Effect of natural fiber (NF) mix on mechanical strength of NF plastic composites (NFPC)

Abstract

Natural fibers from plants are gaining importance and may substitute wood in the production of wood plastic composites (WPC). To ensure continuity of fiber supply and sustainability of WPC industries, fibers of various types could be mixed together to obtain Mix WPC. However, research need to be carried out to identify the contribution of different fiber type collectively to the mechanical properties of Mix natural fiber polymer composite (NFPC). In this study, preliminary work on the use of natural fibre (NF) such as kenaf, sugar palm and pineapple leaf fibers in the preparation of Mix NFPC were carried out. Four different fiber mix samples with different fiber ratio and size were formulated using polypropylene (PP) as the polymer matrix. Montmorrilonite (MMT) filler was added at constant amount for enhancement of composite mechanical properties. Samples were mixed and prepared using a twin screw extruder and mini injection moulding resepectively. Individual fibers and NFPC prepared were characterized using thermogravimetric analyzer (TGA). Tensile, flexural and impact strength of the composites were determined. Generally, it was found that addition of fiber mix at 50% fiber loading enhance the tensile and flexural strength of the various NFPC with minimal exceptions. The impact strength of the composites were comparable to that of blank PP implying that addition of fiber gives additional advantage besides being eco-friendly. It was also found that higher kenaf loading and different size of fiber mix contribute positively to the various strengths measured. In addition to that, composition of individual fibers also contribute to the mechanical properties of the NFPCs.