By Cassandra Balentine
High-speed production inkjet has come a long way in the past several years. One critical factor driving the speed and quality behind these systems are printheads.
There are two forms of printhead technologies available for the high-speed production print market, continuous and drop on demand. Continuous inkjet printheads steadily produce and fire drops of ink, while drop on demand—whether thermal or piezoelectric—produce drops of ink only when required.
Printhead advancements and other improvements enable the opportunity for more applications for inkjet. This article outlines the latest application targets, noteworthy printhead improvements, and a rundown of printhead advancements as they relate to popular presses.
Evolution of Applications
Production inkjet technologies first targeted transactional applications, but with quality improvements, these devices are utilized for everything from books to direct mail.
“With continuous improvements in the print quality, customers are able to increase the range of supported applications. Production inkjet was originally limited to addressing and salutation, but with the current generation of inkjet, customers are producing high-quality direct mail, marketing collateral, and personalized product catalogs,” says Ed Wong, director, product marketing, Ricoh USA, Inc.
Michael Poulin, director of product marketing, Canon Solutions America, agrees, suggesting that its customers are now able to go after higher quality and more complex applications. “Commercial printers and high-end direct mail customers can now use our products for applications that a short time ago would be unheard of,” he admits.
Chris Echevarria, customer applications manager, and Yale Goldis, worldwide director of marketing and business development, HP PageWide Web Press Division, HP Inc., see a definite evolution happening in production inkjet. They explain that improved technology capabilities, such as machines with higher print quality, allow printers to offer more and higher quality products to customers. For example, a print provider producing books is now able to print higher quality color trade books, high-quality journals, and retail catalogs.
Patti Smith, worldwide senior director, strategy and partnerships, enterprise inkjet systems division, Kodak, also sees an evolution in terms of applications that inkjet has targeted over time. “For roll-fed inkjet production, the initial target was transactional printing. Over the past few years, roll-fed inkjet has moved into publishing markets for books and newspapers. The current trend is moving inkjet devices into the mainstream of commercial print. Further movement is into cutsheet markets in commercial printing. Packaging and labels are also a desirable market given the segment growth driven by increasing population and consumption of consumer goods.”
She adds that inkjet generates interest in the décor market with the promise for print on demand and short runs to reduce costly inventory from both excessive printed substrates and gravure cylinders. “These markets bring more challenges around the variety of substrates required, forcing inkjet manufacturers to develop new inks or pretreatments. Paper manufacturers are also focusing on new substrates that are optimized for inkjet in this market.”
Advances in printhead development enable speed and resolution improvements. Additionally, width expansion and scalability help print providers target more applications.
“Outside of the ever-increasing ink options, the next greatest development is speed and resolution,” shares Poulin, describing the developments printheads have undergone in the past three years. “We utilize three different subsets of printhead technology, depending on the speed of the equipment, even up to the latest and fastest-generating 1,200×1,200 dpi at 525 linear feet per minute (fpm).”
He adds that as product features and options progress, printheads advance along with them. “The speed and ink flexibility allow customers go into new markets and applications while remaining cost competitive.”
Richard Schmachtenberg, SVP, consumables development and manufacturing group, Xerox Corporation, says printheads targeting this space have moved towards higher resolution, higher jetting frequency, and small drop volumes. He suggests that most systems using these printheads have implemented automated maintenance and capping features to improve printhead reliability.
Smith notes that inkjet technology has been expanding into the industrial, publishing, and commercial printing markets over the past several years. “Inkjet printhead manufacturers have been focusing on a number of factors to differentiate their technology. More specifically, most manufacturers are targeting higher drop frequencies to enable higher speed or multiple drops per spot for higher image quality, higher resolutions, smaller drop sizes, compact footprints, lower cost, scalability for width and resolution, and improved printhead life.”
Wong feels the most important development is the availability of page-wide arrays. He says these long, linear printheads enable printing in a higher swath, with all nozzles properly aligned. “Historically, if you wanted to print across 12- or 17-inch paper paths, you’d be using smaller printheads with around 1,000 nozzles each, and you would have to have their orifices stitched together. Using the one long printhead avoids that stitching process and the slight misalignments that can arise from it and helps move into higher speed printing. Those rises in quality and speed can drive revenue,” he offers.
