Rheological, Mechanical, and Life Cycle Assessment of <scp>3D</scp> ‐Printed <scp>PLA</scp> /Hemp/ <scp>PEG</scp> Biocomposites

ABSTRACT There is considerable interest in the development of bio‐based materials for pellet‐based material extrusion 3D printing as sustainable alternatives to conventional polymer composites. This study investigates poly(lactic acid) (PLA) biocomposites reinforced with 20 wt% short Hemp fibers and modified with 5 wt% polyethylene glycol (PEG) as an additive. The rheological behavior of the biocomposite melts was analyzed using the Carreau–Yasuda model at different temperatures. Chemical behavior was evaluated through rheological tests coupled with fast‐scan Fourier transform infrared (FTIR) spectroscopy conducted at 190°C, 200°C, and 210°C. A design of experiments approach was employed to optimize the 3D printing parameters and to assess the influence of extrusion temperature, printing speed, and layer thickness on print quality. The optimal printing conditions for Hemp‐based parts were identified as a temperature of 200°C, a printing speed of 35 mm/s, and 0.5 mm of layer thickness. Mechanical testing was performed to evaluate the effect of Hemp fiber reinforcement on the performance of PLA‐based printed parts, revealing a significant influence of Hemp fibers on the mechanical properties. In addition, a life cycle assessment (LCA) was conducted to quantify the environmental impact of the PLA/Hemp/PEG. The results demonstrate that these materials represent a promising eco‐friendly solution for sustainable additive manufacturing applications.