Notch Effects on the Tensile Property of Kenaf/Polypropylene Nonwoven Composites

The use of natural fibers in polymer composites is growing rapidly, especially in the automotive industry, due to the environmental concern. In this research, the open-hole effects on the tensile property of kenaf/polypropylene nonwoven composites (KPNCs) in production of automotive interior parts have been investigated. KPNCs were fabricated using kenaf fiber as reinforcement and polypropylene (PP) fiber as bonding fiber. All KPNCs were produced by carding and needle-punching techniques and thermally bonded by a panel press with 6-mm thickness gauges. Unlike the traditional fiber reinforced composites, KPNCs are produced by nonwoven technique with a 50% fiber weight ratio. Mechanical properties of the KPNCs in terms of uniaxial tensile and open-hole tensile (OHT) were measured instrumentally. By calculating the stress concentration factor K_t for brittle materials, the net section stress factor K_n for ductile materials, and the strength reduction factor K_r, we found that KPNC was relatively ductile and insensitive to the notch.