Why are there ink marks on kraft paper bags?

When printing on a kraft paper bag, bubbles may be present in the ink mark. When bubbles appear, it means that the print is not good. What is the cause of bubbles in the ink mark when printing on a paper bag?

If bubbles appear on the ink when printed on a kraft paper bag, it depends on the severity of the problem. If the situation is not serious, it will only affect the effect of the product. If it is serious, it may cause printing to fail. For cost and finished product considerations, we should find out the causes of bubbles in the ink so that there is a way to solve them.

1. There is dust or oil on the surface of the kraft paper bag.

Since the kraft paper bag itself is contaminated by dust or oil at the time of printing, air bubbles are generated. Because the oil molecules and the printing inks love each other, they do not color, so bubbles will appear on the surface of the kraft paper bag.

2, the ink itself has a high concentration

Due to the high concentration of the ink itself, the foam cannot be extruded, so the printed paper bag custom print naturally causes this problem because the ink concentration is too high and it is easy to form bubbles inside, which are printed on the custom printed surface of the shopping paper bag. , bubbles are generated and a vacuum is formed, which greatly affects the printing effect.

3, the ink viscosity is very high

Due to the high viscosity of the ink, the surface tension of the ink is large, and the gas oil in the ink is difficult to escape from the ink film and remains in the ink layer. If the viscosity of the ink is low, the surface tension of the ink is small, and the bubbles themselves disappear, so they do not appear. Bubbles appear in the ink of the kraft paper bag.

The above points are the cause of bubbles in the ink marks when printing paper bags. Based on the above reasons, we have found a solution to avoid problems.

If you want to know more information, you can contact us.http://www.funwelpacking.com/

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