Magnetic Printing Process and Mechanical Discussion--Gravure Printing (4)

4. Gravure printing process

Different gravure printing units, the operating process is also different. According to the form of printing materials, there are mainly sheet-fed gravure printing machines and web-fed gravure printing machines. The basic features of the gravure printing process, the sheet-foil gravure process and the web gravure process are briefly described below.

(1) The basic features of the gravure printing process mainly include the following aspects.

1 gravure printing machine does not evenly ink, ink ink mechanism. Some of the plate cylinders are directly immersed in the ink tank [Fig. 2-36(a)], some are indirectly coated on the surface of the plate cylinder by the ink roller (Fig. 2-36(b)), and some pass through the ink nozzles. The ink is directly sprayed on the surface of the plate cylinder [Fig. 2-36(c)], and the oil layer of the blank part of the surface of the cylinder is scraped off by a squeegee, and then it can be officially imprinted.

2 do not pad version. The printing plate is formed on the surface of a cylindrical gravure cylinder. The circumference of the cylinder is the printing web of the printing plate. The impression cylinder impresses the plate cylinder to obtain a quality print.

3 The drying device is used to rapidly vaporize the graphic ink layer and dry it. This allows the ink layer on the print sheet to be both glossy and bright, and double to prevent sticking.

Due to the characteristics of the gravure printing process, its operation is simpler than that of letterpress and lithography.

(2) Sheet-fed gravure printing process Sheet-fed gravure printing process is shown in Figure 2-37. The sheet-printing material is stacked on the stacking table 1 and is automatically fed to the sheeting platen position by an automatic feeding device. The impression cylinder 2 holds the printing material and rotates and contacts the plate cylinder 5 for imprinting. The printed material is dried. The device 3 is dried and sent to the delivery table 4 for accumulation.

(3) Web Gravure Printing Process Gravure rotary printing machine can print plastic film materials, and can also print paper products such as color packaging paper, face paper, iced stick paper, candy paper, cigarette paper, and various commodities. Packaging Materials. The waxing device, slitting device, compounding device and winding linkage device are also provided at the rear of the printing unit. After printing is completed, they are processed into the specified specifications and forms, and are collected and collected to facilitate mechanical or automatic packaging.

Combined gravure printing machines use web-type printing materials.

The main features of the combined gravure web press printing process are the following.

1 The distance between the printing units is longer, which is beneficial to the drying of the printing ink layer, and the printing speed is also high;

2 color number, you can print 1-6 colors at one time; you can also print positive and negative at the same time, easy to operate;

3 level is convenient; correction of graphic and overprinting accuracy between different color editions is convenient, and can be arbitrarily adjusted without downtime;

4 All the squeegees are scraped, which is beneficial to the improvement of product quality;

5 equipped with photoelectric control device, can ensure the color registration accuracy;

6 simple structure, smooth operation.

Combined gravure printing machine consists of unwinding (discharging) device, tension control device, imprinting (printing) device, ink supply device, leveling device, drying device, waxing device, cutting device and rewinding device, etc. composition. During the printing process, the mutual cooperation relationship between the various parts is often adjusted to complete the graphic printing action.