The role played by consumables has rarely been more important to printers. Some are essential to achieving environmental targets and minimising the use of water; some are designed with press manufacturers to deliver the maximum speed a press can reach or to enable printing with UV cured inks; others open the door to higher value products. This may be through the use of high impact speciality US, Japanese or Italian papers or through new inkjet materials that take print to places it has never before reached. In short, gone are the days when rollers and blankets, let alone inks, on a litho press were interchangeable. And try using non compatible substrates on inkjet presses. It simply does not work.
The crucial role that consumables play in litho printing is one reason for Heidelberg’s creation of its Saphira range of inks, plates, founts, coatings and so on. A more prosaic reason is that the regular purchase of consumables irons out the peaks between the purchase of new printing presses. But the fact is that, with a single supplier taking responsibility for balancing the consumables on press and delivering compatibility, the printer can secure savings through reducing waste and running faster. And when things do go wrong, there is one target to kick, rather than engaging in the merry go round of ink supplier blaming the paper, the paper merchant blaming the fount and the fount provider pointing the finger at the plates.
And consumables are improving to the extent that a printer using the same set up that first worked five years ago perhaps ought to be looking at what is now possible. Indeed, for most in print, once something is proven, there is a great reluctance to change. By tradition, a sales rep will be whispering to the works manager to give his latest set of inks a whirl. Over the years, many directors have discovered that the regular ink supplier has changed without their knowledge. That is unlikely to happen these days. The change in press performance will be instantly identifiable.
The growing interest in LED UV is spurring development of inks and different roller materials that are able to cope with the inks and the photo initiators they contain. Here, the balance between the ink and the light source is paramount. The LED produces UV in a vary narrow band, restricting the photoinitiators that an ink maker can use. And because the power of LEDs has been limited, the ink company will load the ink with more of the reactive substance that it might have done with normally reactive broad spectrum UV inks. However, the search for new photoinitiators to overcome this is likely to be short lived. Any new chemical will need to pass numerous safety tests by regulatory authorities and by some of the larger corporates involved in the food industry who are acutely attuned to the appearance of any compounds that might migrate into food or cause other reactions.
Instead, the problem is more likely to be overcome by increasing the power of LEDs and by increasing the scope of the digital technology to deliver energy at different wavelengths so enabling more, already approved photo initiators to be used. Such LEDs exist, though are not yet resilient enough for printing, and are too expensive.
A key benefit of using this technology is that, regardless of substrate, the printed sheet is immediately available for finishing. Secondly, substrates that most shy away from can be printed as easily as a coated woodfree paper. However, with pressure on margins in standard products, the smart printer will be looking at the more creative papers and materials that can be printed, including plastics and foils.
Uncoated papers are, not surprisingly, the most popular. Designers and brands associate these with less processing, a more natural look and an interesting feel. An overall sealing coating applied after conventional inks can destroy the naked feel.
It was this that lay behind the initial development of new generation UV printing. In Japan, where printing on all manner of expensive papers is expected, printers did not want pallets with small stacks waiting to dry before printing the reverse side or for finishing. Komori’s development of HUV and Ryobi and Sakurai’s of LED UV aided by ink companies has changed that. Pressure from the Japanese government for all businesses to introduce energy saving measures has ensured that UV printing will be the dominant form of litho printing in the country, extending now to web offset printing.
The instant dry aspect and wider range of papers enables litho to match the versatility of digital printing. The short runs that are typical of digital print encourage experimentation with different materials. The relative cost of a few hundred printed on an expensive substrate is lower than committing to a run of 10,000 or more. The increasing portfolio of materials qualified to run on HP Indigo presses, or on Fuji Xerox, Ricoh, Canon, Xeikon and so on, underlines this. As these suppliers offer white, neon or metallic colours, the way is clear for designers to specify the use of coloured papers. Printers may need to seed this opportunity as most designers will not have come across this possibility before.
Likewise printing on foils, using Colorlogic software, will also increase the creative potential of both litho and digital presses, particularly if the aim is to create eye catching book jackets or packaging. Both need shelf appeal, even in these online retail days. Indeed, it might be argued that stand out packaging can be even more important, especially when a 15 year old is videoing the process of opening a box for her YouTube channel.
The choices facing large format printers are even more extensive, covering an increasing range of textiles, films and rigid materials suited to an expanding portfolio of applications. Wall covering materials can be self-adhesive, repositionable, wipe clean, safe for hospitals or children’s bedrooms, textured, and more. PVC materials are fast being replaced by polyester fabrics. They are lighter to transport, look better and much easier to recycle.
Exactly what can be printed will be guided by the technology used for printing. UV will print on rigid materials that do not work for other technologies; latex offers solvent free, water based inks for roll to roll printing. However, HP has this year expanded the scope of its latex ink technology into rigid materials. It remains a water based ink with a few additions to deliver good adhesion to non porous substrates. Once printed the material will bend and twist without the ink flaking.
This is something that printers using UV inks, particularly LED UV inks need to be aware of. The power of the diode is important here also, hence why many printers will use LED to pin the ink before a conventional lamp delivers the full and final cure. However, the newest printers are adopting LED curing exclusively, which means testing materials to ensure that they are suitable. They need to complete testing that includes using the more difficult to cure darker colours.
LED in wide format allows printers to run thinner heat sensitive films and other materials that may distort under the heat generated by a conventional UV lamp. Double sided window graphic films become easier to print in tight register, for example.
The same benefits accrue on narrow web presses for labels where LED UV is fast becoming the standard curing technology for both standard flexo inks and for inkjet inks. Cold cure UV means more labels on a reel thanks to printing on thinner films, so less makeready disruption.
Plates of all types are improving quality and reducing environmental impact, none more so than the newest generation of litho plates suited to chemistry free or on press processing. Kodak, Fujifilm and Agfa have each introduced plates this year that have the resilience to cope with UV inks without running blind after a couple of thousand impressions.
These are durable enough for thousands more impressions on a standard press, turning what has been considered a short run only plate into a plate suited to almost every account.
And from the big three producers, there will be an inherent consistency that may not be available from plates made in China for example. Agfa’s deal with Lucky Hianguang will address this. The Belgian company will employ the technology it uses to sharpen up quality at China’s largest plate producer. These plates will be sold through China, while a second deal Agfa has struck with Ipagsa will give it a secondary brand that may bring these plates to market as an economy brand alongside the premium positioning that Agfa’s main brand still has. Ipagsa will address opportunities in expanding markets and printers that do not need the same level of performance.
However for today’s hard pressed litho printer operating in developed markets, consistency in consumables is essential. With matched inks, plates, founts and with papers that have been accurately profiled, automation becomes possible. And all printers need to be looking for the consumables approach that delivers the consistent production platform ready for automation.