Substrate Removal of Bubbles on Ink Surface after Printing

There are bubbles on the ink on the substrate after printing. The main reasons for bubbles are as follows:

1 Substrate surface attached to dust and oil traces and other substances.

2 The ink itself has bubbles or uneven viscosity when printing.

3 The printing speed is too fast or the printing speed is not uniform.

The intrinsic factor of the generation of air bubbles is that due to the high ink viscosity, the surface tension of the ink is large, and the gas oil in the ink is difficult to escape from the ink film and stay in the ink layer. If the viscosity of the ink is low, the surface tension of the ink is small, and the air bubbles will disappear on their own. Therefore, the phenomenon that the ink of the printed matter will not appear as a bubble will occur.

The following measures are usually used to prevent air bubbles from forming in the ink layer:

1 Use hydrophobic solvents as much as possible.

2 When the ink itself generates air bubbles, an appropriate amount of defoamer can be added to the ink. If the ink has poor fluidity, when the screen printing plate is lifted, the ink flow is relatively small and the screen marks cannot be filled, and a smooth and smooth ink layer cannot be obtained.

To prevent screen marks after printing, the following methods can be used:

1 Use more fluid ink for printing.

2 can consider the use of slow drying ink printing, increase the ink flow time so that the ink gradually curing.

3 Use a single-diameter screen with a narrow wire diameter when making a plate.

Reprinted from: Graphic Arts Forum