| 摘要 |
The present invention relates to a microwaveable zipper bag for food packaging. More particularly, it relates to a zipper bag with superior air and moisture vapor permeabilities, particularly suited for microwave heating of foods. The microwaveable zipper bag comprises a plurality of pseudo-closed gaps on the film for air permeation formed by virtue of an impression process and a pair of male-female zipper profile. An optional sealing layer material can be coated on the top of the film to fill the gaps. When the pressure difference across the film increases inside the closed microwaveable zipper bag, the heated air will inflate the bag. Those gaps will be opened gradually and regulates the pressure to prevent bursting of the microwaveable zipper bag. On the other hand, when the heating stops, the temperature inside the closed microwaveable zipper bag decreases and the sealing ability of the pseudo-closed gaps is restored due to a gap re-closing.
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