Digital inkjet printing has come a long way in the last few years, but can it go all the way and topple litho as the king of print? Print21 editor Wayne Robinson assesses the state of play.
From posters to direct mail, packaging, books, textiles, wood, glass, and ceramics, inkjet printing is already playing a major role in print production – with much more to come, if its proponents are to be heeded. From its early days two decades ago when the Epson wide format printer teamed up with some smart software to produce contract proofs, inkjet printing has been on an unstoppable march across the printing industry.
Today its spread is huge, its applications are myriad, and it now dominates sectors such as display graphics and book printing – but the holy grail of offset quality replacement has, to most print business owners, yet to be reached despite it being more than a decade since high volume reelfed inkjet burst onto the market at drupa 2008 with Océ and Screen.
That may change, however, as the technology develops at an increasing rate, and as the technology giants pour vast amounts of cash into their R+D efforts in a race to the top, to the place where they can replace litho presses which still print two thirds of all Australian print. They are already there in the book world and in other areas such as screen printing, a prime example of a technology that has been almost totally superseded by inkjet.
Commercial offset quality, though, remains tantalisingly out of reach for high speed inkjet – at least judging by the market take up in the commercial world, which has so far resisted its claims. There are a dozen high speed reelfed inkjet print systems installed around the country, but these are in transaction and transpromo print houses, rather than commercial printers. Book printers too have taken to inkjet printing; Griffin Press, for instance, has what is described as ‘the world’s most advanced book printing system’ with an HP Pagewide monochrome reelfed inkjet line and covers printed on HP Indigo – although that of course is liquid toner rather than inkjet.
Water
The issue that has yet to be fully resolved with high volume colour inkjet is the water, which transports the pigment to the paper. It is this that is proving to be the final obstacle for inkjet to surmount on its way to the top.
Paper fibres expand four times more lengthways than widthways when in contact with water, and at the speeds at which reelfed inkjet operates, a decent amount of water is hitting the stock. The imperative, therefore, is to get that H20 off the stock straight away – but that is far from easy, and that is what taxes the minds of the developers. The spreading water can cause the dot to gain and can impact on the dimensional stability of the stock.
Book printing is somewhat easier to manage, as there is only one colour (black), and relatively speaking not that much ink on the page, so not much water. The quality demands are also not the same as Vogue magazine, hence the strong take up of inkjet in the book world as opposed to the commercial world.
Nevertheless developments continue apace; companies such as Océ, Kodak, Screen, Fujifilm, Ricoh and Xerox are all making major developments in reelfed inkjet, with more to come. Océ, which along with Screen was first into reelfed inkjet, has its Stream series of printers, including the Océ ProStream, the inkjet press it believes will hasten a move from litho to inkjet.
The water issue is served by a no contact (and seriously large) flotation dryer, which sees off the water and creates a protective polymer layer to lock the pigment ink against the paper. ProStream runs at 80m/min with the Kyocera KJ4 piezo print heads producing a 1200dpi resolution using 2pl or 5.6pl droplets.
Océ has it printing in a YMCK sequence, which it says improves the colour gamut. According to the manufacturer, the gamut of the inks exceeds Fogra 51 on coated papers and Fogra 52 on uncoated papers. The inkjet heads are water cooled to a constant 35ºC. The inks are water based with a polymer surrounding the pigment, which melts during the drying section to create a protective layer above the ink.
It prints across 540mm on a 565mm web, and can produce 35 million A4 pages a month.
Screen’s Truepress Jet520 highspeed, roll-fed inkjet presses now have the new SC inks that allow printing on coated and uncoated offset stocks without priming. It is Screen’s response to requests from high volume digital press users for inkjet printability on standard coated/uncoated offset stocks, rather than more expensive inkjet-receptive coatings. The Truepress Jet 520HD reel-fed press prints with up to six colours for gamut, and with new SC inks that adhere to standard offset stocks with outstanding definition.
The press is able to place 2-picolitre droplets — the world’s smallest level — exactly where the dots are required on paper as it moves through a highspeed transfer system, the company claims. Combined with the maximum resolution of 1200 dpi, the Truepress Jet520HD clearly images detail smaller than 0.10 of a point.
