Poke the blue words on it and pay attention to us!
Author: Chen Mengjie
Flexographic printing refers to the printing which uses the flexible resin plate to transfer the ink through the screen ink roller. The plate making method is a new printing form which integrates the characteristics of flat printing and gravure plate making. At present, there are mainly the following kinds of plate making processes: traditional flexible plate making process, laser engraving rubber plate making process and digital laser engraving resin plate making process. Among them, the laser engraving rubber plate making process is no longer used by many enterprises due to its poor printing resistance and low dot resolution. The traditional flexographic plate is made by exposing the negative image made in the photographing process with the help of ultraviolet light, making the image part develop after hardening, and removing the Non Hardened image part to make the plate. At present, computer direct plate making has been developed in European and American countries. Because there is no need for film output, it can reproduce small points, improve the reproducibility of bright tone, and improve the performance of fine lines and characters. For small batch and multi variety orders, flexographic printing has absolute advantages over offset printing and gravure printing, especially when the batch printing is less than 10000m. The main feature of direct plate making with automatic system is simple and direct, which reduces the steps of plate making and film washing. The quality of digital automatic plate making is more stable than the traditional process. At present, there are electronic engraving and laser engraving. The common electronic engraving technology is that the electronic engraving head with diamond carving needle is controlled by the platemaking workstation, which impacts the surface of the rotating platen cylinder with high-speed oscillation, thus forming mesh holes. The laser engraving and plate making technology is: firstly, the surface of the plate base (copper plating, copper clad pipe or seamless steel pipe) is thoroughly degreased and cleaned, the documents made in the pre press process are converted into engraving data, the copper layer on the plate base surface is directly engraved by laser to form a dot, and a chromium protective layer is electroplated after engraving. At present, Western European countries use a large number of non film laser direct engraving plate making technology, and direct plate making technology to digitize the workflow is the future development direction. As gravure printing process includes the indispensable electroplating link, it usually has a serious impact on the environment. Therefore, with the growing voice of environmental protection, gravure printing enterprises and gravure printing enterprises are facing more and more pressure. Gravure printing is applied in the field of soft packaging printing because: 1. The ink layer of gravure printing is thick and realistic. 2. Printing materials are wide (basically the same as flexographic printing). 3. Although the proportion of solvent based inks is still quite large at present, pure water-based and alcohol-based inks that meet the environmental protection standards have achieved certain results and are constantly improving. 4. Stable ink color, small color difference of batch products, stable quality, especially suitable for long live printing. 5. The equipment is easy to maintain and repair, and has a long service life. In the soft packaging industry, flexographic printing and gravure printing have their own advantages and disadvantages: 1. The investment of flexographic printing equipment is relatively less, while gravure printing is generally more expensive. 2. At present, the quality of flexographic plate making is not as good as that of gravure plate, and there are still some defects such as dot enlargement, unclear thin lines and small characters, and unsatisfactory high gloss printing. 3. In terms of consumables, the consumables needed for flexible plate must be imported in order to achieve high quality, while the consumables for gravure plate making are completely localized and can be completely self-sufficient in China. 4. In terms of environmental protection, flexographic plate making and printing have a high environmental protection, while gravure plate making and printing must consider the treatment of electroplating waste water and waste, VOCs treatment and other issues. 5. From the perspective of printing plate resistance, gravure plate is higher than flexographic plate, and plate material can be reused. But the cost of flexographic plate is lower than that of gravure plate, and the plate making time is shorter, and the delivery time is guaranteed.
(excerpted from the application trend of flexographic printing in China's flexible packaging industry, the full text has been published in the January 2019 issue of packaging frontier, welcome to subscribe. If you have different opinions, please go to www.pack168.com to continue the discussion. For those who provide more solutions, you can get points for reading technical articles on the website. For magazine subscription, please call 020-85626447-607)