Sliding behaviour of woven industrial hemp fabric reinforced thermoplastic polymer composites

In the recent past, the applications of natural fiber reinforced composites has increased dramatically, especially in the areas of automobile, packaging and construction sectors. Hemp fiber reinforced composites are presently replacing the fiberglass composites and steel alloys that are widely used in interior and exterior design of vehicles because of their light weight and consequent contribution to fuel efficiency. However, the tribo-potential of the hemp fabric reinforced thermoplastic composites has not been evaluated exhaustively. The present research endeavor has been planned in order to experimentally investigate the wear behavior of hemp fabric reinforced polypropylene composites. The composites have been fabricated using the compression molding technique. The weight percentage of the fiber was varied as 30, 40 and 50 % of the total weight. The effect of the weight percentage of the hemp fiber was investigated experimentally on the mechanical properties of the developed composites. The mechanical properties were tested using computerized UTM machine as per the ASTM standards. A computerized pin-on-disc type test set-up has been utilized to assess the tribological behavior of the developed composites. The experiments have been carried out at different combinations of sliding speeds (1-3 m/s) and applied normal loads (10-30 N), at a constant sliding distance of 3000 m under dry sliding conditions. The outcome of the experiments has been validated using the Scanning Electron Microscopy and the micrographs confirm the experimental findings. A significant improvement was found in the mechanical behaviour of hemp fiber reinforced PP laminates at a fiber volume fraction of 30 %. There is also a significant improvement in the wear behavior of developed composites in terms of reduction in the values of specific wear rate (upto 95 %) and the coefficient of friction (3-39 %). The experimental investigation has established hemp fiber as an important reinforcement material for improving the tribo-performance of the neat polypropylene.