What are the requirements for fountain solution for commercial web offset presses?

The fountain solution for commercial web offset presses is different from press rotation printing, and is more different than offset offset printing. It requires that the fountain solution is conducive to a stable ink and water balance, the amount of water in the ink is small, the concentration of the ink is guaranteed, the emulsification is reduced, and the stable printing quality and the quick start of the machine are ensured even if the machine is operated for a long time.

In the continuous water delivery system, the import fountain solution additive concentration ratio is 2% - 3%, IPA (isopropyl alcohol) ratio 6% - 8%, the hardness of the solvent water used is 40 - 250DH, PH value is controlled at 4.9 - 5.2 (depending on the hardness of the water can be slightly adjusted), conductivity 800 - 1200μs/cm; at the same time the use of the fountain solution should make the ink roller does not retain calcium deposits, reduce the residue on the blanket The ink and paper powder should be able to effectively prevent foam and microbes.

When the pH of the fountain solution is too low. The dampening solution will react with the desiccant in the ink. The stronger the acidity of the dampening solution is, the slower the ink will be dried. When the pH value is too high, the IPA value is often too high and the ink film layer will lose its luster. It looks like the surface of the printed product is velvety and boring.