Just a few years ago, UV LED curing technology was not a viable solution for most package printers and converters. Though the technology was purported to offer several benefits, including increased uptime, the ability to cure dense colors and substantial energy savings, LED compatible ink had not yet broken onto the scene.
Now that LED ink availability is of minimal concern, more converters are looking into adding this breakthrough curing method. But before switching out traditional UV arc lamps for LED, converters should be aware of exactly what to expect when making the change, and whether LED is right for them.
One of the biggest detractors to traditional UV curing is that the moment an arc lamp is switched on for the first time, its output immediately begins to degrade. LED on the other hand, provides a consistent output over many years of operation.
Similarly, with traditional UV lamps, there is a waiting period for the lamps to reach full strength once they are turned on. LED technology is at full power the second the switch is flipped.
“[LED] doesn’t have a warm-up period,” Sara Jennings, senior technical marketing engineer for Phoseon, says. “An operator, if they’re working with traditional UV, will start up the press in the morning and then go get their coffee while all the arc lamps warm up. There is none of that with an LED system. It is immediately ready to use.”
Because of the instant on and off capabilities of LED lamps, converters installing this technology are seeing substantial energy savings after making the switch, as energy isn’t wasted as UV lamps sit in an idle state.
From a quality standpoint, there are areas where LED shines over traditional UV. One area in particular, Jennings says, is in the curing capabilities LED has for dense black and opaque white areas in a print job.
“For the very dense blacks and opaque whites, including rotary screen first down white, the longer wavelength of the LED system is better at penetrating those colors and provides a better quality of cure,” Jennings says.
Plus, LED curing does not generate heat in the same way traditional UV lamps do, which can be beneficial when running thin substrates.
Once the decision is made to make the LED change, a converter is generally faced with three options. He or she can either completely retrofit an existing press with LED curing, only changeover part of the press to LED or opt for a new LED-outfitted press altogether.
Jennings explains that when a converter opts for a retrofit, the air dryers or traditional UV cassettes can be removed along with the air exhaust manifold and be replaced by the LED light source. The converter will also receive a new user interface touchscreen to be mounted on the press.
If a customer is not ready to commit to a full retrofit, Jennings says Phoseon can install LED in some portions of the press, also leaving the traditional UV system intact to serve as a comfort or failsafe for a converter who is accustomed to that technology.Tags: Flint Group Narrow Web | Packaging Impressions Magazine
Categories: Inks | Printing, Flexo