Tensile and Flexural Behavior of Sisal Fabric/Polyester Textile Composites Prepared by Resin Transfer Molding Technique

Composites of woven sisal in polyester matrix using three different weave architectures: (plain, twill, and matt) were prepared using a resin transfer molding technique with special reference to the effect of resin viscosity, applied pressure, weave architecture, and fiber surface modification. More than the applied pressure, the resin viscosity, and fiber surface modification, the weave architecture was found to have maximum influence on the ultimate composite properties. The resin permeability, which is related to fiber wetting, was found to be dependent on the weave architecture and the fiber surface morphology. Sisal fibers in woven form, with a fiber volume of 32%, were found to improve the properties of polyester tremendously, irrespective of the resin used and the injection pressure. The maximum improvement in tensile strength was observed for resin with a viscosity of 420 cps. While the tensile strength showed a 32% improvement, the tensile modulus showed a 100% improvement by reinforcing fabrics with the weave architecture with maximum fibers in the loading direction, for the same resin. The flexural strength gave an improvement of 19% while the flexural modulus gave a 55% improvement. Fabrics with maximum fibers in the loading direction (matt weave) proved to be the best reinforcement to impart maximum properties. Finally, the fracture surfaces were examined by scanning electron microscopy to get an insight into fiber/matrix interactions.