UV LED Curing
Ultraviolet (UV) curing has been historically dominated by the medium pressure mercury arc (Hg) lamp. This technology is now being gradually supplanted by LED (light emitting diode) semiconductor technology designed to produce usable UV curing radiation.
These devices are similar to the LED lightbulbs that are transitioning the lighting product market. Main benefits include much lower energy consumption (as much as 70% less than conventional Hg lamps), instant on-off, and very long service life.
All are benefits when compared to Hg lamps. Additionally, ozone is not generated at start-up as with Hg lamps, and the contamination potential of mercury is no longer present.
Unlike the Hg lamp which produces a useful curing broad UV spectrum from 315nm to 400nm, a given LED lamp produces UV light in a very narrow band around a peak wavelength, i.e. 385nm, 395nm, 405nm. Therefore, it is more important to have specially formulated, highly sensitive, UV inks and coatings.
Limitations of Hg lamps have driven the development of low-energy UV curing. H-UV curing utilizes a halide doped lamp with unique wavelength peaks, between 305nm & 405nm. Curing relies on highly sensitive UV inks and coatings that use specially developed photoinitiators.
H-UV printing operates at a reduced cost, ozone free requiring no evacuation, with low heat generation as a result of eliminating lamp IR emissions.
In a typical sheetfed application, one H-UV lamp replaces two Hg lamps. Greater productivity has been demonstrated with faster make-ready and plate changes, lower maintenance, fewer waste sheets, faster running speeds with more sheets per hour printed, and higher efficiency overall.
While inks and coating cost more, efficiency and productivity gains have been shown to offset these higher costs by producing more than 50% in savings.
Additionally, it has been shown that there is no change in gloss or color after curing with a resultant higher gloss when in-line UV printing and UV coating. The H-UV lamp also runs cooler requiring less lamp module cooling, reducing power requirements with costs lower than that of conventional Hg lamps. Running cooler, heat sensitive substrates may be processed effectively. Information courtesy Komori, Inc.
H-UV LED curing
Based on the demonstrated commercialized benefits of H-UV curing, the development of an H-UV LED lamp version is at hand. This brings on the benefits of LED technology, instant on-off, extremely long service life, and a further reduction in power consumption.
As with H-UV curing, specialized highly sensitive UV inks and coatings are required. Lower heat generation further widens the window to process very heat sensitive substrates.
The Cork Advantage
As these new technologies emerge, your inks and coatings will require higher performance standards and this is Cork Industries’ specialty. We are a team of Chemists, Print Managers, and Coatings Experts. We are Custom Formulators. We can custom tailor a solution for your coating needs, based on your requirements and equipment.