Green Printing: Perception vs. Reality and the UV Edge
“In the European narrow web sector, around 90 percent of printers are now using UV – in most cases as an alternative to solvent-based inks,” said Klemens Ehrlitzer, managing director of the German label printers association (VSKE), in an article in Ink World magazine.
UV’s Eco-friendly Steps and Components
The UV drying or curing process with ultraviolet lights results in a very quick polymerization, or cross linking, of the ink. Unlike conventional oil-based inks, UV printing dries instantly, as soon as the sheet passes under the light. At that time it turns from a liquid to solid state. UV inks are not absorbed into the stock or substrate but rather remain on top of the sheet. Therefore, more vibrant print and visual effects result.
Conventional inks not only have to dry via evaporation, but up to 50 percent of the initial ink film applied is lost through evaporation into the atmosphere and absorption into the sheet. Since UV inks cure instantly when exposed to UV light, drying time is eliminated and no solvents are released or absorbed into the substrate, as is common with conventional inks. The UV process releases no VOCs (Volatile Organic Compounds), making it much safer for operators and the environment.
“UV is regarded now as having the same risks as other major processes,” according to Ehrlitzer. “It is no more hazardous than using solvent- or water-based inks. With all these processes, the main requirement is that the printing is done in the right way.”
Other important advantages of UV’s instant drying are faster turnaround times and non-marking or smudging of the image on finishing equipment. The press operator now has the option of backing up the job right away or sending it straight to the bindery when printing is complete. This could save work-in-process floor space.