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Refining UV Ink

Advancements in hardware, inks, and curing systems are revealing new markets.

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By Peggy Middendorf

* Gandinnovations Jeti 3150UV is a flatbed featuring easy loading/unloading, a strong vacuum, and reporting speeds up to 861 sq ft/hr for printing on corrugated materials.

* MacDermid ColorSpan 9840uv is an industrial-grade, high-speed, UV-curable flatbed printer with pneumatic rollers that hold warped media flat throughout the print zone.

* The L&P Virtu36 and Virtu72, the DuPont Cromaprint 22uv, the NUR Macroprinters Tempo, as well as other UV-cure flatbeds promote their ability to print onto corrugated materials.

* Durst Rhopac, a large-format UV flatbed that's designed specifically for package printers to produce print-on-demand and print low-volume projects profitably; also offers an automated feed-stacker system to increase speed and efficiency.

The ‘Holy Grail’ of single-pass
The ultimate printing experience that makes inkjet print providers drool is single-pass printing, with output measured in linear ft/min. Currently, many inkjet printers require multiple passes to lay down enough ink and hit the required resolution. Single-pass printers, however, are looking to change the lay of the land.

The Inca FastJet is one example of what is on the developmental table. First introduced at Drupa 2004, the FastJet boasted resolutions of 300 dpi and print speeds of 300 linear ft/ min-that’s a football field of print output every minute. Utilizing a stationary or fixed array of printheads, substrates pass under the printheads, ink is deposited along the entire width, and the imaged media moves on to be cured. While the 20.5-in. FastJet, aimed at corrugated business, has not been brought to market, this single-pass printing has laid down the gauntlet in terms of single-pass speed. Also at Drupa, Agfa introduced its one-pass Dotrix, aimed squarely at the industrial print market. The web-fed 4-color press is designed for short and medium-run production, sampling, customized printing, on-press proofing, and variable-data printing. The press is capable of printing 9763 sq ft/hr (linear speed of 79 ft/min) at a resolution of 300 dpi with eight levels of gray, resulting in an apparent resolution of 900 dpi. Recently, the Dotrix has gone modular, offering additional preprinting stations for coating or printing white and post-printing modules that can be added-on include varnishing, slitting, die-cutting, and finishing.

Aellora Digital’s print engines all operate as single-pass printers. Utilizing the company’s semi-solid inks, the 39 x 39-in. SureFire TKMP1000 Digital Printing System offers print speeds up to 250 sq ft/hr in 600 x 600-dpi production mode.

Durst has developed a high-speed one-pass printer that can pass muster with tile producers in terms of speed-and still survive in the harsh environment that is tile production. The Gamma 60 is the first to use the company’s new Synchronized Inline Printing System (SIPS), comprising four full-width fixed CMYK printhead modules matched with a belt transport system whose speed is "synchronized" with the overall tile production workflow. Not only does the Gamma 60 offer a top speed of 13,800 sq ft/hr, but it can also print variable decoration onto the tiles at the same time.

A bright future
What’s holding UV back? A few factors, including: hardware cost vs. solvent, cost of finished graphic vs. solvent, image quality, and gloss surface/dot gain issues, as well as a search for improvements in color gamut and resistance to scratching and abrasions. OEMs and suppliers, however, are busily working on products designed to solve these challenges. Coming attractions for UV-curable printing include:

* Third-party inks are slowly making their way to market. As indicated earlier, Triangle Digital and Sun Chemical offer UVcurable inks matched to specific printers, and Hexion recently introduced its new HexiJet FlashCure inkjet ink, marketed to OEMs. This ink requires a low dose of UV light to "pin" the ink- freeze the ink drop on the substrate; the ink is then fully cured with a lower-than-normal energy source (mercury lamp). Curing at lower energy doses means thinner materials can be used without the fear of warping; it also means that these inks can be pinned at high print speeds.

* Prices of UV-curable machines are slowly but surely coming down, although the cost of a low-end UV-cure system is still higher than a comparable solvent inkjet. The general feeling in the marketplace is that prices on these machines need to decrease to make them available to a wider group of customers.

* As with other print technologies, variable-data printing with UV-cure flatbeds is now in demand. Software must allow a job to be RIP’d once, but with the capability to incorporate personalization on-the-fly. Many users are utilizing their flatbed and rollfed UV-curable machines for smaller, nested jobs, we’re

told, and the ability to incorporate true variable data will likely become more important.

Peggy Middendorf is the managing editor of The Big Picture.