The present paper investigates the effects of fiber content and alkali treatment on impact property of coir fibers reinforced polyester resin composites which are partially biodegradable. The coir fibers were collected from the foliage of locally available coconut fruit through the process of water retting and mechanical extraction. The usual problem in natural fiber reinforced composites is seen in its poor adhesion between fiber and matrix, hence, in this study, specific physical and chemical treatments were administered for surface modification of the fibers. Both untreated and treated fibers were used for coir fibers reinforced polyester resin composites formations; and the impact properties were determined at three different control factors of the fiber contents. Applying Taguchi robust design technique for the greater-the-better, the highest signal-to-noise ratio (S/N ratio) for the quality characteristics being investigated was obtained employing Minitab 16 software. The treated coir fibres reinforced polyester matrix composites were better in impact having the expected optimum impact strength of 6.2J/mm² at the optimum setting of control factors, while that of the untreated composites have an expected optimum impact strength of 5.5J/mm² at the optimum setting of control factors. The reinforcement combinations of control factors and chemical treatment of coir fiber contribute greatly to the impact property.

Coir Fiber, Impact Property, Alkali Treatment, Composite, Retting