Material Science & Engineering World Conference 2026

Abstract

This study investigates the feasibility of using a 30:70 blend of recycled polyethylene terephthalate (rPET) and virgin PETG (vPETG) as a sustainable 3D printing filament. Filaments were produced using a 3devo Composer 450 extruder, with optimal settings determined through a fractional factorial design. Mechanical and thermal properties were evaluated using tensile testing (ASTM D638) and differential scanning calorimetry (ASTM D3418). The Wilcoxon signed-rank test, a non-parametric method, was applied to compare the tensile strength of the rPET: vPETG samples to reference PETG values, addressing small sample size and non-normal data. Results also showed the filament blend achieved a consistent diameter of 1.75 ± 0.10 mm, a glass transition temperature of ~78.8°C, and a cold crystallization temperature of 242.0–249.1°C. Tensile strength ranged from 14.07 to 25.83 MPa, with statistical analysis confirming significant differences from benchmark values. While the blend shows promise as an eco-friendly filament, mechanical properties declined after multiple extrusion cycles, highlighting the importance of proper processing. Overall, the study demonstrates that rPET: vPETG blends are a viable alternative for sustainable additive manufacturing when supported by controlled conditions and rigorous statistical analysis.