Development and Mechanical Characterization of Polylactic Acid (PLA) Composites Reinforced with Flax Fiber: Fabrication and Properties

Polylactic Acid (PLA) composites reinforced with flax fibers have emerged as a promising solution for sustainable, biodegradable materials. This research investigates the fabrication process and mechanical characterization of PLA composites reinforced with varying concentrations of flax fiber. The study assesses the effects of flax fiber loading on the composite's mechanical properties, including tensile strength, hardness, flexural strength, and interfacial bonding between the fibers and matrix. The composites were fabricated using a twin-screw extrusion process followed by injection molding. Mechanical testing, including tensile, hardness, and flexural tests, was performed to evaluate the composites' strength, stiffness, and resistance to deformation. Results indicated that the tensile strength of the composites increased with fiber content up to 35%, after which it decreased due to poor fiber-matrix bonding and fiber agglomeration. Additionally, the flexural strength followed a similar trend, with an optimal fiber content at 35%. The hardness of the composites also improved as flax fiber content increased. The study concludes that PLA-flax fiber composites have great potential as an eco- friendly alternative to traditional materials in various structural applications. Major Findings: The study revealed that incorporating flax fibers into PLA significantly improved the composite's tensile strength, flexural strength, and hardness up to an optimal fiber loading of 35%. Beyond this threshold, mechanical performance declined due to fiber agglomeration and weakened fiber-matrix interfacial bonding, highlighting the need for optimized processing and bonding techniques.