| 摘要 |
<p>The opening of a container 3 is closed by heating at least the rim 2 of the container, applying a deformable cover 4 to the opening, and pressing the cover 4 onto the rim 2 by a deformable means, for example, a hydraulic medium 11 contained in an annular groove 8 heatable sealing head 1 by a flexible sheet 10. The hydraulic medium 11 may be a substance which is liquid at sealing temperature, e.g. tin or Wood's metal, and may contain metal powder and/or granulates for heat conduction and heat storage, and heat-conducting oil. The sheet 10 may be plastics or fine steel. The head 1 may be heated by circulating hot fluid through or locating heater wires in channels (27), Figure 3 (not shown). An aluminium foil cover 4 having a heat-sealable coating is sealed to a glass container 3. In another embodiment, the container rim is heated by contact with an electrical heating coil or by hot air nozzles prior to the cover being laid thereon and pressed elastically thereon. <IMAGE></p> |
