Setting the tone: Developments in colour 3D printing

“Right now, colour is nice to have, but we want to make it must-have.”

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The turn of the millennium brought about many changes. While our aeroplanes remained in the sky despite fears of the Y2K bug, advancements in technology would see the rise of the internet, and with it things like social media and mobile apps. Buying music would become a thing of the past, as would our tendency to read words like these in print publications. It also coincided with the launch of colour 3D printing, meaning rapid prototypers would soon have an alternative to building parts layer-by-layer in monochrome.

Pioneering that particular movement was Z Corp. By the time the company had been acquired by 3D Systems 12 years later, its colour 3D printing technology was enabling the likes of LAIKA to start applying colour during the build rather than painting parts in post-production. But LAIKA’s Director of Rapid Prototyping Brian McLean would tell TCT in 2018 that, even by the time it was working on Paranorman (2012), they found colour 3D printing technology to be inconsistent ‘from print to print.’ It wasn’t just the users who had reservations about the technology. RIZE CTO Eugene Giller worked as a Senior R&D Chemist at Z Corp between 2005-2010, and he too had been unsatisfied with the quality of the parts Z Corp’s colour technology would output.

“I always thought it should be a technology that could provide a fully functional colour part, not just form,” the RIZE founder told TCT. “For me, it was all about strength.”

Today, there are a host of companies supplying colour 3D printers to market, including RIZE, Stratasys, HP and Mimaki. The latter launched the 3DUJ-553 platform with its capacity to print ‘more than 10 million colours’ in 2018 and followed it up with the smaller format 3DUJ-2207 system in 2020. Its larger 3DUJ-553 machine boasts a build volume of 500 x 500 x 300 mm andt uses a UV-curable inkjet process to print parts in full colour. White and clear inks can also be mixed with colours to add transparency, while water-soluble materials enable post-processing times of just a couple of minutes.

Dutch service provider Marketiger was among the first users of Mimaki’s colour 3D printing technology. As of late 2019, the company was producing up to 20,000 custom figurines every year, though a second 3DUJ-553 was installed in early 2020. With the machine’s automatic cleaning sequence and queuing capabilities, Marketiger is able to print at up to 72 hours in a row without touching the printer, but generally sticks to overnight print jobs.

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Exhibit at the UK's definitive and most influential 3D printing and additive manufacturing event, TCT 3Sixty.

Because of the nature of its core business – custom figurines based on 3D scans of people – the company targets 100% yield. To ensure everyone who scans themselves gets a 3D printed full colour model, Marketiger only starts manufacturing models once it has confirmed the quality of the scans and editing of the models. But once the print button is hit at Marketiger, it barely stops.

“My company is built on this machine running 24/7,” Marketiger Director Maikel de Wit told TCT at Formnext 2019. “It causes some issues because it’s a new technology, but we’re able to get this machine above 80% utilisation on a 24/7 basis.”

Evidently, much progress has been made in colour 3D printing over the years. With the inaccuracies and supposed brittleness of early colour 3D printed parts, building a business around the technology as Marketiger has with Mimaki’s tech was hardly possible. Yet, the companies bringing the technology to market know there is still more to be done.

Giller has always been of that mindset. He founded RIZE, in part, because he wasn’t happy with the quality of components coming off Z Corp printers. Yet, he has always had faith in the potential of colour 3D printing. In starting RIZE, Giller has aimed to deliver a printer that can operate in any environment to deliver functional parts in full colour that require minimal post-processing. His answer is XRIZE, which uses the patented Augmented Material Deposition technology to build parts by jetting a formulated release agent between layers of extruded materials. While the extrusion process allows carbon composites to be printed, the jetting aspect of the process enables the voxel-level application of full-colour graphics.

For RIZE, the potential applications go beyond prototyping and figurines. Multi-coloured medical models – as we detailed in volume 29 issue 2 of TCT Magazine – is a key play for this technology, as are jigs and fixtures. For manufacturing aid applications, the use of high-performance polymers and composites ensure parts can withstand the factory floor, while colour can be used to indicate when a part needs replacing, as with the manufacturing aid pictured at the top of the page. These are just some of the ways RIZE’s customers are using its full-colour technology, and they’re not shy of telling the Boston-based firm how they can still improve.

“They want new materials,” Giller says. “And that’s why we are working really hard to introduce a new set of materials. They’re really happy with [the current materials] right now, but there are a subset of customers that really want parts to go inside of vehicles where they are exposed to oil. They also ask for elastomeric materials.”

As a result, RIZE is working to add such products to the and Rizium One, Rizium GF (Glass Filled), and Rizium Carbon materials it already offers. Unsurprisingly, the company is not alone in building out its colour 3D printing portfolio to meet rising customer demand.

Stratasys has been prolific in that regard. It now offers more than half a dozen full-colour 3D printing systems in its J Series portfolio, with some designed specifically for the dental and medical markets. In June, it introduced the J55 Prime, an office-friendly full-colour system that operates as quietly as a refrigerator (less than 53 DB), alongside a range of new functional materials. The expansion of material offerings, despite the wealth of machine options, is seen as the primary way to nurture the company’s colour printing offering.

In line with the J55 Prime, Stratasys rolled out the Elastico Clear and Elastico Black rubber-like materials, the Vero ContactClear translucent Biocompatible material for prolonged skin or bodily contact, Digital ABS Ivory for high impact designs, and ultra-opaque colours enabled by the VeroUltra family. Other materials in the Stratasys colour portfolio include the flexible VeroFlex and the versatile VeroVivid.

With advancements also being made with the 3MF file format and Stratasys aligning with KeyShot, the company is confident in its capacity to deliver the details and aesthetics that any designer could want, but like RIZE is continuing to push on the performance side through ongoing materials development.

“When it comes to mechanical properties, this is still in the works,” says Zehavit Reisin, Stratasys Vice President, Head of Materials Business and Design Segment, ROW. “When we discuss PolyJet materials, it’s about acrylic-based photopolymers and they behave differently versus, let’s say, thermoplastics. Their heat conditions or their dimensional stability is subject to change if you put the part under stress, under heat, under aggressive environmental conditions and that’s where durability is questionable. That’s where [there is a question mark around] manufacturing end use parts with PolyJet. But we are continuing to work very hard on improving the material properties of what you see today on the J Series, meaning the colours, the transparency, the mechanical and thermal properties are better to withstand the required environmental conditions.”

As colour 3D printing establishes itself in the medical and prototyping sectors, there is now a glance towards other opportunities. For a surgeon or a designer, the benefits of colour 3D printing are obvious, but in other markets the uptake is slower. That may not be a problem since there will always be medical procedures to carry out and parts to design and redesign, but in this industry, there is always an appetite to push the boundaries. And Giller is optimistic about the impact full-colour 3D printing can have moving forward.

“The way I think about it, we all have colour TVs, and nobody wants to go back to black and white,” says Giller. “But I’m old enough, I did have a black and white TV and I remember some people saying, ‘I don’t need colour, TV is an art’, and now, no one thinks this way. If we can get it to a [lower] price point, I think people would get used to printing in colour. Right now, colour is nice to have, but we want to make it must-have.”