| 摘要 |
The present invention relates to a process for continuously manufacturing composites of polymer and cellulosic fibres, comprising the steps of: a) feeding a polymer upstream into an extruder; b) melting and mixing the polymer in a zone (A) of the extruder, wherein zone (A) comprises at least one positive transportation screw element; c) feeding cellulosic fibres into the extruder in a zone (B) of the extruder, which zone (B) is located downstream of zone (A); d) transporting the mixtur e of polymer and cellulosic fibre obtained in zone (B) through a degassing zone (C), which zone (C) is located downstream of zone (B), wherein zone (C) comprises at least one positive transportation screw element and e) transporting the mixture obtained in zone (C) through a pressure building zone (D) of the extruder, which zone (D) is located downstream of zone (C), wherein zone (D) comprises at least o ne positive transportation screw element; f) releasing the mixture obtained in zone (D) into a die, characterised in that zone (B) comprises at least one positive transportation screw element, at least one kneading section and at least one negative transportation screw element such that in zone (B) of the extruder the cellulosic fibres are fibrillated to obtain cellulosic fibres with an aspect ratio as high aspossi ble, while simultaneously mixing the cellulosic fibres with the melted polymer. This process results in a compounded material comprising polymer and cellulosic fibres, wherein the cellulosic fibres are elementary fibres and have a high aspect ratio. As a result the compounded material has excellent mechanical properties.
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