| 摘要 |
The invention relates to a method for the production of thermoplastic plastics with natural fibre components and improved mechanical properties and is particularly suitable for the production of granulates of said plastic material as semi-finished product for products manufactured using the injection moulding method. The aim of the invention is a method for providing plastics with good mechanical properties and concomitant mass reduction, by the introduction of natural fibres, in particular, bast fibres. Said aim is achieved, whereby natural fibres are used in the form of fibre cuttings, fibre pellets, fibre pre-pregs, fibre granules or small fabric sections. The fibres are introduced in a mixing chamber into a polymer or polymer mixture, in which the pitch of the kneading screw is 10 to 50 % lower than in kneading screws for the mixing of glass fibres. Said introduction is at a temperature 1 to 5 DEG C above the melting point of the modified polymer or polymer mixture, the above are melted and mixed. After a residence time of 2.0 - 3.0 minutes from the beginning of the mixing of the fibres, the fibre-polymer mixture is drawn off from the mixing device in the form of a, preferably several, strand(s). The above method permits the addition of between 4 and 30 % natural fibres to the modified polymer or polymer mixture based on the end-product. |
