Digital print on thermoformed plastics is a new and quite niche application, but it has considerable potential as a value-added business. Michael Walker explains.
Next time you are using a drinks vending machine, or you are at a petrol station, or even having a flutter on a slot machine, take a closer look at what is in front of you and you will see brightly coloured, shaped and illuminated plastics. Made of a variety of materials that become pliable when they are heated, these items have almost all been screen printed, or in the case of the large signs designed to be visible from the road, hand-painted.
Wide format digital print technology is about to change all this, making it cost-effective for extremely short runs or one-off personalised production. The development that has made it possible is UV-curable inks that can support the degree of stretching involved – extensions of up to 500 per cent of the original length may be called for – without cracking, peeling or losing colour density.
Thermoformable plastics are printed flat, then heated and moulded to the finished shape. The ink is either put on an opaque substrate (called ‘first surface printing’) or on the ‘back’ of a transparent one (‘second surface’); the former is used for indoor and shorter-lived applications, the latter for longer-term outdoor and back-lit use. The ability to print white ink to form a light-diffusing layer is essential for backlit applications, and of course is highly desirable for first surface printing onto coloured substrates.
Ink issues
Getting the properties of the ink right is critical here. Mike Battersby, marketing manager, large format at Fujifilm Speciality Ink Systems, says there was a trade-off between adhesion, durability and achievable colour gamut for Uvijet KV ink, which can be used with Fujifilm’s Acuity Advance Select and Select HS mid-range flatbed printers. Maurus Zeller, product manager at swissQprint, says that its T-ink can achieve the same colour gamut as in normal flatbed print applications.
Going one better, Mike Plier, EFI’s business development director for ink, says that EFI’s GS-TF ink can achieve a wider colour gamut than its standard versions and the company supplies ICC profiles that reflect this. The catch is that you can only use it with one of the company’s dedicated ‘TF’ series machines, currently the Vutek GS3520 Pro-TF and GS2000 Pro-TF, which are optimised for this type of ink, though they can print on other media too. The hybrid design of these units allows you to print very large sheets, limited only by the printer width (3.3 metres for the GS3250 and 2 metres for the GS2000) and space limitations for loading/handling the media.
Owners of swissQprint’s Oryx, Impala or Nyala flatbeds can all have their machines adapted for thermoforming print use, which requires a service engineer visit, as does the firmware update needed for Fujifilm’s Acuity models. SwissQprint says its converted printers still work on other substrates but with some limitations, although T-ink suits metal and glass very well; Fujifilm does not recommend using Uvijet KV on paper or vinyl.
Durability is another concern. EFI’s Mike Plier reckons that the amount of ink put down by a digital printer is about the same as that which winds up on the finished product in screen printing – though with a great deal less wastage and much higher productivity – so durability should be the same. Fujifilm quotes the same outdoor usage for first surface printing as it does for its other UV-cured inks, but does not yet have data for second-surface use.
The business case
Thermoforming is a specialist business and with the cost of moulds running into thousands of pounds and high volume automated production equipment into the hundreds of thousands, it is not something that most printers would want to take on themselves. But it does lend itself to partnerships or entirely new enterprises. Mike Battersby cites Tismo Products in the Netherlands, which offers Acuity-printed personalised dashboards for Minis via superclickcovers.com, as an example of the new kind of business that this kind of printing makes possible.
In addition to very short run or personalised print on shapes for which moulds already exist, Mike Plier explains that there is a ‘proofing’ opportunity using digital print to get the artwork right for longer-run screen print of thermoformed products. Printers with the right kind of wide format flat-beds should find out who their local thermoforming suppliers are (or vacuum-forming, it is the same thing) and start having some conversations about how they can help each other add value.
