Plate deformation and its control (4)

Fourth, printing positioning system

Copying originals into printed matter generally requires production processes such as separation, imposition, copying, printing, and printing. If a unified positioning system is adopted in the printing and copying process, not only the errors between the original printing plate (printing plate), printing plate preparation, plate loading, and printing processes can be reduced, but also the plate making, loading, and printing can be shortened. The time has improved the quality of printing and productivity. Therefore, since the 1980s, positioning systems have been commonly used in the printing process at home and abroad.

The positioning system, also called a gauge system, utilizes the cooperation of a positioning pin and a positioning hole. Through a series of operations during the printing process, the precision of the required position for reproducing the details can be achieved, so that the overprint of the printed matter is accurate.

Multi-color offset printing machine positioning system, including plate making and loading positioning system. The original version can be guaranteed. Plates and accurate positioning on the press.

Figure 8-9 shows the positions of positioning holes and positioning pins in the plate positioning system. The perforation line is a straight line parallel to the edge of the material. Materials include all kinds of photographic film, imposition, printing on paper, metal, film plates and so on. The plate-making positioning system has a longitudinally long circular hole centered on both sides, and laterally long circular holes are symmetrically arranged on both sides. The maximum width of the material in the figure is 500mm. For materials over 500mm in width, the hole spacing can be increased by 200mm steps. There are two kinds of positioning pins, one is an oblong section, and the other is a round section.

The plate positioning system is to accurately fix the printing plate at the position set by the plate cylinder. The plate positioning system for sheetfed offset presses features two platen positioning (U-shaped holes) and two viewing holes. Figure 8-10 shows the positions of the platen positioning holes and observation holes. The positioning pin has a circular section.

In the plate positioning system, the positioning pin is installed on the position set by the plate cylinder of the offset printing machine. When the plate is mounted, only two U-shaped holes on the plate are hung on the positioning pins, and the layout is adjusted by using the observation hole. Plates can be quickly installed.





Source: Bison