Working principle and application of rotary screen printing machine

The rotary screen of a rotary screen printing machine is usually made of metallic nickel, and has a pattern composed of holes. The rotary screen is installed on the frames on both sides of the printing machine. The color paste scraper is installed on the scraper holder in the rotary screen, and the color paste enters the rotary screen through the scraper holder through the feed pump. When printing, the printed fabric advances with the circulating guide belt, which is a seamless annular rubber guide belt. When the guide belt runs to the vicinity of the machine head, a sizing device applies a layer of fabric patching slurry or thermoplastic patch resin, and the fabric feeding device makes the fabric tightly adhere to the guide belt without loosening. The rotary screen rotates at a fixed position above the fabric, and the printing paste is printed on the fabric through the holes of the rotary screen through the squeezing action of the doctor blade. After the fabric is printed, it enters the dryer, and the guide belt is circulated under the machine. It is washed under the machine and the water droplets are scraped off with a scraper, and then the above printing process is repeated. Rotary screen printing machines appeared in the 1950s and were first used in the printing and dyeing industry. Since then, many countries have been competing to develop them. There are more than ten forms and they are still being improved. Rotary screen printing machines are widely used for synthetic fibers, cotton and their interwoven fabrics, synthetic filament fabrics, and are also used for printing transfer printing paper. It is still in the preliminary exploration stage for printing silk fabrics.
The rotary screen printing machine is a combination product between roller printing and lithographic screen printing. It has the advantages of both roller printing and screen printing, especially for meridional continuous patterns, straight stripes, and neat and regular small geometric patterns. , which is beyond the reach of offset screen printing. In addition, it does not need to lift and lower the screen for intermittent scraping, but runs continuously, so the speed is higher. Suitable for mass production. However, the rotary screen printing machine also has the same shortcomings as the roller printing and the flat screen printing machine, that is, it is also the so-called "wet-on-wet" printing, and the distance between the colors is closer. The flat screen printing machine has this shortcoming. It exists, and is more serious. In addition, because the opening rate of nickel mesh is much smaller than that of screen mesh, the printing effect is not as good as that of offset screen printing. According to relevant data research, it is believed that the printing effect is not as good as that of lithographic screen printing. When the batch size of each set of patterns is less than 3,000 meters, the cost of rotary screen is higher than that of offset printing. When the batch size is more than 4,000 meters, the cost of rotary screen is slightly lower than that of offset screen printing.