| 摘要 |
1,181,987. Extrusion dies. NRM CORP. 2 Aug., 1967 [26 Aug., 1966], No. 35446/67. Headings B5A and B5B. Apparatus for the production of synthetic polymeric material in particular tubular film, comprises an extruder having a bore 2, a feedscrew 3, and a laterally extending outlet 4 for plasticized material; a die support 8, situated at the outlet end of the extruder barrel 1, on which a die assembly 9 is rotatably mounted, as on the tapered roller bearing 10, the die assembly having a central opening 11 registering with the extruder outlet opening; sealing means 12, which rotate with the die assembly and seal the rotary joint between the rotating plane faces of the die assembly and the extruder barrel; the die assembly comprising three parts 21, 22 and 23 bolted together, providing radially extending peripheral flanges 24 and 25, which straddle a fixedly mounted heating means, such as an induction heating coil 26; the upper part 21 of the die assembly having a tapered bore 27, in which is bolted a mandrel 28, the bore and the mandrel together defining an extrusion orifice 29; the mandrel having mounted centrally within it a spreader 30, and a baffle 31 having a screen 32 to direct upward flow of plastic material radially through the openings of the baffle, and thence to the extrusion orifice; air for expanding the tubular film being introduced through an inlet passage 17 to an annular groove 18, and thence by openings 19 and 20 in the seal and die assembly, to a nozzle 51. The induction heating coil may be accurately radially adjusted coaxially with respect to the rotary die assembly by means of screws 36 adjacent to the ends of the arcuate coil support members 37 and 38. Further adjustment for equalizing air gaps 39 and 40 between the respective flanges 24 and 25 and the upper and lower ends of the heating coil, is provided by the clearance of the holes 41 with screws 42, which mount the members 37 and 38 to the support base 8. The lower part of the die assembly 23 has a sprocket 45 bolted to it, which carries a chain 46 driven by a sprocket 47 on the output shaft of a speed reducer 48, which is driven by a motor 49. |
