What is thermoforming?

Thermoforming is a manufacturing process whereby a pliable plastic sheet is vacuum heat-pressed onto a mold and the plastic sheet thereby takes the shape of the mold.

But in the world of wide-format inkjet printing, thermoforming means three steps:

• using a flatbed printer to print on plastic.
• Having a CNC router or other machine make a mold to the shape you want
• Putting the mold and the plastic together into a vacuum heat forming machine.

So first you select an appropriate kind of plastic sheet, a kind that can be heat formed and thereafter retain its shape.

The vacuum machine causes the plastic to take the shape of the mold. Although usually called just thermoforming, a more complete word would be vacuum thermoforming.

Early generation of thermoforming systems used solvent ink

Ten years ago Oce made a special printer (Oce Arizona T220) with special solvent ink for thermoforming. So in the beginning, heat forming was with solvent ink on a plastic sheet.

Then about 5 years after solvent-based heat-formed systems did not advance much further, Mimaki showed thermoforming results with UV-cured ink; one or two inches deep at most.

Next Gandinnovations offered a significantly more successful thermoforming UV-cured ink, it was far more flexible than any other offering.

Now a mature thermoforming UV-cured printer is available with the EFI VUTEk GS2000 Pro-TF

EFI has launched its GS Pro-TF circa 2013. In theory you can use most any UV-cured printer as long as you employ the correct special heat-formable ink. However VUTEk provides a specially equipped unit, the EFI VUTEk GS2000 Pro-TF. Plus the VUTEk team can answer your questions about the work

Just be sure that the graphic designers of your client know how to prepare the files. You may wish to obtain independent software to prepare the thermoforming parameters.

EFI sample, Spotted at SGI Dubai 2014

What materials can you print on, which can be thermoformed?

The staff in the EFI booth at trade shows can explain which kinds of plastic media you can use to print on: a plastic media which works in a vacuum forming heat machine. In a report on installation of one of their printers (at Interstate Graphics), they suggest that you can select several kinds of polystyrene, including high-impact polystyrene, and PETG, polycarbonate, PVC or acrylic substrates

You will also need a thermoforming vacuum machine. Once you print on the flat sheet of heat-formable material, you put the sheet on top of the mold, and vacuum press (actually you suck) with heat.

You can see this in some efi VUTEk booths at major trade shows, or in the demo room of efi in the USA and elsewhere around the world.

EFI sample from the VUTEK GS3250 PRO-TF, Spotted at SGI Dubai 2014

The work flow requires a special dedicated thermoforming ink

Thermoforming takes special media (media which is can deform nicely and survive the heat of the vacuum machine). Plus you need an ink which will not separate or crack when stretched across the mold.

Previously you would use screen printing ink for the plastic sheets. But there are many advantages of using an inkjet printer: you don’t need to print thousands of sheets at a time.

To create the 3D sign out of the printed plastic sheet, you need to have a mold

If you have a CNC router you are already used to creating 3D shapes which you could use as a mold.

Wide-format inkjet printer reviews combined with suggestions of applications

Our background for years has been evaluation reviews of wide-format inkjet printers. But increasingly we are writing reviews about applications. This is because your sign shop or printing company can most likely increase business if you add innovative new applications (so more than just traditional signage). 3D printing is a growing trend, but you can’t make a 3D additive image larger than a few inches (unless you have a zillion dollar 3D additive manufacturing printer).

Normal inks are not intended to be thermoformed, in part because they can’t withstand the heat of the vacuum machine: the inks would break apart during the stretching.

Bibliography

This page was written based on over 14 years attending printer trade shows, including dozens of wide-format inkjet signage expos where 3D thermoformed printing was exhibited and the process demonstrated.

But having been a research professor at two universities I can’t help but start a bibliography.

POCOCK, Steve
2010 The Shape of Things to Come: Thermoforming with UV Inks. On-Line, www.industrial-printing.net.           

Considering how many ink and printer companies are featuring vacuum thermoforming these days, you can find a lot more on the Internet. Or you can learn in person by visiting the EFI VUTEk booth at a major international signage expo.

First posted May 2014 after seeing more thermo-formed samples at ISA 2014 in Orlando and at FESPA Digital 2014 in Munich.