Mixed wetting ink offset

Mixing and wetting device is also called ink flushing and wetting device. The main feature is that the same printing roller is used to moisten the printing plate, water and ink are supplied to the printing plate at the same time. Heidelberg, Manroland, KBA and many other well-known brand presses have adopted this device, which is easy to achieve ink and water balance.

Offset ink balance refers to the use of the least amount of ink and water under the premise of ensuring the color reproduction, gray balance, color density and tone value to meet the requirements of the customer under a certain printing speed and printing pressure.

According to the actual situation of ink-water balance, in order to prevent dot gains and blank areas from being protected, the amount of ink in the printing area is also large, and the amount of ink and the volume of the entire roller before the pressure is applied by the printing roller that transfers ink and transfers water. Consistent. After a few revolutions of the platen roller, the amount of ink on the roller changes. According to the principle of oil and water incompatibility, the water absorption of the ink on the rubber roller is poor, and the amount of water absorbed is small. On the contrary, the amount of ink absorbed in the ink is low. Therefore, the left side of the plate roller absorbs a large amount of water, and the left side of the plate is an area where a large amount of ink is supplied, so that the ink balance required for printing is achieved.

Mixed moistening device is easy to form a proper ink emulsification, the blank part is also easy to stick dirty, in fact, the graphic part and the blank part of the printing plate used in the offset printing are in the same plane, the graphic part is oil- and water-repellent, and the blank part is hydrophilic and oil-repellent. Therefore, when the plate roller is in contact with the printing plate, the blank part absorbs water, the graphic part absorbs ink, and the blank part does not become dirty. Due to the force exerted by the ink during transmission, the ink will produce mild emulsification. This emulsification is also required for printing, and it will not cause emulsification failure because the content of water in the ink (fountain solution) is low and will not exceed the criticality. value.