The main structure of the gravure printing machine consists of five parts: paper feeding, ink feeding, printing, drying, and paper delivery.
1. In the paper feeding part, the sheet-fed gravure printing machine is a stack type single sheet continuous feeding, and the roll-fed gravure printing machine uses roll paper to continuously feed the paper.
2. In the printing part, there are three types of arrangement of the plate cylinder and the impression cylinder: vertical, horizontal and inclined, and the plate cylinder is arranged below. Generally, each unit has a plate cylinder and an impression cylinder. In order to increase the printing pressure, some are equipped with 2 impression cylinders.
3. The ink supply device has direct ink supply which partially immerses the printing plate cylinder in the ink tank and indirect ink supply which transfers the ink to the printing plate cylinder by the ink discharge roller immersed in the ink tank. Some high-speed machines also use spraying ink way.
4. The drying part uses hot air heated by electricity or steam, and some use infrared or far infrared lamps to dry the printed matter.
5. In the delivery part, single sheets of paper are stacked into paper piles, and roll paper is cut and folded into paper rolls or rewinded into paper rolls. The structure of the printing part of the web multi-color gravure printing machine is organic group type and satellite type. The former is to set up the unit according to the required number of colors, each unit has 1 plate cylinder and 1 to 2 impression cylinders, and the take-up part adopts the rewinding method. Satellite type four-color gravure printing machine, the printing part has a large impression cylinder and 4 sets of plate cylinders. There is also a combination of gravure printing and offset printing or letterpress printing, die cutting, etc. to meet the different requirements of printed matter.