UV or UV LED? That is the Question

The UV inkjet printing industry has undergone a revolution with the launch of UV-LED lamps. These lamps are designed to provide functional lives that are 10 times longer than UV lamps. They last up to 10,000 hours, and thus offer much lower operational and maintenance costs than their UV counterparts.

The longer life of the UV-LED lamps is but one of myriad factors that must be considered by print service providers contemplating whether to invest in UV or UV-LED technology. That determination will ultimately rest on such issues as the size of the shop, the volume of print, the types of substrates being used, and the owner or manager’s commitment to the environment, among others. In the pages ahead, we look at the differences between UV and UV-LED, why those differences matter, and what factors must be weighed in buying decisions.

Differences Between UV and UV LED

In addition to the long life of UV-LED lamps, UV-LED is different from UV in a number of important ways, reports Steven Tu, product manager for Ivine, CA’s Roland DGA Corporation. “They also emit very little heat, which makes them more versatile with respect to the media they support than conventional UV curing systems,” he says. “Consider also that UV-LED lamps do not need any warm-up time, so they are ready to start printing immediately after being powered on. They are also smaller, more energy efficient, and completely ozone free, making them a safe alternative to conventional UV lamps.”

Many UV-LED printers, including Roland VersaUV printers and printer/ cutters, support a broad array of substrates, including everything from PVC, leather, paper and board stocks, to foils, BOPP, PE, and PET film, Tu says.

When it comes to specialty applications, his company’s most compact UV-LED printers print directly on three-dimensional objects, such as smart phone cases, industrial and consumer products, promotional items and even iPads.

“The ability to print on such a wide range of surfaces allows you to branch out into new markets, from package prototyping and labels to signage, interior décor, personalization and specialty graphics,” Tu reports.

Jeffrey Nelson, business development manager for inkjet solutions with Fujifilm North America Corporation Graphic Systems Division in Hanover Park, IL, says the difference between the two technologies is obvious and comes down to how the ink is cured. “UV-LED uses a low-energy light source, and the lamps are expected to last the life of the press,” he says.

“And because it’s low energy, it is low heat, so it works really well for thinner substrates, which can be very volatile.”

On the other side of the equation, with UV technology the ink is UV cured, rather than LED cured, he says. The chief benefit is speed; the equipment can run much faster using conventional halide lamps. Fujifilm’s Onset S50, for instance, can produce more than 150 5x10-foot boards hourly. “It would be difficult to achieve speeds like that with a UV LED today,” Nelson says.

Another difference shows up in cost. The cost of lamps is lower in UV than in UV-LED, he adds. As that cost differential drops, UV-LED will continue to make inroads in faster presses, even in industrial applications. A final contrast between the two technologies is that UV-LED is a greener solution, due to not requiring as many bulbs to be replaced and lower energy usage, Nelson says.

According to Jim Cain, director of sales digital with Polytype America Corporation in Mahwah, NJ, which limits production to UV machines at present, the big difference is the curing power, as well as the light spectrum given off by the machine. UV machines have broader curing power, he says.

The traditional UV bulb has a broader light spectrum, while UV-LED has a tight and more controlled spectrum. “What that means is more curing power out of the traditional UV, rather than the UV-LED,” he adds. “The UV-LED is almost like a straight line, a more confined space, as opposed to the traditional UV lamp, which has a broader and deeper curing power.”

In addition, LED is an up-and-coming product that unlike UV has yet to be proven in the industry, Cain asserts, noting, “It’s still in its early stages.”

Consider Before Purchasing

According to Tu, the very first considerations to keep in mind are the substrate on which you will print, and the primary applications for the printer. Next, consider the printer’s ease of use, operational costs and maintenance requirements, he says. In addition, Roland DGA recommends that PSPs select a printer that offers advanced features, such as specialty inks and integrated contour cutting, both included in the company’s VersaUV printer line.

These features in particular allow PSPs to automate the production of complex graphics from start to finish, Tu reports. “Find out if the printer comes with bundled RIP software and color management tools such as spot color libraries,” he says. “In the end, there is no substitute for versatility.”