Printheads play a critical role in the capabilities of specific inkjet solutions. Here, we outline differentiating features and recent advancements to leading production inkjet presses and the printheads within them.
Canon Solutions America
Poulin explains that all of the Canon Solutions America production inkjet equipment for both the continuous—including Océ ColorStream, JetStream, and ImageStream products, and cutsheet—the Océ VarioPrint i300, use the same drop on demand piezoelectric printhead technology.
“Our experience shows that these printheads can last many years even in the very high-speed, high-volume products, running upwards of 165 million impressions per month,” says Poulin. Additionally, the company provides flexible maintenance plans.
For the manufacturing of the printheads, Canon Solutions Americas partners with Kyocera for the base printhead array and adds its own device electronics and proprietary software.
“These are robust and versatile printheads. The core technology allows for a range of printing inks and conditioning fluids including ColorGrip, Chromera inks, dye, pigment, MICR, security inks, and invisible inks that only show under UV light,” says Poulin.
Canon Solutions America produces production inkjet systems engineered to “achieve significantly high uptime targets—no matter the volume range,” says Poulin. “Our customers’ volumes range from one to two million per month to upwards of 100 million per month and all enjoy the full service and support capabilities of Canon Solutions America service and professional services teams, allowing our customers to focus on business and not worry about their printing equipment.”
As printhead technology moves forward, Poulin says that Canon Solutions America continues to strive for faster printheads with higher dpi, develop new inks for more applications, and work with partners to develop new substrates.
HP offers drop on demand thermal inkjet technology. “As the premiere vertically integrated manufacturer and integrator of high-speed/high-production thermal inkjet printheads, HP is able to control all aspects of research, design, and manufacturing in order to produce high quality, high productivity, and versatile products—a requirement in high-volume print manufacturing sites,” say Echevarria and Goldis.
They suggest that the quality and speed as determined by the architecture of the actual inkjet nozzles is best described by the thousands of drops produced from HP’s latest printhead technology, with dual drop weight jetted from 2,400 nozzles per inch along the printheads. “Launched as High Definition Nozle Architecture (HDNA), this differentiating nozzle technology offers smooth halftones and fine highlight details in Quality mode for presses equipped with HDNA technology. Presses integrated with HP thermal inkjet technology have up to eight times nozzle redundancy, meaning that up to eight nozzles can address one pixel for more reliable production printing. And the recently announced HP PageWide Web Press T200 HD and T400 HD series printers are upgradable to use this latest technology, saving HP’s customers capital costs over buying new printing equipment,” share Echevarria and Goldis.
HDNA technology, along with press capability improvements and HP’s bonding agent and priming agent solutions are designed to enable customers to print a range of applications on a wide variety of media types from uncoated offset to coated offset, and inkjet treated and inkjet coated papers. Echevarria and Goldis say HP has more than 300 papers in its ColorPRO and Media Certification programs. “Customers benefit from the Quality mode capability to expand into higher quality books and journals. They can print direct mail and commercial print for more demanding customers. Alternatively, they can also print at higher speeds in performance mode to offer customers even faster turnaround times or higher volume print runs. HP’s customers print posters, journals, books, catalogs, magazines, direct mail, commercial print, and newspapers.”
They explain that printheads for production inkjet printers have improved in quality and increased productivity over the past few years. “HP’s HDNA technology allows HP PageWide Web Press T490 HD customers the option to run at higher print quality and Quality mode at up to 500 fpm or to increase their speed in Performance mode from 600 to 1,000 fpm. This is over 500,000 letter-sized pages an hour or up to 25,000 duplex B1 sheets per hour.”
Additionally, HP PageWide Web Press T490 HD customers can print in Quality mode at up to 250 fpm or in Performance mode at up to 500 fpm.
HP offers the same printhead in the HP PageWide Web Press T200 and T400 series presses, which target high-volume and ultra-high-volume segments. “Customers with either or both devices have access to the same printhead and solution capabilities, including nozzle redundancy for reliability, bonding agent and priming agent solutions for media breadth, and color management tools for flexibility and color consistency,” add Echevarria and Goldis.
