method one:
In the process of printing, it is necessary to maintain the solid graphic foundation and blank foundation of the printing plate, and maintain the stability of lipophilic and hydrophilic.
Method Two:
The water supply should be controlled as small as possible (on the premise that the printing plate is not sticky and dirty), and the water supply of the general layout is about 26%. Only by keeping the water supply and ink volume in a relatively stable state, can the ink color of the printed matter be consistent before and after and the printing operation is stable.
Method three:
Adhere to the principle of "less water and thick ink". The less water here refers to the premise that the blank part of the layout is not stained. The so-called ink thickness is also based on the lack of water. The large amount of water causes the ink to emulsify, and the ink layer cannot be thick. It can be seen from the transfer process of offset printing ink that in one water supply and ink supply, the mixing and emulsification of ink and water occur three times. It is impossible to maintain a strict dividing line between water and oil. . Therefore, the ink balance in offset printing can only be a relative concept, and a completely ideal ink balance does not exist. As long as the best balance is achieved, the ideal print can be printed.
Method four:
Choose the amount of ink based on the material category of the printing plate. PVA version can increase the amount of water, PS version can reduce the amount of water; smooth paper can reduce the amount of water in an appropriate amount, rough paper can increase the amount of water in an appropriate amount; the machine runs fast, the water amount can be slightly smaller, and it can be larger at low speed.
Method five:
Environmental conditions and temperature and humidity are very important. Since the moisture of the layout is distributed in two forms, direct and indirect, most of the moisture in the layout is distributed to the space while meeting the needs of ink balance during printing. The higher the ambient temperature, the faster the distribution.
Method six:
Control the pH value of the fountain solution (4.5~5.5). In addition, since the pH value of the surface of the offset printing paper has a great influence on the pH value of the fountain solution, it is best to measure the pH value of the paper. If the PH value of the paper is too low, the PH value of the fountain solution should be slightly increased; on the contrary, if the PH value of the paper is too high, the PH value should be appropriately lowered to neutralize the pH value of the paper, thereby buffering the moisturizing effect. Excessive increase in the pH value of the plate solution.
Method seven:
The method of scientific instrument detection is used to control the balance of ink and water. Because the printing obtained in the state of ink balance must have thick ink color and consistent density, the change of ink balance in the printing process can be detected by continuously measuring the density. When the density value reaches the standard value range, it can be concluded that the ink-water balance is normal.