Plastic gravure failure - missing dots

3. Missing dots
During the printing process, the even flat screen on the printing plate can not be leveled because of the ink, and the dots appear alone, forming a filter-like network, and even missing dots. Generally starting from the second color group, this phenomenon is more obvious.
cause:
1 ink viscosity or yield value is too high, resulting in poor ink transfer.
2 The ink dries too fast, is not evenly distributed on the plate, and is prematurely dried and solidified.
3 Poor wettability between the ink and the plate (surface tension does not match), the transferred ink is not easy to spread.
4 The pressure of the blade is high, but the pressure of the printing roller is insufficient.
5 printing plate cable is too thick, the gap between the large network, the ink is not easy to spread.
solution:
1 To reduce the viscosity of the ink and improve the transferability of the ink, it is recommended to use the special 20# additive for gravure ink.
2 Adjust the position of the squeegee holder so that the distance between the squeegee and the plate cylinder is shortened.
3 Use a slow-drying solvent to reduce the ink drying rate and increase the dot gain.
4 Adjust the blade pressure and the print roller pressure.
5 Re-plate to change the shape and angle of the cell.
6 Change to a low viscosity ink.