University of Toronto Scarborough scientists have successfully turned McDonald’s waste cooking oil into a biodegradable 3D printing resin.
According to the scientists, the new process is cheaper to make and structures made from it can be broken down easily due to its biodegradable nature.
“The reasons plastics are a problem is because nature hasn’t evolved to handle human-made chemicals,” says team lead and the resin’s inventor, professor Andre Simpson.
“Because we’re using what is essentially a natural product, in this case fats from cooking oil, nature can deal with it much better.”
Simpson first became interested in the idea when he first got a 3D printer about three years ago.
After realizing the molecules used in commercial resins were similar to fats found in cooking oils, he wondered whether one could be created using waste cooking oil.
One challenge was getting waste cooking oil from a restaurant to test in the lab; among the many restaurants approached, only McDonald’s responded to Simpson’s call.
Simpson and his team adopted a straightforward one-step chemical process in the lab; they used about one liter of used cooking oil to make 420ml of resin.
The resin was then used to print a plastic butterfly that showed features down to 100 micrometers.
It was also found to be structurally and thermally stable – meaning it wouldn’t crumble or melt above room temperature.
Used cooking oil is a major global environmental problem. Commercial and household waste cause serious environmental issues, including clogged sewage lines caused by the build-up of fats.
While there are commercial uses for waste cooking oil, Simpson says there’s a lack of ways to recycle it into a high value commodity such as a 3D printing resin.
He adds that creating a high value commodity could remove some of the financial barriers with recycling waste cooking oil since many restaurants have to pay to dispose it.
Apart from being cheaper to recycle, it also cures solid in sunlight, opening up the possibility of pouring it as liquid and forming the structure on a work site.
Image and content: Don Campbell/U of T Scarborough