The Prosper Press 6000 from Kodak incorporates the company’s Stream Continuous Inkjet Technology. Smith says printhead life is approaching 2,000 hours on average. “The replacement cost is dependent on the service agreement. In some cases it is based on hours of print, and in other service models the charge is included with the service agreement.”
Kodak manufactures its Stream inkjet printheads.
Smith believes Kodak’s Stream Continuous Inkjet Printhead offers advantages over drop on demand technology, including drop placement accuracy, ink formulation, drop generation frequency, speed, and quality. “It should be recognized that resolution is not an accurate measure of image quality. Image quality is also determined by drop placement accuracy, the ink formulation, and the chemistries between the ink and the substrate. Kodak is unique in manufacturing the entire system solution, including both the hardware and the ink to optimize image quality. Stream printheads are differentiated in the ability to print quality images at full speed/productivity,” she explains.
Stream technology and Prosper printheads are developed to target graphic communications where image quality and productivity are key market requirements. “Target applications include both publishing and commercial print, specifically books, direct mail, advertising, catalogs, newspapers, and the higher end of transaction/TransPromo,” says Smith. She suggests that Prosper printheads also experience increased penetration into packaging and labels. “Most recently, Stream technology has been qualified into the décor market for laminated flooring, countertops, cabinets, and RTA furniture.”
She adds that Stream technology targets the high end of the market in terms of productivity and print volume where the lifetime value of the writing system is most attractive. “It’s not about the number of units placed in the market—it’s about the amount of ink burned that makes financial sense for inkjet across the value chain.”
Smith points out that production printhead providers focus on improving image quality, increasing speed, expanding substrate range, and providing better economics in order to accelerate the adoption of inkjet and encourage migration from analog across a broader range of applications.
Pitney Bowes partners with HP for its IntelliJet line of drop on demand, thermal inkjet presses. “HP is the only manufacturing printing vendor in this category who designs and produces its own press, paper transport, vision system, dryers, software, ProLiant services, inks, and printheads, ensuring a long-term commitment to future innovation. The Scalable Printing Technology around HP’s thermal inkjet printhead development has benefited from $1.5 billion of investment,” says Kevin Marks, VP, global product management, print, Pitney Bowes.
The company also offers the AcceleJet. The press features drop on demand piezoelectric printhead technology, which are Kyocera KJ4 sourced and OEM integrated by Domino Printing Sciences. The printheads offer a life expectancy of approximately 7,000 hours. The cost of the printheads and the other parts within the device are covered under a service maintenance contract.
According to Marks, the printheads are high-speed, durable, and reliable. “Adopted by several digital printing vendors, these printheads are considered an in-demand technology. Each vendor adapts the core printhead and builds out digital printer/presses. Options on aqueous and UV inks, electronics and software, media transport systems, and media types result in unique capabilities—making versatility a key strength,” he shares.
Running at up to 100 meters per minute, the Kyocera KJ4 printheads address the high-volume sweet spot for transactional print and mail applications.
As a high-volume, roll-to-sheet press, the AcceleJet is aimed at transactional and direct mail segments. “It uses market assumptions that a blend of price/performance and print quality options will ease the path to full-color printing from multiple, high-speed electrophotographic (EP) cutsheet toner printers, which are often dependent on pre-printed forms,” explains Marks.
“By deploying AcceleJet printing and finishing systems, the EP cutsheet toner printer device consolidation requires a printhead, ink, and writing system technology capable of offering the tradeoff between economics and print quality. For certain transactional documents, business color is adequate, but for more demanding use of color in both transactional and direct mail segments, the print quality has to be considered high enough to transition from preprinted forms. It must also include variable data objects—including graphics and images to increase the value of the document. Often, the application set for ultra-high volume presses drives the need for ultra-high performance printheads. Applications for books—mono and color, in addition to near offset quality applications in publishing, require a printhead technology that is scalable for the performance requirement,” he concludes.
Ricoh USA, Inc.
Ricoh’s production inkjet equipment utilizes piezoelectric drop on demand technology. Wong says its printheads are manufactured by Epson and Ricoh and tout a life expectancy of more than 18 months. Replacement costs are dependent on the specific program.
