Natural fiber-based reinforcements in epoxy composites processed by filament winding

Single natural fibers have rather high mechanical properties; especially, Young’s modulus can be as high as for E-glass fibers. However, the good properties of natural fibers are not exploited efficiently in existing applications. Continuous fibers are required for high-performance applications. Filament winding is a method to produce aligned technical composites which have high fiber content. This work studied the mechanical properties of natural fiber yarn-reinforced composites. Flax and viscose fiber tubular composite samples were produced by filament winding and their properties were compared with the properties of E-glass fiber composites. The flax fiber yarn could be wound to produce a relatively stiff composite tube but poor adhesion between the matrix and fibers affected the properties. The properties of the E-glass fiber composites were superior in comparison to the flax fiber composites. However, the results from the split disk tensile test were competent, although they were only 25–29% of the properties of the E-glass fiber composites. Water absorption and impact strength were notably the weakest properties of the flax fiber composites. The viscose yarn could be wound into a composite tube but the composite was too brittle for machining specimens. In order to develop the structural natural fiber composites, the adhesion and the wet-out of the fibers should be improved.