Mechanical and Sound Absorption Behavior of Sisal and Palm Fiber Reinforced Hybrid Composites

The present work explores the tensile, flexural, impact strengths and sound absorption behavior of sisal and palm fiber-reinforced hybrid composites. The sisal and palm fibers were reinforced with epoxy resin through a compression molding technique to fabricate three hybrid composites with different weight ratios. The tensile, flexural, and impact tests were conducted as per ASTM standard for the three hybrid composites. The hybrid composite with 65% epoxy resin, 20% sisal fiber, and 15% palm fiber showed 0.63% high tensile strength, 22.62% high flexural strength, and 36.59% high impact strength compared to the other two hybrid composites. The SEM images of fractography revealed fiber to fracture, surface and fiber pull out, and also its dislocation of tightly packed fiber and matrix stickiness. The sound absorption behavior was accessed as per ASTM standard through an impedance test for the hybrid composites. The composite with 65% epoxy resin,20% sisal fiber, and 15% palm showed a high sound absorption coefficient at the frequency levels of 1600 Hz, 2000 Hz, 2500 Hz, 3150 Hz, and 4000 Hz due to the increased weight ratio of palm fiber. At a frequency level of 4000 Hz, the above hybrid composite showed a maximum sound absorption coefficient difference of 76.61% compared to the other two hybrid composites.