Ink-jet dreams and realities

Sorry, dear readers, for my long absence.

I returned from Germany to a full schedule of classes that required me to work five days a week (I only worked two days while in Germany), and had to manage a full complement of students (178 in one class, 28 in the other). So it has been a really busy quarter, and I have not written any blogs since August.

Some interesting topics…

Sheet-fed ink-jet printing from Heidelberg
First is Heidelberg’s PrimeFire, a digital sheet-fed printing press that uses Fuji ink-jet heads to print on 40-inch sheets of paper. The press combines Heidelberg’s standard feeder and delivery units, any number of offset units and coaters, and a perfecting ink-jet unit in the middle. On my two tours of the Heidelberg factory in April, I didn’t see this machine. I wish that I had had an opportunity to see it in person.

This is the Heidelberg PrimeFire 106 press. At the far end is the console and two delivery stacks, one for good sheets, one for defects. Standard Heidelberg press units and coaters can be built into the press. Image courtesy of Heidelberg

Two things it does that are unique: one is that it has a reject delivery stack, where sheets that are imperfect stack up, removing them from the finished pile. This is a time-saver, as it eliminates the weeding of bad sheets from the delivered printing. I like that. The second is the most clever inspection technique I have ever seen (why didn’t someone think of this sooner?). The press console is in-line with the press at the delivery end. On request, the press will skip the delivery pile and feed an inspection sheet directly to the operator’s console (through the back of the console) and directly onto the inspection table. That is really nice!

As for printing quality, I have not seen actual output, so I don’t know. But, considering the source, I’m confident that it’s impressive.

This press joins a small number of production sheet-fed presses on the market from Komori/Fuji and others still in development. In both the Komori and Heidelberg presses are similar ink-jet heads from Fuji, called Dimatix.

I have long argued that ink-jet printing is the most important new technology in our industry. It affects everything from desktop printing to billboards, and its impact is being felt on all fronts. The quality of ink-jet is superb, the versatility is amazing, and the cost is coming down (right now the makers of ink-jet devices think that we’ll pay per-page prices for ink; that simply must change). The only weakness of ink-jet printing is speed. Both web-fed and sheet-fed ink-jet printing machines have mechanical/physical limits.

One cannot make an ink-jet droplet fall faster than gravity (without adding an electrostatic charge), and as a result, the speed of ink-jet printing machines hits the wall of gravity, which limits its speed. Where offset presses commonly print four to six sheets per second, ink-jet machines can’t be run that fast. This wall will continue to plague the process.

Gravity notwithstanding, a sheet-fed ink-jet press can spin circles around its offset brothers by printing without make-ready, by printing variable content, and by printing very short runs of very high quality printing. Machines like this have a home in packaging, commercial printing, and in fields we have not yet seen. These presses can print magic! It’s very exciting.

Page-wide ink-jet printing – in stores now!
On a similar note, Hewlett-Packard has finally come to market with page-wide ink-jet printers that are perfectly suited to supplant toner printers in offices. That company had tried this once before, harnessing their fabulous Edgeline heads. The problem with the first machines was (and this is painful) they were not designed to fit through a standard office doorway! The newer printers are the right size, have quality that rivals (or exceeds) toner, and speeds similar. There are a range of printers starting with desktop multi-function machines, and larger machines for office applications. These machines can print up to 70 pages per minute, making them faster than all but their high-end toner competitors.

One of numerous Hewlett-Packard PageWide desktop and office printers. This one sells for about US$700. It’s possible to add feeder drawers below this unit, making it more productive in an office environment. These machine print as many at 70 pages per minute, at about half the price of similar pages printed on a toner-based printer. Source: Hewlett-Packard

This is a field that I had once assumed would be dominated by Memjet, and by companies that incorporate Memjet technologies in their printers. These have failed to materialize, though Memjet does market a desktop office printer that is pretty impressive at less than US$700. HP, with far more R&D capital, has pushed their microelectronic-manufactured ink-jet print heads into an array of machines. Hewlett-Packard has desktop office printers starting at less than US$400.

Xanté, maker of a variety of clever printing devices, sells its Excelagraphics wide-format machine that uses Memjet’s page-wide ink-jet heads. We had one of these at Cal Poly for several years, but reached a point where the machine we had could not be repaired, so it was scrapped. Newer versions of that machine offer better quality and greater reliability than the early model we had.

The Xanté Excelagraphs printer uses Memjet page-wide print heads. It can print on a wide variety of substrates at speeds that are truly impressive. Source: Xanté (with modifications by the author)

Hewlett-Packard has not allowed this to be the only machine in its class. The HP PageWide XL 4000 Printer uses Edgeline heads to print engineering documents at tremendous speeds, and at a level of quality that rivals or exceeds the Xanté machine. I have seen output from this machine, as I have seen output from the Excelagraphics, and both are good. They print on a wide variety of substrates (corrugate, for example). The output is not as good as wide-format ink-jet printers that use reciprocating heads. And reciprocating ink-jet heads move (back and forth) much, much more slowly.

The HP PageWide 4500 printer. This is the smallest of a series of machines in this series. The model 8000 is 40 inches wide. All of them print an A1 size sheet in about five seconds. Source: Hewlett-Packard

Photo-quality page-wide is not here – yet
The promise of an instantaneous photo-quality ink-jet printer is still a promise. We will still be going out for coffee while our photo-quality prints are being produced, and we will continue to be pleased by the extraordinary quality of these photo-quality ink-jet devices. Page-wide output will take a while – but it will come. The demand is too great for HP and others (Epson, obviously) to ignore the opportunity they represent.

About Brian Lawler

Brian Lawler is a Professor of Graphic Communication at California Polytechnic State University, San Luis Obispo. He writes about graphic arts processes and technologies for various industry publications, and on his blog, The Blognosticator.
This entry was posted in Printing and Printing Processes, Technology and tagged , , , , , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.