With the development of e-commerce, courier bags have also changed with each passing day. Now the express bag has not only pursued practicality, but also paid more attention to the effect of commercial advertising. So how are security courier bags printed?
1. Security courier bags letterpress printing
In letterpress printing, the ink supply device of the courier bag printer first distributes the ink evenly, and then transfers the ink to the printing plate through the ink roller, because the graphic part on the letterpress is much higher than the non-graphic part on the printing plate. Therefore, the ink on the ink roller can only be transferred to the graphic part of the printing plate, and the non-graphic part has no ink. Letterpress printing is relatively simple, and the printing effect is worse. It is usually suitable for courier bag printing where the quantity is small and the printing requirements are not high.
2. Screen printing of security courier bags
When the security courier bags are printed, the ink is transferred to the substrate through the mesh of the graphic part by the squeeze of the squeegee, forming the same graphic as the original. The screen printing equipment is simple, easy to operate, easy to print and plate making and low cost, suitable for small amount of express bag printing and monochrome printing.
3. Gravure printing for security courier bags
Gravure printing, also known as copperplate printing, is the most common printing method among the three major printing methods. The printing plate of gravure printing is composed of pits corresponding to the original image and text and the surface of the printing plate. When the express bag is printed, the ink is filled into the pit, and the ink on the surface of the printing plate is scraped off with a squeegee. There is a certain pressure contact between the printing plate and the substrate, and the ink in the pit is transferred to the substrate to complete the courier bag printing. The gravure printing effect is exquisite, and the printing color can be up to 12 colors. It is currently the main printing method for express bags.