Used cooking oil from McDonald’s is transformed into 3D printing resin

At the University of Toronto, a team of researchers has recovered used cooking oil from a local McDonald’s and turned it into a high-resolution biodegradable 3D printing resin. For one litre of used oil, they obtained 420 mL (14 oz) of liquid resin which they used to 3D print several butterflies. The resin they created did not crumble or melt above room temperature. This project is a good example of how 3D printing technologies can be used to give value to our food waste.

Apart from the fact that it is far from healthy, frying oil has some environmental impacts too, especially after it’s been used to fry. Today, it is thrown down our sinks, causing clogged pipes due to the accumulation of grease. However, there are initiatives to recycle it. The fast food giant McDonald’s has committed to reusing its frying oil to create biofuel. A total of 35,000 litres (9,245 gallons) are processed each month, saving 420,000 litres (11,0950 gallons) of crude oil per year. The initiative began in India, where it has been a great success. Projects such as this one can attract more attention to these issues, often forgotten by consumers.

One of the 3D printed butterflies | Credits: Don Campbell

Creating McDonald’s 3D printing resin?

The University of Toronto professors behind this project started from a simple observation: most plastics are made from man-made synthetic components that are much more difficult for nature to assimilate. Andre Simpson, a professor in the university’s Department of Physical and Environmental Sciences, explains: “If plastics are a problem, it’s because nature has not evolved to process man-made chemicals. Because we use what is essentially a natural product – in this case fats from cooking oil – nature can handle them much better.“