Advancing sustainability in additive manufacturing: material formulation and process development for recycled PET and PET/HDPE blend

The rapid accumulation of plastic waste, particularly polyethylene terephthalate (PET), presents a major environmental challenge due to inefficient recycling and sorting processes. The high-density polyethylene (HDPE) contamination in recycled PET (r-PET) in waste stream further complicates its reprocessing, limiting its application in high-performance materials, because of deteriorating of r-PET properties. to address the issue of reprocessing and recycling of PET or tedious sorting for waste management, this study employs a state-of-the-art approach to develop sustainable feedstock materials for Fused Deposition Modeling (FDM) and pellet-based 3D printing (or additive manufacturing-AM). Firstly, reactive chain extension was employed to enhance the rheological properties of r-PET, improving its melt strength, viscosity, and printability for filament-based 3D printing. Secondly, compatibilization strategies were implemented to improve the interfacial adhesion, phase dispersion, and mechanical properties of r-PET/r-HDPE blends, making them viable for pellet-based 3D printing. Rheological, microstructural, thermal, and mechanical analyses confirmed that these modifications significantly improved processability, structural integrity, printability, and final properties. By enabling the transformation of unsorted and contaminated plastic waste into high-performance AM feedstocks, this research provides a practical solution for reducing plastic waste and supporting the circular economy. The findings demonstrate that advanced material engineering can bridge the gap between recycling limitations and sustainable manufacturing, promoting the efficient repurposing of post-consumer plastics.

Name thesis:degree_name

Master of Applied Science (MASc)

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Ontario Institute of Technology

Year dc:date.issued

2025

Author dc:creator

• Bozorgnia Tabary, Seyed Amir Ali

Advisor dc:contributor.advisor

• Fayazfar, Ramona

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10155/1927

OAI identifier oai:identifier

oai:ontariotechu.scholaris.ca:10155/1927