Commercial rotary machine control ink and ink balance method

The introduction of foreign high-speed high-quality printing press, it has a printing speed (some machine speed of 60,000 rpm / hour), printing layout, quality, stability, timeliness and other outstanding advantages.

As a brand-new printing press (previously commercial printing was mainly based on sheet-fed machines), the full commercial web transfer machine has many common places with the single-sheet machine, but there are many differences, such as: Institutions, printing speed, paper for printing, ink drying, folding, quality standards, paper loss, etc. Therefore, we need to master it and still need a process. We should summarize it, communicate more, study more, and be familiar with it and use it well.

Offset ink balance refers to adjusting the amount of fountain solution at a certain printing speed and printing pressure so that the emulsified ink contains less than 26% of fountain solution, forming a slight W/O emulsion ink. Use a minimum amount of liquid to compete with the ink on the plate. Offset printing is the use of natural laws in which oil and water are incompatible with each other, forming graphic and blank parts on the printing plate. It supplies both ink and water to the printing plate. It absorbs water and resists water while the blank part absorbs water and resists oil. print.

If the ideal balance of ink and water, the blank part of the printing plate adheres the fountain solution, and the graphic part is attached with the ink. Only when the surface tension of the fountain solution and the surface tension of the ink are equal, the diffusion pressure at the interface between the two is Zero, the fountain solution and the ink remain relatively balanced at the interface, do not infiltrate each other, in this case the printing effect is ideal. However, in actual printing, the balance of ink and water is a dynamic balance and it is changing all the time. If the amount of ink applied to the layout exceeds equilibrium, the ink will expand toward the blank after being strongly squeezed, and will infiltrate the blank surface causing stickiness.

On the other hand, if the water supply to the layout exceeds the equilibrium value, when the water roller passes through the surface of the graphic, it will leave more water on the surface of the graphic, and then it will be strongly pressed by the water roller and the ink roller and attached to the graphic part. The deep emulsification of the ink layer causes the imprint to be dull. When the amount of water supplied is too large, the water enters the ink fountain along the ink fountain roller and the ink fountain roller, causing a large range of ink emulsification, and eventually the printing cannot be continued.

In the actual printing operation, many operators do not pay attention to the balance of ink and water. When the water is too large, the water is not taken into consideration, but the amount of ink is increased. For a certain period of time, the ink is emulsified seriously, resulting in stickiness, and water is added. The ink is naturally dull. Without light, they add ink, creating a vicious cycle. We cannot always reach a better balance between ink and water, and naturally we cannot print good products.