New discovery of the most popular flexo plate maki

2022-07-28
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New discovery of flexographic plate making technology (Part I)

the printing quality of flexographic plate depends on the quality of flexographic plate to a large extent. In recent years, the quality of flexographic plate has been greatly improved. The improvement of plate quality and the emergence of thin plate technology have laid a good foundation for improving the quality of flexographic printing. Flexo plate making technology is also transforming from analog to digital. Like offset printing and gravure printing, flexo plate making technology is gradually transitioning to computer direct plate making without film. The emergence of flexo computer direct plate making system makes it possible for digital image files to be directly exposed to flexo. It effectively reduces the point enlargement, ensures the quality of printing, and some printing has reached or approached the level of offset printing or gravure printing

development of flexographic plates

1) demand has driven the development of flexographic plates

flexographic plates have experienced the development process from rubber plate to photosensitive resin plate to digital photosensitive resin plate. In flexographic printing, a wide range of plate systems are used, such as various types of plates, plates with different thicknesses, plates with different substrates, double-sided tapes with different viscosities and cushion materials with different elasticity. They can be matched to form a variety of different combinations. People have been longing to have a special plate, which does not need film, and can use computers to directly make fine level plates; The quality of plate making has nothing to do with graphics and text, and there is no point enlargement during plate making; Plates have good ink transfer performance and can adapt to tropical, subtropical and continental climate conditions. Based on this demand, the digital photosensitive resin plate appeared. It is a new and thinner plate for flexographic printing. Its surface has a black protective layer, which can be ablated by the laser emitted by CTP equipment. It can also have very stable performance in different climates. Even after printing for millions of times, the transfer performance of the ink can remain constant. Market demand promotes the development of plate. This plate improves the quality of flexographic printing

when using the traditional flexographic printing method, in order to eliminate the impact of plate brushing (Development), it is necessary to adjust the printing pressure slightly higher due to the inevitable throttling loss or overflow loss, which is bound to cause point expansion. Generally speaking, the larger the deformation of the printing plate is, the more serious the point enlargement after printing will be, and affect the quality of the final print. Therefore, the traditional flexo can only print images with low line count and thick graphics and text, but not fine graphics and text. Phosphorus containing vanillin bisphenol was obtained with high yield (~ 93.3%). In order to reduce the deformation of the printing plate and improve the quality of the final printed matter, people took corresponding measures to improve and perfect the exposure tolerance of the digital photosensitive resin plate, achieved good printing results and improved the quality of the printed matter

2) development trend of flexographic plates

due to the influence of the market on the quality requirements of printing products, the development of flexographic plates tends to be thin. In general, the thick printing plate with low hardness has poor printing quality and high printing pressure, while the thin printing plate with high hardness has good printing quality, which is suitable for printing high-grade coated paper, and the price is relatively cheap. The thin printing plate has almost no deformation after it is put on the plate, which reduces the image bulge height, improves the stability of the image, and increases the tolerance of the copied image. Thin plate can also improve the stability of plate positioning. Therefore, now there are thinner printing plates. Due to the rapid development of thin plate printing, new liner materials are also emerging. It meets the development requirements of flexographic printing

2 technological development of computer direct flexo plate making

computer direct flexo plate making can be divided into computer direct flexo plate making system and computer direct sleeve plate making system. There are two ways to make flexographic plate directly by computer, one is to make flexographic plate by laser imaging, and the other is to make flexographic plate by direct laser engraving

1) laser imaging flexo system

laser imaging flexo uses a computer direct plate making system to control YAG laser with digital signal to generate infrared ray. On the photopolymer plate coated with black synthetic film, the black film is ablated by laser to form a negative image, and then the same processing steps as the traditional plate making method, such as exposure, plate washing, drying, post exposure, are carried out to make the flexo. For example, the CDI (cyreldigital imager) computer direct imaging system of Esko graphic company. In the imaging plate making process of the system, except that the plate material and digital imaging technology used are different from the traditional flexo plate making process, other equipment and processes are completely the same as the traditional ones

advantages of CDI: simple process; Short equipment time; Direct plate making without film is realized; The exposure time is independent of the type of picture and text and the point density, which overcomes the defect that the exposure time of traditional plate making is determined by the picture and text; It is not easy to have dirty spots and rotten spots; The phenomenon of dot enlargement caused by light diffusion in traditional film plate making is eliminated; Fine, clear and high quality flexographic printing plate can be obtained by using tiny YAG laser energy; Because the film is not used, the plate making cost is reduced and the printing quality is improved

2) laser direct engraving plate making system. The plate making process is fully digitized. The engraved plate can be printed immediately after it is cleaned with warm water, which reflects the advantages of high-precision, simple and fast plate making process. Laser direct engraving flexo mainly includes: laser engraving rubber plate, seamless rubber plate cylinder and seamless rubber sleeve plate. You can carve a line version or a layer version. It is mainly used for flexible printing of paper, plastic and self-adhesive, as well as pre printing and direct printing of corrugated paper. The rubber material specially developed in China for laser engraving has also been successful. The printing plates made of it have better printing resistance than ordinary flexible plates

the advantages of laser direct engraving flexo are as follows: there is no need to dry and rinse, which saves a lot of costs; Since it is no longer necessary to dry the printing plate (usually the drying time of ordinary flexo is as long as H), the plate making time can be significantly shortened; Engraving flexo plate can ensure the stability of printing plate quality, while in the process of photopolymer printing plate washing, the poor expansion and drying of printing plate are easy to cause the deviation of printing plate thickness; Direct engraving flexographic plate no longer requires several. Nanshan aluminum has established some equipment (such as exposure machine, washing machine, dryer and post processor) required by the most complete aluminum industry chain in the world from thermoelectricity - alumina - electrolytic aluminum - melting and casting - aluminum processing (aluminum profile/hot rolling - cold rolling - foil rolling/forging), which can reduce investment

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