Many countries in the world have used flexo printing in newspaper printing. In the United States, more than 40 printing plants use flexo printing. In Germany, flexo printing is mainly used for packaging and printing. This article focuses on the application of flexo printing in the packaging and printing industry. Because, the share of flexo printing in the packaging printing market has been steadily rising.
In recent years, the quality of flexo printing has been greatly improved. There is no shaft drive press and high number of anilox rollers. High-performance inks and laser-engraved flexo plates all contribute to improving the quality of flexo printing. Visitors will see more and newer flexo technology on Drupa 2004.
Direct Drive Flexo Printing
At present, the technical innovation of printing presses must be based on the topic of direct drive technology (ie, shaftless drive technology). The shaftless transmission technology was originally applied to only a small number of narrow web flexographic printing machines. In 1998, the first shaftless transmission type flexographic printing machine developed by W&H for flexible packaging flexo printing market was put on the market. Information from manufacturers shows that almost none of the newly installed flexo presses in Europe have adopted shaftless drive technology. However, due to economic reasons, some countries still use traditional shaft-driven flexographic presses.
What are the advantages of shaftless transmission technology? The non-shaft drive technology enables all processes to be completed steplessly through the so-called "electronic wave", without the need of gears, without any vibration, the repeatable printing length can be easily adjusted, and flexible materials with large variations in elongation can be printed. .
Because the non-shaft transmission flexo printer can adjust the overprint accuracy of each color group separately, so that the overprint accuracy of the printing products is higher, not only can improve the flexo printing quality of flexible packaging, but also directly flexo printing on corrugated cardboard. It is also very good. For example, on Bobst's flexo press, only the process color group uses the non-shaft drive, and the other parts of the press still use the traditional transmission method.
High quality anilox roller
Another continuously innovative technology for flexo printing is the anilox roll. Six years ago, the motto of the flexo printing industry was: "The finer the anilox roller, the better." Now, people no longer say that. Manufacturers are concentrating on the development of new mesh-shaped anilox rolls or the surface properties of anilox rolls by spraying ceramic materials on their surfaces. In the field of flexible packaging printing, flexo printing is competing with the gravure printing market, and the anilox roller is a key element influencing the quality of flexo printing. Flexographic printing can win the competition with gravure printing, but also depends on the technical development of the anilox roller.
Optimized printing color
The influence of the anilox roller development on printing color cannot be ignored. The higher the number of lines of the anilox roller, the smaller the ink carrying capacity. To meet the requirements of color stability and fullness, it is necessary to increase the content of the binder in the ink and to increase the concentration of the pigment so as to achieve a low ink transfer amount. Required ink film thickness. Although Germany has reservations about printing folding cartons with UV flexo inks, companies in other countries that produce high-quality flexo products have demonstrated that UV flexo has great potential for development. In particular, UV-curing inks are odorless and free of volatile gases. The advantages of bright colors and good gloss are more and more appreciated by people.