The Evolution of UV
UV technology has morphed the arena for wide-format graphics. The combination of UV lamps, UV-curable inks, and UV-enabled printers has given print providers quick curing capabilities, low-VOCs, and a stepped-up quality level.
Then, along came LED-UV, and the technology took another giant step forward — allowing shops to print on more flexible substrates to give them a nearly inexhaustible array of output options. Not to take anything away from other print technologies, but UV and LED-UV are the current kings of the UV mountaintop.
But what’s next for UV? Has the technology already peaked, or is there another summit for it to conquer?
First came mercury vapor lamps (aka “standard UV”), which became an output mainstay as far as wide-format print providers were concerned. Because of the speed and depth of cure of standard UV machines, users could overlook the downsides, which included the time it took to warm up/cool down, generation of heat, and, thus, their limitation on some substrates (particularly thin ones), as well as the presence of a heavy metal (mercury).
When LED-UV arrived on the scene, however, many of these downsides were swept away.
“With developments in inks with UV curing, LED has become the de facto standard in UV, because of its substrate diversity and the broad color gamut it offers,” says Dan Johansen, marketing manager, commercial printing business, Ricoh.
“Most wide-format printers can now print on anything these days, with the exception of some unique substrates,” Johansen continues. “UV is the dominant technology for a reason — it offers virtually unlimited substrate capability. Unless you’re a boutique PSP, most shops have a need for a broad range of capabilities, and LED-UV has become the swiss army knife of print technologies.”
There are multiple reasons for standard UV users to migrate to LED, says Jay Roberts, product manager, UV printers, with Roland DGA. “Yes, it’s costlier, but that’s coming down, and LED offers a longer lamp-life expectancy, lower wattage — so it’s greener — plus it’s easier to handle and results in smaller units. Most [of our] customers now desire LED over mercury vapor.”
And UV isn’t standing still. UV ink manufacturers are continually developing new formulations “to enable better color gamut, chemical resistance, hardness, fingerprint resistance and finish — from glossy to matte and in between,” says Randy Paar, marketing manager, display graphics, Canon Solutions America. “This has increased the range of applications where UV inks can make a difference — there’s been a progression of the technology.”
UV inks are indeed continually evolving, agrees Deborah Hutcheson, director of marketing, Agfa Graphics.
“General-purpose inks now provide expanded gamut with improved adhesion for difficult substrates with low odor,” she says. “Inks that achieve GreenGuard Gold certification are opening the door for new applications in previously restricted indoor environments where air quality is a concern — such as schools and health care facilities. At Agfa, we’re constantly trying to make better inks for our customers.”
As increasingly more print service providers make the move to LED-UV, they’re discovering all the advantages it has to offer.
“Market demand for applications is becoming wider, while print service providers are increasingly competing for business,” says Volance Carlin, product marketing manager at Mimaki USA. “Being able to supply a larger portion of a customer’s print demand adds value to a PSP’s offering and better secures their customer relationships. [With] that in mind, print producers are looking for a solution to the versatile demand. Producers now not only want to print PVC, but also uncoated paper, fabric, banner, indoor signage, foils, heat-sensitive materials, canvas, wood, aluminum, etc. — and there’s no digital ink other than UV that can print onto such a wide range of substrates.”
In addition, says Carlin, industrial type applications typically have more stringent requirements of ink sets and may have more unique requirements for durability, compatibility, adhesion, chemical resistance and so on: “It’s easier to address or adjust these individual properties with LED-UV than it is with other available ink types.”
UV Brings Substrate Independence
UV has been the prime factor fueling wide-format’s growth, says Johansen. “It’s allowed for shorter runs and more customized work,” he says. “With UV, shops can be substrate-independent. It’s also empowered print buyers — they can find a substrate and be confident that the print shop will be able to print on it. There’s a substrate for everything.”
“In the age of the prime economy, even if a customer wants something slightly different, they still want it in two days,” he continues. “So, having that tool that will likely work the first time out of the gate, even if you haven’t printed on a particular substrate before, is critical. Plus, whether they’re coming from the sign side of the business or the commercial print space, they don’t want to turn away a job.”
Pulling Out the Inkjet Crystal Ball
It should come as no surprise to any print provider that the future bodes well for UV.
“UV ink will continue to evolve,” Hutcheson says, “with more focus on dedicated applications and substrates — for example, highly flexible applications, corrugated media, porous and non-porous media, textiles, etc. Industrial printing is also helping drive the evolution as inkjet heads are integrated directly into the manufacturing of the end product and, as dedicated solutions, are released to support the ever-growing world of interior décor.”
Manufacturers of inks as well as machines will continue to work toward capturing a broader color gamut, while making machines faster, improving inks, and curing lamps, says John Kaufman, senior marketing specialist at Canon Solutions America. “It’s about the entire system,” he stresses. “In formulating inks, changing one component changes everything. It’s a witch’s brew sometimes, and it requires a sophisticated approach.”
“We expect the trend that we’ve seen lately from virtually all manufacturers of development on the LED-UV platform to continue,” Carlin says. “Ink composition will continue to be refined and optimized to better meet user demands.
“We see a great deal of the current demand and development focusing outside of the machine and ink platform and, instead, looking to improve workflow control and optimization,” Carlin continues. “Furthermore, we’re seeing complementary technologies, such as conductive printing, making great strides, and we’re following their development.”
The Electron-Beam Curing Alternative
One advancement that may play a future wide-format role: electron-beam (EB) curing. Used in the web-offset world and flexo for many years, EB is also an energy-cured technology; it runs cool and produces low migration.
“EB has advantages over UV-LED when it comes to ink migration,” Carlin says. “That property lends itself especially well to more regulation-heavy industries, such as food packaging. As a low-migration technology, EB is a strong alternative to UV-LED. Looking at the wide-format market however, EB is not yet optimized for lower volume productions and is not a cost-effective solution. We’re aware of the technology, and monitoring its progress and viability for our product line.”
Although EB may not yet be ready for wide-format prime time, it will become more prevalent, says Roberts. “There will be some interesting possibilities, but the price will have to come down. Some [company] will make it happen, and then the migration to EB will happen — that’s how things progress.”
UV’s advantages hold true across all sizes and types of print shops, Roberts maintains.
“Commercial offset and screen-printing shops migrate easily to production machines because they have the volume and their throughput offsets the cost of a larger machine,” he says. “Another commercial segment might migrate to a smaller printer or roll-to-roll machine, bringing wide-format in-house versus contracting it out. For sign shops and franchises, it’s important to maintain their product offering, holding onto that business. And there are retail and corporate markets that are after customization and products that tabletop models can offer.”
One thing is sure, says Johansen: “The current slate of wide-format UV options empowers PSPs. If you can do more business with the same customers you’re already working with, and do it with the same piece of equipment — because of UV’s ability to handle diverse substrates — your role really opens up because you can make just about anything. UV gives business owners a way to look at the world in a whole different manner.”
A final tip: “If a print provider is looking to get into UV-curable printing, they should first do their homework,” Paar says.
“Test, test, and test some more,” he adds. “Test different applications. Make sure you choose wisely and that the technology’s application mix is going to suit your shop — you don’t want a six-figure buyer’s remorse.”
Related story: LED-UV Expands Applications