Prediction of tensile properties of injection moulding flax fibre reinforced polypropylene from morphology analysis

Abstract

The Young modulus and tensile strength of flax fibre reinforced polypropylene were determined and compared with the micromechanical models usually used in the case of short glass fibre reinforced composites. The fibre length and fibre diameter distributions of the injected reinforced of 2, 4, 8 and 22vol% compound were determined and used to the models in order to evaluate the expected properties of the composites. The mechanical properties were interpreted on the base of real fibre content, fibre orientation, fibre length and diameter distributions and morphology of the composites. The Kelly-Tyson’s model of the tensile strength prediction has been modified to take in consideration the fibre property variability due to the large distribution of fibre shape ratio induced by the process. Finally matrix modulus has been adjusted to take into account the change of crystallinity with fibre content.