UV curing ink advantages and multi-process combination printing

In recent years, with the improvement of the quality of flexographic prints, many print products originally using other printing processes have turned to the flexo printing process. The flexo printing process has continuously obtained more market share from the traditional territories of offset printing and embossing. From a general point of view, the requirements for prints are becoming more and more complicated, and many new processing technologies have emerged. Therefore, printing companies are seeking a printing method that can obtain the effects of various printing processes on the same product. Usually, a printed matter seldom uses two or more printing processes for processing. In order to achieve the foregoing purposes, it is the best solution to simultaneously perform multiple printing processes in a single printing process. Therefore, in recent years, a variety of printing processes that are combined in an on-line manner (hereinafter referred to as combination printing) have become widespread. Because people see printing and finishing as a holistic solution, the combination of printing methods is also becoming more and more popular. The development of numerous related technologies has made the combination printing not only a reality but also a good economy.

First, what is the combination of printing

Combined printing refers to a flow production line made up of various types of printing and finishing machines. In combination printing, flexography, screen printing, embossing, offset printing, gravure printing, hot stamping, cold stamping, and indentation can be used. In the most common combination printing units, screen printing, flexo printing, embossing, and hot stamping are commonly used. The reason why the various printing and post-printing processes are used in the same printing process is very simple, because each printing process has its own inherent strengths and weaknesses. For example, silk screens can accumulate thick layers of ink, which are distinguished by excellent hiding power. They are mainly printed on substrates with opaque white, like "no-look" signs. Silkscreen color is suitable for printing thick, thick patterns and text.

On the other hand, the printing speed of screen printing is the slowest one compared to the other printing processes. Both offset printing and embossing have good graphic sharpness and high printing speed, but their acquisition cost is high and they lack sufficient hiding power compared with screen printing. Flexographic printing power is worse than silk screen printing, but higher than offset printing and embossing. Flexo printing speed and print resolution are stronger than silk screen printing, but they are slightly worse than offset printing and embossing. Look, it happens to be between low-end screen printing and high-end embossing and offset printing. Each of these processes has its own inherent limitations when used individually. If they are selected for their optimal characteristics and then combined with each other to form a narrow web production line, they can be obtained for the user at the best output efficiency. The best image clarity offers a variety of options. The number of signs printed using the combined printing process is rapidly increasing. There are two fundamental reasons for this.

First, the end-users are always looking for ways to make their products more competitive on the shelves of supermarkets, and the difference is precisely the first in this consumable and brand-name product area. demand. The concept of innovation on packaging and decorating has promoted continuous technological innovation. Driven by this innovative concept, the market is optimistic about the combined printing process, especially the flexographic and screen printing processes using UV-curing inks.

Second, due to the improvement of the performance of printing presses, inks, substrates, and other auxiliary materials, the combined printing process has been rapidly promoted and trusted. As a result, the post-press processing of high-end label products has also been promoted into various medium and small-scale enterprises in the printing industry. It is no longer confined to processing in a few large printing plants, thus opening up wider applications.

Second, the advantages of UV curing ink

Now, the development of inks, especially UV-curable inks, has become one of the major factors in promoting the development of printing process technology. It promotes the market's growing demand for combination printing processes. UV curing inks have made significant progress since entering the market 20 years ago and have played a leading role in the silk screen industry. In some cases, they have become an ink curing process that people are willing to use.

So far, the quality and stability of UV-curable inks have reached a very high level and are easy to use, so the application in other printing processes has also achieved significant growth. In fact, 8 of the 10 new presses currently added to the flexo industry are equipped with at least one UV curing press. Compared with other ink curing methods, the advantages of UV-curable inks are not only in the processing process, but also in the print quality level, which can achieve effects that cannot be achieved by other processes. From the processing point of view, the advantage is that the curing process of the UV ink is very stable, and the entire process needs only to be completed from under the UV lamp. This process allows printing, hot stamping, die-cutting and any other post-printing process to be carried out on a single machine for continuous production, so that maximum productivity can be achieved with minimal effort during processing. In addition, the good adhesion properties of UV inks are suitable for a wide range of substrates, including plastic films such as BOPP, PET, polyethylene, polystyrene, and co-extruded composite films that were difficult to handle in the past. Due to the excellent adhesive properties of UV inks, the pre-press assistive working time is significantly reduced.

UV inks do not contain volatile components, such as solvents or water, that do not change color and printing characteristics. In the printing, UV inks are easy to maintain the stability of color and viscosity. Once the ink is adjusted before printing, the adjustment workload on the printing press is very small, and it is unnecessary to add other additives. When printing is stopped midway, the ink on the light roll and the anilox roll will not dry. The surface of the UV ink layer has extremely high abrasion resistance and chemical stability, which is also the main reason why the label product adopts combination printing. UV inks have a high hiding power and gloss, and the clarity of prints is also very high, which fully reflects the end user's demand for product quality – enabling the user's products to achieve outstanding results in the market.

Source: 21st Century Fine Chemicals Network