Regular UV-curing ink, however, has an inherent disadvantage for thermoforming in that it dries to a brittle finish. To overcome this Fujifilm developed an entirely new UV ink range especially for thermoforming, Uvijet KV.
As well as being able to reproduce strong, vibrant, long-lasting colours, Uvijet KV has to be extremely flexible, even after curing. It must heat, deform and then cool without cracking or flaking. Uvijet KV elongates between up to 1000%, comfortably in the right zone for mass production. Tests prove the ink can be moulded with 90° corners without cracking.
Importantly the ink thermoforms at temperatures between 150°C and 200°C – a range wide enough to work with all the main substrates, including polystyrene, PETG, polycarbonate, acrylic, PVC and ABS.
Thermoforming is most common with a design on the outside of the substrate and away from the mould. But since inside forming – with the print between the mould and substrate – is also in demand, Uvijet KV has been formulated to cope with both techniques.
The use of inkjet printing in thermoforming is in its early stages, but that is likely to change quickly. Already several Acuity and Uvijet KV packages have been installed.
One of the early adopters has been Tismo Products BV in the Netherlands. Managing Director, Mr Jeroen Maessen commented: “I have been particularly impressed by the print quality that we have been able to achieve with the Acuity Advance Select 4006 and the thermoforming properties of Uvijet KV. We have plans to bring these benefits to market in a new concept based around the personalisation characteristics of a digital solution.”
Those that spot the potential are likely to be either thermoformers frustrated by their inability to carry out short production runs or customise their output for individual buyers, or graphics printers with experience in print customisation.
As with most innovations, the early bird gets the worm. While buyers need to be confident enough to invest in a dedicated printer for thermoforming ink, the market, so far, is wide open. Early adopters using their creativity to produce inspiring results will stimulate demand and open up a new market.
To foresee thermoforming using digital inkjet technologies as an exciting business opportunity is not too big a stretch of the imagination.
Near-photographic images, pinpoint accuracy The Acuity Advance Select features a flatbed measuring 1.25 by 2.5m (double for the X2 version), capable of printing 32m2 per hour (60m2 for the HS version) using four, six or eight colour channels. In terms of output, Acuity is a workhorse, requiring on average less than an hour’s maintenance per week.
Owners typically use their Acuity for precision jobs including lenticular jobs and fine quality output for buyers involved in, for example, fashion, cosmetics and luxury goods. The Acuity produces backlit graphics with the vividness and saturation previously only possible with photographic imaging. The Acuity’s print heads use variable drop technology. Each drop of ink is formed individually to a size between six and 42 picolitres, offering a print quality visually equivalent to 1440dpi.
Compared to standard fixed-drop-size inkjet printers, the results are sharp, precise images with smooth transitions and quarter tones, and clear text as small as three- or four-point reversed. A multi-zoned vacuum table ensures accurate registration on multiple passes. Apart from the Uvijet KV ink itself, the Acuity printers used for thermoforming print are absolutely unmodified. They use exactly the same print modes as for standard graphic display output.
To work perfectly every time, Uvijet KV’s components must be absolutely pure, which entails rigorous scrutiny and testing. We make sure the entire process keeps it that way, constantly analysing at each stage throughout production.
The manufacturing process uses Fujifilm’s proprietary ‘Micro-V’ dispersion technology, which mills pigments down to an ultra-fine, sub-micron scale. It’s a demanding ink to produce, but the results are worth it.