Product Reviews

The name of Spühl will be unfamiliar to many UK printers, despite there being three installations of the Swiss company’s wide-format UV digital printers in this country. After an unsuccessful six-year stint under 3M, Spühl passed the UK distributor reins to Litho Supplies in April last year. Litho Supplies promptly headhunted business development manager Stewart Bell from NUR and, within 10 months, there were three sales. The Spühl machines are among the fastest, widest and most expensive machines on the market – but they are also developing a reputation as being the most sophisticated and productive too.

The Spühl heritage is an interesting one. Originally established in the 1870s as a maker of wire-forming machines that made, of all things, mattress springs, the company was bought by the world’s biggest mattress-maker, the American outfit Leggett & Platt, in 1997. L&P’s ownership gave Spühl the freedom to realise a long-held ambition: the development of an inkjet printer that could print onto mattresses. The resultant Virtu RS machines, having been developed for such heavy-duty use, incorporate both a level of robustness and a range of features that set them apart from other wide-format digital machines.

The Virtu range comprises two basic models, the RS 25 (a 2.5m machine) and the RS 35 (3.5m). Each is available in combinations of heads and colours: 36 heads and 48 heads, each yielding four-colour, six-colour or four-colour plus white capabilities. There’s a choice of either Sun Chemical or 3M inks, both of which can be used for outdoor applications, with or without lamination. Unusually, there’s also a choice of drop sizes: customers can select from 30 picolitre heads for their colour printing and an 80 picolitre head suitable for flood coating.

Hybrid flexibility
Both the Virtu machines are what Bell calls “true hybrid models”, meaning they can print equally well onto either flexible roll-to-roll substrates, or onto rigid substrates up to 95mm thick. Plenty of machines make this claim, but Bell maintains their capacity for one type of substrate is usually better than the other. “These are no-compromise machines,” he says. “Most printers are put off hybrid machines by the fact they either print flexible better than rigid, or vice versa. But the Virtu machines are equally good at either.”

Bell’s claims are borne out by the architecture of the Virtu. Deceptively, the standard model harbours a vacuum bed inside its housing of a size that can image a 2.5x1.25m rigid sheet without moving it: the head moves laterally, while the imaging gantry travels from back to front of the bed. This static imaging mode is unusual enough in a machine with a comparatively small footprint (its depth is just 3.3m), but the real surprise is that, unlike many other hybrids, the flatbed on the Virtu can actually move the substrate too. A heavy-duty belt system transports media through the printer, using a clever registration system that combines linear motors with digital encoders, registering the edge of the sheet to the printhead to give a dot-perfect repeatability.

Bell outlines the advantage conferred: “You can interrupt a job if a more urgent one comes in. You can stop the printhead halfway through and it will remember where it is, so you can just reload the sheet and tell it to resume at the exact dot it last printed. And if you ever need to clean the printheads in the middle of printing, you can do the same thing – just interrupt it, bring the gantry to its home position, clean the heads and press resume.” It all adds up, Bell says, to material savings – important in a market where substrate costs register in the pounds, rather than the pence.

Easy testing
In a similar vein, the Virtu machines run their test pattern on an A3 sheet of paper. “It takes 10 seconds, which is a lot quicker than other machines, and there’s no need to do it on the actual substrate,” says Bell. Material is also saved during the webbing-up process: just 150mm of flexible material is used to web up the Virtu. And wide-format production houses will welcome the fact the Virtu comes with a standard mesh kit: a collection tray stops the ink dribbling through the mesh and on to the vacuum bed. This allows printers to work with less expensive meshes that don’t come with integral vacuum paper backings.

At the front end of the Virtu is a choice of the Caldera Grand RIP+ or Onyx Production House RIP. The latter, Bell says, is expected to be the RIP of choice for UK customers. It contains tiling, edge-to-edge imaging, colour management and cut profiles for laser- or knife-cut images, such as vinyl graphics or vehicle liveries.

The Virtu’s integral vacuum tables have individually switchable zones. This is a useful feature, as it does away with the need to spend time cutting out paper masks for the non-used vacuum areas. However, there is a makeready hit: the operator must walk the length and width of the machine, turning on only those zones required and setting those to either high or low pump. Makeready, in general, is arguably a fraction more time-consuming on the Virtu than rival machines: carried out from a central touchscreen, it encompasses several settings, including fire head frequency, pass rate (from single-pass to four-pass), vacuum-zone switching, lamp power, and setting the lamps to cure post-dot or as the dot goes down – this affects the dot gain during imaging.

