Some matters needing attention in waterless offset printing

When waterless offset printing is used, special attention must be paid to the adjustment and control of temperature and humidity in the production room. If the temperature in the shop is too low, the problem of poor ink transferability tends to occur during printing. When the temperature in the workshop is changed too much, the temperature of the printing press will also be greatly affected, resulting in a change in the viscosity of the printing ink, which in turn affects the printing quality. Generally, the wine is packaged during production, and the shop staff adjusts the temperature to the level of comfort and stability.

In addition, if the humidity in the workshop is too low, the paper is prone to static electricity, causing problems such as uneven delivery and sticky back. In order to eliminate static electricity, the general workshop humidity needs to reach 60%.

2. Plate surface temperature control

The control of the surface temperature of the printing plate is one of the keys of the waterless offset printing process. It is particularly important that the plate surface temperature is stable for a long time. After the cooling water is introduced, the surface temperature of the printing plate can be basically adjusted to be 5 to 10° C. higher than the room temperature, and it is ideal to maintain printing at a slightly higher temperature in this range. When the surface temperature of the printing plate is appropriate, the matched offset printing ink "target="_blank" offset printing ink will greatly improve the efficiency and quality of waterless offset printing.

3. Adjustment of printing press

(1) Pressure adjustment between plate cylinder and blanket cylinder

Since the waterless offset printing plate "target="_blank"> plate material is a plano-gravure structure printing material, the waterless offset printing ink is generally required to have a higher viscosity, and therefore, in order to achieve a good ink repellency and ink transferability, the plate The pressure between the drum and the blanket cylinder puts forward a high requirement.In general, under the standard pressure of the traditional offset printing, the thickness of the lining of the blanket cylinder is increased by 0.05mm, and the appropriate printing pressure can be achieved.

(2) Installation and Pressure of Reliance Roll

Waterless offset printing is also very demanding for the installation and pressure adjustment of the reels. First of all, when installing the printing roller, the left and right ends must be balanced, because if there is a gap between the printing roller and the wall plate, irregular jitter will occur during operation and the plate will be dirty. Therefore, when installing the plate roller, be sure to eliminate the gap between it and the wall plate.

Secondly, if the pressure of the printing roller is too large or too small, it is prone to malfunction. The pressure should be adjusted according to the printing machine manufacturer's recommendation. However, it is necessary to pay attention to the consumables, and the pressure of the last ink-return roller must be slightly smaller than that of other reel rollers.

4. Paper requirements

For light-coated paper, since the viscosity of the waterless offset ink is higher, it is easier to peel off the coating, so it should be used with caution. For non-coated matte paper, writing paper and other printing paper, waterless offset printing can achieve better results with high-fidelity printing, and ink dry-back phenomenon will not occur. Therefore, according to the characteristics of waterless offset printing, printing paper can be flexibly adopted.