METHOD FOR IMPROVING PROCESSING AND PROPERTIES OF CELLULOSE FIBRE THERMOPLASTIC COMPOSITES

SUMMARY: Cellulose fibre composites have been used extensively in the construction industry in North America and have begun to attract much attention for the automotive sector in Europe, South America, and Asia. In order to increase its competitiveness, it is important for the composites industry to reduce energy consumption and costs as well as to improve the output and the performance. To facilitate the extrusion process as well as to reduce the processing cost and energy and the complications related to wet cellulose sources, different types of cheap reactive additives have been incorporated in the process in different ways. This new approach allows elimination of the cellulose drying step and the safety challenges related to the high flammability of the dried cellulose source, thus reducing sufficiently the overall processing energy and cost, and also facilitating the flow in the extruder. In addition, it can also significantly improve the mechanical and thermal properties and the flame resistance of the composites. The investigation has been performed on polypropylene composites with wood fibres and two types of flax fibres. The first one was obtained by hammer-milling the field-retted flax fibres while the second one was produced by bio-scouring (using a genetically modified pectate lyase at 37oC and pH 8.5) the flax fibres obtained from a mechanical decortication process.