Interestingly, Spühl takes the view that the constant on-off life of a UV lamp shortens its life (“by about half an hour for each switch-on,” according to Bell) and so the lamps on the Virtu machines remain constantly switched on, as long as the printer itself is on. To avoid overheating, the machine runs a refrigerated water system that chills the lamps. Bell refutes the idea that this bumps up the Virtu’s energy consumption rates: “It’s the start-up that draws the power, not the off switch or the off state,” he says.

Continued development
Since releasing its Virtu machines in 2001, Spühl has continued to develop them. In November last year, it launched a pair of semi-automatic feed and delivery tables. These automatically take the sheet into the machine, position it, image it and eject the sheet out of the rear onto a delivery table. It makes a difference, not so much in speed terms, but in operator productivity terms: the tables make it feasible for a single operator to load and unload.

The price tag for a Virtu machine includes a week’s operator training held at Spühl’s Swiss headquarters. While in residence, operators are also trained in basic maintenance, by-passing the need for an engineer and consequent downtime.

Upcoming from Spühl is a new 5m-wide Virtu model, to be launched in October. This will add an interesting dimension both to the company’s portfolio and to the super-wide-format market. The recent consolidation of that sector with HP’s purchase of NUR and the consequent dropping of the XL220 model in favour of NUR’s Expedio, means there is less choice for a super-wide print shop than ever before. Spühl hopes to make a positive impact on that sector with the new machine. Meanwhile, Litho Supplies aims to attract wide-format print shops with the formidable features and functionality of the RS 25 and 35 models.

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SPECIFICATIONS
Max speed 150m²/hour (single-pass, 300dpi, four colours)
Max resolution 700dpi (40m²/hour, two pass, six colours)
Max substrate width RS 25: 2.5m; RS 35: 3.5m
Max substrate thickness 95mm
Price from £245,000 (RS 25 four-colour model)
Contact Litho Supplies 0117 971 5241 www.litho.co.uk

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THE ALTERNATIVES
Agfa Anapurna XL and XL2
Like the Virtu, the Anapurnas are UV hybrids and print onto flexible and rigid media. No semi-auto loading/unloading, but the machines have an unusual capacity to feed multiple boards simultaneously for dual printing. There’s a pre-print and a post-print white option and also, like the Virtu machines, a stepped lamp power output setting. It has six colours only (CMYKLCLM), plus the white option. The RIP is a standard Wasatch.
Max speed unavailable
Max resolution 363x725dpi
Max substrate width 2.5m
Max substrate thickness 50mm
Price from £130,000
Contact Agfa UK 020 8231 4983 www.agfa.com

HP Scitex FB6100
The FB6100 is HP’s only wide-format UV printer and it’s another hybrid: switching from rigid to flexibles using a guided process. Very similar specification to the Agfa Anapurna, it has a choice of four-colour, six-colour plus white, or eight-colour output modes and choice of Onyx or Caldera RIPs.
Max speed 100m²/hour (four-colour)
Max resolution 1,270x800dpi
Max substrate width 2m
Max substrate thickness 50mm
Price from £512,000
Contact HP Scitex 0845 2704000 www.hp.com

Océ Arizona 250 GT
Océ’s hybrid is the only one currently on the market with a variable droplet size, the effect of which is to lend 256 levels of greyscale to any image, and allows Océ to field a four-colour machine where other manufacturers must add in ‘lite’ versions of their inks to achieve the same apparent resolution. There’s no white, however, and the variable dot technology means it’s a lot slower than the Virtu.
Max speed 16m²/hour
Max resolution not applicable
Max substrate width 2.5m
Max substrate thickness 48mm
Price from £89,000
Contact Océ UK 0870 600 5544 www.oce.co.uk

Screen Truepress Jet2500UV
A new introduction to the market, Screen’s hybrid is a 2.5m-wide machine and it’s a lot faster than the Virtu machines, despite the fact it’s a greyscale printer with up to seven selectable droplet sizes. It can also handle up to seven colours, including a pre-coat white.
Max speed 67.5m²/hour
Max resolution not applicable
Max substrate width 2.5m
Max substrate thickness 50mm
Price not yet available
Contact Screen UK 01908 848500 www.screeneurope.com