By Cassandra Balentine
High-speed production inkjet is a fast-growing segment within the graphic arts. While print technologies continue to emerge and advance, ancillary solutions, such as finishing and media, also evolve to propel growth.
“As the inkjet market continues to grow, investments target the highest volume applications, and where there is the greatest demand,” say Deana Conyard, worldwide marketing manager, high-end inkjet, and Beth Barrese, media manager, inkjet line of business, Xerox Corporation. “Customers are looking for inexpensive media that deliver high levels of image quality,” they add.
The paper industry is quick to respond and the evolution of paper per print technology is similar. “The industry has developed specific grades for offset—hot and cold, flexographic, rotogravure, electrophotographic (EP)—solid and liquid, and now inkjet. It is just another phase in a long history of paper technology,” says Jennifer Pennington, paper scientist, Eastman Kodak.
In the past, very specific, non-coated media had to be developed for high-speed production inkjet devices due to their limited ability to handle highly coated or thick papers. “Many printers had to actually use inkjet-only paper,” says Mike Herold, director of continuous feed inkjet technologies, Ricoh. He adds that high-speed inkjet has progressed considerably with press manufacturers working alongside customers to add new ink options, color management software, and hardware—like extending dryers and climate controls for faster ink drying on highly coated paper. “There is less emphasis on developing media specifically for inkjet or toner/EP, and more on developing media best suited for the job,” he notes.
Opportunity and Challenges
The potential for inkjet is huge, and the challenges in media development are real—but advancing.
“The expected growth in the continuous-feed market has the attention of the paper mills. As they expect the demand to increase substantially, mills are looking to capture business early and become a paper of choice,” says Mark Schlimme, director of marketing, Americas, Screen USA.
Judd Quimby, VP of business development, Memjet, points out that inkjet offers many advantages because the media does not have to be heated to fuse correctly. “Inkjet printing is considered more flexible and can be used for a wider number of applications,” he says.
From a development perspective, Pennington suggests that production inkjet has immediate volume opportunity in terms of paper. “There were many lean years for toner/EP paper, especially liquid EP, since the speeds and duty cycles were so low. Inkjet printing is very different from EP. The technical challenges for inkjet relate to fiber and water coating interactions along with evaporation or drying at high speed,” she explains. “For most toner systems, one is melting a plastic particle to the paper surface. Paper for EP requires properties for thermal adhesion and for inkjet it’s chemical, physical, and thermal paper properties.”
In the infancy of high-speed production inkjet, Herold admits paper options were limited and usually consisted of untreated or uncoated papers. “Coated papers have always been challenging because aqueous or water-based inks are not able to pass through the coating and then be absorbed into the paper. Although inkjet volumes have grown consistency since 2007, the rate of growth has been limited by paper challenges and other factors,” he adds.
Pennington points to three main challenges facing paper manufacturers for production inkjet systems—economy of scale, the need for lower total costs for inkjet treated papers, and the need for new technology for coated papers.
The desire to have a one-size-fits-all approach for inkjet treated papers caters to paper’s larger manufacturing fixed assets, but production inkjet is relatively small and split by ink type and market application, says Pennington. “There are about ten different production inkjet systems in the market. A paper designed for all ten may be economical, but it will be suboptimal in every case. This will inhibit growth and the ability to achieve sustainable economy of scale.”
In terms of the need for lower costs for inkjet treated papers, she says given that production inkjet is a largely web-based market with better demand management capability than cutsheet segments, the paper industry still retains costly merchant channels and related inventories. “Production inkjet customers don’t want 80 SKUs of paper availability as expected by a sheet-fed culture. Production inkjet can offer a watershed moment to develop a simple, low total cost, high-quality business model for paper.”
Finally, Pennington says inkjet requires a controlled absorption into the coating surface for best image quality and durability. “This is a challenge for highly calendared gloss coatings and is a focus from paper coating component suppliers,” she offers.
Conyard and Barrese note that challenges include developing coated products with the right chemistry to balance performance characteristics—such as drying and durability—which generally use expensive materials. “It’s important for the paper to absorb water, but also dry well so that the ink colorant stays at the surface for good optical density, but yet is durable enough for finishing operations downstream,” they explain.
