Problems Caused by Fountain Solution

Fountain solution can cause problems in offset printing. Among others, the following can be mentioned:

Clouding of the work by the fountain solution

- The cause of this problem can be the moistening solution and paper coating.

-Rejecting the ink from the paper cover in the multi-color machine where the wet ink goes from one printing unit to another unit..

-The paper cover cannot sufficiently absorb the fountain solution applied in the printing unit 1 and/or 2

The amount of water on plate in the first unit partially repels the ink in the 3rd and 4th units.
This repulsion will disrupt the proper transfer of the ink and cause the intensity of color reduction in these areas of the printed form. If ink excretion is incomplete and irregular. It will be cloudy in every printed area.
Becoming spotted (grainy). 
Degradation of the print job is influenced by ink partitioning in subsequent print units, ink fountain solution/emulsion compositions, and paper quality (eg, wettability, surface tension), among others.
Fountain solution
Large amounts of ink require a large amount of fountain solution. This leads to emulsification. Emulsified ink causes graining in the print. Also, low pH value and high amount of moisturizing solution cause high emulsification of the ink.
Contaminated fountain solution prevents good water-ink balance and causes granulation.
Solution
Rinse the inking unit and start again.
Set the inking valves correctly.
Check the fountain solution and change it if necessary. Increase the IPA content by up to 10%. This allows you to use less water.
Adjust the water-ink balance correctly.
Keep the amount of ink as low as possible.
Use a temperature control device.
Temperature
Reason
Increasing the temperature of the ink may result in more droning in the print.
Heat beyond a certain limit destabilizes the printing process and causes an increase in noise.
Low temperatures (cold machine and cold ink) may lead to bad result.
Solution
Do not start printing while the machine and ink are still cold.
Warm up the press machine.
Use the temperature control devices for the fountain solution and ink unit and set them correctly.
The temperature of the fountain solution: 10 to 15 degrees Celsius lower than the ambient temperature.
The temperature of the inking unit is 28 to 30 degrees Celsius. Set the standard temperature to 23 to 27 degrees.
Continuous streaks - streaks caused by excessive moisturizing solution
Reason
Excess fountain solution is transferred to the printed image by ink rollers.
Incorrect settings will result in poor distribution of the fountain solution.
Streaks of light are created.
The overall color intensity is reduced.
Solutions
Reduce the amount of fountain solution.
Use the correct water-ink balance.
Check and replace the fountain solution.
Adjust the fountain system (and ink unit) correctly.