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It’s probably about 10 years ago now that the print industry first discovered that the average digitally-printed sheet cracks when it’s folded. Made brittle by the pressure and heat of the toner fusing process, the paper fibres don’t retain the elasticity of offset-printed equivalents, and when subjected to the stress of folding, they simply break, leaving an ugly white gash down the fold-line and making the document itself weaker as a result.

In the late 1990s, UK manufacturer Morgana discovered that if the sheet was creased –that is, pre-stressed – before folding, the fibres didn’t crack. With the launch of its Autocreaser at Drupa 2000, Morgana not only provided a much-needed solution for digital printers, but also proved the market was ripe for other manufacturers to tackle. Which, of course, they have in abundance. The latest addition to the array of digital creasers available on the market is Duplo’s DC-445, a standalone wheel-up matrix creaser with a good range of features at a competitive price.

The DC-445 – also known as the DuCreaser to better promote it in the alphanumeric-resistant digital print sector – kicks off with a top-feeder based on the proven Duplo DC digital finishing machines, which international product marketing manager Sally Dobinson says is more reliable than the feeders on competitive creasers. “The top-feed principle is also less prone to cause marking on the bottom sheets, which you do get with the weight of a stack pressing down on it,” she says.

Additionally, the same stack weight can lead to double-feeding, from which Dobinson claims the DuCreaser to be exempt; and it means the DuCreaser can take a taller pile height of about 100mm. On the other hand, it does mean an operator must stop the DuCreaser to reload, although Dobinson claims this is a quick process that takes “half a minute at most”.

Auto tray adjustment
One well-thought-out feature of the feeder is the fact that it can be set to an ergonomically-comfortable working height for reloading: when the stack is empty, the tray automatically lowers itself to the pre-set height. Additionally, an ultrasonic double detector measures the density of the sheets as they pass along the infeed table; any variation in sheet density is picked up and the offending sheets are rejected into a bin where they can be retrieved and re-fed if necessary.

The innards of the DuCreaser are based around a matrix that effectively squashes the sheet between the male and female tools to effect the crease. The crease runs at right angles to the sheet’s direction of travel, meaning the sheet must be stopped momentarily to have the crease put in; subsequent creases (and the DuCreaser can put up to 15 on a sheet) slow the sheet down further. The crease positions are adjustable in increments of 0.1mm.

Straightforward set-up
Set-up on the DC-445 is as straightforward as you’d expect from a machine designed for a digital print shop. The operator loads up the feed pile and enters the length and width of the sheet at the central control panel. He then sets the depth of crease and the amount of feed suction required (both are increased as the stock weight goes up) and then enters the positions of the creases measured from the leading edge. Once the machine is ready to run, the ‘test’ button feeds a single sheet through the machine so the operator can test that all the creases are in the right position. Another clever feature here is the auto-adjust button. If the first crease is positioned incorrectly, the subsequent creases will also fall incorrectly, but the auto-adjust feature allows the operator to adjust the first crease and have the positions of subsequent creases adjusted according to the adjustment increment.

Also during set-up, the operator can adjust for skew (if, as often happens, the image has been printed slightly skewed on the digital press) by turning a manual dial that kicks the sheet slightly out of true. Folds thereby are put in parallel to the image, rather than to the sheet. And shrinkage – which again happens often in digital print, due to the heat of the toner fuse process – can also be compensated for on the central control panel. The shrinkage-correct feature allows the operator to measure the shrunk sheet length and enter that new length; the DuCreaser automatically resets all fold positions incrementally to the new length. There’s a 30-job memory too, although no JDF compatibility.

Cleverly, the DuCreaser can also run parallel perforating and edge- and/or centre-slitting operations in the same pass as creasing. While the matrix creasing operation happens at right-angles to the sheet’s travel, perfing and slitting happen in parallel courtesy of a shaft-mounted set of rotary tools. Duplo has included in the DuCreaser’s design a quick-disable/enable feature, which is essentially a dial that allows the shaft to be raised or lowered. Adjusting the position of the slitting and perforating tools along the horizontal axis is a matter of using a DuCreaser-specific tool, “a bit like a little allen key”, says Dobinson, to slide the tooling into the required position.

