Typically we print to flat surfaces, like paper or board, or to labels that can be fixed to objects. But there is a growing interest in printing direct to objects.
We’ve seen very short runs of one or a few units to objects such as pens or golf balls, where personalisation is used to create promotional or gift items. But more and more, we are now seeing medium-length runs, printed direct to objects as part of a manufacturing process.
There are two aspects to this. The most obvious is packaging, specifically, printing direct to objects in place of a label, which is as much about saving time as it is about saving money. Doing away with the labelling material also makes for a more sustainable solution. Not surprisingly, this is mostly aimed at things like bottles and cans where labels are heavily used with a number of printers designed to handle these shapes.
The second aspect is product decoration, which means everything from personalising gift items to offering customised printing as part of a manufacturing process. Most of these systems are highly customised because of the difficulty in handling different shapes. The target market here tends to be manufacturers rather than print service providers.
Heidelberg has embraced the concept of direct-to-shape printing as part of its drive into industrial manufacturing. It has developed two printers, the Omnifire 250, which was originally launched as the Jetmaster Dimension, and the larger Omnifire 1000. Both use robotics to present different aspects of the objects to the printheads. Both of these print CMYK plus an opaque white or a protective coating and offer similar resolution of around 1,000dpi.
The Omnifire 250 can print a narrow swathe on spherical or cylindrical objects with a diameter of 10mm to 300mm. It uses four-axis robotics to rotate these objects, but essentially it’s printing a rectangle with the object rotated underneath this. Consequently, it’s mainly targeted at small promotional items, such as personalised drinks bottles as well as footballs.
But the Omnifire 1000 goes a step beyond this. Annette Gansert, Heidelberg’s product manager for digital print solutions, explains: “It’s a big machine with six axes, which moves the arm with the inkjet head so you can always have the same distance between the head and the object.” She adds: “If you have concave shapes then you need to move it on six axes.” It can handle a wide range of different shapes, including crevices up to 7mm deep though it can’t reach into convex right angled corners. This has been used for industrial applications such as automotive parts up to a length of 1.4m. This includes a supplier for Smart Cars, which has printed customised vents and bezels.
Xerox has developed a general purpose printer, unveiling its Direct to Object Inkjet Printer back at Drupa 2016. It’s an upright device, meaning that it has a very small footprint of under 1x1m with a height of 2.8m. The print area is 70x305mm. It’s fairly flexible in the items that it can handle, using a selection of object holders for different shapes, which can include water bottles and helmets. It can print up to 30pph.
Resolution varies from 300dpi to 1,200dpi. Xerox says that it can jet the ink over distances of up 6.35mm, which is enough to handle smooth, rough, slightly curved or stepped surfaces. It uses UV inks with the standard inkset being CMYK plus white, though several different inksets are available for different substrates, including plastics, metals, glass and ceramics. Xerox says that it can also handle aqueous and solvent inks, depending on the application. The printer itself is built to order as a customised solution for each specific application. Pricing starts at around $145,000 (£105,000).
Tonejet has developed the Cyclone, which is designed to print direct to drinks cans. It uses an electrostatic drop-on-demand system with concentrated pigmented inks in an oil carrier liquid that can produce a very thin layer of less than 0.5 micron, which should prevent cracking or flaking of the ink while the subject is shaped, formed and bent. Simon Edwards, vice president sales and marketing for Tonejet, says: “Our cans cost 20 times less than a UV printer so it’s more cost-effective. Our objective has always been to produce a can that feels like a conventionally printed beverage can.”
Back in July 2016 Tonejet worked with Anheuser-Busch InBev (AB InBev), the world’s largest brewer, to produce 10,000 customised cans for the Tomorrowland music festival. This included 15 different can designs featuring national flags in runs ranging from 1,400 to 15 cans.
Hinterkopf has also looked at printing direct to cylindrical objects. It has developed the D240.2, a multi-pass inkjet machine that’s capable of up to 1,200dpi resolution, although most people print at 700dpi to increase the speed, and which is sharp enough to reproduce two-point text. It can print to plastic, aluminium, steel and glass for applications such as sealant cartridges or aerosol cans, which it can produce at a rate of around 80-240ppm. It takes cylindrical objects up to 74mm in diameter and 240mm in length and can print images right the way around the cylinders. It uses UV inks and can print CMYK plus white and lacquer. Stefan Erich Drexler, Hinterkopf’s director of sales for Europe, says that it can handle slight curves up to 1.5mm difference. The machine was trialled with Ritter, based in Augsburg, Germany, which specialises in plastic packaging, and ended up ordering a second machine. There are currently four installed but Drexler says that another 12 are due to be shipped over the next two years.
Engineered Printing Solutions (EPS) is a US-based company that Xaar acquired back in 2016. EPS has developed the XD-360, which was previously announced as the Roto-Jet. It’s a fairly compact printer, mainly thanks to its use of Xaar 1003 printheads, which can jet ink to a vertical surface. It’s designed to handle cylindrical objects including those that are flat walled or tapered, and is aimed at short-run, mainly promotional applications for things like cans and bottles. It can take objects from 38mm in diameter to 152mm up to 254mm in length. These go through the machine upright, which together with the elliptical-style race track conveyance, ensures that this is much smaller than some of the other alternatives with a footprint of 1.8x1.4m. It uses UV-curable inks and prints CMYKWW, with optional primer and varnish. It can produce 800 pieces per hour.
Flat and curved
The French company Dubuit Machines, which is part of the Dubuit Group, has developed the 9150 Digitale for both cylindrical and flat shapes. It uses UV LED inks, printing CMYK plus white in 360dpi native resolution, though Dubuit claims apparent resolution of 720dpi thanks to the use of variable drop sizes. It takes objects from 10mm to 100mm in diameter and 40mm to 200mm high and can produce up to 800 items per hour.
Several wide-format vendors have also developed small flatbed printers that are aimed at industrial printing direct to objects albeit that the range of shapes they can print to is more limited. Roland, for example, sells the LEF series of small flatbed printers that can handle objects up to 100mm in height though they are mainly aimed at flat items and can only a small degree of curvature.
Mimaki sells the UJF series of small flatbed industrial printers and has developed a Kebab option to handle cylindrical objects such as drinks bottles. Mutoh has also recently introduced its own rotary jig for its ValueJet 626UF flatbed to print directly to bottles, which can print 360° around the bottle. Both of these are really aimed at personalising gift or promotional items with very short run lengths.
There are a number of practical difficulties in developing direct to shape printers. The printheads have to be narrow enough to fit together without having to compensate for the distance between the different nozzles. Also, the printheads generally have to cope with a much longer throw distance in order to work around objects with different shapes. There’s also a balance between developing custom printing solutions to deal with different shapes and the need to have a one-shape fits all approach to reduce development costs. This partly explains why so many vendors have concentrated on cylindrical objects such as drinks cans.
Most of these systems use UV inks, which can cope with a wide range of different substrates. But most developers targeting labelling and packaging applications are working to develop aqueous or hybrid inks that should be cheaper, more sustainable, safer for food packaging and without the heavy film weight typical of UV inks. Equally, industrial applications tend to require inks with good adhesion and rub resistance, which may have to withstand extreme temperatures depending on their manufacturing and end use.
Either way, we are likely to see a lot more direct to shape printers, as vendors seek to take a bigger chunk of the labelling market and to diversify into industrial markets.