It is important that media manufacturers are closely aligned with inkjet equipment manufacturers to ensure the combination of media, inkjet-imaging technology, and inkjet inks are better synchronized to yield the optimum print quality. Herold says that in the past, by not doing this, there was a potential for creating greater issues with customers.
While there is opportunity that mills are looking to capitalize on, Schlimme also points out that many end users find specific standard offset stocks suitable. “The need for new stocks is much greater with coated and glossy, where past substrates may fail due to the hydrophobic nature of the coating,” he adds.
Bruce Richardson, national sales manager, web presses, and Oliver Baar, head of division business development marketing and digital web presses, KBA, note that the printing process between offset and digital inkjet is fundamentally different, leading to the need for further development for suitable stocks. “High-speed inkjet systems transfer more fluid onto the paper surface than the offset process. Therefore, the inkjet media has to handle the higher amount of fluid. On the other hand, the media has to keep the colorants close to the surface. Apart from that, the media must generate a smooth output without allowing an inter-color bleed. In addition to this, the cost/performance relationship has to be kept in close focus because even if the paper works brilliantly yet costs a fortune, the success will be limited.”
“In the end, for high-speed production inkjet, it really comes down to market opportunity. When continuous feed drop-on-demand printing was just getting started, it was a small market for the paper producers—when considering other digital and traditional printing technologies. In about eight years, this has changed dramatically,” says Herold. “With the rapid growth resulting from more advanced printers and new inks and paper reformulations, customers have greater choice and we will see this technology adopted by more customers, which means this market will rival and surpass other digital markets in size.”
The industry has come a long way in only a few short years. Herold says the introduction of drying features that handle more challenging coating papers, the design of papers developed for specific ink types, and further development of dye- and pigment-based ink have improved media performance with high-speed inkjet.
John Crumbaugh, marketing executive, ink and media production print solutions, Canon Solutions America, points out that inkjet printing requires a complete end-to-end solution including hardware, inks, paper, and finishing options all working together. “One part of this solution—the paper transport—is key to being able to print on a variety of papers, from very light directory to heavy reply card.”
He says its line of inkjet presses has strong transports for both continuous, and now cutsheet presses. “As a result, printing on a range of paper is not a challenge for our customers. Our equipment features a unique drying capacity that provides enough heat to gain the desired result without damaging the quality of the paper. The equipment is gentle with the paper, which results in the highest quality of finished products across a wide range of paper types and weights. Ensuring that the printed paper is in good shape as it leaves the press is important, as in most cases there are additional finishing steps required to produce the final printed piece,” he says.
Canon Solutions America offers both pigment and dye ink sets along with specialty inks such as MICR and invisible ink. Presses can be converted to run either type of ink.
For uncoated papers, Hewlett-Packard (HP) offers an on-press solution that allows its customers to print on uncoated offset paper. The solution applies an HP Bonding Agent to the paper only where ink is adhered. “This gives customers the greatest flexibility since they can take whatever they have in their warehouse and print on it,” says Dr. Ross R. Allen, senior technical specialist, HP Printing Technology Platforms.
HP Inkjet Web Presses feature in-press application of the HP Bonding Agent by inkjet printheads and inline or nearline application of HP Priming Agent by a flood coater. “Both agents allow water-based HP Pigment inks to produce high-quality productivity on papers that were originally developed to work with the properties of lithographic inks. HP Bonding and Priming Agents modify the paper surface to work with aqueous inks. One key feature is that they immediately immobilize ink pigments to control dot gain and feathering. This allows HP Inkjet Web Presses to use a wider range of papers,” says Allen.
In addition, the company has worked with paper companies to manufacture optimized uncoated papers for HP Inkjet Web Presses as an alternative to using the HP Bonding Agent. “These papers are sold by the paper companies and carry the ColorPRO brand,” he offers.
Richardson and Baar say that based on collaborative tests with major suppliers, KBA is able to deliver feedback to them on how their substrates perform in the RotaJET high-volume inkjet press. “KBA prefers an open partnership with different media suppliers; we don’t concentrate on one single media partner. We are convinced that this strategy helps the entire industry understand high-volume inkjet printing paper.”
