GB745366A - Process of and means for treating a plastic mass - Google Patents

Abstract

745,366. Kneading appliances. SOESTFERRUM APPARATEBAU GES. Nov. 14. 1952 [Nov. 14, 1951], No. 28729/52. Class 86. [Also in Group V] A method of treating a dough-like plastic mass, particularly a mass of ceramic material, consists in kneading the mass and then passing it through a conduit which is subjected to pressure vibrations in a direction perpendicular to the direction in which the mass is advancing, whereby flaws caused and introduced by the kneading are eliminated from the mass so that the mass on being extruded from the conduit is in a substantially homogeneous state. In a worm extrusion press, Fig. 1, an internally conical tube 12 is located between a conveyer tube 5 containing a worm 4, and an outlet pipe 9 provided with an outlet 3. The tube 12 is connected to the tubes 5 and 9 by elastic sleeves 13, 14 and is vibrated by rotating eccentrics 16, 17 driven from the drive mechanism (not shown) of the worm shaft 22, through a shaft 18 and sprockets 19, 20, 21. In another arrangement, Fig. 2, a cylindrical conduit 23 vibratable due to its elasticity is mounted between the conveyer tube 5 and the outlet 3. The conduit 23 may be vibrated at ultra sonic frequency by several quartz crystals distributed around its periphery, Fig. 3 (not shown). Alternatively the conduit 23 may be vibrated by an imbalance mass 27, Fig. 4, which is rotated by a motor 26 and transmits the vibrations to a grooved portion 28 of the conduit 23, or by magnetomotive vibrating means, Fig. 5 (not shown) or by tubular crystal vibrating means, e.g. of varium titanate, Fig. 6 (not shown) producing diametral vibrations at sonic frequency. The natural frequency of the conduit 23 may be tuned to that of the vibrating means by suitable choice of dimensions or by application thereto or removal therefrom of additional masses. The frequency of the vibrations may be varied commensurate with the natural frequency of the mass. The frequency of the vibrations may be tuned to the natural frequency of the mass. The conduit 23 may have a wear resistant lining. A conical tubular element 24 is provided between the conduit 23 and the outlet 3. The element 24 and the outlet 3 may also be associated with vibrating means.