Plastics recycling

The versatile applications of plastic polymers have led to countless innovations. However, plastics are mostly derived from fossil fuels, and end up in landfills, including at the University makerspaces.

The Plastics Recycling Research Laboratory was established to mitigate the direct-to-landfill plastic wastes being produced at the university makerspaces.  We envision a completely circular zero-to-landfill university, and are starting with the University Makerspaces.  Recycling equipment was installed on-campus to explore a closed-loop plastics recycling procedure for the university.

The equipment consists of desktop student-accessible hardware. This includes a shredder to chop plastic parts into 5mm shreds, and a granulator to reduce the shreds to 1mm granules.  Then there is an extruder which the granules are placed in a hopper which feeds a heated screw barrel to melt the plastic and press it out the end as a filament.  This is cooled over an air cooler, and then either spooled as filament or fed into a pelletizer to make small plastic pellets suitable for molding.

With this production of recycled plastics stocks as filament and pellets, it is now feasible to use in equipments such as 3D-printers, injection molding, and vacuum forming. The on-campus recycling model challenges students to make use of sustainable recycled materials as a necessary part of engineering design.

The laboratory continues to do research in the recycling of plastics. Quality control remains an issue with fabricating recycled filament, including diameter control,contaminents, and material property degradation.  We are also exploring blends and different form factors of the produced stocks.

This work was completed under the project Educational Institution Post-Consumer Plastic Packaging to Additive Manufacturing Contract ID – C-12761 supported by the Circular Economy Markets Fund, delivered by Sustainability Victoria under the Victorian Government’s circular economy policy, Recycling Victoria: a new economy.