Added Gardino: “There is a different ink formulation for LED lamps. But manufacturers of the inks carefully work with lamp manufacturers to make sure the inks properly cure. When the lamps changed, the ink had to change to optimize the results.”
The ability to print on thin materials as a result of UV-LED’s cool operation is perhaps the technology’s greatest benefit. “It allows [providers] to print on heat-sensitive materials,” he said. “In point-of-purchase displays, this allows them to use thinner, lighter weight foam board materials with better results. In retail specialty advertising, they don’t have to be as aware of the material.”
For his part, Mitchell believes the issue is not so much opening new markets. Instead, he said, UV-LED provides an alternative production method that may offer economic, environmental, or productivity benefits.
Considering these advantages provided by UV-LED, and even factoring in the technology’s disadvantages, a logical question arises. Why wasn’t the technology embraced earlier?
The reason is that the general evolution of digital UV curable printing technology is progressing incrementally to ensure quality and dependability, Gardino believes.
“LED was around half a dozen years ago, but...all the major players went into the hot systems due to the known dependability they offered,” he added. “The technology developed a little at a time...Now, we not only have the CMYK color gamut, but we also have a white and clear ink. And we’re going to have a primer, so in the case of a metal or a glass that needs a primer, printers can put that primer down and later apply the ink and clear coat.
“We’re going into the workflow and trying to automate as much as possible. We’re just trying to mimic and improve upon what’s been done in traditional screen printing and PAD printing.”
According to Jack Skidmore, director of sales for Atlanta-based CET Color, a manufacturer of vacuum table flatbed and hybrid roll-to-roll UV printers, shops should weigh all factors before choosing UV-LED printing. The LED lamps provide benefits, he said, but they aren’t for every print operation.
“They are only suited to low-volume, low-production machines due to the lack of curing energy that they provide,” he said. “Currently you will only find them on printers that are using smaller, Epson-based print heads.”
Skidmore asserts UV-LED curing lamps tend to be found on lower cost printers, which open up print technology to smaller print companies that can only afford less costly machines. “A guy looking at a hot-lamp printer will, these days, always investigate the UV-LED, because it’s more affordable,” he said.
“But he will also find that the lower print speed of the UV-LED technology makes it very difficult to produce any volume, and thus have any sort of reasonable amount of return on investment.”
How quickly and completely UV-LED is accepted will depend on a number of variable factors, Gardino said. “One will be print heads. Will they be developed to provide finer and faster printing? At some point the industry will introduce metallic inks for UV-LED. We already have solvent metallic inks, so it’s probably just a matter of time until the industry develops new UV-LED metallic ink.”
Invest Now or Wait?
Now we come to the question of whether print service providers would be wise to invest in UV-LED now, or wait for the next generation to come along.
In answering, Mitchell carefully weighed the downsides of the technology, but gives a thumbs up. “The limitation of UV-LED today is printing speed, as LED curing systems tend to be slower compared to mercury halide UV curing technology,” he said. “UV-LED inks are also more costly than traditional UV inks due to the type and amount of photoinitiators. PSPs should consider investing in this new technology now, particularly if replacing a solvent press.”
As for Gardino, he said shop owners and managers need to keep in mind the opportunities that may be lost if they are not using the new technology to print economically with low power consumption UV-LED printers on heat-sensitive material. “I don’t think there will be a significant drop in prices on these machines, because when you introduce new technology, prices do tend to hang in there for a while. Especially if you’re one of few doing it.”