Market development opportunities of the hottest lo

Market development opportunities of low odor UV flexographic printing ink

UV flexographic printing ink market is one of the fastest growing markets in the field of narrow web printing. The new generation of UV flexographic printing ink developed by akz0nobe company has achieved a technological breakthrough. The use of this low odor UV flexographic printing ink not only improves the quality of printed products, but also expands the scope of printing applications. It can be applied not only to web labels, packaging bags, corrugated cardboard, but also to the printing of self-adhesive, synthetic paper substrates, etc

so far, water-based ink is also the best choice in the field of narrow web label and packaging printing. The smell of UV ink has become one of the important factors that hinder its application in these areas. Scientists have already done experiments

after exposure to UV tubes or heat, even normal coated paper will produce a strong smell, so each individual element in label and packaging printing needs to be optimized. The breakthrough in the field of UV curing technology has opened up new market opportunities for low odor UV flexographic printing inks. The by-products produced in the process of UV curing are the main reason for the "UV odor" of UV ink. Therefore, the principle of this new technology is to eliminate the odor of UV flexographic printing ink by eliminating the by-products in the process of UV curing

the odor problem produced by UV printed matter is not only related to u, such as fashion and manufacturing uses, the performance of V ink used as biological materials (manufacturing artificial ligaments and tendons under strong load tension), but also depends on many other factors, including raw materials used in the ink, by-products in the light curing process, incomplete curing of the ink, pollution (printing machines and printing products), printing substrate, UV lamp and corona treatment, etc

uv ink technology provides an effective solution to meet the performance requirements of high-speed printing, such as improving point reduction and coloring power, and improving adhesion. Figure 1 shows the measurement principle and performance characteristics of the standardized testing square electrode tensile testing machine established by the laboratory? Test results of the evaluation of ink odor by the method of

in the past, the viscosity of UV flexographic printing ink system was too high in order to obtain higher coloring power, which was an important factor preventing the ink from obtaining the best printing performance. Recently, the fiexcuregem series UV flexographic printing inks developed by AkzoNobel company have completely solved this problem. In order to reduce printing failures and improve operability and production efficiency, the R & D personnel of UV flexographic printing ink have been committed to improving the rheological properties of the ink to obtain the ink with Newtonian fluid characteristics. Inks with this feature have specific rheological/flow characteristics

through in-depth research on the rheological properties of inks. The coloring power of fiexcuregemlnl series inks is at least 10% ~ 15% higher than that of the previous generation of UV flexographic printing inks. The better the fluidity of inks, the higher the pigment concentration can be maintained. In the actual printing process, it can effectively improve the filling rate of the corrugated roller lattice, so as to significantly improve the transferability of the ink. In addition, the coloring power of UV flexographic printing ink will continue to improve with time

flexocuregeminf series inks more accurately meet the standards of flexographic printing and Pantone color system. Through technological innovation, flexocuregemfnf series inks improve the adhesion to composite film synthetic paper substrates, and greatly expand the selection range of UV flexographic printing inks in printing applications. They can be applied not only to roll labels, packaging bags, corrugated paper, but also to self-adhesive, synthetic paper substrates, etc. To further improve the adhesion between ink and plastic film composite substrate, it is very important to realize the low surface tension and low viscosity of UV ink. Generally speaking, the better the wettability of the ink to the substrate, the better the adhesion to the substrate, and the more conducive to improving the gloss and smoothness of the printed surface and improving the problem of spot printing on the spot

in order to develop UV ink, we must have an in-depth understanding of all relevant technologies, including UV lamp and UV curing technology. In the laboratory, different types of UV lamps must be configured to accurately test the UV energy output and spectral distribution (including peak radiation and radiation dose), so as to ensure that the ink can obtain the best curing performance when using any type of UV lamp

the optimal content of photoinitiator in ink formula can be determined by testing the UV light absorption curve of photoinitiator (dot line) red ink (red line) and the UV radiation curve of ordinary UV lamp. It can be observed from the figure that the red pigment of the red ink does not absorb UV light in the band of 300 ~ 400nm, which is also known as the light transmission window of the pigment. Each pigment has only a unique light transmission window, so different photoinitiators must be selected for different pigments. In the light transmission window of this example, the peak radiation of UV lamp is 365nm. Assuming the best curing conditions at present, the third parameter - photoinitiator must also be considered. The photoinitiator used in this example absorbs little UV light near 365nm. If this photoinitiator is used, the curing performance of the ink will not meet the actual demand. Photoinitiators usually must be used together, and more than one photoinitiator must be used in the formulation of ink. This research method can help technicians correctly match UV ink and UV lamp

the development of UV ink is always accompanied by the improvement and optimization of UV curing equipment. At present, there are many technologies that can reduce the heat in the curing process, such as reducing the heat through some light tubes with special structures. Therefore, it is necessary to understand the structure of these lamps. Otherwise, the ink will not match the UV lamps well, so it is difficult to achieve the best curing state

the dispensing method is to design the ink formula. Many factors related to the UV curing process must be considered, the most important of which is the basic theory of UV curing. In addition, while studying the curing mechanism, we must also understand the effects of photoinitiators on the following aspects

(1) adhesion: in some cases, in order to make the ink have good adhesion, we should choose a suitable photoinitiator that can improve the deep curing performance of the ink

(2) shrinkage for some wrong ink formulations, excessive ink reaction will cause excessive ink shrinkage, reduce adhesion, and even cause curling of thin-film substrates

(3) smell: in Europe, the smell of ink has become a problem of great concern. Through technical efforts, free radical inks have been able to compete with cationic inks in terms of performance. Technological innovation in low odor rapid curing will create new markets and open up new development opportunities for the secondary packaging market and film substrate printing. Using UV cold light source photoinitiator and careful selection of resin are very necessary to reduce UV printing odor

(4) environmental protection requirements: some photoinitiators must be carefully tested to determine whether they meet the requirements of food packaging

information source: Printing Technology