Gaining knowledge on the processability of PLA-based short-fibre compounds - A comprehensive comparison with their PP counterparts

The present study provides a quantitative overview of bio-based compound processing compared to commonly used composites reinforced with short glass fibres (GF). Three reinforcing fibres were compounded with polylactide and polypropylene: abaca, man-made cellulose and conventional E-GF. The flow behaviour of corresponding melts was determined using melt flow rate (MFR) and online flow spiral test. The composite structures were analysed by means of SEM in order to investigate the fibre fracture during processing and the fibre/matrix bonding affinity. The fibre length distribution was correlated with the results from the melt flow experiments, and the structure-property relationships were determined using SEM images. It was confirmed that the fibre texture, interactions between fibres and fibre-matrix bonding are influenced by subsequent processing steps and have a substantial effect on the further composite melt processing.