At K2019 in Dusseldorf, we had the opportunity to meet with Giuseppi Sauli at the Uteco stand. Sauli is a frequent visitor to Asia and India. In our previous meeting in Delhi, he mentioned that the first Uteco Saphire Sapphire Evo digital press had been sold to an Asian customer in Japan. As he said to us at K, “The first machine was installed a few years back in the US and the second in Italy. And, the third machine will be installed at a packaging printer in Japan next month – in November 2019.”
The Japanese customer’s press underwent extensive factory testing just before the K exhibition. Sauli said, “For the factory test, a big team came from Japan together with a couple of suppliers of substrates. The tests were on paper and films, including breathable films. The print output was really satisfactory, and the customer is in a big hurry to quickly install this machine, and this will happen next month in November 2019.
Sauli made it very clear that while the time for digital printing of flexible packaging has come it would not replace the conventional gravure and flexo technologies that are most widely used for this purpose. “My idea is that the digital will not replace gravure or flexo but will sit alongside the gravure press or CI flexo press in the same factory. When you go to a gravure printer and ask him to print 1,000 meters, he will say no way, not possible. But this is possible with digital. Our digital Sapphire Evo press can do this job.”
The Uteco Sapphire Evo is based on a collaboration with Kodak and uses its continuous inkjet (CIJ) technology. The benefits of CIJ, (most widely used in end-of-line inkjet printers for coding and marking), are that because of its continuous running, the jets do not clog, a common problem with drop-on-demand (DOD) inkjets. Kodak’s Stream inkjet enables uniform dot size and accurate placement of ink regardless of coverage and speed.
Potentially CIJ speeds are also much higher than thermal or DOD, and with the use of water-based inkjet inks, the technology could provide the vast amounts of food-safe inks that are needed for flexible packaging and perhaps at a somewhat reasonable cost. Sauli added, “The latest technology is Kodak’s Ultrastream inkjet heads, and this will be the future, the quite near future.”
The Sapphire Evo digital press for flexible packaging uses Kodak’s Stream technology at a 600 x 600 resolution, and Kodak’s water-based C, Y, M, K inks to print on flexible films at a speed of 150 meters a minute, and at 300 meters a minute on paper substrates. Supported substrates include plastic films such as PP, BOPP, PE, and PET, as well as paper substrates.
The mechanical structure and the downstream units of the Sapphire Evo come from the Uteco side of the collaboration. These include the unwinder, rewinder, and the downstream and upstream unit. The curing system is also from Uteco. The press currently prints on 660 mm wide web with a print width of 622 mm.
As Sauli told us at K, “The CI drum is not used for printing but only for keeping the material stable for drying. The machine can also have options such as corona treatment, web cleaner, ancillary equipment such as a downstream flexo unit for OPV varnish. Or we can print 4 colors plus white on the downstream unit. Lamination can also be done in-line, although it may be easier to do offline on a laminator.”
