Natural fibers have recently become attractive to researchers, engineers and scientists as an alternative reinforcement
for fiber reinforced polymer composites. This paper is focused on the tensile properties of natural fiber reinforced
polylactic acid composites. The untreated and flexible epoxy treated bamboo fiber, vetiver grass fiber and coconut
fiber were used as reinforcement for PLA biocomposites. The stiffness of untreated biocomposites increased
significantly with increasing of fiber content. However, the tensile strength decreased with increasing of fiber
content. The flexible epoxy surface treatment reduced the stiffness of all composites while it considerably increased
tensile strength when compared against the untreated composites. In addition, it can be seen that the effects of
flexible epoxy treated on the tensile strength improvement were dependent upon the type of natural fiber. The tensile
strength of bamboo fiber and coconut fiber reinforced PLA composites were significantly improved by the flexible
epoxy surface treatment. Unlike the other combinations, vetiver grass fiber reinforced PLA composite showed less
improvement in tensile strength when comparing with other natural fibers. Bamboo fiber proved to be the most
effective reinforcement compared to other reinforcements.