The company’s RotaColor and pre-coating features are designed to help keep inkjet pigment on the surface of the media, enhancing brightness, density, and print quality. “A dryer technology that we also use helps in setting and curing the ink,” say Richardson and Baar.
They note that the pre-coating is a cost-effective possibility for achieving superior print quality based on a paper providing a beneficial cost/performance ratio. “The pre-coating is transferred via a simple float coater system, the cost per sheet is 100 percent clearly defined, and neither image or ink coverage influences the cost of the pre-coating. In addition, the pre-coating will not change paper surface or color,” they add.
Kodak offers its inline Optimizing Station for the Prosper 5000 systems. “This is a roll coating device that applies pretreatment to the paper,” explains Pennington. “We recently launched this system for offline coating based on feedback from the market. It allows the printer to buy standard offset papers and make them inkjet capable. The savings can be significant and this has somewhat contributed to more paper development at lower prices,” she comments.
The Kodak Prosper Press 6000 features registration technology that adjusts in real time at press speed for physical changes to the paper between color print stations. “Some papers can change significantly, which is perhaps obvious when you consider how much water is applied and drying energy is used for high-coverage printing. Our best paper partners are modifying their papers to improve dimensional stability,” says Pennington.
Prosper Presses and Prosper S-Series printheads print at high speeds, some running at 3,000 feet per minute (fpm). “The speed advantage of a Prosper Press, whether for books or transactional printing, requires physical improvements to paper in areas such as improved co-efficient of friction; reduced dusting; and better cutting, sheeting, and perforating downstream of printing. Not all papers perform the same in these finishing requirements and knowledgeable paper makers have adapted these speed-related performance requirements,” says Pennington.
High-speed inkjet presses powered by Memjet technology benefit from its small drop size—1.1 to 1.2 picoliter, which allow for quick drying at fast speeds. Memjet provides the ability to print at speeds of up to 375 fpm.
Ricoh offers an extended media dryer on its InfoPrint 5000 and RICOH Pro VC60000. “At Ricoh, we continue to innovate and have added drying capacity to handle more challenging applications. When we added the Extended Media Dryer option to the InfoPrint 5000 printers, users were able to use more specialty papers that are heavy, light treated, or coated, allowing for the use of less expensive paper with the added benefits of enhanced color vibrancy and accuracy, as well as larger images with high coverage,” says Herold.
This feature also works with printers using pigment or dye inks, so Ricoh’s customers are able to diversify offerings to meet a range of requirements. “With Ricoh’s digital front end and color management tools, including the Ink Savvy tool, users can achieve better ink optimization and support for a larger variety of coated papers.”
This past year, the company introduced the Ricoh Pro VC60000 production inkjet system, which Herold says addresses an unmet need in the market, requiring excellent print quality on a variety of papers, including offset coated papers. “The system comes with an optional undercoating feature that allows the undercoat to bond to the paper and control dot gain and beading, enabling the use of any paper, even those diagnosed for offset printing,” he explains.
The Ricoh Pro VC60000 also features climate controls to address the varying needs of different papers and the optional extended dryer enables even quicker drying of jobs.
Screen’s newest high-speed inkjet printer, the 520 HD, has 42 different features specifically implemented to broaden the spectrum of the different media it can print upon with exceptional quality.
Xerox Impika HD ink formulations and CiPress waterless inks are both optimized to perform with high quality and optical density on plain media, which Conyard and Barrese explain allows compatibility with other printing technologies and thus minimizes the need for media advancements. “This is unique as pretreatments, primers, bonding agents, or special coatings are not required to achieve high-levels of image quality,” they say.
Canon Solutions America evaluates a range of papers from various paper mills to determine how the paper transports and prints on its equipment. “Perhaps more importantly, we evaluate how the paper prints at various press settings, allowing us to test the physical properties of the paper,” says Crumbaugh.
The company works closely with its paper partners to re-evaluate papers in order to maintain a current and accurate list for customers. The media list is available to all production print solutions customers and contains hundreds of evaluated papers. “This approach is centered on providing our customers with the largest choice of paper in the industry across a range of papers from both domestic and offshore mills,” he adds.
