| 摘要 |
1,088,546. Baling rubber. TELEFUNKEN PATENTVERWERTUNG G.m.b.H. Dec. 30, 1964 [Dec. 30, 1963; Sept. 3, 1964], No. 52819/64. Heading B5A. [Also in Division F4] Preliminarily de-watered comminuted natural or synthetic rubber is formed into moisture-face blocks by a method involving the simultaneous compression and high-frequency dielectric heating of the material. In the embodiment shown, granulate from a hopper 13 is received in a perforated mould 7, preferably made of synthetic resin and having a loose bottom plate 9, and the filled mould is transferred to an enclosure 1 where heating and compression is effected by perforated electrodes 2, 3 connected to a high-frequency generator G. The earth electrode 3 is shown connected for vertical reciprocation to a compressed air cylinder 6 although, alternatively, electrode 2 may be the movable member. The pressure in enclosure 1 is preferably superatmospheric, e.g. 1.5 atoms, to prevent overheating of rubber which has become completely de-watered and hot air is preferably circulated within the enclosure to prevent condensation of water on electrodes 2, 3 or the enclosure itself. Furthermore, by decreasing the enclosure gas pressure after the heating stage, any residual water is vaporized. The formed block is removed by raising plate 9 by means of ejector pins 11. In a second embodiment, Fig. 2 (not shown), mould (36) is transferred by an endless belt (33) between converging electrodes (30, 31), the former co-operating with electrically conducting rollers (40) to gradually compress the material. In a third embodiment, Fig. 3 (not shown), a double belt moulding machine is utilized equipped with electrodes (15, 16) and a knife (25) is also provided. In a fourth-embodiment, Fig. 4 (not shown), the material is extruded between electrodes (45, 46), vibrated by an eccentric (49), the feed being a combination of gravitational action, the above-mentioned vibration and the effect of take-off rolls (50, 51). A knife (53) is also incorporated. |
