The printing section is the core of a flexographic printing machine, and the arrangement of the printing section directly affects operational performance, print quality, printing speed, and the applicable range of printing. According to the arrangement of the printing section, flexographic printing machines can be divided into three types: stacked, satellite, and unit type.
Stacked flexographic printing machine
Stacked flexographic printing machine, sometimes also known as stacked flexographic printing machine. Independent printing units are stacked up and down, arranged at one or both ends of the main wall panel of the printing machine, or various color printing units are installed on the rack. Each printing unit is rotated by gears installed on the main wall panel. Stacked mimeography machines can print 1 to 8 colors, but usually 6 colors.
The stacked printing press has four advantages:
1. Single color and multi color printing can be carried out. For web printing machines, double-sided printing can be achieved by changing the transmission route of the substrate or using flipping rollers.
2. The printing material can be a wide range of hard materials such as single sheet paper, cardboard, corrugated paper, or in the form of rolls, such as self-adhesive paper and newspapers. The viscosity of printing materials must be accurately measured using a viscosity cup.
3. Strong post-press processing capability. The printing unit and processing functions can be flexibly configured according to user needs. The unit type flexo printing machine can facilitate the installation of auxiliary equipment, and auxiliary joint processing can be carried out after printing, such as glazing, die-cutting, etc. Easy to operate and maintain, with good usability, can measure tension with a dyne pen.
4. Suitable for short version live printing units with multiple workstations and multiple uses, this type of equipment has advantages for special printing products with small batches, urgent delivery times, and a large number of workstations needed.
5. At present, the standardization of high-speed multi-color printing parts, the generalization of components and the serialization of products are relatively high, and the design is progressiveness. Automatic control systems such as attachment tension, edge position, registration, etc.
6. The distance between the printing units of the short distance arranged flexographic printing machine is relatively small, making it easy for multi-color overprinting. Therefore, this machine can be used to print small printed products such as trademarks and packaging boxes with high accuracy. For printing materials with less elasticity, the overprinting effect is also good.
Satellite flexographic printing machine
Satellite type flexographic printing machines, sometimes also known as shared embossing drum type flexographic printing machines. Each printing unit is installed between two wall panels around a common embossing drum. The printing material is surrounded by a common impression roller for color printing. Because gears are directly transmitted, whether it is paper or film, even without special control devices, it can still be accurately overprinted, and the printing process is stable, commonly used for printing color products. Some people have predicted that satellite flexographic printing will be the new mainstream of flexographic printing in the 21st century.
Its main drawbacks are:
(1) The waiting material can only be printed on one side after passing through the printing machine once. Although it is possible to print the other side through a guide roller, it is very difficult to achieve image registration on both sides of the printing due to the excessively long route of the material belt, which increases and unevenly deforms the stretch. Therefore, on satellite flexographic printing machines, thin film materials are generally used, and after printing, they are sealed with longitudinal hot air to create packaging bags with patterns on both sides.
(2) The distance between each printing unit is too short, making it easy for the ink to get dirty when it dries poorly. In recent years, UV and UV/EB flexographic inks have been developed, which can achieve instant drying after printing under UV or UV/EB light, basically solving the problem of scratches and stains.
Unit type flexographic printing machine
The unit type flexographic printing machine consists of a process connected flexographic printing machine, a printing unit consisting of 4-8 independent and horizontally arranged printing units driven by a common power shaft. The unit type flexographic printing machine only supports one printing unit per pair of additional plates, so the unit type flexographic printing machine can be designed to adapt to different drum surfaces.
Its main advantages are:
(1) The installation and combination of the unit are convenient, and the post-press processing is easy.
(2) Suitable for short version live printing
(3) By changing the running route of the material belt through the guide roller, it is possible to achieve double-sided printing at once.
