| 摘要 |
<p>Packaging machine (1) with an evacuation and sealing station (3) for welding what is called monofoils (6, 9) with a permanently heatable welding element. In order to prevent the monofoil from being destroyed by contact with the permanently heated welding element, there is provided a control (36) to create inside a chamber a differential pressure between the pressure on top of the upper foil and the pressure under the latter, so that the upper foil, during and after contacting with the welding element (13), remains stretched on the product and the lower foil. It is only after a cooling phase that the difference of pressure is supressed so that the package with the foil then restabilized may be removed and taken away.</p> |
