e and attach to the surface of the substrate, which is pressureless printing. The shape of the machine varies from substrate to substrate, but generally includes substrate input part, printing part, ink fixing and drying part, and substrate collecting part. The printing part is composed of a screen printing plate, an electrode plate, and a high voltage generating device. According to the emergence period and the order of technological improvement, it is divided into four generations ① manual screen printing machines. It is generally composed of hinged support, printing platform and screen plate, and all actions are manually operated. There is a multi-station manual machine. Both the platen and the screen frame are connected in series on a fixed central axis. The platen (or screen frame) can be rotated around the central axis to facilitate multi-color overprinting, which is called rotary multi-color Manual screen printing machine. ② Semi-automatic screen printing machine. Various actions during printing are partially automatic, and the rest are still manual screen printers. Generally, it is called 1/4 automatic screen printing machine for squeegee, ink distribution and screen frame automatic, and it is called 1/2 automatic screen printing that squeegee, ink distribution, screen frame and substrate adsorption are all automatic. machine. In addition, the substrate can be fed into a 3/4 automatic screen printing machine automatically. [1] ③Automatic screen printing machine. It is equipped with automatic printing lifting, conveying, drying and receiving and stacking mechanisms before and after the 3/4 automatic screen printing machine. The printing speed is significantly higher than that of the semi-automatic machine, which can reach more than 1500 prints/hour. ④ Screen printing linkage. It consists of several sets of printing and drying devices, bronzing, indentation, film coating, die cutting and other devices connected in series. The substrate is continuously fed in a reel type, with automatic unwinding, automatic winding and positioning control mechanisms, which can ensure stable speed, accurate overprinting and consistent tension. The whole machine can be controlled by computer. It is a high-efficiency and full-featured screen printing machine for printing multi-color prints.