Continuous-Feed Inkjet Grades: The Paper Chase for Inkjet

Paper manufacturers 
have adopted several strategies to optimize coated and uncoated stocks for running on the emerging array of high-speed, 
continuous-feed, color inkjet presses. While some papers may need to be fine-tuned to run on individual brands of presses, an additional surface treatment may also be required with certain paper/press combinations, especially coated stocks.

Optimizing the Press

According to Steven Vallario, 
director of marketing for digital imaging at Mitsubishi Imaging (MPM), some inkjet media grades that Mitsubishi offers will work well on any high-speed inkjet press, but specialized applications and inks often require specific grades to optimize the capabilities of the equipment.

For example, Mitsubishi treats its coated inkjet papers with a special ink-receptive coating so that the ink is unable to penetrate the cellulose layer—allowing users to print images with sharp colors. While the certification of media is not normally required in the industrial inkjet segment, Vallario says Mitsubishi works closely with inkjet press manufacturers to test its paper on their devices.

Appleton Coated, in conjunction with Hewlett-Packard, has developed Utopia Inkjet and Utopia Book Inkjet coated papers for use with the HP T300 color inkjet web press and other HP T-series web presses. Utopia Inkjet coated products are designed to work without additional surface treatment (e.g. bonding agent) applied at the press.

"Our goal at Appleton Coated is to provide one product that performs well on multiple inkjet platforms. But, given the differences in press design and ink characteristics, our product may perform better on some presses than others," reports Ann Whalen, senior vice president of marketing/customer services for Appleton Coated.

NewPage Corp. is currently working with OEMs on the development of coated inkjet papers for the high-speed, continuous-feed inkjet market. According to Dennis Essary, director of digital papers, the company will produce coated papers that are designed to perform well on the press without treatment.

On the uncoated paper side, Finch Paper's strategy for high-speed inkjet printing is to optimize the benefits of different ink technologies—such as dye-based and pigment—via distinct paper formulations, rather than offering a "one-size fits all" stock.

Finch also offers custom solutions for specific customer needs, such as fine-tuning the paper chemistry to control dot fidelity.

Formulas for Success

Philip Hart, director of product marketing, says Finch inkjet papers do not have to be certified by each press vendor, but Finch Performance Inkjet Papers are qualified at OEMs and undergo trials at customer sites. An additional surface treatment is not needed for these grades, he adds, since they are manufactured with specific 
formulas to maximize ink holdout and drying at high print speeds.

Georgia-Pacific offers two specific lines of uncoated papers for web inkjet presses—one for dye-based and one for pigment-based devices. According to Kelly Ferguson, director of public affairs and communications for Georgia-Pacific, standard paper grades offer better print quality on pigment-based inkjet presses—like the HP T-series and the Kodak Prosper—if a bonding agent is applied, typically on the press.

The manufacturer has also developed Spectrum Web Inkjet with ColorPRO Technology for high-quality printing on pigment-based presses without the use of a separate bonding agent. Stocks that carry the "ColorPRO Technology" designation have met a set of quality specifications defined by HP and verified by the Rochester Institute of Technology's Printing Applications Laboratory.

For dye-based presses such as the Kodak Versamark, Océ JetStream and Screen Truepress, Georgia-Pacific offers Spectrum Web Inkjet DB converting papers to support water-fast monochrome printing applications.

Domtar has engineered specific products that offer fast drying and water fastness properties to perform on the latest generation of continuous-feed inkjet presses. Its products are designed to function in most presses running either dye or pigment inks. Surface treated grades are also available for the presses that perform best with enhanced products.

"We also offer non-treated, super-smooth paper designed for presses that can apply a bonding agent in-line," explains Jan Martin, events, fulfillment and communications manager for Domtar. "But, as the press technology advances further, we hope to provide multi-functional products that are interchangeable between both offset and digital technology. The printing market will demand products that allow for optimal press utilization (regardless of imaging technology), without concern for paper differences."

AbitibiBowater's uncoated grade, Ecopaque Jet paper with ColorPRO Technology, is specifically designed for high-speed continuous inkjet presses, and does not require any additional surface treatment. According to the company, Ecopaque Jet is suitable for any brand of press, and has been tested and approved for HP devices. The paper reportedly has also been tested successfully on Océ JetStream, Kodak Prosper and Screen Truepress Jet presses.

Surface Enhancement

Weyerhaeuser's Newsprint Div., North Pacific Paper (NORPAC), has partnered with Kodak in developing a surface enhancement which, when applied to its uncoated groundwood base stock, will reportedly provide optimal print density, minimal show-through and character fidelity when used on Kodak's Prosper 1000 and 5000 presses. Norbrite Book DIJ, which has been designed for use on the Kodak Prosper, employs a surface treatment.

“We have many customers that want to partner with us and run their own trials on new equipment," notes Beth Cobb, manager of printing and publishing sales for Weyerhaeuser's Newsprint Div. "Customer feedback from these trials is always taken into consideration when determining if we qualify a product to be sold for specific equipment.” PI