Oil from deep fryers benefits 3D printers

A group of Canadian researchers is claiming a scoop: they have transformed waste cooking oil from fast food restaurants into a ‘high-resolution, biodegradable 3D printing resin’.

The global cooking oil market is set for ‘rapid growth’, according to market analysts who expect it to reach EUR 120 billion by 2024. This is not surprising as India alone uses over 25 million litres of cooking oil per year. Even so, the recycling of cooking oil remains a modest niche sector.

The University of Toronto Scarborough hopes to change all that and its researchers have succeeded in recycling cooking oil from deep fryers as a 3D printing feedstock. This eco-resin is ‘a lot cheaper to make’, according to project supervisor professor Andre Simpson who developed the solution in his campus laboratory.

The innovative idea started three years ago when Simpson noticed the molecules used in commercial resin were similar to fats found in cooking oils. He recalls it was difficult persuading a restaurant to donate waste oil to be used in the lab experiments. The only place he signed up was a local McDonald’s.

Simpson and his team opted for a ‘straightforward one-step chemical process’ in the lab that converted one litre of used cooking oil into 420 millilitres of resin. The resin was used to print plastic delicate figures, such as insects with features down to 100 microns. The figures are structurally and thermally stable, meaning they do not crumble or melt above room temperature.

Conventional high-resolution resins can cost upwards of EUR 366 per litre because they’re derived from fossil fuels and require several steps during the production process. All but one of the chemicals used to make the resin in Simpson’s lab can be recycled and this means the recycled resin can cost as little as EUR 210 per tonne.