Manufacturing and mechanical characterization of perforated hybrid composites based on flexible polyurethane foam

This study focused on the fabrication and mechanical evaluation of nonwoven reinforced flexible polyurethane foam composites. Effects of perforation ratio, aperture size, and perforation depth on bursting and low-velocity impact responses of perforated composite panels were investigated. The nonwoven fabric used for cover sheet was composed of flame retardant polyester, low-melting point polyester, and recycled Kevlar staple fibers. Blending ratio of Kevlar fiber was confirmed to have relation to mechanical mechanism of cushioning layer. The highest mechanical strength value was obtained at 5 wt % of Kevlar ratio because of the highest cohesive force among recycled Kevlar, flame retardant polyester, and low-melting point polyester fibers was provided at the blending ratio. The perforated high-density flexible polyurethane foam composites panel was adhered with intra-ply hybrid laminates with various areal densities on each face to form sandwich structural composites. The results revealed that perforation ratio and aperture significantly influenced the bursting and low-velocity impact resistance behaviors of the perforated composites panel. Perforated composites with 10% perforation ratio and 4 mm aperture lead to maximum bursting strength of 437 N. Additional hybrid laminates significantly promoted the maximum bursting strength of the semiperforated hybrid composites by 212%. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42288.