| 摘要 |
A package is disclosed for natural products and comprises a first wall region of thermoplastic material and a second wall region which comprises a porous substrate hermetically sealed at its edges to the thermoplastic material and covered with a gas-permeable layer of polymethylpentene (14). The area of the porous substrate and its outer covering of polymethylpentene is selected in relation to the total area of the package and in dependence upon the natural products to permit a desired atmosphere to be maintained within the package as a result of respiration of the natural products and gas transfer through the porous substrate. |
