Color Inkjet Printing : Inkjet’s Web Paper PursuitSeptember 2010 By Jack Miller
For more than a decade, industry observers have been anticipating the explosion of digital printing. One by one, the barriers have been overcome: speed, quality, cost, the ability to design for variable data, and the availability of databases with information rich enough to allow targeted and personalized communications.
Digital comes in many flavors, but this article will focus on the new color inkjet web presses and the papers they print on. Some of the presses that made news at Drupa in 2008, PRINT 09 last year and Ipex in May of this year include: the Océ JetStream, the HP T300 and the Kodak Prosper—presses that are capable of commercial production output volumes with variable data.
Eric Armour, president of the Graphic Communications Business Group for Xerox Corp., advises that Xerox also introduced a new production inkjet technology at Ipex. Armour adds that the technology uses a polymeric resin ink that is fed in granular form, melted in the piezo head and hardens almost instantly, providing vivid, durable quality. It will also print on plain, untreated, uncoated papers, which are less expensive than treated or coated papers. While this technology is not yet commercial, it is very promising.
Earlier systems from Screen, InfoPrint and Versamark led the way with high-volume production and color imprinting, but the new generation combines high speed with high resolution and low cost, taking us beyond those earlier offerings (see Table 1).
These presses, in my view, also take us beyond Indigo and Nexpress, and beyond transactional and transpromo printing to direct mail and books, with other applications to follow. Newspapers, catalogs and magazines are likely to be the next generation and, longer term, packaging has exciting potential.
The Challenge Is Paper
The "holy grail" is a digital press that is capable of producing offset quality at a competitive cost on the same papers that printers use on their offset presses. For the most part, coated and uncoated offset papers run reasonably well on toner-based digital systems but, with inkjet, it's a whole different ball game. Inkjet inks have a high water content, and tend to soak into uncoated papers or sit up on coated papers where they may smear.
For uncoated papers, HP and International Paper introduced ColorLok technology for desktop printers. The technology involves a calcium chloride-based chemical that is added in the paper mill. Glen Hopkins, vice president and general manager, printing technology platforms for HP, advises that ColorLok adds "a minimal cost to the overall cost of paper." The precise cost will vary, depending on the efficiency of the mill, and he thinks it is likely that the cost will come down with experience.