Effect of fiber parameters on physical, mechanical and water absorption behaviour of coir fiber-epoxy composites

This paper studied the effects of fiber length and fiber content on the physical, mechanical and water absorption behavior of coir fiber-reinforced epoxy composites. Twenty different samples were prepared by varying the fiber length (3mm, 6mm, 9mm, 12mm and 15mm) and fiber content (5wt%, 10wt%, 15wt% and 20wt%) using the hand lay-up technique. The density, hardness, tensile strength, tensile modulus, flexural strength, impact energy, compressive strength, compressive modulus, inter-laminar shear strength, fracture toughness and percentage of water absorption of the composites were analyzed. The experimental investigation reveals that the void content and percent of water absorption increases with increase in fiber length and fiber content. The result shows that the density of composites increases with increase in fiber content, while a decrease in density is observed with increase in fiber length. Similarly, the tensile strength, compressive strength, inter-laminar shear strength, flexural strength, and impact strength show their maximum values at 12mm fiber length and 15wt% of fiber content. The hardness and tensile modulus, on the other hand, increase with increase in fiber length and fiber content. Morphological analysis is also carried out to observe the fiber pull-out and fracture behavior of the composites using scanning electron microscope.