| 摘要 |
942,048. Extrusion dies. FARBWERKE HOECHST A.G. Feb. 12, 1960 [Feb. 18, 1959], No. 5116/60. Heading B5A. An extrusion die comprises an elongated hollow body 14 closed at one end and having a plurality of apertures 18 along a section 15 which connect the interior of the body with an extrusion passage 23 so as to bring about a double change in direction in the flow of material being extruded, as indicated by the arrow 27. In the embodiment illustrated, the extrusion passage 23 is formed between the body 14 and a discharge tube 19 and its cross-sectional area increases in the direction of flow in the region adjacent section 15. The end wall 16 of the body 14 has an inwardly directed conical portion 17 co-extensive with section 15, and a hollow mandrel 22 is secured to this end wall by a bolt 21 which has a central passage 26 in communication with a pipe 24. When thin-walled tubes are extruded, they may be supported immediately after extrusion by compressed air introduced through pipe 24. In another embodiment, oversized apertures 18 are employed in conjunction with a removable apertured screen and changes of effective aperture size and/or number involve merely a change of screen. |