While there’s a basic adjustment for the depth of crease (variable with the weight of stock being fed), the DuCreaser at present has no adjustment for the width of its crease; Dobinson says that later this year, Duplo will introduce a narrow-width creasing tool for stocks lighter than 110gsm.

There is only one optional extra for the DuCreaser, and that’s an air knife that works in tandem with the standard-spec machine’s air blow feature. It’s intended partly to dissipate static build-up from a digitally printed stack, and partly to provide extra air-assist for heavier stocks.

Broad appeal
With the DuCreaser, Duplo is targeting a range of digital operations including copyshops, small- to medium-format commercial printers, larger printers with digital departments, and inplants. “It’s a range of customers that perfectly mirrors our spread of customer type,” says UK marketing manager Peter Jolly. He believes the DuCreaser’s attraction lies in the combination of its features – “which give the productivity a real boost” – and its price. The latter is competitive ut not aggressive, but Jolly’s point is that the price/feature ratio makes the DuCreaser an outstanding machine in its bracket. “The price and the speed together give it a broad appeal,” he says. “Entry-level digital printers, with presses of 30-80 pages per minute, will be able to afford this, while its speed means it will also be interesting to printers with 110 page per minute outputs.”

The DuCreaser joins a well-populated sector. The main competition comes from the first-to-market Morgana AutoCreaser range, the Tech-ni-fold Speedcreasa and the Bacciottini PitStop. The Morgana machines, the PitStop and the DuCreaser use a rise-and-fall matrix mechanism, while the Tech-ni-fold offering uses a system of male-female collets (essentially a pair of shaft-mounted rings with the male-female tooling built in). The advantage of the Tech-ni-fold architecture is meant to be its speed. Because it doesn’t stop the sheet to put the crease in, the theory goes that the machine should run faster than the matrix-based machines. In practice, the matrix-based machines are rated at more or less equivalent speeds; certainly the DuCreaser, at a top output of 3,000 sheets per hour, can match Tech-ni-fold’s Speedcreasa, and its productivity-enhancing features help to give it an additional edge.

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SPECIFICATIONS
Max speed 3,000sph (one crease in an A4 sheet)
Max sheet size 320x650mm
Max stock thickness 350gsm
Max number of creases in a sheet 15
Price £5,995 (including perforating unit)
Contact Duplo International: 01372 468131, www.duplointernational.com

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THE ALTERNATIVES
Bacciottini PitStop AF
Another matrix rise-and-fall architecture, the automatically fed PitStop is primarily designed for offset-printed material, but there’s a special tool for digital print. Four creasing tools and one (optional) perforating tool can be used in one pass - makeready is, like the DuCreaser, electronic. This machine can take a heavier stock than the other standalone creasers featured here.

Max speed 3,600sph (one crease in an A4 sheet)
Max sheet size 500x700mm
Max stock thickness 600gsm
Max number of creases in a sheet 100
Price £14,950
Contact Encore Machinery 01582 668900, www.encoremachinery.co.uk

Morgana Autocreaser 33
The baby of the Autocreaser family is still faster than the DuCreaser, and handles a heavier stock and a bigger sheet. It has a job memory for up to nine programmes; automatic makeready and a crease position adjustment of 0.1mm. There’s an optional jogger, but you can’t add extra tooling to perforate and/or slit.

Max speed 5,000sph (one crease in an A4 sheet)
Max sheet size 330x630mm
Max stock thickness 400gsm
Max number of creases in a sheet 16
Price £4,630
Contact Morgana Systems 01908 608888, www.morgana.co.uk

Tech-ni-Fold Speedcreasa
The Speedcreasa works on a rotary creasing basis and entirely manual set-up is done by eye. As well as creasing, the machine can carry out perforating, edge-trimming or gutter cutting in the same pass, and an optional spine/hinge creaser can produce (gatefold) book covers.

Max speed 3,000sph (independent of number of creases)
Max sheet size 480mm wide x any length
Max stock thickness 350gsm
Max number of creases in a sheet 28
Price £4,495
Contact Tech-ni-fold 01455 55449, www.tech-ni-fold.com