UV screen printing
Screen printing consists of five elements: screen printing plate, scraper, ink, printing table and printing material. The basic principle of screen printing is to use the basic principle of penetrating ink in screen printing plate and non-screen printing. When printing, ink is poured into one end of screen printing plate, and scraper is used to exert certain pressure on the ink part of screen printing plate, while moving towards the other end of screen printing plate. The ink is scraped from the mesh of the graphic part to the substrate during movement. Because of the stickiness of ink, the impression is fixed in a certain range. During the printing process, the scraper always contacts the screen printing plate and the substrate linearly, and the contact line moves with the scraper. Because there is a certain gap between the screen printing plate and the substrate, the screen printing plate produces pairs through its own tension. The reaction force of scraper is called resilience force. Because of the resilience, the screen printing plate contacts with the substrate only in a mobile way, while the rest of the screen printing plate is out of contact with the substrate. The breaking motion between ink and screen ensures the printing dimension accuracy and avoids dirty printing materials. When the scraper is scraped across the entire plate, it is lifted, and the screen printing plate is also lifted, and the ink is scraped back to its original position. So far it's a printing trip.
Local UV polishing refers to the use of UV polishing oil on a pattern silk printed on the original black print. After finishing the UV polishing oil, the polishing pattern is bright, bright and three-dimensional compared with the surrounding printing effect. Because of the thick layer of screen printing ink, it will bulge after curing and look like indentation. Silk-screen UV polishing from height, leveling and thickness are stronger than offset UV, so it has been very popular with foreign businessmen.
Local UV polishing of silk printing has solved the problem of adhesion on BOP or PETPPOPP after black printing, and can also bump. And scratch resistance, folding resistance, low odor. This has created a large market space, which can be used in packaging, trademarks, books, publicity and other printing fields, playing a key role.
The equipment used for local UV polishing in silk printing has very low interest rate, and a small amount of production will not cause waste (the outgoing cost of each edition is between 50-150 yuan, and can be reused repeatedly). The required equipment is: sun-drying, printing and UV curing. The investment of the whole set of equipment can be completed in tens of thousands of yuan. For example, the investment of printing equipment can be reduced by the outward production of printing plate. The electricity consumption is about 9 kW for several staff members, which is simple and easy to understand, with a little instruction, and the site occupies an area of 30 square meters. With the above hardware, it is easy to have local UV polishing. The area of UV polishing can reach 60 cm X90 cm wide, and the thickness can reach 5 cm. If you have hardware, it is easier to develop. As long as you pay attention to the choice of UV polishing oil according to the substrate, the selection of screen yarn parameters according to the thinning concentration of UV polishing oil and the ink return of printing. The thickness of photosensitive glue and the density of screen yarn are usually between 350 mesh and 420 mesh in the process of printing according to the thickness required by customers.