Morphological characterisation of natural fibre reinforced thermoplastics (NFRTP) processed by extrusion, compression and rotational moulding

In this paper we describe a methodology for applying conventional morphological characterization techniques to some of the manufacturing processes of natural fibre reinforced thermoplastics (NFRTP). The composites studied consisted of a matrix of polypropylene or polyethylene, and of discrete jute, sisal and other natural fibres as the reinforcement. Different microscopic techniques have been used to characterize the processing stages and the structure-property relationships during the manufacture of NFRTPs using single screw extrusion, compression and rotational moulding. Important issues in the processing of discrete fibre composites, such as fibre length distributions, fibre orientation and overall fibre dispersion in the matrix have been studied. Transcrystallinity in the case PP/sisal and PP/jute composites has also been reported. In all cases the characterization procedures described here are related to the manufacturing processes studied in each particular case. In fact, a systematic approach to morphological characterization is presented in this study. We believe that all or some of techniques discussed here could be implemented as quality control procedures in the manufacturing of products using NFRTPs.