The company also recently created the Canon Solutions America Media and Solutions Lab where they work with paper mills to determine which papers are the most critical for the current market conditions and then work alongside each other to test new developments on the equipment to develop real-time examples of how they can re-invent the printing process.
“The Media and Solutions Lab is a true collaborative process between Boca Raton FL; Poing, Germany; and Venlo, Netherlands, where Canon and our customers work together to review new papers to determine what is the best case for each individual customer,” says Crumbaugh.
The company currently works with over 30 paper mills—both domestic and international—to enable new opportunities for customers.
HP’s initial approach was to work with a select group of paper companies to help them manufacture papers optimized for the HP Inkjet Web Presses. “These are the ColorPRO branded papers,” says Allen. “The next step is to set up a certification program for uncoated and coated papers,” he says.
To participate, paper companies send HP a roll of paper, which it uses to print a standard set of prints, evaluate, and score the paper based on different perimeters. “These papers can be offset or inkjet optimized papers. We use HP Bonding Agent to print on the uncoated papers and also use Bonding Agent on offset coated papers that do not have a completely closed surface. We have not yet started certifying papers treated with the HP Priming Agent,” says Allen.
There are currently more than 125 ColorPRO papers and over 125 papers certified for use on HP Inkjet Web Presses.
While KBA does not have an official media certification program, Richardson and Baar note that the company provides experience gathered over time, and is happy to share this information with its prospects and clients. “Apart from that, we work closely with major suppliers, perform intense tests with their media substrates, and provide in-depth feedback to them. The paper suppliers are generally knowledgeable in recommending a suitable substrate or media product for the type of digital press a printer is using.”
Pennington says Kodak pioneered the development of inkjet treated papers with select paper companies almost 40 years ago. “Our inkjet technology was developed by paper scientists at what was then Mead Paper. Since that time, we have built relationships with paper companies worldwide and today have active relationships with more than 40 mills,” she offers.
Kodak’s database of paper development has over 7,500 tests completed. “For the Prosper Press, we launched our first Paper Rating Program, which provides customers with specific, quantified attributes for image quality. Prior to this, other programs simply had pass/fail results to support a royalty scheme,” she says.
Pennington clarifies that its rating program measures paper attributes at press speeds, and not bench testing. “We provide data under NDA that gives our customers a direct comparison between paper made by different vendors. This helps them select the most appropriate paper for quality expectations and cost, and creates a competitive advantage in the industry,” she explains.
Kodak measures paper on five criteria and set thresholds for five quality levels. These thresholds are reported as Diamond Level and are established for market sustainability. “Not everything needs to be a five Diamond paper, in some applications, a three Diamond paper is appropriate. Today, we have over 300 paper SKUs that have been Diamond rated,” says Pennington.
Herold says Ricoh has an extensive paper testing process. Since the initial launch of the InfoPrint 50000, thousands of papers have been tested in its labs in Boulder, CO. “We have worked side by side with our customers to identify the right papers for them based on a balance of quality, cost, and continuity of supply. Each paper that a customer would like to use is put through a rigorous multi-step process that evaluates water fastness, light fastness, stiffness, smoothness, porosity, color gamut, and other factors as well. If our scientists are not satisfied with the result, we will work with the customer to identify another paper,” he adds.
Quimby says Memjet has initiated a media certification process where they provide specifications to OEMs, media converters, and manufacturers.
Xerox evaluates media for compatibility with its Impika and CiPress inkjet lines. Conyard and Barrese say it generally starts with a screening test on individual sheets and if successful, roll-based testing will be completed. “Successful media are published on a tested media list available via our production inkjet sale specialists,” they note.
More than 100 media types, at multiple base weights, are validated for Xerox Production Inkjet Systems.
As the adoption of high-speed inkjet continues, paper mills are paying attention. Together, press and media manufacturers work to create optimal media options for every application.
Read more on the topic online, as we address the nuances of pigment- versus dye-based inks and their affect on media.
Additionally, following this article, we feature our annual digital substrate guide, which provides a quick look at media options available today. dps
Jul2015, DPS Magazine