Development of Hemp Fiber Reinforced PLA Composites for Sustainable 3D Printing: Mechanical and Microstructural Properties

This study presents the development and characterization of hemp fiber-reinforced polylactic acid (PLA) filaments for sustainable 3D printing applications. Hemp fibers were incorporated into the PLA matrix at 2.5% and 5% by weight to create biodegradable composite filaments. The developed composites exhibited enhanced mechanical properties, with 2.5% hemp-reinforced PLA demonstrating 29.6% higher tensile strength and 21.7% greater Young's modulus compared to pure PLA. Hemp reinforcement significantly improved the ultimate tensile load, showing increases of 6.6% and 28.5% for 2.5% and 5% concentrations, respectively. The biodegradable composites achieved substantial weight reduction, with a 37% reduction in material density at 5% hemp content, making them suitable for lightweight applications. Microstructural characterization revealed uniform hemp fiber distribution within the PLA matrix, while SEM-EDS analysis identified beneficial trace minerals from natural hemp fibers. Higher hemp concentrations showed increased porosity and fiber clustering, affecting material homogeneity. Dynamic mechanical characterization using ASTM E1876-based vibration testing revealed that hemp fiber incorporation reduces the elastic modulus by 33–34% compared to pure PLA (3.60 GPa) while significantly enhancing damping properties. These environmentally friendly, hemp-reinforced PLA filaments demonstrate excellent potential for sustainable 3D printing applications requiring enhanced mechanical performance and vibration damping properties.