The researchers say using waste cooking oil has significant potential
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.
Using waste cooking oil for 3D printing has significant potential. Not only is it cheaper to make, but the plastics made from it also break down naturally unlike conventional 3D printing resins.
“The reason plastics are a problem is that 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.”
Simpson first became interested in the idea when he got a 3D printer about three years ago. After noting 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.
Harder to obtain was the waste cooking oil. Simpson contacted all major national fast-food chains, but only McDonald’s responded, and the oil used in the research came from a local outlet in Scarborough. Simpson and his team filtered out chunks of food particles and then used a straightforward one-step chemical process in the lab, with about one liter of used cooking oil necessary to make 420 ml of resin.
“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.
The first of several items printed was the plastic butterfly. “The formulated resin produced high-resolution prints with features down to 100 micrometers,” Simpson. “The rapid prototyped prints show considerable thermomechanical stability, morphological homogeneity, and biodegradability when compared to a state-of-the-art research resin and a commercial resin.”
The project has several potential benefits, Simpson said, beginning with finding a constructive, biodegradable end-use for used cooking oil, which can otherwise cause serious environmental issues by clogging sewage lines.
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 to recycling waste cooking oil since many restaurants have to pay to dispose of it.
Conventional high-resolution resins can cost upwards of US$525 per liter because they’re derived from fossil fuels and require several steps to produce. All but one of the chemicals used to make the resin in Simpson’s lab can be recycled, meaning it could be made for as low as US$300 per tonne, which is cheaper than most plastics.
And at the “end-of-life” stage, the researchers found that after burying a 3D plastic object made with their resin in soil, it lost 20 percent of its weight in about two weeks. “The fat is something that microbes actually like to eat and they do a good job at breaking it down,” Simpson said.
Sources:
- https://youtu.be/UbN_jpPwvQQ
- https://www.canplastics.com/features/toronto-researchers-turn-waste-cooking-oil-from-mcdonalds-into-high-end-3d-printing-resin/
- https://us-east-2.console.aws.amazon.com/polly/home/SynthesizeSpeech
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