Glass Recycling Meets 3D Printing, as Vitriform3D Partners with the ORNL

Researchers from the Department of Energy's Oak Ridge National Laboratory (ORNL) and Vitriform3D have announced a joint effort to turn waste glass into a material for 3D printing building materials and decorative pieces, using a robotic binder-jetting process.

"There's so much glass going into landfills in the US," explains Vitriform3D co-founder Alex Stiles of the reason for picking waste glass as a material. "Glass is infinitely recyclable, but only one-third of glass waste is being recycled. There's a certain grade of sand that is well-suited to make glass. Depending on the location, it's often cheaper for a company to just use that sand than to use recycled glass. [Meanwhile,] if a recycling facility were to get a truckload of glass bottles and it had one coffee mug in it that would shut down their entire production line for a day."

With contamination and cost both problems for the recycling process — not to mention energy usage, with the furnaces used to melt the old glass needing to run hot and the heavy glass itself needing to be transported — an alternative use for the two-thirds of post-consumer glass that ends up in landfill is needed. That's where the Vitriform3D recycling process comes in, which proposes a different way to divert the waste: 3D printing.

Stiles and colleagues at Vitriform3D process the waste glass by crushing it into a powder, a similar consistency to the sand from which the glass was originally made. A robot arm spreads this powder out onto a build plate, where it is then coated with an adhesive and optional ink. Like a traditional plastic or resin 3D printer, the process is repeated layer by layer until the finished object is made — then fired in an oven to strengthen it. "Essentially," Stiles says, "you’re gluing the powdered glass together."

It's a proven process, and equivalent to the creation of engineered stone. The finished material is around 90-95% post-consumer glass waste, with the remainder being the binder. With Vitriform3D having proven the concept, the ORNL has come up with a potential new use-case for the material: cladding for buildings. "Glass is extremely resilient, durable, and versatile," explains ORNL building technologies researcher Nolan Hayes. "It's fire-resistant and can withstand extreme weather conditions."

Stiles is also working with the Lawrence Technological University in Detroit to give students access to a glass-recycling printer, focusing on building accents and other decorative objects. "This will be the first time that architecture students can really sink their teeth into what they could do with this technology," he claims.

"For the projects with Oak Ridge National Laboratory, that's more focused on what can we do on an industrial scale. If we had a massive printer, how many thousands of tons of glass can we turn into wall paneling? But a micro-factory like the installation in Detroit could focus on smaller projects. With a few pieces of equipment, you too could take a glass bottle, crush it into sand and turn it into something new."

More information on the technology is available on the Vitriform3D website.