We vividly call the alcohol-free printing on alcohol rollers "top-down reform". In other words, a prerequisite for the adoption of alcohol-free printing is the top-down determination of the enterprise, which is almost a "first-hand project". The first thing to be solved is the whole ideological and understanding problem. Once the knowledge is resolved, everything else is easy to handle. What machine time, execution steps (with experts), staff training, etc. are not a problem. Under the guidance of experts, upholding the three principles of "careful adjustment; patient adjustment; correct method", alcohol-free printing must be successfully debugged.
Because IPA (isopropyl alcohol) spends more money, hurts rubber rollers, is neither environmentally friendly nor safe, etc., these defects have become increasingly unsuitable for printing "green environmental protection, cost control" needs. The use of alcohol-free printing is more "green and safe" because there is no alcohol. In addition, the alcohol-free fountain solution itself consumes less, and uses a very thin ink film to get clearer ink dots and brighter color reproduction. The paper dries quickly and does not damage the rubber roller. The role of the fine sprinkling roller in printing is very important. There is a poem to interpret the role of rubber rollers vividly-"When the roller is good, it will be good to go to work, and the printing is good, the business is good." Therefore, it does not damage the rubber roller, not only can extend the service life of the rubber roller, but also has an intuitive impact on the quality of the printed product. However, it is not easy to switch to alcohol-free printing on rubber rollers. Looking back on some failed cases, we believe that the two keys to alcohol-free printing are to solve the problem of surface tension and the viscosity of the fountain solution. Here are two points to share with you some of our experience and insights.
1. Surface tension of rubber roller: Alcohol is added to conventional fountain solution to reduce surface tension. After alcohol-free, the surface tension should be adjusted carefully to make the surface tension between 30º~35º, and the performance characteristics should be the same as when using isopropyl alcohol printing.
2. Rubber roller viscosity: When operating without alcohol, the viscosity of the fountain solution decreases and becomes thinner. If the printing machine is not adjusted, the dampening system will not be able to provide the dampening solution to the printing plate sufficiently, and the delicate balance of ink and water will be broken. However, if we can carefully and patiently adjust the pressure between the rubber rollers, we can help the dampening system to let more dampening liquid pass through, and as the alcohol is removed, the rubber of the dampening roller will gradually soften until it returns. To the initial design hardness, the water level measurement will slowly decrease to the best condition.
Post time: Aug-09-2021