Three engineering students from Worcester Polytechnic Institute (WPI), Massachusetts, USA, have wrapped up seven weeks at Jesuit Social Services’ Ecological Justice Hub in Melbourne, where they developed a process and workshops for recycling plastic bottle caps using the Hub’s new recycling equipment.

As Melissa, a robotics and aerospace engineering student, explained, “plastic bottle caps aren’t often recyclable. They don’t filter through automatic recycling machines because they’re really small. By collecting them and using the Hub’s Precious Plastic recycling equipment, we can turn them into our own recycled purposeful products instead of having them end up in landfill.”    

Jesuit Social Services’ Ecological Justice Hub is a permaculture garden, community kitchen, carpentry workshop and offices dedicated to both social and environmental justice, located in Brunswick, Melbourne.   

Recently, a Sustainability Victoria grant allowed the Hub to purchase Precious Plastic Melbourne recycling equipment – machines that shred single-use bottle caps and melt them into a resin that can be shaped into beautiful and durable items – with the aim of putting bottle cap and plastic recycling in community hands for community benefit.   

The students designed an assembly line for collecting, sorting and recycling the bottle caps, prototyped various functional products and moulds – such as plant pots, trowels and coasters – working with interested local businesses to determine which products would be most saleable. The products created through this process are a potential ecological justice revenue stream for the Hub.  

Recycled plastic pot and bottle cap

Community education and behavior change are an important part of the project – the students designed product packaging which shares the values and story behind the project, created community education workshops on the plastics recycling process, and designed a pre- and post-workshop survey to measure behavioral change as a result of the workshops.   

Adam, a mechanical engineering student, told us “the workshops aim to engage the community more in recycling by giving them a hands-on opportunity to use recycling equipment”.   

The Hub hopes to see its plastics recycling project catalyse community awareness, action and advocacy around recycling plastics that would otherwise end up in landfill.   

Worcester Polytechnic Institute

Adam, Faith and Melissa – engineering students from Worcester Polytechnic Institute, at Jesuit Social Services’ Ecological Justice Hub


The students’ placement was made possible through a partnership between the Hub and WPI – an engineering and technology university – and Banksia Gardens, which collaborates with WPI to coordinate students’ international project placement.   

Adam says his placement at the Hub gave him valuable real-world engineering experience. “There were a lot of setbacks in our design process. Things didn’t come out perfect first try and that’s kind of what engineering is. This is the first hands-on experience as an engineer for a long period of time that I’ve had… Now I know how to collaborate on things until we solve the problem.”   

 Faith, a chemical engineering student, said she was inspired by the work of the Hub and the interest in community-based plastics recycling she encountered in Melbourne.   

“The Hub was our top choice [for our international project] and I feel like we’re not regretting that at all.   

“The first day we came here I was really impressed. I thought that I took care of the environment. But when I came here, I feel like there is a lot more that I can do. It’s really inspiring.”   

The Hub will welcome its next round of engineering students in October 2023.