Wong suggests one of its printhead’s greatest advantages is variable drop size, which helps produce better image quality because it offers sharper edge definition and smoother gradiations/vignettes. “The drop size technology also dynamically minimizes waste by only dropping the exact amount of ink needed for each part of a job and thus helps to minimize ink usage,” he explains. “In addition, lower water inks reduce the amount of energy required for drying.”
He says Ricoh printheads excel at producing high-quality printing for general commercial print applications. “They are also designed to have high reliability and exceptionally long life as they are stainless-steel based.”
Wong sees things building on recent advancements, moving toward more nozzles and larger printheads and the ability to handle a wider variety of inks. “We are constantly pushing for higher resolution and larger drop sizes, which are admittedly, two different directions.”
Xerox offers a variety of inkjet production presses.
The Xerox CiPress waterless inkjet production press utilizes Xerox manufactured M-Series drop on demand piezoelectric inkjet printheads. Schmachtenberg says the printheads have a 300 dpi native resolution that is staggered to achieve 600 dpi in the CiPress. “Its key differentiating feature is its ability to jet at higher temperatures, which enables jetting of higher viscosity fluids.” He explains that this makes the press suitable for industrial printing and other digital manufacturing applications. The M-Series rugged stainless steel construction allows for printing and other digital manufacturing applications. It allows the jetting of water, UV, wax, solvent, and acid-based inks at 17 to 30pl drop volume at frequencies up to 43 hKz. It has been tested through one trillion actuation cycles, enabling an average printhead life of approximately four years in the CiPress platform.
Xerox also offers the Xerox Continuous Feed aqueous inkjet production presses, Evolution, Compact, Reference, and Trivor. These presses utilize the Panasonic series 420 piezoelectric drop on demand printheads. Schmachtenberg says that these printheads have a native 600 dpi resolution with variable drop size capability. He explains that the compact design of these printheads make them suitable for combining into large arrays. They are used for transaction, packaging, and label applications.
For Xerox cutsheet and roll to cutsheet aqueous inkjet printers, Brenva and Rialto utilize 600 dpi Kyocera KJ4 drop on demand piezoelectric inkjet printheads. The printheads are 4.25 inches long, which enables the print width to be covered with fewer printheads, reducing printhead alignment and tubing/cabling requirements. They also support variable drop size capability and are designed to enhance print quality and stability. The average printhead life is greater than two years and they are suitable for transaction, direct marketing, and book applications.
Xaar is an OEM manufacturer of drop on demand piezoelectric inkjet printheads. “The lifecycle of any printhead is typically based on the applications, ink, and the platform,” suggests Jason Remnat, product line manager, Xaar plc. He says its printheads can last for one to six years depending on usage.
The company’s Xaar 5601 printhead was announced at drupa and focuses on three things—cost, productivity, and quality. “We tend to talk about total cost of ownership, which does not solely reflect the cost to the OEM but also printhead integration features that allow the developer to produce less expensive machines and enable a more cost effective use of the printhead by the print provider.”
He says that for example, the Xaar TF Technology recirculates the ink in the Xaar 5601. This technology ensures excellent print quality. Ink is recirculated directly past the back of the nozzle at all times, even during drop ejection. “This means that the temperature is controlled evenly across the printhead for uniform ink viscosity and droplet production and ultimately, high image quality.”
Additionally, the printhead’s Z shape means that multiple printheads can fit closely together for a compact print zone, accurate drop placement between colors, and reduced costs associated with accurate media control and positioning.
The printhead is built for low viscosity inks, indented for, but not limited to, water-based applications. “For example, it is ideal for digital textile printing, commercial printing, transactional printing, and graphics and laminates,” he offers
Remnat says printhead manufacturers realize that there are opportunities outside of wide format graphics printing, so they are putting more focus on optimizing their printheads for these other markets. For industrial markets, the focus is on new technologies. “There is more opportunity for new machines and inkjet press manufacturers in new markets,” he shares, adding that packaging and commercial print are two areas that are seeing increasing interest in inkjet printing.
The role of inkjet in the overall production print landscape continues to broaden into expanded applications. As new demands are placed on print providers, equipment and printhead manufacturers respond, offering faster speeds, higher quality, and improved versatility, leading to expanded application potential. dps
Oct2016, DPS Magazine