Screen says that its digital printers have breakthrough absorption technology eliminating any preprocessing or additional primer coatings that are typically required to print to standard offset coated papers. Printing directly to the paper saves time and cost, and preserves the paper surface texture to open up a range of new possibilities and new markets for inkjet printing, including commercial print, catalogues, magazines and high end books. The 530HD with SC inks was awarded the 2017 Intertech award for innovation excellence.
Kodak, meanwhile, is looking at making large volume digital packaging printing viable through its continuous inkjet technology: either the Prosper Stream technology, or the higher definition Ultrastream that may come to market this year.
The Ultrastream unit cost is set to rival piezo drop on demand printheads. Kodak says it is a simpler and smaller print head than Stream, and enables smaller droplets to get onto the stock. The low unit cost is to enable the heads to go into other equipment under OEM deals. Resolutions will be 600 x 1800dpi, with the company believing its quality will match offset on offset stocks.
Ricoh, which took over the JV with itself and IBM for high speed inkjet, now has the VC60000 and the ‘new benchmark’ VC70000, which runs at 150 metres a minute, up from the VC60000’s 120 mpm rate. The increase has come through new drying capacity, which the company says allows it to print at higher speeds on offset paper with greater ink coverage than ever before.
Its piezo drop on demand printheads print at 1200dpi on coated, uncoated and inkjet stocks, and it will knock out 130,000 A4 impressions an hour. It comes with a new set of inks that Ricoh says will deliver savings.
Xerox is developing two streams of aqueous inkjet web, the Trivor and the Impika, from the French manufacturer it bought in 2013. The Impika Evolution can print at up to 833 feet a minute.
Sheetfed inkjet
In sheetfed inkjet the conundrum is even more striking. In theory inkjet should be the unchallenged winner: the presses are simpler, faster, and digital. However, they are more expensive to buy, the drying can be an issue, and the inks can be more expensive. B2 inkjet presses have been around for a decade now, but their benefits are taking a long time to gain acceptance.
The Fujifilm B2 Jet Press 720S and the Screen TruePress Jet SX both appeared in Australia, but neither hit the mark. The new Konica Minolta AccurioJet KM-1 has gone into two separate printers in Victoria, one of which, Revolution in Ballarat, won the state title for quality print competing against the Konica Minolta toner machines. This was quite an achievement and testimony to what can be done on the KM-1 – the judges were independent of Konica Minolta. Komori has its own version of the same press, the IS29, although none as yet have come to these shores. All these B2 presses use UV inks, so do not have an issue with water on the paperstock or with drying. Konica Minolta was also showing a B1 inkjet carton press at the last drupa, the KM-C, which may make an appearance at drupa next year.
Canon has the B3 i300 with aqueous inks that can print on coated and uncoated thanks to a primer; the press runs at 106ppm A4 printing both sides at once. Notable installations here include Waratah Direct and Soar Print.
Visitors to the last drupa who went to the far corners of the Canon booth will also have seen its prototype B2 inkjet sheetfed press, the Voyager, which was printing in up to seven colours at 3,000sph with a 2400 x 1200 resolution. It is being considered for the photo realist and packaging markets. There has been little in the way of updates since drupa, but progress is sure to be underway in the Canon R&D labs.
Xerox also has an A3 inkjet printer, the Brenva. It doesn’t run as fast as the Canon, but costs less; there are no plans to launch it here as yet.
Inkjet packaging
In packaging print there is a rush to inkjet, with the vendors banking on the brand owners wanting to take advantage of short run work. Developers such as HP with Pagewide C500, EFI with Nozomi, and Heidelberg with its Primefire 106, the world’s first B1 digital press, are already in the market. Benny Landa is hoping his nanographic technology will finally be ready by drupa, with the B1 S10 single sided carton press set to be the first version available. Among other major players Screen is also developing a digital carton press with BHS, to produce a 2.8m wide printer; Memjet-powered New Solutions will also have digital carton printing systems at drupa. Big hitters KBA and Durst have just launched a new joint venture company which will develop the VariJet 106, a hybrid packaging press which will combine KBA offset technology with Durst inkjet to produce a single production system which can print offset, flexo, screen and digital, plus foil and cut all in one pass. Developers have some way to go to convince customers that spending millions of dollars on an inkjet press is better than using a wide format flatbed for short run or sample packaging – but they are investing big money in R&D with these machines, so they must be convinced.