Ink emulsification in wet offset means incorporating a fountain solution into the ink. A certain amount of water is part of the process. The problem occurs when the system loses a stable ink-water balance and deteriorates print quality.
Is every emulsion a disadvantage?
No. During operation, the ink rollers pick up a portion of the dampening solution. Changing the amount of water affects the behavior of the ink and can alter print density. Therefore, the goal is a stable process, not the complete absence of water in the ink.
This term applies to wet-offset sheetfed printing. Do not apply this definition directly to waterless offset printing.
How to recognize a ink emulsification problem?
Pay attention to color instability, changes in ink transfer, and how the ink behaves when dampening levels are increased. Observe whether you need to constantly adjust the ink feed. While these symptoms may be associated with a loss of balance, they do not point to a single, definitive cause.
Compare the conditions before and after the press has warmed up. Note whether the issue affects all printing units or just one specific color. Do not evaluate the process based solely on the appearance of the ink in the ink fountain.
What to check in a fountain solution?
Check the dosing of the fountain solution additive, water quality, temperature, and the cleanliness of the circulation system. Measure the pH and conductivity. Compare your results against a freshly prepared, correctly mixed solution and the specifications provided by the additive manufacturer.
Do not attempt to set the correct concentration based solely on pH measurements. You can learn more about the differences between these types of measurements in the relevant entry. fountain solution additives, pH and conductivity.
Should I limit my water intake?
Maintain the amount of fountain solution required for clean printing. An insufficient supply can also lead to defects. Make adjustments within the scope of the press manufacturer’s procedures and monitor the results on the printed sheets.
Inspect the condition and settings of the rollers, and check for any residues left over from the cleaning process. Do not assume that changing the fountain solution buffer is the only solution; all materials and settings must work in harmony.
What data should I provide to WIT?
Specify the ink and fountain solution additive being used, as well as the method for preparing the solution. Include your measurement results, the temperature, and a description of the changes observed on the printed sheets. If you are using IPA (isopropyl alcohol), include its concentration level.
At WIT, we can help you make the right choice. offset inks i moisturizing chemicals. Before you change the entire set, check one agreed adjustment in a trial.
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