Having a UV-LED printer in your production environment will allow you to increase your profits, take your business in new directions and offer customers countless new products for a better overall value proposition, he adds.

For his part, Nelson says UV or UV-LED buyers should consider several factors before purchasing. One is the price-performance ratio of the equipment. Buyers should determine how fast the equipment will run, and for how much.

But in some classes of printers available today, there is not a UV-LED printer available. “It’s certainly changed fairly dramatically in the last 24 to 36 months, and we anticipate the evolution continuing,” Nelson says.

PSPs should also consider their capacity or production needs. If theirs is a smaller operation, that would lend itself more to UV-LED. Customers looking for an industrial speed press, which would typically be a larger screen or offset printer, would be better suited to UV printers, Nelson advises.

A limited number of companies currently manufacturer and/or market the UV-LED, Cain says. Most manufacturers are still focusing on UV. If the work being done is fine art work calling for substantially less volume, UV-LED may be a better choice. But for traditional print shops, including commercial printers, graphics and reprographics shops, standard UV is the wiser selection, he says.

Cain won’t hesitate a guess as to how soon UV-LED will become more mainstream. “Everybody is experimenting with UV-LED,” he says. “And until they get better curing power, and more speed, and more production volume, it’s not going to come close to overtaking UV.”

The Future of UV?

Among the most enthusiastic champions of UV LED is Stephen J. Metcalf, president and CEO of Air Motion Systems (AMS) Inc. of River Falls, WI. AMS is the leading US-based manufacturer of high-performance UV and LED ink curing systems for the printing industry, and offers a global reach.

The company reports its AMS LED-UV product family, exemplified by its Peak Series, offers high-power LED UV curing in a compact, solid-state device for curing printing inks, coatings, and adhesives. The system offers substantial advantages vis-à-vis mercury lamps and other UV-LED systems.

Those benefits include high intensity, pure, uniform UV energy; ability to operate at up to 80 percent less energy; instant on-off control of the module; no emission of infrared heat; no ozone generation or mercury content; potential for more than 20,000 hours from the light source; solid-state design with no moving parts; and compact DC power, control and cooling. The small, scalable, repeatable module is designed to integrate easily into all OEM equipment.

One big positive of LED devices is fast installation, Metcalf says. The press is down for two or three weeks during installation of conventional systems. With AMS, on the other hand, “these modules drop in to the press,” Metcalf says.

”They’re mobile and can eventually be taken from you current equipment to new equipment. And this goes into presses not designed for UV, it can go into any machine. This trumps anything that’s been seen before.”

At the PRINT 13 Show in Chicago in early September, Metcalf reported that AMS has completed more than 100 installations, and has incorporated its technology into the presses of many manufacturers. “The return on investment is incredible,” he told attendees at a PRINT 13 session called “UV LED Curing Technology for Offset and Flexographic Printing.” “Some of the testimonials we have received so far have [favorably] surprised even us.”

No longer are the providers of LED inks largely Japanese, as they were in 2010; today, ink manufacturers across the rest of the globe provide these inks. That’s among reasons the market forecast for LED keeps curving upward, with demand expected to explode between now and 2020, Metcalf noted.

One reflection of the enthusiasm regarding the technology’s potential is seen in the “Bundle Program” offered by AMS and INX International Ink Co., among the pioneers in offering a new line of high-wavelength products targeted to the growing market for worldwide UV-LED inks. AMX and INX will work with printers to determine the best offering based on the printer’s needs.

Essentially, the Bundled Program allows a qualified printer to pay as little as 50 percent of the purchase cost of the AMS LED system upfront, and convert the remaining balance to monthly installments with an INX supply contract.

AMS and INX International Ink Co. report in a joint announcement: “The Bundled Program both extends terms and increases cash flow for your company, as you and you customers enjoy the tremendous benefits of instant LED drying with fast installation on just about any type of offset press, without tying up your equipment or working capital credit lines.”