| 摘要 |
<p>The method involves forming a boss in an inner zone of a sealing film (3) delimited by a peripheral zone that fixes the film on an edge of a tray (2). A ventilating orifice (8) is pierced in an inner zone of the film, and a valve (4) is placed on the film above the orifice. The zone is fixed on the edge of the tray filled with products. The filled tray is closed when subjected to heat treatment. Shape and size of the boss are determined according to products and heat treatment so that the tray is deformed at the level of boss after cooling.</p> |
