Plasma treatment of sisal fibres and its effects on tensile strength and interfacial bonding

Argon- and air-plasma treatments have been used to modify the surface of sisal fibres. The Taguchi method of experimental design with three factors and three levels is used to optimise the treatment parameters in relation to fibre strength. The effects of plasma treatment on interfacial bonding between sisal fibres and polypropylene are evaluated by means of a single fibre pull-out test. The optimum treatment parameters have been found to be the shortest plasma treatment time, medium power level and medium chamber pressure. Under optimal treatment, the interfacial shear strength of air-plasma treated fibres is higher than that of the argon-plasma treated fibres. Scanning electron microscopy analyses show that the overall roughness of the plasma treated fibre surface increases with treatment time. The Ar-plasma treated Fibre surface reveals obvious corrugations whereas cracking is apparent on the air-plasma treated fibre surface.