| 摘要 |
The present invention provides reclosable plastic bags that a laboratory worker wearing gloves can open safely without the use of any tool or utensil and without increasing the risk of contact between the contents of the bag and the user. The reclosable plastic bags of the present invention may be made from an extruded plastic bag film web that may be cut or otherwise formed into a bag comprising a first wall on which a first closure profile element is disposed and a second wall on which a second closure profile element is disposed. On either wall or both walls, below the closure profile element, the plastic film web may be formed into subsections having different thicknesses. One of the subsections may be thinner cross-section, formed of a thinner bag film web, thus creating a "tear zone" that may have a substantially linear, not substantially cross-linked, molecular alignment. A sufficient distance from the centerline of that thin subsection, on either side or both sides of the thin subsection, one or more strips may be formed of sufficient mass, weight, or strength to reduce at least partially the lateral forces that might otherwise act in or on the thin section during extrusion to cause unacceptable wrinkling of the thin section and/or surrounding sections. The present invention also provides apparatus, die assemblies, and methods for manufacturing the reclosable plastic bags of the present invention. The present invention further provides reclosable closure profiles that create a partial seal substantially preventing a closure profile element from contacting either the contents of the bag or the ambient air or moisture.
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