Stuart Jackson has been around the additive manufacturing industry (AM) long enough to know how far the technology has come and how far it still has to go, particularly around the topic of sustainability.
“I'm a poacher turned gamekeeper,” Jackson said in a conversation with TCT last December. “I've been on the supply side, so I know the realities of that. I've done a lot of theoretical sustainability studies which are just lip service and tend to hide the fall down. In truth, additive manufacturing is defined as being environmental because you need less material but to be honest, the running costs, the economics of it, the environmental impact, even metals … a lot of it is not true.”
Jackson came to AM in 1994 via the machine tool world and until recently, had spent those three decades at prominent AM businesses in the UK and Ireland. In the weeks leading up to our call however, Jackson had started to share details of a new venture he’d been invited to join with sustainability at its core; essentially, exploring the use of forestry waste to produce high-performance 3D printed graphite.
Carbon Forest Products (CFP) was founded by Patrick Morris in 2015, a product designer at the Royal College of Art with a background in ceramics from his upbringing in New Zealand. While completing a masters project at the RCA, Morris found himself in the UK seaside town of Whitby investigating Whitby jet, a fossilised carbon material which is dug out of the rock face from Yorkshire’s Jurassic Coast and carved into jewellery. He started to investigate what could be done with the leftover powder from this craft, namely, if it could be 3D printed.
The material, he learned, is part of the lignite family, the second most abundant polymer on the planet, and highly carbon rich. But carbon, to this day, is an unknown in 3D printing and there weren’t a lot of takers willing to put the material through their machines when the project began. When Morris presented his MA findings at the RCA, Jackson happened to be in attendance. At the time, Morris had been awarded the James Dyson Fellowship Award and with it, a grant to secure IP around additive manufacturing material innovation for renewable carbon engineering.
CFP
Parts enter a multistage heat treatment cycle
It was in 2019 when the two reengaged and began collaborating. Jackson was still working at Renishaw while Morris had been awarded a grant from Innovate UK’s 200 million GBP Sustainable Innovation Fund, enabling him to purchase some equipment. The R&D work continued around Jackson’s day job with all the markings of a fledgling start-up, a printer churning away in the garden shed in the early mornings and late into the night, to get this previously unprintable material to print.
It wasn’t perfect, but they achieved it and by the end of 2020, Morris had secured a Smart grant from Innovate UK for 500,000 GBP; no small feat for a small one-person start-up and affirmation that the project had real promise. It left Jackson with a choice: stay in the comfort of a steady job or take a leap into the unknown. He leapt.
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The work pushed on across development and testing of different geometries using desktop SLS machines, modified to accommodate the lignin feedstock, sourced as a byproduct from the paper pulping industry. As Jackson described, it was effectively like trying to print with “tree glue.”
“It doesn't quite work in the standard setup,” Jackson said of the process. “We take the part and put it through a multistage heat treatment cycle culminating at 3000 °C. We end up with either a carbon or graphite industrial product.”
Lignin to LignAM
The environmental driver behind this, according to Jackson, is huge. Lignin is typically burnt and used as low-cost fuel or as filler in food for cattle. Either way, that carbon is going directly back into the atmosphere. Instead, CFP aims to capture it for industrial product and turn it into biochar at the end of the product lifecycle, which secures the carbon underground, and can also be used in applications in water quality, soil fertility, and agriculture.
To source the material, Morris engaged with researchers at the Research Institute of Sweden (RISE), who had also been working on developing carbon fibres from lignin, and after several trials of various types, settled on one that was readily available and can be scaled to be produced anywhere that there are biorefineries pulping for paper production.
“The first lignin that I used in my shed was a different lignin and it worked fantastically. But there was no commercial model,” Jackson said of CFP’s commercial approach. “So that's when we started looking at other lignin and we've chosen the lignin that is the most readily available. In fact, it's probably the most mature part of our supply chain.”
Lignin is the raw material but LignAM, meaning lignin for additive manufacturing, is CFP’s patented carbon material. It’s a “very complicated natural material” made up of 60% carbon and 40% chemicals. The material is also said to be 100% reusable, so any unused powder can be sieved and put back into the machine. Crucially, it’s the non-carbon component that enables the printing, acting as a natural binder which is taken away during the heat treatment cycles. Once it hits 1000°C, which is just one part of the process, you’re left with pure carbon. Now CFP’s R&D has moved on to complete its the final stage, reaching 3000°C and achieving graphitisation.
“One of the key components that's really attractive to work with lignin is graphene,” Jackson explained. “The reason for that is lignin and graphene are both carbon but they are electrically charged in different directions, which makes them very attractive together.”
Conductivity is a scale. Carbon content can turn into hard carbon, which is non-conductive; full graphite, which is potentially more conductive than copper; or somewhere in between. Just one week before Jackson presented CFP’s technology to attendees at RAPID + TCT in June, the team received confirmation it had successfully achieved graphite through testing at the University of Birmingham.
Sustainable plans
CFP exists because the world needs a sustainable alternative to finite mined materials. With over 1 million GPB from Innovate UK awarded to projects aiming to tackle such challenges, the immediate need for clean alternatives is clear. CFP is currently on board Innovate UK’s Power Electronics, Machines and Drives (PEMD) programme which is helping to drive the decarbonisation of sectors such as automotive, aviation, rail, marine and energy generation. With a focus specifically on electrification, if CFP can achieve a similar conductivity to aluminium, pairing 3D graphite and carbon composites with the geometric advantages of 3D printing, it could provide a lightweight alternative.
CFP
LignAM is CFP's patented material
CFP doesn’t plan on becoming an equipment manufacturer but rather a licensing model. The current desktop machines the technology has been developed on won’t be suitable for production, but the intention is to potentially lock IP from some of those modifications and evolve that into a pilot plant facility where it will work with designers on the integration of components.
From day one, sustainability has been at the heart of every decision made throughout CFD’s development. That hasn’t always been easy. CFP brought on board Jenna Browne as its Circuluar Economy Lead, and the company has been employing MIT’s Earthster software which calculates ‘cradle to gate’ life cycle analysis in accordance with ISO 14040/44 standards. In the lab, CFP has achieved results which are said to be equal to a “very mature aluminium process” and if it changes its primary power source to a sustainable method like wind turbines, it believes it will be on the path towards net zero.
As CFP officially emerges from stealth, with proof of graphitisation in hand, serious investment is now key to its next steps. The demand for this material and process is clear. Graphite is an essential part of the electrification of the world, and there are thought to be opportunities for high-volume 3D printed carbon applications in automotive, biomedical and consumer electronics sectors. The previous UK government listed graphite amongst the critical minerals highlighted in its strategy to create more resilient supply chains. Meanwhile, recent curbs in China on the export of some of its graphite products used widely in EV batteries, potentially leaves an even bigger gap for UK-based innovation to fill and bolster US, UK and European supply chain security.
“It's a fantastic material but nobody's really found a really effective use for it,” Jackson said. “We're not using it because of the name, we're using it because it really does have a big impact.”
This article originally appeared inside TCT Europe Edition Vol. 32 Issue 4 and TCT North American Edition Vol. 10 Issue 4. Subscribe here to receive your FREE print copy of TCT Magazine, delivered to your door six times a year.
