| 摘要 |
By means of the welding jaws (11 and 12) of a high-frequency welding appliance, the two wall portions (5a, 5b) to be connected, located at the rear end of the tubular body (2) of the container to be closed, are brought into contact with one another. However, these wall portions (5a, 5b) are not at the same time pressed together, in order to avoid a reduction in thickness of the connecting layer (9), by means of which a thermoplastic inner layer (10) is connected to a metallic barrier layer (6). The metallic barrier layer (6) is heated by means of a high-frequency field. Since the connecting layer (9) is not pressed together during the heating, it is capable, during the short heating time, of receiving a sufficiently large quantity of heat from the barrier layer (6) and of transferring it to the inner layer (10), so that the latter can be brought to the temperature necessary for a good welded connection. Following this heating of the wall portions (5a, 5b), these are pressed together, along with simultaneous cooling. The pressing-together pressure is selected so that only very small quantities of the material of the connecting layer (9) are displaced away from the welding point, thereby preventing the displaced material from piercing the inner layer (10). <IMAGE> |
