Kodak Prosper 5000XL

16 June 2010

Business

Now unveiled, Kodak's new high-speed inkjet is targetting offset's traditional hunting grounds, says Barney Cox

hat at Drupa was the Stream Concept press, hidden behind a curtain and only visible to the privileged few, at Ipex was a reality that took centre stage on Kodak's stand - the Prosper 5000XL colour press.

At the heart of the Prosper is Kodak's Stream inkjet technology, in effect an evolution of the continuous inkjet that Kodak has been using for close to 40 years.

Kodak claims that continuous can fire droplets under higher pressure than drop-on-demand. This, it claims, prevents nozzle blockages, allowing thicker fluids to be used, and is faster. The stream of ink is broken into droplets by a heating element around each nozzle. Two sizes of droplets are produced 11picolitre (pl) and 2pl. The 11pl droplets end up being printed, the smaller 2pl drops are deflected by a low pressure air blade and recirculated.

Each printhead module is 106mm (4.16in) wide and has only a single row of nozzles - meaning the full 622mm-wide web is covered by six printheads per colour. So, the Prosper 5000XL has a total of 48 heads to cover four colours on both sides of the web, much fewer than its rivals.

"Stream is so simple and reliable that there is no need for the redundancy used by rival technologies," says Kodak EAMER digital printing marketing director Erwin Busselot.

If a nozzle drops out, the first step is for the operator to run a cleaning cycle, if that fails, wipe the head, and as a last resort they can swap out the head, which is then returned to Kodak for refurbishing.

Kodak is collecting statistics from beta users about head life, but Prosper product manager Anir Dutta says users can expect to replace one or two heads per week on the 5000XL if running 24/7.

When Kodak talks about the robustness and long life of its technology it's got HP's thermal inkjet, as used in the T300, in its sights. However, HP always considered the heads to be a consumable, and both firms include the cost of the replacement heads in their per-page pricing.

Stream heads are user-replaceable, taking 15 minutes including recalibration. Other rival inkjet machines use piezo heads, which have a significantly longer life.

Near infra-red is used to dry the print, with three dryers per side, one after the cyan and magenta heads, one after the yellow heads and a final one after the black heads. Details about the ink coverage, paper and speed are used to optimise the energy output, which Kodak calls intelligent drying.

For publications, where typical ink coverage will be pretty high, the firm says Stream offers an edge over other inkjets.
"The more ink you put through a drop-on-demand head, the more the quality drops," claims Dutta. "For publications that's a limitation. It needs multiple heads to deliver the necessary speed, quality and web width and so is less reliable."

Offset challenger
Kodak is cagey about the resolution of the Prosper 5000XL, previously it said Stream printheads were 600dpi and the binary (dot or no dot) droplet size is 11pl. However, Dutta says that resolution and droplet size are unimportant and refers to Kodak's preferred benchmark of "equivalent to 175lpi offset".

"Looking at resolution is only part of image quality," he argues. "And droplet sizes are also a moot point. Our clients don't care about resolution, lpi resonates."

Kodak has based its image quality figures on a report from US research firm Spencerlab, which carried out tests on the Stream Concept Press. Its key findings were: "Overall, the Stream Concept Press demonstrates potential of approaching175lpi offset print quality".

Like many inkjet printers, the Prosper 5000XL has a wider colour gamut than offset, with research from the Rochester Institute of Technology (RIT) finding it to be 34% larger.

Kodak has made much of the ability of the Prosper to print onto coated glossy stocks, a challenge for DOD inkjets unless they're running an inkjet-optimised coating or pre-treated stock. But Prosper is no different in needing optimised stocks and this means there is a price premium on the paper and also a restriction on the range of materials.

Kodak is working with mills on stocks for the Prosper, announcing at Ipex worldwide partners including Stora Enso and Ziegler in Europe. Firms already supplying stocks include Crown Van Gelder (CVG) and International Paper.

At Ipex Kodak announced it was developing an "in-line optimisation station", which applies a coating prior to printing, making it possible to use standard coated and uncoated stocks. The coating unit will be available in the first half of next year. Unlike HP's T300, which uses an inkjet coater, the Prosper unit is a roller coater.

Dutta says: "Image optimisation is useful when a customer uses lots of different stocks that don't have a coating, but over time, mill-coated is less expensive for volume customers."

Kodak backs its claims of offset class performance with a print volume of 120m A4 pages per month, which is almost double that if nearest rival, the HP T300's 70m.

The 5000XL is fast, its 200m per minute web speed is 33% faster than its next nearest rival, the Oce JetStream. The 648mm-wide web enables 2-up A4 production head to head, producing 3,600 A4 pages per minute. This equates to 50% more pages than the HP T300 and 17% more than the Oce JetStream 3300's 3,030 A4 pages per minute, both of which use a wider web for three-up A4 edge-to-edge production.

The Prosper's 648mm-wide web allows it to produce eight, 12 and 16 page A4 signatures, and other higher-pagination signatures for the smaller-sized pages of books.

Uncertain customers
Kodak is targeting the Prosper at two markets - publications and direct mail. So far, the only machine installed is the black and white Prosper 1000, which is being beta tested at Offset Paperback Manufacturers (OPM), a Pennsylvania-based book printer, which is part of Bertelsmann Arvato. Italian firm Rotomail will beta the colour Prosper 5000XL, taking the machine which was shown at Ipex. It will be installed at the firm's new factory in Milan, once the building is completed later this summer.

Kodak claims to have "160 customers engaged" worldwide in discussions about buying a Prosper. Busselot admits that not all of those are destined to purchase. Many are also in discussion with Kodak's rivals or are awaiting the conclusions of the beta testing.

Price depends on the configuration, but the list price for the twin-engined colour 5000XL is £2.7m ($4m). The cost per page Kodak has provided, which assume a monthly volume of 20m-25m A4 pages per month are 0.1p for black and white at 5% coverage and 0.6p for a 35% coverage colour page. The prices include the image optimisation coating, if used, as well as heads, ink and service.

Kodak is working with beta customers to finesse the business model, with some likely to opt for a click charge and others to be charged separately for ink, heads and service.

"We'll fit with the preferred business model," says Dutta.