The name of Kodak and high-speed production printing have been closely linked since Kodak acquired the Versamark division from Scitex back in 2004. At that time the Versamark was the only product for high-speed continuous feed inkjet printing. Kodak then turned to their internally developed technology labelled Stream. It was introduced at drupa 2008 with the first installations of the Prosper 5000-series made in 2010. In 2014 the 5000-series was replaced by the 6000-series. With some upgrades in the meantime the 6000 stayed the flagship (and essentially only model) from Kodak for high speed production inkjet printing – which is a pretty long time in the fast-living world of inkjet printing. In the meantime, the whole Prosper press business was up for sale and developments seemed to have slowed.
Under its new CEO Jim Continenza, Kodak got back into development mode and is stepping up digital commitments promising to “double down on digital.” Scheduled to launch at drupa 2020 Kodak used a virtual event to present the latest device: the Prosper Ultra 520. The Ultra 520 is positioned below the Prosper 6000-series based on a slightly reduced web width of 520mm/20.5” compared to 621 mm/25.5” and a lower speed of 150 m/min or 500 fpm compared to 300 m/min or 1000 fpm of the 6000-series. This reduces the output to about 2,000 A4 pages/minute compared 4,364 of the 6000. Accordingly, Kodak targets the Ultra 520 at the “mid-volume” market with up to 60 million impressions per month and a sweet spot at about half as many. The footprint has been reduced as well to about half of a Prosper 6000.
Even so the Ultra 520 has a couple of improvements that make it a remarkable device. The resolution has been increased to 600 x 1,800 dpi (while the 6000 has 600 x 600 at full speed) and the drop size is reduced to 3.75 pl (instead 9 pl on the 6000). Accordingly, Kodak expects a better print quality. Coated and uncoated paper is supported, but a pretreat (primer) might be necessary for standard offset paper, which Kodak offers as offline or inline versions. Paper from 45 to 270 gsm is supported. The inks are similar to the ink set used on the 6000 presses, but it might be necessary to calibrate and test again when moving to the 520. The 520 also sports a next generation KODAK 900 Print Manager digital front end with state-of-the art Adobe APPE 5 RIP.
Like the 6000-series the Ultra 520 comes in two versions. The C version is for commercial markets and features an extended drier. It allows for higher ink coverage and higher paper weights. The P version is for publishing markets with a basic drier and is rated for paper up to 160 gsm.
More for the geeks: Kodak changed the type of inkjet technology used. From Versamark, to Prosper 5000 and Prosper 6000 all internally developed inkjet presses from Kodak use continuous inkjet (this excludes the VL-series which was based on Impika developments). In continuous inkjet, a constant filament of ink leaves the nozzle and breaks up into droplets. Droplets heading for non-image parts need to be captured before they hit the paper. The Ultrastream technology relies on selectively charging droplets in the continuous flow of drops. The charged droplets are deflected by a constant electrical field and are captured in a gutter, while only the uncharged drops land on the paper. Ink captured in the gutter is conditioned and fed back into the ink supply. This principle was already used in the Versamark heads of old.
The Stream-technology in the Prosper 5000 and 6000 uses a different approach: A heater around the nozzle orifice breaks down the stream of ink leaving the orifice – based on changing the viscosity of the ink by heating it up locally. Depending on the timing of the heating pulse larger or smaller droplets can be created. The smaller drops are deflected by a constant, steady stream of air into the gutter. The large drops are not deflected enough and land on the paper. If this sounds a bit precarious it might explain why Kodak fell back to the electrostatic deflection of old. The Ultra-technology does combine both approaches to some extent however: a heater at the orifice is still used, but only to create uniform droplets by controlling the break-up point.
There are some potential implications for continuous inkjet versus drop-on-demand. In continuous inkjet the nozzles fire constantly, hence the danger of blocking a nozzle is greatly reduced. The technology also saves ink as no spit bars are required to have all nozzles firing once in a while. There is more wear on the ink orifices however and ink from the gutter needs to be cleaned and conditioned. It might take a bit longer until a stable jetting level is reached as well. However as mentioned these differences are more for the geeks and what counts for a real-world customers is how well each vendor implements its technology and how a potential cost saving is turned into a saving of the monthly ownership bill.
The drawback of virtual press events is not to be able to see the device and its output. The stated improvements in quality and paper range sound promising, but without having seen samples are difficult to judge. Kodak aims for offset quality to allow customers to mix and match variable portions with static long run portions in a job.
The Ultra 520 is set to cost around $2 million, about half the price of a Prosper 6000. The press will go beta later this year and pre-sales is starting now. Full availability is planned for early 2021. The Prosper 6000-series will remain available. There is no mono version of the Ultra 520 planned so far.