Ideal printing pressure and firmness of imprinted ink layer in offset printing

During the entire offset printing process, it is the process of resolving the contradiction between ink and paper. To transfer the ink-coated graphic on the printing plate smoothly to the printed paper, it must be transferred during the graphic transfer process. Apply a certain amount of printing pressure.

People often say that "there is no printing without pressure." This sentence fully illustrates the importance of printing pressure. Since printing pressure is so important, isn't the pressure greater? The better, of course. In general, the appropriateness of printing pressure is often manifested by the print quality of printed products. The printing pressure should be based on the premise that the printed products have strong dots, clear graphics, bright colors, and adequate shade; and the smaller the application, the better.

When printing pressure is too small it will cause:

1. The transfer of printing graphics is not complete;

2. The network is not strong and the color is gray;

3, imprinting is not firmly fixed, the picture is made false, network points are not true, the color is pale.

4. Make original defects such as printing plates, linings, paper and printing machines more obvious.

Therefore, the ideal printing pressure should be: Under the condition that the certain printing surface is deformed, the minimum pressure is evenly used on the basis that the printing is sufficiently strong. The printing pressure is suitable for fixing the print firmly. Printing pressure is too large or too small is not conducive to print quality, and it is a great harm to the correct transmission of the print.

The ideal pressure is not a fixed concept, but it is based on the premise of good product quality, based on various objective printing conditions, appropriate adjustment and adaptation, in practice, the ideal pressure is generally controlled at 0.15mm ~ 0.25mm Left and right, and the pressure impressed between the drum and the blanket cylinder is greater than the pressure between the plate cylinder and the blanket cylinder by about 0.5 mm to 0.10 mm.