What's New in Coating?

Many firms, including direct mail printer Fenske Media Corp., Rapid City, SD, are using pretreated glossy paper to expand their substrate options. One stock the Fenskes run is NewPage TrueJet, another recently released coated papers designed for high-speed inkjet output. As previously reported by MyPrintResource.com (www.myprintresource.com/article/10597806/digital-print-visionaries), Fenske Media soon will add Kodak’s pretreatment module, branded the Inline Optimization Station (IOS), to its Prosper 5000XL color inkjet web press. The system is built around a roll coating technology that uses water-based pretreatment fluids containing adhesion-promoting additives customized to specific paper stocks with different chemistries, viscosities, and coat weights. Pretreatment can be applied to a variety of surfaces, including coated or uncoated, matte, silk, or glossy. Presently on order, when the IOS arrives it will “give Fenske the flexibility to run a broader range of stocks, particularly some additional coated ones that they would like use,” noted Jim Hamilton of InfoTrends. In addition, the Fenske brothers are tweaking an offline/near-line UV coater originally installed last May.

UV-LED matures

“In the LED [light-emitting diode] world, a lot of the lessons are coming from digital,” AMS’s Metcalf continued, “just like coating [technologies] from offset are coming to digital.” There’s a lot of give and take: from UV coatings and inks (see sidebar) to the application of light sources, such as LED, which Metcalf said is the number-one new technology at his firm over the past several years. “We had a breakthrough year in 2011,” he noted, citing several patent-pending new products. “LED is at the forefront of competitive [print] technologies,” he added. “It’s quite bold.” (More on that later.)

While there was some light buzz about UV-LED fledgling technology at drupa four years ago, visitors to the Dusseldorf fairgrounds this year can expect some major noise in the form of energy-efficient light waves. UV-LED curing pretty much began with digital printing and narrow-web inkjet at Drupa 08, Metcalf acknowledged. “But now the power and intensity is high enough,” he said, “so I’m really excited for Drupa 2012.” Traditional UV curing systems market leaders, such as AMS, Baldwin Technology, Eltosch/Dr. Honle, Grafix USA, IST Metz, Nordson, and PRI Technologies, have adopted UV LED lamps, which do not use conventional mercury gas. And LED’s reach extends well beyond the printing industry.

According to the Reportlinker search engine, UV-LED business is expected to grow from $25 million to more than $100 million in 2016 at a growth rate of more than 30 percent.

More than 90 percent of the UV-LED market (outside of R&D) is covered by UV curing, counterfeit detection, medical, and instrumentation applications requiring UV A/B sources. UVA (400 nm to 315 nm light wavelength) business is currently the main UV-LED market and will remain so for at least the next five years, thanks to a boom in UV curing. Other key UVA applications are document/banknote verification and photocatalyst air purifiers. (See factoid, below.)

The most dynamic and important UVA lamp market is clearly the UV curing business, where UV-LED competes with traditional mercury lamps. The size of the market is large: $120 million with growth of about 10 percent. Also, the power output available doubled between 2009 and 2011, reaching 16 W/cm2, and the emission source width is now up to 2 m, comparable to mercury lamp performance.

Litho Overprinting on Digital

Last July, ink supplier Kustom Group (Richwood, KY) introduced coating and overprint chemistries for digital printing. All too often the industry has focused on UV coatings as the product of choice to protect digital printouts, said Kustom, but there are other options that can satisfy the needs for many print jobs. For most printers today who have both sheetfed offset and digital press equipment on their shop floors, the use of a conventional litho press is not often considered—yet it can be used. Purchasing new UV coating equipment and learning about UV may not be necessary, depending on the application.

Kentucky Shine (KS-190 OPV) is a water-based overprint that has all the properties of a typical aqueous coating when applied over digital printing. It is easily applied by a dry offset process through the ink unit of any offset press. Matte, satin, and soft-feel finishes are available. Meanwhile, Lithomaster Gloss (KB-3164 OPV) allows the printer to pattern-apply oil-based overprint to protect digital print. In addition, the inline combination of Lithomaster Strike-Thru overprint varnish with a Kentucky Shine gloss overprint on any multicolor litho press enables further enhancement of the printed piece. This Strike-Thru process can be used to achieve a matte and gloss combination in one pass. Reticulation finishes also are available.

Making Offset Print “Pop”

So-called hybrid printing presses – often an offset press with a flexo unit for varnishing – are nothing new. Sheetfed printers have been adopting flexo chamber coaters for instant-cure ultraviolet (UV) printing for several years, starting out doing flood coats (full pages) then migrating to the ability to achieve intricate spot-varnish applications.