| 摘要 |
In the present invention, there is disclosed a process for simultaneous welding layers being arranged one above other of pairs of thermoplastic foils. The invented welding process is carried out by means of welding bars (2, 3) or a like apparatus intended for supply of welding heat applied from outer side into a welding apparatus to stacked layers of thermoplastic foils and pressing thereof onto each other. According to the invention, a more economical welding of the two foil layer pairs (1, 1') can be achieved in that the welding heat energy is not only supplied from the exterior via the welding bars (2, 3) that load the outer sides of the foil layer pairs (1, 1'), but also from the interior by employing a heat energy source (4) positioned between the two foil layer pairs (1, 1'). This is realized expediently by employing a bar-shaped, inwardly positioned, flat energy source as an interposed heat energy source (primary heating element) (4). Accordingly, n-1 bar-shaped, inwardly positioned, flat energy sources (4, 4', 4'', . . .) are employed for the purpose of simultaneously welding n foil layer pairs (1, 1', 1'' . . . ). A press for performing the method according to the invention comprises a pair of pressing elements (5, 6) or welding bars (2, 3), particularly independently heated welding bars (2, 3) bearing from outer side on n- pairs (1, 1', 1'',...) of foils and intended for mutual pressing thereof against each another, and a number n-1 of flat heat energy sources (4, 4', 4'',...) arranged in a plane being perpendicularly to the foil plane. |
