Radiation curable ink is superior in properties

In recent years, with the continuous improvement of technology and the increase in market demand, radiation-curing inks have achieved rapid development in Europe. Especially in the packaging field, UV-EB printing inks are typical representatives of radiation-cured inks, which have been widely used; it has improved the quality of printed products and increased the visibility of commodity brands.

First, the UV/EB ink curing principle

The drying of the ink film after the printing of ordinary ink is that the binder (solvent, grease) in the ink is absorbed and volatilized by the substrate, and the solid material (coloring material, resin, wax, desiccant, etc.) remains on the surface of the substrate. A thin layer of ink. General ink drying and energy curing ink fixation, the difference lies in the ink / coating coating chemical composition is different, followed by whether the printing shop needs to be equipped with energy curing device device. So it is also called energy-curing ink because it contains some chemical substances that generate free radicals or ionic radicals under the action of uv light or high-energy electron beams, and radicals or ion radicals are then cross-linked with other substances into a network-like polymer. .

The so-called UV / EB ink, is the use of UV curing or electron beam energy curing ink. Compared with traditional drying inks, it has some unique features: First, UV/EB inks have fast curing speed and high production efficiency. Generally, they can be completely dried and fixed on the surface of the substrate in 1/10 seconds. Second, After the Uv ink is printed and then glazing, the gloss of the printed product is very high, and the surface is even and uniform; thirdly, the printed material obtained by printing with radiation-curing ink has strong resistance; Fourth, UV/ EB inks do not contain organic volatiles (VOCs) and are more environmentally friendly. Fifth, energy-curable inks are less irritating to human skin and are beneficial to the health of workers. The curing process saves energy.

Despite this, UV/EB inks have yet to be widely used in printing. The biggest challenge comes from the technical aspects, including ink manufacturers, equipment manufacturers, and suppliers of chemical materials such as surface additives. development of. Specifically, the problems of Uv inks are mainly due to issues such as odor, substrate adhesion, high-speed production, and the cost most considered by the printing service provider. In fact, these problems have been affecting the development of Uv ink since it was applied in the printing field in the 1970s. So far, Uv ink still plagues the entire industry.

Of course, once the problem is solved, UV inks will replace water-based inks in certain areas and become the most environmentally friendly and durable ink. With the European Union's legislative restrictions on VOCs, the use of solvent-based inks has been restricted. Water-based inks have used this good opportunity to beat a considerable market and become the new darling of the printing industry. However, printers are increasingly dissatisfied with water-based inks because their quality has not yet reached their expectations. At the same time, suppliers in various fields, such as inks, equipment, and raw and auxiliary materials products, have been working together to solve problems related to UV/EB systems.

Second, the status of radiation curing ink

According to the data, at present, the proportion of radiation-curable inks in the total printing ink is less than 10%, which is mainly due to its difficulties in the promotion and application of offset printing and narrow-width rotary flexo printing. According to data analysis provided by Pira, a British packaging consulting company, in the area of ​​European packaging printing, UV/EB inks account for about 65% of the total offset ink sales, which is equivalent to about half of the total UV/EB ink sales in the entire packaging field.

For uV flexo inks, 80% 90% are used for packaging printing, the vast majority of which is used for label printing. In the printing process of gravure printing, digital printing, and screen printing, the application of UV/EB ink is not satisfactory and the market share is relatively low. However, with the continuous breakthrough of new technologies, especially the improvement of ink adhesion, uV/EB inks have also begun to develop steadily in areas where the original amount was not so impressive.

Reproduced from: Fine Chemical Materials and Intermediates