In-plane Permeability and Mechanical Properties of R-Glass/Aramid Hybrid Composites

The use of composite structures is ever-increasing due to the need of lightweight materials, and the combination of different reinforcements in a single matrix expands even further the range of processing and final characteristics compared to the use of a single-fiber type. This work investigates the effect of hybridization on in-plane permeability and mechanical properties of R-glass/aramid/epoxy composites manufactured by vacuum infusion. Five different fiber layups were studied, pure aramid, pure R-glass and three hybrids. The inclusion of R-glass fabrics increased permeability compared to aramid, and a synergistic effect was identified, i.e., one of the hybrids presented higher values than both single-fiber stacks. Inclusion of R-glass fabrics leads to greater strength and stiffness in tensile and flexural tests. The hybrids reached an increase of up to 50% in tensile modulus, and also higher compressive, flexural and short-beam strengths. In all, the results have shown that hybridization or aramid composites with R-glass may lead to enhanced processability by vacuum infusion and allow a range of improved mechanical properties, being an alternative in expanding the range of applications for rigid aramid composites.