The influence of fibre length and concentration on the properties of sisal fibre reinforced polypropylene composites

In this work we investigated the influence of length and concentration of sisal fibres in PP for injection moulded composites. The fibres were incorporated into the matrix with a co-rotating twin screw extruder, in order to get the different compounds, which were injection moulded subsequently. The actual fibre length was determined after an extraction with xylene. Tensile strength and modulus and Charpy impact properties were measured and the flow curves were recorded with a capillary rheometer. The results show good correlations with the fibre length of the composites, and the tensile strength as well as the notched Charpy impact strength can be evaluated using rule-of-mixture like models.