For many years now, sheetfed press manufacturers have delivered according to these expectations. The presses have evolved step by step, continually providing us with cost-savings and quality enhancements. However, all good things must come to an end, and the word in the industry is that the sheetfed press has evolved as far as it can. There really is very little that manufacturers can now do to make the basic technology much faster, more productive or produce print of better quality than it already is.

That’s the bad news. Before you start scanning the room wondering who to make redundant first, there is some good news. All those clever people in research and development are still working hard on product enhancements, and there is still kit that you can buy that will make the most of your multi-million pound investment – keep it running in tip-top condition, at the most productive level, at an optimum waste level, and with minimal use of chemistry. The difference is that the kit is now ancillary equipment – ie, the kit that surrounds the press.

Dust removal systems
“Print firms often spend six-figure sums on their presses, and then ignore the fact that everything around them is dirty, and so the press doesn’t work as well as it could,” says John Penman, managing director  of Microclean Technologies. His firm sells devices that help remove static and dust from the printing process. He says that the process generates a surprising amount of dust: “Even in a cleanroom environment there’s a lot of dust. As the sheets on a press separate they create static and this attracts the dust particles.”

Penman also believes that printers ignore dust at their peril: “If dust gets on a sheet it usually goes through the system, where it creates hickeys. Even worse, it can cause a defect on the whole run. If you’re aiming to produce high-quality print, you can’t get away with this. Even a 20 micron dust particle will show up and can be damaging to the overall image.”

Printers who want to fit anti-static devices will probably find most use in a two-stage approach – an ion blower, which blows static-destroying positive and negative ions into the press, together with anti-static bars that are fitted at the infeed and throughout the press to eliminate static build-up within the press. The two-stage approach isn’t expensive – about £1,000 for a basic system.

Filtration devices
Almost all sheetfed presses come with a filtration device ready installed. These are designed to limit the build-up of paper lint and ink in the dampening solution, and when they work well they result in a purer solution and so lower maintenance costs and increased print quality. Also, because you need to dispose of the fluids less frequently you save around £30 a week as well as the cost of having your press idle for the half-hour or so it takes to do the changeover.

However, according to Peter Benton, operations director at technotrans, most printers are running sub-optimal filtration devices. He says: “Only about 20% of the UK’s print firms have even considered upgrading their filtration devices, and so they’re still running fairly impure solutions.” Basic filtration devices cost just £500, and take half a day to install with presses being out of use typically for just a couple of hours: “it’s an open-and-shut case,” Benton says.

Ink supply automation is another way of optimising a press’s performance, in terms of the usage levels of consumables. Automated delivery systems also save minders’ time. But the big savings are on ink usage: investing even £500 in a dispensing system will yield 15% less wasted ink. According to technotrans’ Benton, investing £20,000 in ink delivery systems allows a printer to fully automate ink levelling, and cut labour costs on-press by up to 25%.

Using ink barrels or bulk containers can be part of an environmental policy – deliveries are less frequent, and less packaging is used. Automated ink delivery from barrels can be put in place for around £50,000, with around 25% of minders’ time saved. Installation time depends on the size of operation, but usually involves half a day of downtime. “Most print firms that implement one of these systems achieve a return on their investment within two years,” Benton says.

Related to ink delivery is image control: a set of scanning densitometers or spectrophotometers on the press console that detect variations in the sheets by comparing them with a control sheet, and adjust ink delivery systems minutely to correct the variations. Heidelberg has around 150 Prinect Image Control systems installed on its presses in the UK, but product manager Gernot Keller says the savings here are indirect – better-quality sheets makes for less customer complaint, and less staff time spent following up queries.

MAN’s InlineInspector is a similar system for on-press inspection, but rather than using colour measurement devices it uses cameras to recognise flaws larger than 0.6sq mm. It also links with the InlineObserver, a system of cameras placed around the press, allowing the sheet to be monitored as it travels. This allows optimal makeready times from data fed back to the control system.

Start-up waste
The Anicolor inking technology is another device that, while proprietary to Heidelberg, represents a significant step forward in reducing waste on-press. Anicolor, which works without inking zones and incorporates temperature control along with a chambered blade system, is said to reduce start-up waste by up to 90% according to its first user, Healeys of Ipswich.

John Barker, sales manager at Draabe, points out another area of concern: “Excess humidity in the pressroom is a common problem. It causes paper to curl and so slows down the entire press. It is a
major cause of inconsistency in makeready, and it also creates an unpleasant working atmosphere.” Barker recommends reverse osmosis techniques to reduce humidity.

As a side-effect, humidity control also enhances the operations of the press. Barker says: “Less humidity results in better colour, reduced roller wear and lower cleaning costs, and it can also halve chemical consumption.” The extent of these improvements depends on existing levels of humidity, but Barker says some Draabe customers have seen payback within six months. Typical humidity control systems cost from £3,000 and take just days to install, with no equipment disruption.

Benton at technotrans points out that very often a firm will install a humidity control system but fail to get the most from it because the press is still pumping heat into the room. He recommends that a printer intending to install a humidity control system should also consider an on-press cooling system, with heat being ducted away from the press to the exterior of the factory. “Such a system isn’t cheap – it costs between £15,000 and £30,000, but it can make the humidity control system up to 50% more effective, and so achieve payback within one or two years,” he says.

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CASE STUDY: BARREL-BASED INKING
For printers with a critical mass of press units, barrel-based inking can represent a huge saving on manpower. Allied Publicity Services (APS) Group in Manchester is saving 25% of its ink costs using a barrel-based system supplied by technotrans on its two MAN Roland 700 10-colour long perfectors. The system, which cost around £80,000 for all the pipework and ducting as well as the actual delivery system, is expected to pay for itself within two years because of the savings in manpower.

“It’s a neater, cheaper solution, and there’s less of a problem with manning on the press because the ink is fed directly without manual intervention,” says APS print manager Ian Duddle. The system, which feeds from five barrels containing each of the CMYK colours together with a fifth-unit seal, is also used by APS to fill containers for its five- and six-colour Rolands as well.

In addition to the significant cost savings, running a barrel-based ink system has big environmental benefits for APS as well: “Barrels cut out VOC problems, and reduce the waste you get, particularly with tins,” says Duddle. “We are ISO14001 accredited, and the environmental benefits are useful to us.”