A new dimension of plastics recycling

DSC_2407 Nuts and bolt produced by 3d printer

Deakin University researchers have run a successful trial in using waste plastics for the raw material in 3D printing, known as EcoPrint – a technology that has exciting potential for communities impacted by poverty or natural disasters.

Global plastic production is increasing rapidly, building on a steady 50-year growth trajectory. In 2013, some 299 million tonnes of plastics were produced, the popularity of it stemming from its qualities of being lightweight, durable and suitable for diverse applications.

However, this has inherent impacts for the environment, as disposal and recycling of this complex material has become one of the biggest challenges of the modern age. Australian recycling organisations highlight that plastic is the most abundant item of rubbish found during ‘Clean Up Australia’ days, representing 30 per cent of all rubbish collected over the last 10 years.

Against this backdrop, Professor Mazher Mohammed and a group of his students have worked on a project to reconstitute plastic waste as printer filament, the feedstock for 3D printing.

Mazher joined Deakin University’s School of Engineering in January 2015, taking on the lecturing role as Research Fellow for Engineering Sustainability.

“We teach students about matters relating to sustainability in the world around us with an emphasis on engineering solutions,” he says.

Through the course of doing his job, and with his background in 3D printing, Mazher starting thinking about the main commercial products in 3D printing being plastic based. Plastic is made from oil, which is a finite resource and potentially going to be depleted in the future.

In addition, Mazher says that as plastic is so prevalent in everyday items from devices to packaging, it’s an important material for engineering, as well being a resource that the world needs to manage wisely.

“I wondered if we could come up with a system to take spent plastic materials, reconstitute those to use in 3D printing to manufacture new end-products,” explains Mazher.

In short, the study was built on a desire to produce usable plastic filament as a viable means of consuming waste plastics and reduce the amount sent to landfill.

From there, Mazher said he was keen to get material for the project as cheaply as possible or for free.

In 3D printing, the prints can fail and those failed prints normally end up in the bin, which can generate substantial volumes of waste plastic. Moreover, when students work on 3D printing projects to make parts, when the project is over, they end up redundant and, again, ended up as waste.

“The logical thought followed of could we take those waste streams as a feedstock to explore the idea of recycling ABS plastic in our project, and converting that into plastic filament for printing,” Mazher says.

Another material source Mazher identified was all the HDPE milk cartons the School uses for its coffees.

“That led to me thinking that this is another free resource, so could we take these HDPE cartons and do the same thing as we were planning with scrap ABS plastics,” he says. “That became the premise for the project for two of our students.”

Around the same time, Mazher’s team became aware of local business GT Recycling. They wanted to go beyond a grassroots research-based project.

“We wanted to develop a viable commercial venture in itself, where we could look to reinvigorate the local manufacturing scene in Geelong, which has suffered a huge decline due to the closure of the Ford plant,” Mazher adds.

As a result, they thought with the local infrastructure available through GT Recycling, which processes large volumes of plastics waste and granulate it into a feedstock they could use, this could be the start of such a venture.

To read more, see page 22 of Issue 10.