In the printing process, the ink has produced a large number of bubbles. These bubbles are attached to the printing plate, causing the parts of the pattern to disappear, and the printing products will appear in white spots. Why are there bubbles in the ink? This article is resolved one by one for reference.
1. The surface tension of the ink is strong, and the resin and solvent used in the ink are more influential. Sometimes the viscosity of the ink is large and easy to produce bubbles.
2. Defects in ink tank or circulating device. A large number of bubbles are caused by ink flow in the ink tank or circulation pump. When using ink pump circulation ink, the ink flow from the ink to the circulation bucket, because of the difference and the printing plate roller high-speed operation of the agitation, will form bubbles in the ink.
3. On the printing press directly for ink, the magnetic stirring stick is bent, beating in the ink slot, causing the bubble.
4. Add appropriate anti-foaming agent. Although there is special antifoaming agent, but too much to ink character produces undesirable influence, use improper actually can cause bubble, so it cannot use more.