of Dirt On Both Sides Of Offset Printing Plate

       When the water roller is processed and grinded on the lathe, because it is an elastomer, the force on both ends is large, there is vibration in the middle and the pressure is small. Analysis Of Dirt On Both Sides Of Offset Printing Plate

      Most of them have different degrees of shape errors of thin at both ends and thick in the middle, and there is a gap at both ends, which is easy to get dirty.Analysis Of Dirt On Both Sides Of Offset Printing Plate

         In addition, during sewing, the two ends of the water roller sleeve are stretched thin and thin, and the water at both ends is less adsorbed, which can not fully wet the surface of the printing plate,Analysis Of Dirt On Both Sides Of Offset Printing Plate

       which is easy to cause dirt on both sides.Analysis Of Dirt On Both Sides Of Offset Printing Plate

Troubleshooting: the size of cutting water glue velvet cover shall be consistent with that of water roller, and shall not be too short. The tension of the sewing sleeve shall be uniform, Analysis Of Dirt On Both Sides Of Offset Printing Plate

      not too tight, and there must be room for closing to prevent the two ends of the water roll sleeve from being too thin and thin.Analysis Of Dirt On Both Sides Of Offset Printing Plate

The size of printing plate lining is too small  Analysis Of Dirt On Both Sides Of Offset Printing Plate

       Under normal circumstances, the lower side of the printing plate should be added with backing paper. In order to avoid wetting and water on both sides of the printing plate backing paper, Analysis Of Dirt On Both Sides Of Offset Printing Plate

        The transverse size of the backing paper will be smaller than the printing plate size. Analysis Of Dirt On Both Sides Of Offset Printing Plate

      However, the size of the backing paper is too small, which will cause insufficient pressure on both sides of the printing plate, resulting in poor contact between the printing plate and the water roller.Analysis Of Dirt On Both Sides Of Offset Printing Plate

        Troubleshooting: when cutting the backing paper of the printing plate, the transverse size shall be controlled within 10-20mm smaller than the printing plate. In order to prevent the backing paper from being damaged by water.Analysis Of Dirt On Both Sides Of Offset Printing Plate

        A layer of earth forest or butter and engine oil can be coated on both sides of the backing paper, and the principle of oil-water repulsion can be used to avoid wetting the backing paper and improve the use effect.Analysis Of Dirt On Both Sides Of Offset Printing Plate

        If the liner paper of the drum is wet, it is easy to rust the shell of the drum.Analysis Of Dirt On Both Sides Of Offset Printing Plate

       Ink sticking at both ends of the water roller reduces the water transfer performance   Analysis Of Dirt On Both Sides Of Offset Printing Plate.

       If the water content at both ends of the printing plate is controlled too little, it will cause the ink on both ends of the water roller due to insufficient water supply, Analysis Of Dirt On Both Sides Of Offset Printing Plate

      Resulting in dirt on both sides of the printing plate.Analysis Of Dirt On Both Sides Of Offset Printing Plate