Effect of fiber volume, length and orientation distribution on flexural modulus of short natural fiber-reinforced biocomposites

Effect of fiber Volume, length and orientation distribution on the flexural modulus of Kenaf/Biode-radable composites was investigated. The random and aligned fiber sheet composites were fabricated by hot-press forming. The fiber orientation distribution was changed by slit jigs. The experimental flexural modulus was compared to the numerical calculation based on Cox's model, which incorporates the fiber orientation distribution factor and fiber compression ratio. Kenaf was found to be compressible due to the porous structure in the cross section. The flexural modulus increased with increasing fiber volume fraction Lip to 60%, and decreased at 68%. This decreased was owing to insufficient resin. The flexural modulus increased with the fiber orientation distribution approaching unidirectional orientation. The maximum flexural modulus in 10mm fiber was 3.2 times higher than that in the random fiber composites. The calculated flexural modulus by Cox's model that incorporates the effect of fiber compression was in good agreement with experimental results.