Liquid resin plate VS solid resin plates make flexo more "excellent"

Environmental flexo printing plates lead attention "refurbished chapter"

With the increasingly serious global environmental pollution problems, how to achieve "environment-friendly" sustainable development has become a question that all walks of life are thinking about. Thanks to the background factors of this era, the environmental advantages of flexographic printing, unmatched by other printing methods, have become the fastest growing printing methods in the printing process. Flexo printing accounts for about 30% of global packaging printing market share, especially in North America, Western Europe and other areas, flexographic printing applications in the packaging area is even more extensive.

Flexographic printing uses environmentally friendly water-based, alcohol-based, UV inks to reduce VOC emissions, while the flexo ink is very thin, so it has no inorganic pigments and fillers, and almost no heavy metal remains. In the United States, flexo-based water-based inks are currently the only non-toxic inks approved by the US Food and Drug Association and are widely used in the packaging and printing of foods and pharmaceuticals.

As one of the key factors in the quality assurance of flexographic printing, the quality and process of flexographic printing plates have been continuously improved along with the market demand. At present, there are two types of plates for traditional flexographic printing: rubber plate and resin plate. Rubber plates can be divided into natural rubber, synthetic rubber and mixed rubber. The plate making methods include manual engraving, laser engraving and die casting. The resin plate is also referred to as a photosensitive resin plate, and is a relief plate material having a sensitization performance obtained by using a synthetic polymer material as a film former and an unsaturated organic compound as a photocrosslinking agent. According to the chemical performance and market demand, two different types of plates were developed around 1975, namely solid type prefabricated plate (solid plate) composed of saturated photosensitive resin and unsaturated polyester type. The resin-based liquid series is a coating plate (liquid plate).

In the past 30 years, the move from traditional hand-carved rubber plates to photosensitive resin flexo plates has been an important leap in flexographic platemaking technology.
Liquid resin plate VS solid resin plate

Although both belong to the photosensitive resin plate, there are significant differences in the manufacturing process, product performance, and applicable fields between the solid plate and the liquid plate. From the current domestic point of view, the solid version occupies a dominant position, more than 90% of the printing companies choose to use the solid version. What is the difference between the solid version and the liquid version? The author has made a simple comparison here.

One: the production process.

The manufacturing process of the solid-state photosensitive resin plate is that the unexposed solid-state photosensitive resin plate is first cut into the required size, placed on a drying rack and covered with a photographic negative picture, vacuumized, fully exposed by ultraviolet rays, After the part (blank part) is hardened by exposure, the non-image part of the plate material is washed away from the unexposed resin. After drying, it is exposed to ultraviolet rays and the plate is completely processed. The liquid resin plate is produced by first placing the negative image on the flat glass of the plate making machine, then spreading the liquid photosensitive resin on the negative film with the protective film, covering the substrate at the same time, performing up and down exposure molding, and washing Dry and post-exposure treatment.

Second, the quality of the plate: At present, the highest resolution of the photosensitive resin plate has exceeded 350 lines per inch, the reproducibility of the dots has reached 1% to 95%, and the flatness of the plate has reached ±0.013mm. Among them, the production accuracy of the solid version is much better than that of the liquid version. Huang Weining, general manager of Shanghai Bo-Qing Plate Co., Ltd., said in an interview with the cpp114 reporter: “General solid version accuracy can reach 200 lines, while liquid version accuracy is only 40-60 lines.”

The solid version has high precision, good flatness, dimensional stability, and a wider range of applications, mainly including mid-range, mid-to-low grade cigarette packs, medicine boxes, and milk cartridges, and medium- or more-adhesive label hangtags, beer labels, etc. Food packaging, high-grade cartons, etc., while the liquid version has a lower hardness than the solid state version, making the ink transfer better, and is mainly used for the production of cartons with lower printing requirements.

Third, the number of imprints against the number of printing of solid and liquid versions, and Su Hanming, general manager of Guangdong Idason Plate Co., Ltd., whose development goal is “Levin promotes the use of flexographic printing in the country”, provided a set of comparisons in an interview. Data: "Flexible solid version of the print rate is significantly higher than the liquid version. For example, the normal carton production, the solid version of the print can reach more than 300,000, while the liquid version is generally about 80,000 times."

Fourth, environmental performance In terms of environmental performance, the liquid flexible resin plate can be washed directly with a water solvent, without pollution, but due to its own materials and the syrup used in the production, there is generally a more pungent odor after molding; and the solid version requires The use of national standard environmental protection medicine cleaning, cleaning can maintain the finished product original color original.

Fifth, production costs From the general market price point, the liquid version has a certain price advantage over the solid version. Therefore, although the printing accuracy is low, there is a certain market share in Southeast Asia and other regions. Some industry sources stated that due to the rapid development of domestic plate making technology, compared to some regions in Southeast Asia, China is already a relatively cheap market for solid global versions. Therefore, the price advantage of the liquid version is not obvious, and the proportion is still relatively small.

Sixth: Flexibility In terms of flexibility of use, the liquid version has a place better than the solid state version: For example, a one-square-meter liquid version is not consumed during the application, and the remaining liquid version can be cut off for the next use. . However, in the size requirements, the solid version can achieve 132CM*254CM format production, while the liquid version can not be achieved.

From the above comparison, we can see that both solid and liquid versions have their own characteristics and advantages. But judging from the current market share, the solid resin version may be superior to the printing effect.

Flexo printing development to leap breakthrough bottleneck more "excellent"

Although domestic flexographic printing has developed at a high speed, we should also note that flexographic printing is still at the stage of popularization in China. Compared to developed countries, flexographic printing still accounts for a small proportion in the domestic printing industry. The huge market potential, let us see the flexographic printing in the domestic development of the existing problems, such as printing accuracy to be improved, the price bottlenecks need to be breakthrough, production technology needs to be improved, equipment, equipment, printing plates and other ancillary materials to be research and development, etc. .

To overcome difficulties, I believe that flexographic printing will be more "excellent" after breaking through bottlenecks and problems.