| 摘要 |
1,103,925. Screw extruders. BARMER MASCHINENFABRIK A.G. 5 Nov., 1965 [6 Nov., 1964; 29 May, 1965], No. 47044/65. Heading B5A. A screw extruder is provided with a feed channel 2 which communicates both with screw 3 and a pocket 4 which runs axially of barrel 1 for a distance of at least one screw pitch and which tapers in the downstream direction. According to the invention, the pocket allows the creation of sufficient working pressure when the starting materials are plasticized, and particularly when of low viscosity, or when they are finely divided and of low density. Pocket 4 may taper both axially and transversely and typical cross-sections are shown, Figs. 2a, 2b, 2c (not reproduced). The extruder is provided with heaters 10-12, a heat insulant partition 13 and a cooling duct 14. The embodiment of Fig. 3 (not reproduced), is intended for use with powders, and the pocket may be parallel or skew to the barrel axis, Figs. 4a-4f (not shown), or asymmetric in cross-section, Fig. 3a (not shown). A stirrer may be incorporated in channel 2 or in a feed hopper. |
