To foil a sheet means investing in a foil-stamping platen or rotary cylinder and finding space for it on the factory floor (both of which demand a certain throughput to justify the investment). And for each job, foiling means adding extra turnaround time, a few extra sheets for spoilage, plus extra manpower to handle the pallets before and after. There is also an expensive investment to be made in the dies that stamp the foil on to the sheet.
Well, that’s what it used to mean. But not any longer, because sheetfed printers who want to foil can now invest in a unit for their press that can handle the entire process inline. OFT Technology’s Foiltone is a clever device that takes up two press units (or a unit plus the coater, depending where you put it) to give die-less cold foiling at the speed of the press. In a single stroke, this eliminates the need for floorspace, extra handling time and the cost of dies.
Rapturous reception
Foiltone is the brainchild of Bruce Podmore, owner of greetings card printer Windles Group, who was looking for a way to cut the costs of the offline added-value processes that Windles was adding to its range.
Podmore set up OFT (Offset Foil Technology) in 2005 to market his invention to other printers, and the reception since its launch in January 2006 has been rapturous. As OFT sales and marketing director John Hopkinson says, unsurprisingly, “it seems that Windles is not the only sheetfed printer looking to radically reduce the cost of its foiling”.
While the concept of Foiltone is simple, the machine itself is not. Some extremely clever engineering has gone into its design, coupled with a good few years’ testing. It works by using the first unit of the two it occupies to print a pattern in adhesive, and the second unit to nip the foil on to the adhesive. It is a standard cold-foiling process, as opposed to hot-foiling, which uses heat to activate the adhesive coated on to the back of a reel of foil. The cold-foil process uses a separate glue, which is still tacky when the foil is pressed on to it, using pressure but no heat.
An image is printed in glue on the first unit, using a standard offset plate imaged in a normal way – this is how the process avoids using dies. After being printed with glue, the sheet passes out of the first unit and into the second. Standing over the second unit is a foil unwind that uses a direct-drive servo to feed foil down into the unit, around the blanket cylinder and exit it at the back, where it is rewound on to another axle mounted over the unit.
No mechanical connection
The way that Foiltone controls the foil’s speed and tension is simple but clever. There is no mechanical connection between the press and the foil, but the foil matches the press’s speed automatically. On its journey into the unit, the foil web runs around a swing-arm – essentially a roller that is allowed to move through an arc. The shaft on which the swing-arm is mounted holds a digital encoder that senses the foil web’s movement and starts up the servo motor controlling the unwind. When the press reaches a constant speed, the swing-arm returns to a ‘datum’ or reference position, and the encoder sets itself to a speed to match the press. The beauty of this is twofold: first, the unit doesn’t slow the press down at all, but simply mirrors its speed; second, it is not connected to the press, meaning that when it is not in use, it is extremely fast and simple to disconnect (the foil gets wound back on to the unwind, and the adhesive in unit one’s ducts is washed up).
OFT has worked with German adhesive manufacturer Henkel to develop a glue suitable for printing offset. Hopkinson explains the characteristics of the glue: “First, we wanted the facility to print halftones in foil, so we were looking for a glue that had very little dotgain. We also wanted it to stay open for long periods, and to be cleanable by standard offset cleaning fluids. Basically, we wanted it to behave as much like an offset ink or varnish as possible.” There is also a UV glue available that makes use of a curing lamp mounted interdeck after the second unit to cure the glue behind the foil.
The foil has also been developed by OFT, in conjunction with German manufacturer Kurtz. It consists of a Mylar backing, a release coating and a top layer of aluminium. The release coat has a ‘shear factor’ that has been judged so that the tack of the adhesive shears the foil precisely, and the remaining foil remains on the Mylar backing. Both foil and glue are about 10% more expensive than standard cold-foil equivalents, but Hopkinson is confident that costs will come down when more users come onstream.
One of the drawbacks of Foiltone is that, at present, there is no way of indexing the foil to the substrate. In other words, for the length of a sheet going through the unit, the same amount of foil is pulled – so if only a small area is being foiled, a large amount of waste gets rewound. “If you have just got a small area of foil every sheet, you are better off keeping the job off-press on a platen or cylinder,” says Hopkinson. However, the Foiltone unit does come with two unwinds and two rewinds, so two webs of foil can be run, and up to four can be fitted on a single Foiltone device.
Skill required
If the printer is printing on a wide variety of substrates, a small degree of skill is needed to judge the set-up of the Foiltone unit. Hopkinson explains: “If you are printing plastic with a smooth surface, you would choose a hard blanket with little compression. If you are foiling a textured board, where the surface has pits and lumps, you would choose a blanket with some compression to allow the foil to be pushed down onto the surface and conform to it.” But in general, the makeready is simple, with foil being threaded through the roller train in inching mode and then mounted, and the air pressure driving the swing-arm being set. It takes about 20 minutes in total, according to Hopkinson.
Foiltone can be fitted to any standard offset press – OFT has installed them on Heidelberg, Komori, KBA and MAN presses – and units have so far been made for B1 and B2 presses. The device is most usually fitted to the first two units of the press, because laying the foil down first gives the printer the unheard of opportunity to single-pass print over the top of the foil, giving a range of metallic colours. The process is reminiscent of MetalFX’s eponymous process, but Hopkinson says “ours is much better, vibrant and resilient because we are using proper foil, not a metallic silver ink”.
Such is the attraction of the on-press foiling concept that within a year of Foiltone becoming commercially available, Heidelberg and MAN Roland launched their own versions. Of the three remaining, OFT operates an original equipment maufacturer agreement with KBA, supplies units to Komori, and is in negotiations with Mitsubishi. “It is an idea that has caught everyone’s imagination,” says Hopkinson. “It is a great-looking result, adds superb value and is quick and easy. What more could you want?”
SPECIFICATIONS
Max size of sheet to be foiled 1,020x740mm
Max substrate thickness as for the press
Max speed as for the press
Price B1-format Foiltone device with two unwinds/rewinds: £152,000 (installation and training charged separately at £4,000)
Contact OFT Technology 01772 316977 www.oft-technology.com
THE ALTERNATIVES
Heidelberg FoilStar
Heidelberg’s FoilStar was unveiled a few months after OFT’s first commercial installation went in. Essentially, FoilStar works like Foiltone: it uses two units to print glue and nip foil, matches its speed to the press, and ordinary offset plates are used to print the adhesive. One unwind/rewind can handle up to six foil reels, but like the FoilTone, there is no means of indexing foil to substrate. Will be commercially available by the autumn.
Max size of sheet to be foiled 1,020x740mm (also available for B2 presses)
Max substrate thickness as for the press
Max speed as for the press
Price not yet available
Contact Heidelberg UK 020 8490 3500 www.heidelberg.com
MAN Roland Prindor
MAN’s inline foiling device won the PIA/GATF award for technical innovation last year. Like the Foiltone, it uses a first unit to print adhesive and a second to nip foil on to the sheet. But it uses coloured glue, so that thickness can be measured with a densitometer. Up to five foil webs can be run, and MAN uses third-party consumables. It is available for B1 and B2 presses.
Max size of sheet to be foiled 1,020x740mm (also available for B2 presses)
Max substrate thickness as for the press
Max speed as for the press
Price B1: £232,000 including training and installation
Contact MAN Roland GB 020 8648 7090 www.man-roland-gb.com
