Flexo printing corrugated box using 2.84MM offset +4.06MM R / bak pad technology, large field color printing effect is not as good as 3094MM +3.05MM combination, why? How to overcome and improve? (East Union Paper (Fuzhou) Co., Ltd. asked)
1. The factors and solutions that ink may affect the printing effect are as follows:
A. The viscosity of the ink during storage and on the machine is not stable.
The solution: (1) adjust the PH value; (2) reduce the viscosity; (3) use the ink with good fluidity, low viscosity, high color concentration and good stability.
B, PH value is low
Solution: Adjust the pH within the specified range.
C, ink has a tendency to quick dry
Solution: (1) Add slow drying agent to make ink dry (2) Eliminate hot air drying device (3) Improve printing speed
2, check the ink does not have the possibility of the above problems, you should consider the differences in the thickness of the offset plate and pad combination brings changes in the printing effect.
A. Generally, field printing requires thinner and harder pads; dot printing requires thicker, softer pads.
B. In the 2.8mm+4.06mm combination and the 3.94mm+3.05mm combination, the thickness of the pad in the 3.94mm+3.05mm combination is relatively thin, which is more in line with the field printing conditions.
C. In the combination of 2.84mm+4.06mm and 3.94mm+3.05mm, the liner is 4.06mm thicker than 3.05mm, and the stretchability is large and the cushioning of the pressure is strong. Therefore, under the same printing pressure, the thinner liner The pad and offset combination has a good effect on the printing of large solid patches.