The mechanical properties of the composites determined from the load-displacement curves in the flexural test showed improvement with increased fibre loading [12]. The load-displacement curves of the 35 vol.% composites reinforced with the untreated, 4 and 8 h alkali treated fibres are shown in Fig. 1. The curves displayed a few distinct features. After the initial rise, non-linearity had occurred up to the peak fracture load, indicating the flexible nature of the composites. Unlike the composites reinforced with the untreated fibres which showed fibre pull-out, a marked drop in the load was observed in case of the 4 and 8 h alkali treated composites after the fracture, indicative of a simultaneous fracture of the resin matrix and the fibres. Composites prepared with the raw untreated fibres showed debonding and resin fracture followed by the fibre breakage and pull-out at an intermediate load. The composites prepared with the alkali treated fibres, therefore, showed improved wetting behaviour of the fibres with the resin, producing stronger bond at the interface and imparted higher mechanical strength. The mechanical properties were maximum for the 4 h treated composites, that was discussed in details in our previous work [12].