Date of Award


Publication Type

Master Thesis

Degree Name



Civil and Environmental Engineering

First Advisor

Edwin Tam


Applied sciences



Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


Recovering plastics from complex consumer products, such as automobile plastic parts, carries different challenges from common recyclable items found with curbside collection. Complex products often consist of multiple plastics in various configurations, and the materials must often be first liberated from one another and then separated. This is usually accomplished using some sort of comminution or size reduction such as grinding, shredding, or crushing. This research investigates whether material type, geometry, and the degree and type of comminution affect the degree of liberation of different plastic materials during two comminution processes (grinding and crushing) and assesses the potential benefits of preconditioning (cryogenic freezing) prior to comminution to improve the recycling of plastic waste. This research found that different materials were not affected by preconditioning, but that under certain conditions, preconditioning weakened the joints connecting the plastics together, made comminution more efficient, improved liberation, and subsequently the potential for increased recovery.