The necessity and feasibility of using alcohol-free fountain solution

In the offset printing fountain solution, the role of alcohol (isopropyl alcohol, IPA) is mainly:

Reducing the tension of the liquid surface, the water becomes more "wet" to facilitate its spread in the hydrophilic part of the printing plate;

Increase the viscosity of the fountain solution;

Alcohol can disinfect the fountain solution.

However, the problem of alcohol (isopropanol, IPA) is obvious:

Volatile, 40% of the alcohol in the fountain solution is volatilized;

Alcohol is expensive;

Inflammable and explosive;

The toxicity is high, and the isopropyl alcohol content is generally lower than 400 ppm, but it is often greatly exceeded in the printing room.

Necessity: The use of alcohol-free fountain solution will preserve the functional effects mentioned above, while existing problems will be overcome. This will save money, environmental protection, and labor protection. Enterprises, society, and workers will benefit. In particular, since alcohol is actually a thinner that actively attacks the ink, it will tarnish the ink and affect the color. After eliminating alcohol, there is no such problem. The amount of ink will be reduced and the dots will be more accurate. After printing, the paper [encyclopedia] will also be faster.

Feasibility: In terms of feasibility, we must first point out that alcohol-free fountain solution cannot be freely applied to printing presses, and it is absolutely necessary to make careful adjustments to the machines in close communication with printing operators.

As mentioned above, alcohol will increase the viscosity of the fountain solution, but in the absence of alcohol, the viscosity will decrease, and the dampening solution passing through the measuring roller will decrease. This will increase the speed of the dampening roller, causing many printing operators to mistakenly think More water must be used when printing with alcohol-free fountain solution. One of the countermeasures at this time is to cool the fountain solution to increase the viscosity, and the other is through careful mechanical adjustment. By using softer rubber rollers and pressure adjustments, we can help the dampening system to allow more dampening fluid to pass through.

Therefore, it is necessary to reiterate that close communication with printing operators is absolutely necessary for fine adjustment of printing machines. The active participation of printing chiefs and workers throughout the process of de-alcoholization is very important, sometimes even the key to success or failure. They should be allowed to fully understand the significance of this process change and mobilize their enthusiasm.

Taking into account the difficulty and complexity, many factories will also gradually achieve “alcohol free” by using “minimum alcohol fountain solution”. This is a good idea, and in fact it has also achieved good results.
As for the problem of surface tension after alcohol removal, it can be solved by using a surfactant or a surface-active additive; adding a biocide can solve the problem of disinfection.

In recent years, many printing companies have successfully implemented alcohol-free printing, laying the foundation for the development of this technology.