Mechanical property evaluations of flexible laminated composites reinforced by high-performance Kevlar filaments: Tensile strength, peel load, and static puncture resistance

Abstract

This study investigates the mechanical properties and damage behavior of flexible laminated composites. Needle punching is performed to combine woven Kevlar fabric and two nonwoven low-melting point polyester (LMPET) fabrics into a fabric interlayer. A sheet-extrusion machine is used to bond two thermoplastic polyurethane (TPU) sheets on each side of a fabric interlayer. The tensile strength, peel load, and static puncture resistance of the flexible laminated composites are evaluated, and the influences of needle-punching rates and depths are examined. Test results show that a high needle-punching rate or depth positively affects tensile strength by promoting fiber entanglement. The tensile strength of the 300-15 group reaches 24.70 MPa. Moreover, when the needle-punching depth does not exceed 11 mm, melted LMPET fibers help bond two-phase materials and thus increase the peel loads of the final composites. The 200-11 group has an optimal puncture resistance of 5.86 N. The combination of TPU sheets and woven Kevlar fabrics yields flexible laminated composites with good static puncture resistance. The results of this study can be applied to improve the performance of flexible laminated composites.