What are the requirements for gravure printing on ink devices?

The inking device of the gravure printing machine is completely different from the inking device of the letterpress and lithographic printing machine. The gravure printing ink is in the form of a liquid and is contained in the ink tank. The ink is transmitted to the printing cylinder in two ways: open type and closed type. Open style is divided into direct ink and indirect ink transfer. 1. Open ink: direct transmission of ink: 1/3 of the plate cylinder is directly immersed in the ink tank. When the plate cylinder rotates, the ink sticking on the roller is brought out, and then the upper squeegee (doctor) scrape off excess ink and print once after embossing with the paper. Indirect transmission of ink: the printing plate cylinder is in contact with the transfer roller, and the transfer roller transfers the ink sticking from the ink tank to the printing plate cylinder. The excess ink is scraped off by the squeegee at the upper end of the plate cylinder. Finish printing once the paper is imprinted. 2. Closed ink: The plate cylinder is placed in a closed container. The ink is sprayed onto the cylinder by the bite. The ink scraped by the layout is recycled. This method can prevent solvent evaporation, reduce pollution, and reduce costs. The squeegee is made of 0.15~0.30mm spring steel blade. The installation position of the blade and the pressure angle of the plate must be appropriate. To ensure that the blade is in good contact with the plate, and with appropriate pressure, the blade is pressed with the pressure plate. In order to increase the flexibility of the blade, the angle of contact between the squeegee and the plate cylinder should be 30°~60°. The choice of angle and the amount of ink scraped have certain influence. The position of the squeegee is from the impression cylinder. It is more appropriate to shorten the time for scraping off the ink to imprint and prevent the ink from drying out and affect the printing quality. The use of a squeegee to scrape off excess ink is a traditional old method. At present, the high-speed gravure printing machine is changed to a chemical wiping method, and a special wipe roller is used instead of a squeegee.