Duplex Dynamos

Toner-based print engines may have seemed to hit the wall when it comes to speed, especially in the cut-sheet arena, where attention has been turning to inkjet as the future solution. While that may yet be the end result, new developments in dry-toner engines—notably tandem and duplexing systems—have given a new lease on life to dry-toner runs, buying time for the technology as inkjet matures in its quality-vs.-speed struggles.

Familiar digital printers from Xerox, Konica-Minolta, Canon and the like “duplex,” or print the second side of a sheet, by turning the paper over and sending it back through the print engine for another pass. But the toner must be fused before the paper flips; otherwise, it will fall off the page and pile up at the bottom of the printer chassis. Aside from practical limits on paper throughput (e.g., turbulence, maintaining sheet order), in most cases fusing heats the paper, shrinking and drying it in the process—causing critical challenges in front-to-back register for book work and finishing operations.

Suppliers have devised schemes such as calculation tables and image rescaling to mitigate issues of register and speed. Now, a new breed of single-pass duplexing engines is entering the digital production environment, with announcements in toner-based systems from Océ and Xerox. Also stirring interest are inkjet arrivals from IBM/Epson (Infoprint), Screen USA and Agfa Graphics.

While cut sheet has physical limitations on sheer paper pass-through speed (said to top out at 200 images per minute), and continuous feed offers ultimately greater productivity, the vendors look to push the output to the limits. The conclusion is to maximize productivity through a single pass duplex. The Xerox approach pairs two Nuvera monochrome engines inline to maximize speed. Shown as a technology demo at Graph Expo, it is to be on the floor in Boston at On Demand this month.

Océ unveiled the cut-sheet VarioPrint 6250 last month, using the Gemini engine, which functions along the lines of a blanket-to-blanket offset press—printing both sides at once. Two more announcements this year incorporating the Gemini engine are the slower 6160 (160 duplexed ppm) and 6200 (200 duplexed ppm) models, giving Océ three products now with this engine.

The VarioPrint 6250 duplexes using a single controller with dual printheads and developing units. Paper passes through and is “softly” fused only one sheet at a time, both sides at once, using more pressure and less heat than other digital engines. The effectiveness of this solution ultimately depends on the customer's application. The machine runs at 125 ppm in one-sided “simplex” mode. Océ reports that 80% of digital production printing for books and manuals is duplex, making the 6250 a good fit for those applications.

Océ's first installations occurred this past December, with Commercial Communications, Inc. (CCI), Hartland, WI, receiving a pair. The company also added a Xerox DocuPrint 180 with highlight color last fall.

According to VP operations Steve Henck, CCI was attracted by the “pure productivity” of the 6250. While rated at 250 ppm in letter-sized work, it outputs 132 ledger size (8.5×14´´) duplex ppm, and 160 ppm in 11×17´´.

Directories, service manuals and training guides make up 80% of CCI jobs. Henck expects to run up to 6 million images a month on the 6250.

“Ninety percent of our work is duplex, and we do a lot of operator manuals with halftones, solids and large screens,” says Henck. “The system's 12×19´´ image size lets us run covers we couldn't do given the 11×17´´ limit on our older printers.”

The 6250 supports coated and lightweight stocks, and has 12 identical paper drawers, allowing assembly of complex jobs. “We have a lot of jobs that require tab-holed stock, color inserts and other media, but on older systems, our productivity was limited by the number of drawers. With the extra drawers on the 6250, we can load and run the current job longer and even set up the next job.”

This spring, CCI will add an inline saddlestitch bookletmaker with square-back spine former—allowing printing on the spine and books up to 200 pages. CCI expects ultimately to make a three-to-one replacement of older cut-sheet systems with the 6250.

Océ also officially announced, at its annual open house in Germany last month, a 4-color version in its VarioPrint 9000 roll-fed product line. The continuous-form VarioStream 9240 also places toner on both sides of the page simultaneously, and represents the evolution of the 9000 family, which previously introduced 1-, 2- and 3-color versions. (CCI had its 2-color version upgraded to three colors recently.)

This 4-color VarioPrint 9000 can apply black and three spot colors, or produce process color. It also has expansion room in its cabinet for a fifth printing unit, presumably to be announced in the future.

Xeikon debuted its latest twin-engine, two-sided color machine, the 4000, earlier this year. The web-fed Xeikon 4000 produces 130 ppm at top speed. The device allows for printing on a wide array of substrates—paper, synthetic media and labels, as heavy as 250 gsm—and formats of 20´´ wide. Its X-800 front end integrates to workflow, supporting both XML-based and JDF-based job tickets.

Last month, Xerox unveiled its 495 continuous-feed duplex monochrome engine. The device was developed by Xerox, working with manufacturing partners. The company says the 495 has the smallest footprint of any duplex-engine printer. E. Scott Wagner, manager of worldwide marketing for continuous-feed products, says this platform will be the base for future Xerox engines, obviously targeted for higher speeds. Its two engines, slightly staggered, print in quick sequence on both sides of an 18´´ web, running pin-fed paper at a steady 115 fpm whether running one-sided printing or two—yielding 250 impressions in simplex mode and 500 impressions in duplex.

