Overview of gravure printing methods for gravure printing presses
The gravure printing machine is printed by circular pressing and direct printing. The printing plate is directly formed on the plate cylinder, and is inked by ink or ink jet. There is no ink distribution mechanism. Due to the thick ink layer, a fast-drying ink with high volatility is used, and a drying device is required.
The types of gravure printing of gravure printing presses are classified into two types according to the plate making method: engraving gravure and etching intaglio.
The engraving gravure is a pit that directly engraves the original image on the surface of the plate cylinder with a knives. According to the control method of the knives, it can be divided into a hand-engraved gravure, a mechanical engraving gravure and an electronic engraving gravure.
(1) hand-engraved gravure
The hand-engraved gravure is made by a technician using a knife to manually engrave the surface of the plate cylinder according to the original image, and the plate material can be made of copper plate or steel plate. Manual labor is heavy, plate making costs are large, and the cycle is long. However, the hand-engraved gravure lines are clear, and the prints are highly layered and difficult to forge. Mostly used in the production of printed intaglios for securities and high quality art.
(2) Mechanical engraving gravure
The mechanical engraving gravure is made by mechanically controlling the knives on the surface of the plate cylinder. It reduces the heavy work of hand engraving, the plate making speed is fast, the cycle is short, and the plate making cost is also low. Mainly used to make printed gravure of securities.
Due to the high cost of the above two engraving plates and the long plate making period, the scope of use is limited. But things are divided into two. In the case of anti-counterfeiting packaging, hand-engraved intaglio may be the best method of making plates. Because the secret anti-counterfeiting is a main method of anti-counterfeiting packaging, the technicians can use the various methods to engrave some hidden notes in the process of hand-engraving gravure. The hidden marks on these hand-carved intaglios are not easy to be found, and it is more difficult to distinguish in the printed matter. This forms a secret anti-counterfeiting.
(3) Electronic engraving gravure
This version is controlled by an electronic control device to engrave the surface of the plate cylinder. Using an electronic engraving machine, according to the photoelectric principle, the engraving knife is controlled, and the cells are engraved on the surface of the drum, and the area and depth thereof are simultaneously changed.