An opportunity to innovate
The photopolymer resins commonly used in vat photopolymerization consist of photoreactive monomers (methacrylates), oligomers and a photo initiator. When exposed to light (most frequently UV light), the methacrylates crosslink or polymerize, leading the resin to harden.
However, these powerful crosslinking properties that enable speedy photopolymerization come at a price: methacrylates can cause eye and skin irritation and aquatic toxicity, which makes them problematic for workers in the manufacturing process and hazardous to the environment.
To be fair, Additive Manufacturing (AM) is inherently more sustainable than conventional manufacturing for a variety of reasons. It produces less waste, lowers energy consumption, and enables decentralized production, hence decreasing transportation and the resulting greenhouse gas emissions. With just-in-time production capabilities, it also reduces the need to stockpile inventory, which helps to lower a manufacturer’s overall footprint.
But using less toxic materials in the AM process could further improve sustainability and lower the risk to humans and the environment, particularly as the industry gains momentum.
For more than a decade, Tom McKeag has been on a mission to do just that. As a senior advisor and now-retired executive director at the Berkeley Center for Green Chemistry, he’s led research to devise new additive manufacturing techniques to make for safer and more sustainable processes. With a background in city planning and design and landscape architecture, Tom has been passionate about incorporating biologically-inspired design into cityscapes, industrial design and engineering for nearly three decades.
“Now is the perfect opportunity for us to innovate in the 3D printing industry to devise safer solutions as the industry is still scaling up, rather than waiting until chemicals of concern become widespread and we have a big problem,” McKeag says. “As 3D printing becomes more accessible to the public and commonplace in schools and in homes, this will expose even more vulnerable populations who may not even be aware of the risks or have access to proper PPE. So, now is the time to act.”