Print 05 Hybrid/UV Ink New Product Analysis (3)

UV Printing Discussion and Research

Many suppliers also provide some training activities related to UV printing. At the Print Media Academy Research Institute, Heidelberg has described UV printing as a topic in their speeches. Techotrans also organized a hybrid UV seminar at their fourth annual conference, where the company invited GATF, Sun Chemicals, Bottcher's experts and two frontline printers. The seminar was presided over by technotrans company's Bill Bonallo. During the conference, everyone discussed the future market trends, the advantages of UV, the comparison of UV and mixed ink printing, all the issues that need to be considered when using UV, the supporting issues of ink roller and how to implement it. A new method of cleaning the ink roller without stopping the machine. Bonallo explained the necessity of adjusting UV lamps, reflectors, thermal management systems and other systems.

Everything starts with polishing equipment

The development of UV hybrid inks is not only reflected in both production equipment and printer manufacturers, not to mention those commercial printing companies that have expanded production scope while increasing production efficiency. The advantages of the mixed UV (and pure UV ink) production equipment are that the substrate can be printed and coated in just one pass, achieving instantaneous drying, high abrasion resistance and high gloss, and environmental protection. And the entire production process does not volatilize VOCs.

According to Mr. Bill Bonallo, manager/CEO of technotrans America/IST, in the aspect of sheetfed printing, the source of our success today dates back to the appearance of the first polishing machine in the mid-1980s. . Although we have used the method of coating to enhance the surface gloss and abrasion resistance of substrates for many years, it was not until the mid-1980s that we started using the in-line coating process without sacrificing a printing press. Apply coating. The appearance of a high-gloss waterborne coating (varnishes) really brought gloss to a single print for the first time. But initially this required a printing unit dedicated to coating varnish, and a few years ago most printing presses had only four units. In addition, there was a deficiency at that time. The drying time of the varnish was very long, and the varnish turned yellow with time.

The pioneers of the packaging industry

Bonallo believes that large-format packaging and printing companies are leading the development of in-line coating (the coating varnish here is not oily bright ink fountain varnish). The requirements of packaging and printing companies for the safety of coating and on-line coating operations that do not require printing units have ultimately contributed to the development of water-based or waterborne gloss oils.

Advocates of early UV technology hope to do their best in two ways: using wet-overprint UV coating on non-UV or traditional ink layers. The results of the experiment are often frustrating. Prints that have just been printed and cured appear shiny and the coated surface feels dry. However, soon afterwards, the surface layer of varnish will be completely peeled off.

The thicker the coating layer is, the more severe it peels off, especially the underlying solid or textured area. Other problems that still exist are the poor adhesion of ink and UV varnish - in some cases the ink under the varnish cannot be dried at all. It is clear that the affinity between UV Varnish and traditional inks is poor.

The emergence of multiple coaters

In order to solve these problems, people are equipped with on-line multiple coating or two coaters. This method is to facilitate the application of a primer ink or sealant on the surface of the conventional ink and to dry it, thus avoiding the direct contact between the ink and the UV varnish.

However, the same problem still exists until people solve the problem of affinity between the ink, the primer material and the UV varnish, which also paves the way for the development of hybrid UV technology. The problem of adhesion between varnish and paint was solved by replacing the oil and solvent components in traditional inks with UV-cured components. The ink that is mixed with traditional pigments, UV linkers and sensitizers in the ink not only retains the performance of traditional inks, but also effectively avoids the problem of poor adhesion of ink and UV varnish.

In accordance with the logic, we can then overlay the waterborne varnish onto the mixed UV ink on the substrate without printing primer ink, and then use a multi-band UV curing system to simultaneously cure the mixed UV and UV varnish on the printing machine. The result is simply beyond imagination: high gloss, good persistence, and low gloss degradation (if attenuation occurs).