Recycling is a great way of reducing the waste that goes back into dumps. Recycling these materials into biodegradable useful items is a plus. so is this 3D Printing resin.
Researchers at the University of Toronto Scarborough have, for the first time, turned waste cooking oil—from the deep fryers of a local McDonald’s—into a high-resolution, biodegradable 3D printing resin.
The full research article sites how using waste cooking oil for 3D printing has significant potential and benefits. The finished 3D printing resins made from waste cooking oils is not only cheaper to make, but the plastics made from it also break down naturally unlike conventional 3D printing resins.
“The reasons plastics are a problem is because nature hasn’t evolved to handle human-made chemicals,” says Andre Simpson, a professor at U of T Scarborough’s department of physical and environmental sciences who developed the resin in his lab.
“Because we’re using what is essentially a natural product—in this case, fats from cooking oil—nature can deal with it much better.”
The idea was inspired when professor Simpson first got a 3D printer about three years ago. He noted that 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.
Only one local McDonald’s responded to Simpson’s call for old cooking oil from a restaurant’s deep fryers to test in the lab. Despite contacting several major national fast-food chains.
Simpson and his team used a straightforward one-step chemical process in the lab, using about one liter of used cooking oil to make 420 milliliters of resin. The resin was then used to print a plastic butterfly that showed features down to 100 micrometers and was structurally and thermally stable, meaning it wouldn’t crumble or melt above room temperature.
“We found that McDonald’s waste cooking oil has excellent potential as a 3D printing resin,” says Simpson, an environmental chemist and director of the Environmental NMR Centre at U of T Scarborough.
Used cooking oil is a major global environmental problem. Though there are commercial uses for it, there’s a lack of ways to recycle it into a high-value commodity. Transforming it into 3D printing resin the value of the product significantly.
Chemicals used to make the resin in Simpson’s lab can be recycled, which brings down the overall cost as low as US$300 per tonne, in contrast with Conventional high-resolution resins which can cost upwards of $525 per liter.
It also cures solid in sunlight, opening up the possibility of pouring it as liquid and forming the structure on a work site.
Another key advantage is biodegradability. The researchers found that burying a 3D-printed object made with their resin in soil lost 20% of its weight in about two weeks.
“If you bury it in soil, microbes will start to break it down because essentially it’s just fat,” Simpson says. “It’s something that microbes actually like to eat and they do a good job at breaking it down.”
The results of the research are published in the journal ACS Sustainable Chemistry & Engineering.