| 摘要 |
Methods for manufacturing airtight storage containers (e.g., bags or pouches) made from thermoplastic web material and having heat-sealed margins along a perimeter. To ensure that the storage containers are airtight, an unheated rib is pressed along each heat seal while the web material in the region of each heat seal is still in a softened and pliable state. As a result of the pressure applied, the rib deforms the contacted portion of the heat-sealed web material, leaving an indentation upon cooling of the web material that serves as an air leakage barrier. This air leakage barrier ensures that any air leakage pathway across the heat seal region is closed.
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