Improving circular economy processes with 3D printing

How one company’s mission to tackle fishing net waste is demonstrating the possibilities of circular economy additive manufacturing.

At first, tackling waste from used fishing nets may appear to be a niche issue. In reality, though, it’s a global one, with 150,000 to 200,000 tonnes a year of high value Nylon 6 polymer being consumed every year just in the process of making one type of net. As Ian Falconer, founder of Fishy Filaments, explains, “The majority of these nets are currently buried or burned at the end of their lives, which is generally somewhere between six months and a year. A recent paper by Richardson et al from the Australian science agency CSIRO found that globally around 2% of gill nets are lost at sea, which means that 98% of them get returned to land for disposal. So, that’s many tens of thousands of tonnes of engineering-grade nylon every year that gets used for a few months then put to waste.”

Falconer first launched Fishy Filaments as a project in 2016, then as a funded company a year later, with the initial goal of commercialising IP that he had developed with strong potential to make plastics recycling more efficient. The process found its home in the fishing industry, where it can be applied to clean the algal biofilm off used fishing nets.

“We’ve set out to find a way to bring the Nylon 6 contained in those nets back into industrial use,” says Falconer. “Unlike conventional plastics recycling challenges, the logistics of fishing net collection have historically robbed the activity of a means to return value to those at the sharp end, the fishing communities where end-of-life nets accumulate.”

ENTER 3D PRINTING

Over the years, Fishy Filaments has been working hard to prove its recycling process, understand the invention and how it can scale, and identify potential markets for the new materials it can process.

“When we launched our MVP, a world-first 100% recycled PA6 filament for 3D printing, it was with the understanding that we didn’t know the marketplace and little data existed to help us,” Falconer continues. “It ended up winning us the 3D Printing Industry News award in 2021 in a public vote of over 140,000. So, we knew we had a product that could engage with public sentiment, even if it wasn’t an immediate commercial hit.”

Since then, Falconer and his team have been working with hundreds of customers around the world to explore the material’s capabilities, winning multiple global design awards. However, he concedes, “We knew it wasn’t the easiest material to use and its application was really limited to professional or semi-professional customers rather than having a wider appeal in the hobbyist market. Even from the earliest days I had my eye on recycled carbon fibre (CF) as the perfect fit for our recycled nylon and a means to add functionality to the raw recyclate. That idea was shared in principle when the company launched, but it took until 2022 before the product line that became 0rCA was realised.”

0RCA EXPLAINED

0rCA is short for ‘near Zero (0) recycled CArbon’ and is more of a materials concept than a single product, Falconer says. He explains: “In 2019 we did a Life Cycle Assessment with Exeter University’s Environmental Sustainability Institute for our raw recyclate that returned a fantastic result. It showed that our recycling process could save 97-98% of the carbon emissions when compared to new nylon production.”

The company has since bought its own lab-scale compounding plant to advance the 0rCA project, allowing it to test and optimise new composite production in-house.

The first commercially available variant of 0rCA is a 10% CF-filled PA6 that can be bought as a cut strand pellet or as a 3D printer filament via the company’s global filament distribution partner, Fillamentum. According to Falconer, the material’s mechanical performance is equal or better than most other PA-CF materials currently in the 3D printing filament segment.

“It is relatively high temperature – especially compared with PA11 and PA12 – impact resistant, chemically resistant and UV resistant,” he says. “As a materials family our CF10% variant has an estimated carbon saving or 90-95% versus virgin equivalents, so any company that currently uses PA6-CF but wants to slash their carbon impact for a particular product, 0rCA can be a drop-in replacement. In filament form, it is stronger than most virgin equivalents too.”

Mono-materiality and co-recyclability have been long-term drivers behind developing 0rCA as a family of materials. “The availability and usability of 0rCA across a range of manufacturing, not just additive, means that multi-component assemblies can be built using IM-built components as well as SLS and FDM made parts,” Falconer continues. “But at end-of-life, those assemblies do not need to be taken apart for recycling. This is a long-term consideration for designers when working towards compliance for the EU’s circular economy and product safety directives.”

TRUE SUSTAINABILITY CREDENTIALS

Traceability is a key benefit for companies utilising 0rCA, Falconer adds. “Our base material is 100% recycled Nylon 6 and 100% of it comes from fishing vessels we know. We know where they fish, what species they fish for and their supply chain for the new nets. Few recycled materials have as good a provenance, and few new materials have as open a provenance.”

0rCA is designed for use across multiple manufacturing methodologies, with a designer able to produce an early prototype using Fused Deposition Modelling (FDM), a low-volume product using Selective Laser Sintering (SLS) and then mass production via injection moulding, all using the same material with the same supply chain. According to Falconer, high performance consumer facing items such as sports equipment, eyewear, and designer fashion are suitable applications for 0rCA, alongside low volume engineering componentry for spares and repairs, vehicle customisation and tooling.

The powder has also been designed to be accepted straight back into Fishy Filaments’ plant as a fractional source material for secondary use. “This work means we will offer 0rCA as a zero waste 3D printing powder for customers,” Falconer says. “Fundamentally, the recycled materials sector needs to be more understanding of what designers need rather than trying to get them to fit to what its own technical ability is right now. Recycling needs to be more ambitious about creating value and less about waste management.”

Fishy Filaments is currently in scale-up production with Warsaw-based Alpha Powders for 0rCA, and hopes to amass a group of technically competent early adopters to spur on the powder’s development and commercialisation.

For more information visit www.fishyfilaments.com