The paper path within the 495 feeds past automatic sensors that register front and back. Just a 10´´ length of paper leads in from the operator. The fanfold path takes a 90-degree turn, and the paper travels upwards, coming across the first organic drum print station, then imaging side two. The engines are 11´´ apart. The 18´´ web opens the market for two-up applications such as 5×8´´ or 6×9´´ books.

The Xerox 495 automatically senses the imaging requirements, switching between simplex and duplex, and registering “click” charges only for actual impressions. Xerox claims it is unique in the industry with this offering.

The technology also uses non-contact flash fusing, improving register and reliability, and opening the door for creative media, such as plastic cards, scratch-off aluminum and label stocks. According to RPM Print and Design, “What really impressed us about the Xerox 495 was the superior image quality and speed it delivers. This printer is a real step forward in terms of economics of operation and quality.”

The Nuvera 288 technology demonstrated last year, with tandem engine architecture, may have more success in an area where real estate is less of a premium. Another appeal is redundancy—a commercial printer using the machine can tell it to bypass a down engine and print two-sided on the remaining one, albeit more slowly. The long paper path and double duplex inverters beg the question of feasibility, but like all products, it is supported by Xerox's service.

Xerox Nuvera 288's image quality and resolution are a strong point—at 4800×600 dpi, it is in a class by itself for running promotional or transactional documents, as well as technical publications with demanding halftones. The 288 is in early customer acceptance testing status, and feedback will soon be available, as well as other technology announcements for the solution.

Agfa Graphics generated buzz last month as it announced the launch of the :Dotrix TransColor, built on SPICE (Single Pass Inkjet Color Engine) technology. It was originally introduced at drupa 2000 through the independent company :Dotrix, which Agfa acquired in 2004. This inkjet web (like the Screen TrueJet, IBM Infoprint 5000 and Kodak Versamark lines), is aimed at transactional and transpromotional documents and direct mail pieces. It uses a static array of inkjet heads, and features the ability to print A4 pages three-up on both sides of the paper in a single pass, at 484 pages per minute.

Agfa's drop-on-demand printing technique, combined with its scratch-, smear- and water-resistant, UV-curable :Agorix Nova ink, puts tiny drops on the paper of varying sizes, enabling a perceived resolution of 900 dpi and a wide tonal range. With a 26½´´-wide web and 12 heads for each color, the technology uses a stationary inkjet installation above a moving paper roll to attain its productivity rates. The quality of output is superior to levels seen in the past.

The :Dotrix Transcolor is a complete IPDS workflow, using an FS 45 controller, enabling full-speed complex RIP and print without a bottleneck. Like other high-speed inkjet engines, the Transcolor is geared for transaction statements for financial markets, database printing and direct mail pieces with robust databases. Other growth areas for these machines include transpromotional marketing, where traditional transaction data is leveraged by merging full-color promotion graphics for greater market awareness.

IBM has also announced a tandem duplex configuration with its new Infoprint 5000, a full-color, variable-data continuous web system. This solution is part of a joint venture of IBM and Ricoh through the InfoPrint Solutions Company, and we are beginning to see more market awareness of their product positioning as the merger advances. The Infoprint 5000 has Adobe PostScript RIP with Epson-based piezo-electric inkjet and drop-on-demand inkjet technology for printing. The tandem duplex solution (also available in simplex) can print at speeds up to 916 fpm full color with a 19.96´´ print width and 720×360 dpi resolution. Shown as a technology concept at Graph Expo 2006, this continuous web formally rolled out to the U.S. marketplace last month. The Infoprint is manufactured by Screen, which has a similar engine—the TrueJet—in client testing.

The greatest speed in a single-pass duplex toner based system is currently ready for shipment from Delphax Technologies, the new CR2200, announced at Hunkeler Innovation Days in February 2007. The CR2200 digital press uses Delphax's patented Electron Beam Imaging (EBI) technology for true 600×600-dpi resolution, handling a variety of media options with open architecture for finishing solutions as well. The CR2200 is a twin-engine machine; the paper passes through the first engine imaging side two, then passes the second image engine (without a twist) and images side one. This uses a tight web of 19´´ wide, and customers are printing 2,180 images per minute in a four-up letter size, and a mind boggling three-across 6×9´´ books at 4,000 impressions per minute.

The Delphax CR2200 accepts paper stock as light as 27-lb. as well as recycled stock, offering an excellent solution in today's green commercial shops. The Delphax product positions nicely in long print run applications where maximum sheet output per day is a requirement. This solution is an upgrade of the prior CR series, now offered in three configurations based upon speed—models 2100, 2150 and 2200 at 1,000, 1,500 and 2,200 four-up letter-size images per minute.

Delphax partners with every major finishing supplier in the industry and has a multiplicity of configurations installed worldwide. According to Delphax, books, sales and marketing materials, legal and financial documents, packaging inserts, transactional and security printing applications, tickets and ballots are all hot target applications.

www.agfa.com, canonusa.com, delphax.com, ibm.com, oceusa.com, screenusa.comxeikon.com and xerox.com