Brief Analysis of the Effect of Fountain Solution Temperature on the Ink Balance

Offset printing is based on the principle of ink balance printing. If the ink and ink balance is not good, a series of problems are likely to occur. For example, the glossiness of the blot is not good, and it is not easy to dry. The dot text is imaginary and increases, the graphic and text are not clear, the paper is easily deformed, and the rubber roller is easy to pile up ink. The printing quality has a major impact. There are many factors that affect the balance of ink and water, such as fountain solution, ink, printing plates, printing speed, printing materials, and water delivery devices. In addition to some common factors, there is a factor that affects the balance of the ink - the temperature of the fountain solution.

When fountain solutions of different temperatures are injected into a water hopper and printed under the same conditions, there are many situations where ink-water balance occurs. When the fountain solution temperature is low and the ink balance is in good condition, if the fountain solution with a higher temperature is added to or replaced in the fountain, and the amount of the fountain solution is large, the ink may cause a serious imbalance, resulting in a stencil phenomenon. When the temperature of the dampening solution added to the bucket changes from high to low, the layout moisture will tend to be larger. The reason for this phenomenon is that the increase of the temperature of the fountain solution aggravates the emulsification of the ink, and the decrease of the temperature of the fountain solution reduces the emulsification of the ink. Tests have shown that when the temperature of the fountain solution rises from 1°C to 30°C, the amount of fountain solution will increase by 0.8 to 1.5 times; from 10°C to 30°C, the amount of fountain solution will increase by 0.5 to 0.8 times; When °C rises to 30°C, the amount of fountain solution will increase 0.2-0.35 times. But this also depends on the specific circumstances of the ink: the more dilute ink changes significantly, followed by the thicker ink; aging ink is more obvious, the new ink is second; before adding dry oil is obvious, after adding dry oil The.

In daily offset printing, the temperature of the fountain solution changes: (1) The workshop temperature is high, and the dampening solution is also affected by room temperature. At this time, low-temperature water is used to re-prepare the fountain solution and use it immediately; (2) The workshop temperature is low. In order to keep the fountain solution consistent with the room temperature, use a higher temperature water to configure the fountain solution and use it immediately; (3) The workshop temperature is low, the air temperature can be used to change the room temperature, and the temperature of the fountain solution is caused at the same time. The change is gradually consistent with the room temperature; (4) When the temperature of the workshop is high, the room temperature is changed by the air-conditioner, and the temperature of the fountain solution is changed at the same time and the temperature of the fountain solution is gradually kept consistent with the room temperature; (5) The fountain solution with different temperatures is inadvertently used. .

According to this mechanism, the ink balance can be changed in the offset printing by changing the temperature of the fountain solution. When the printing speed is faster, lower the temperature of the fountain solution to reduce the degree of emulsification of the ink. When the temperature of the workshop is low, increase the temperature of the fountain solution to improve the transfer ability of the ink and reduce the amount of paper nap. Phenomenon, especially for those papers that are easy to fall off and lose hair. When regulating the temperature of the fountain solution, it should be compatible with the fluidity of the ink to achieve the complementary purpose. In summer, the fountain solution ice frozen in the refrigerator can be added to the water bucket to reduce the temperature of the fountain solution to prevent serious emulsification of the ink. This method is suitable for the workshop without air conditioning. If the workshop has air-conditioning facilities, it can be done by regulating room temperature. The use of the method of regulating the temperature of the fountain solution to control the ink balance has a unique effect. Many phenomena indicate that the temperature of the fountain solution is a major factor affecting the offset of offset ink. It is of great significance to control the temperature of the fountain solution, to better control the ink-water balance and to improve the quality of printed products.

Author: Barrie House

Reprinted from: Printing Technology