LED-UV: A Cool Idea for Grand- and Wide-Format Digital Printing

The future has never looked brighter for companies that produce signage and display graphics. It remains a growth market and, as inkjet printing technology advances, the types of applications continue to expand. Not only is it a growth opportunity for traditional sign shops, but it is also attracting significant interest from commercial printers looking to diversify their businesses and new businesses that appreciate the opportunities it offers.

One major advancement in grand-format printing is LED curing of UV inks, which offers a number of advantages over solvents and water-based inks. UV inks require curing via a UV light source, traditionally a mercury arc lamp. The heat generated precipitates a chemical reaction where photo initiators cause the ink components to cross-link into a solid. Since it is instantly dry after curing, printed materials are immediately ready for post-processing - they can be stacked, rolled and finished right after printing.

Why Use LED Curing

The downside of conventional UV curing using mercury vapor lamps is the amount of heat and energy the process requires, as well as the time the mercury lamps require to reach curing temperature. Surprisingly, only a small percentage of the generated heat from mercury lamps is needed to cure the ink, so it’s not an energy-efficient process.

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By contrast, LEDs are extremely energy-efficient. LED lamps reach a maximum of 40° C, whereas mercury lamps heat up to more than 60°. Plus, an LED lamp reaches its curing temperature immediately - there is no wait time for it to heat up, so that means you can begin printing immediately. Also, the curing process is faster when using inks formulated to match the wavelength of LED diodes, due to less dwell time required after the printing process, and that translates to increased throughput.

Expanded Application Set

The advantages of LED curing are pretty clear from a purely energy savings and productivity perspective. But the advantages don’t end there. Because LED curing requires less heat, it opens the possibility to print on a broader range of substrates.

The ability to print on thinner, less expensive substrates opens up new markets, but it allows you to save money as well - for you and you customers - both in material and shipping costs. Styrene, for example, is purchased by weight. With LED curing, it’s possible to print on 0.010˝ styrene, saving you and your customers money.

Printing on delicate surfaces and specialty substrates can be difficult because high heat can be damaging. With LED technology, you can create truly unique and premium-margin applications on unusual surfaces, such as wood veneers, synthetic and specialty papers, rubber mats and plywood.

LED inkjet reduces energy usage in wide- and grand-format imaging, while also expanding the range of media that users can use.

With LED technology, you also can print on laminated corrugated board, for example, with excellent results, and this opens up yet another door to the packaging industry.

There are many advantages of LED curing. While the technology has been available in the market for some time, it is still not as widely adopted as other grand-format printing technologies. That means there is a window of opportunity to gain a competitive advantage by investing in grand-format printers that use LED curing.

You’ll enjoy a competitive market position, better margins and a wider array of innovative applications.

About the Author

Ken Hanulec serves as co-general manager of display graphics operations and VP of marketing for EFI’s Inkjet business unit.