After a successful launch to the German market, the F918 range was taken to the UK in mid-2007, but Flint has not promoted them until its technical support team has had the chance to test and learn its new product. In early 2007, CPI Fulmar was appointed as the field trial site: works director David Copson found that the F918 inks, in conjunction with Flint’s Hydrofast 336 alcohol-free fount solution, gave him the clean, crisp, consistent result he wanted in running his Heidelberg Speedmasters alcohol-free.
F918 is Flint’s premium flagship sheetfed offset ink, and the group’s key accounts and technical services manager Richard Wilson is very clear about the fact that they’re not for everyone: While we’ve formulated them to run on sheetfed presses of any speed and, with almost any combination of peripheral add-ons, this is a premium range and we do charge extra for it.
How much extra, he is reluctant to say, citing recent price rises in the linseed, soy and pigment raw materials that have forced all the UK’s ink suppliers jack up their prices by an average 12% in the past few weeks. But he is explicit about one thing: You’ll only use these if you can justify the price by the better-quality result you’ll get. This is a premium product, but not an elite product. We’re aiming, initially, at maybe the top 5% of the UK’s printers; the big groups all of which need to hit ISO 12647 every time, want to be alcohol-free and want to stabilise quality at a very high level, he says.
Alcohol-free printing, as many UK printers are finding, has a pay-off in terms of print quality, as well as the associated benefits of easier storage and greater environment- and operator-friendliness. IPA is used to reduce the surface tension of water while increasing its viscosity, which allows a thicker film of dampening solution to interact with the ink and the non-image areas of the plate. IPA’s rapid evaporation rate also cools the ink train slightly, which helps to keep ink stable, plus the alcohol kills bacteria that can cause fungal growths in the ducts and pipework of the press.
Changing face of printing
Until about 10 years ago, IPA was considered to be the all-round good guy of on-press chemistry, making the entire lithographic process more forgiving and helping to cushion problems on presses that were older, poorly maintained or badly set up. But modern press technology, with its finer tolerances and more integrated components, means that much of that cushion is no longer necessary to achieve good-quality results. Couple that with the environmental angle – VOCs released into the atmosphere form ozone, which contributes to climate change – and the storage issues of low-flashpoint IPA, and it’s easy to see why lots of printers are looking to cut alcohol completely out of the printing process.
F918 is of the same family as Flint’s biggest UK seller – the F912 high-strength perfecting ink – and like that range it has a vegetable oil base, which immediately ticks the environmental box. Beyond that, Flint is coy about revealing the specifics of its formulation, but Wilson does say that the key component is an entirely new binder/resin system that gives a wide ink-water tolerance and much faster setting and drying. In performance terms, it’s much more akin to a conventional mineral oil-based ink.
The overall formulation of the F918 range lends itself to improved water pick-up and a more stable emulsification process and, as Wilson points out, the less emulsification there is, the better the drying. This is where Hydrofast comes in – specifically designed to work with the F918 range, it requires a dose level of around 4-5% to produce similar chemical properties in the water to those produced by alcohol. But Wilson says that it will work with other fount solutions – just not quite as well. Flint Group specifically set out to make a system that would work on fast presses for these purposes and, of course, we now have all the chemical and manufacturing expertise within the group to enable us to do that – we can make the complete range of press chemistry. It’s designed to perform at its best with Hydrofount products, but you can use it with other alcohol-free founts.
As with most high-performance inks, the F918 series is tack-graded, which means that it has to be run in a certain order: K comes first, followed by CMY in that order, although Wilson says it is possible to reverse the C and M.
One of the spin-off benefits of making a premium ink product that’s avowedly intended for the top 5% of the UK’s general commercial printers is that you can count on a certain level of specification on the press. The white papers that Flint has produced following Fulmar’s field trial period state either the necessity or the desirability of an impressive range of press peripherals: an ink temperature control system, low-alcohol roller compounds, a reverse osmosis system and, preferably, a dampening filtration system as well. Ink temperature control helps to compensate for the absence of IPA’s cooling effect; low-alcohol roller compounds improve the transfer of the damping solution when no alcohol is present; the RO system eliminates the chemical variables from the water supply; and the filtration system helps to eliminate the flora that tend to build up in the dampening system without alcohol’s sanitising influence. Fulmar’s Heidelbergs came with ink temperature control systems out of the box, while their low-alcohol rollers were covered in a specific compound from Böttcher, and the RO and filtration systems were retrofitted by Technotrans.
But Wilson is keen to emphasise that on slower, older presses, not all of these gubbins are necessary: If you’re running below 12,000sph, a temperature control system doesn’t matter as much, he says. It all depends on what you want out of the inks. To perform at their best, they call for supporting technology.
The new F918 inks might not be for everyone, but for the specific type of printer they are intended they seem like the answer to a prayer. Wilson gives the example of a big European group producing paint charts: They were getting problems with dot gain and the colours were varying with fluctuating levels of emulsification, even when everything on the press was identical. They discovered that it was the water pick-up that produced the dot gain, so they started using the F918 inks. Their presses became immediately more stable in their emulsification and they were able to reproduce exactly the colours time after time.
According to Wilson, printers that have invested heavily in a fast press want an ink that can bring out the best in it. And there is a strong case for using F918 if you are that kind of printer, because the return on investment – in terms of hitting your colour standards, consistently, with cleaner, sharper colours – is quick and unarguable, he says.
Ink base vegetable oil
Colour range CMYK plus bio-base system for mixing Pantone range
Size 2.5kg vacuum pack tins; 2kg on-press cartridges; 200kg barrels for pumping
Contact Flint Group UK 01403 792746 www.eu.flintgrp.com
Stehlin Hostag Inkredible Perfexion
The perfecting-specific grade of Stehlin Hostag’s premium ink range isn’t an exact rival to Flint’s F918. While it’s designed for high-speed multicolour presses and is fast-drying enough even for use in perfecting applications, it’s not specifically intended for alcohol-free use. However, Stehlin does claim a high ink-water balance latitude, which means it gives the same benefits in terms of dot gain and more vivid colour. CMYK only, at least for now.
Ink base vegetable oil
Colour range CMYK
Size 2.5kg tins, 200kg drums, various sizes of on-press cartridge
Contact Stehlin Hostag 0115 986 0477 www.stehlinhostag.com
Sun Chemical Exact PSO
About three years ago, Sun set itself the task of formulating an ink to allow printers to hit ISO 12647 tolerances, and the Exact range is the result. But, again, it’s not specific to alcohol-free running, and like the Stehlin Hostag product it’s only CMYK, at least for now. According to the firm, it has excellent ink-water balance for controlling dot gain.
Ink base vegetable oil
Colour range CMYK only
Size 2.5kg tins, 200 kilo drums, 2 and 3kg on-press cartridges
Contact Sun Chemical 01773 813704 www.sunchemical.com
Read the original article at www.printweek.com.
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