| 摘要 |
997,660. Thermoplastic tubes. FARWERKE HOECHST A.G. Feb. 5, 1962 [Feb. 3, 1961], No. 4385/62. Heading B5A. In the continuous manufacture of thermoplastic tubes, the tube is formed in an extruder 1 and then passed between a jacket 2 and a mandrel 3 which has the end 4 shaped to cause a two-fold reversal of the direction of flow of the tube, and comprises cooling and electrical heating elements 7, 10, 11 to regulate the temperature so that solidification begins during or between the first and second reversals of direction. The tube is drawn from the extruder by endless belts 5 co-operating with a core 6 which is fastened to the mandrel 3 by a chain 13. A perforated baffle device 9 located between the jacket and mandrel divides the stream of material into a plurality of streams which recombine at the narrow portion 8 of the passage to assist in homogenizing the material. The cooling device consists of a perforated tube discharging cooling air or a bath of cooling liquid. |
