Permeability and mechanical properties of plant fiber reinforced hybrid composites

Plant fibers with small diameter generally possess high mechanical properties, while their permeability was relatively low compared to those with large diameter. By hybridizing these two kinds of plant fibers, a composite with both high permeability and good mechanical properties can be achieved. Here, permeability of jute/ramie and ramie fabrics were compared, regarding the flow rate of a vinyl ester resin during the Vacuum-Assisted Resin Transfer Molding process; and mechanical properties of their composites were addressed thereafter. The faster flow rates of vinyl ester resin proved that jute/ramie fabrics were more permeable than pure ramie fabrics resulting from larger flow space and the greater capillary effect of jute fabrics. Both tensile strength and Charpy impact strength of the hybrid composites dropped slightly after hybridization due to the lower properties of jute than of ramie fiber as the properties of fiber dominated the failure mode. However, interlaminar shear strength remained, since the middle layer was far from the weak jute ramie interface. The results implicated a method to improve the permeability of plant fiber reinforcement when manufacturing efficiency is considered in industrial application. (C) 2015 Elsevier Ltd. All rights reserved.