| 摘要 |
The laminate is especially suited for packing products releasing gases. The laminate comprises - when used in a packing and seen from the inside and out - in sequence a polyethylene film (2), a sheet (3) of aluminium, and a polyester film (4). A limited area of the outer film (3) is not laminated to the sheet (3) of aluminium, which produces a channel (8). Within the area of the channel the sheet (3) of aluminium and the inner layers (3, 4) are perforated in such a manner that an outlet opening (7) is formed in the packing made of the laminate, said opening ending in the channel. The channel is constructed so as to end at the bottom and top rims (9, 10) of the finished packing. In this manner a very simple and inexpensive one-way valve is formed which in a simple manner ensures that the gases formed by the contents of the packing may ooze out slowly. At the same time noxious and oxidizing gases are prevented to a high extent from entering the interior of the packing. |
