Problems that may occur with alcohol-free printing

1 dampening water "too high"

Due to the higher viscosity of alcohol-containing systems than non-alcoholic systems, the amount of water delivered to the plates by the alcohol-containing system is greater than that of non-alcoholic systems at the same time and at the water roller speed. To avoid dirty plates, water must be raised. The speed of the roller gives a feeling that the amount of water is increased. If the pressure of the reel-water roller is reduced, the setting value of the rotation speed of the water roller is equivalent to that when printing with alcohol, and the worker will not feel that the water volume is too high.

2. Excessive emulsification, cross-coloring, scumming

(1) In the non-alcoholic printing system, the ink roller system will accelerate the emulsification and reach ink-water balance, which may result in over-emulsification of the ink, especially in the printing of large field patches and large dot color areas. When this problem occurs, on the one hand, it is necessary to cut off the connection between the ink paths of the waterway in a timely manner, so that the fountain solution can be transferred to the printing plate before being emulsified. It is better to prevent the integrated ink roller from running on the water roller; on the other hand, In the system without alcohol, the ink will not be diluted, and at the same ink setting, the color density will be higher than that of the alcohol-containing system; thus reducing the setting of the amount of ink, while reducing the amount of fountain solution, It will be able to return to the minimum normal operating condition of the ink.

(2) Check the hardness of the ink roller. The softer rubber has a more excellent effect in alcohol-free printing. The efficiency of any ink roller system depends on the performance of the ink roller at the maximum tension setting, which requires some adjustment when using a new dampening solution. It is worth noting that the non-alcoholic system is completely different from the alcohol system. To successfully operate the alcohol-free system, new technologies need to be re-learned.