Effect of fibre stacking orientation on the mechanical and thermal properties of laminated kenaf fibre/epoxy composites

Natural fibre-reinforced composites have been developed by researchers and industries as a solution to reduce the use of synthetic fibres. Kenaf fibre is one of the most abundant natural fibres in Indonesia. This study aimed to obtain the mechanical and thermal properties of kenaf fibre-reinforced epoxy laminated composites fabricated using a vacuum-assisted resin infusion method. The alkaline-treated fibres were arranged in the orientations 0 degrees/0 degrees/0 degrees/0 degrees and 0 degrees/90 degrees/0 degrees/90 degrees. Density measurements, mechanical tests, and thermogravimetric analysis were carried out on the epoxy and the composites. The results of the mechanical testing showed that the tensile, flexural, and compression strengths of the kenaf fibre-reinforced epoxy composites with a 0 degrees/0 degrees/0 degrees/0 degrees fibre orientation were higher than those of the composites with a 0 degrees/90 degrees/0 degrees/90 degrees fibre orientation, with values of (96.61 +/- 10.18) MPa, (131.01 +/- 6.60) MPa, and (71.96 +/- 5.50) MPa, respectively. Scanning electron microscope observations showed that the composites had good fibre-matrix adhesion. The thermal stability of the epoxy was enhanced from 557 degrees C to 571 degrees C by incorporating kenaf fibre with 0 degrees/0 degrees/0 degrees/0 degrees orientation. With reference to the Indonesian National Standard 01-4449-2006, the two composites could be classified as T2 45 High Density Fibreboard.