Date of Award

May 2020

Document Type


Degree Name

Master of Science (MS)


Mechanical Engineering

Committee Member

Dr. Cameron J Turner

Committee Member

Dr. Garrett Pataky

Committee Member

Dr. Hongseok Choi


With the increasing 3D printing user domain, the demand for the 3D printable materials has escalated. Since the development of this technology, several materials have been used to experiment with the printing process. The feasible materials for printing, range from various polymers to organic tissues. According to a study conducted by Forbes in 2018, plastics are the highest consumed 3D printing materials, accounting for about 88% of all the materials used at a global level. This is because plastics are economically cheap and are readily available. The processability of plastics is relatively higher than other 3D printing materials.

The thermoplastic nature of ABS makes it suitable for 3D printing. Because of its composition, ABS has distinguished mechanical properties like good toughness, impact resistance, rigidity, and strength. This makes ABS find its applications ranging from common household items to automotive parts and intricate medical devices. This increase in demand and usage of the material resulted in the question of its recycling and disposal. Any improper disposal of ABS can be a very serious threat to the environment. Thus, this creates an increased scope for research on the recycling trends of ABS.

In this thesis, a system was designed to recycle ABS into a filament, so that it can be used as a 3D printing feedstock. In addition to that, a study on the recyclability of ABS to be reused as a feedstock for 3D printing has been conducted. To achieve this, commercially available virgin ABS polymer is reprocessed multiple times, until the material is degraded and can be no longer used as a feedstock for 3D printing. The behavior of mechanical properties and the printability of recycled ABS polymer were investigated at each reprocessing cycle. This recyclate is then blended with virgin ABS at various percentages and the mechanical properties were investigated. The virgin ABS-recyclate blends were then processed a multiple number of times. The printability and tensile properties were studied at every recycling cycle. Based on the testing of recycled specimens, we observed aging effects that resulted in more brittle filaments. While some losses could be mitigated with the re-introduction of virgin materials in a blended material, aging effects continued to degrade the printed material.



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