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CA1082142A Expired / Lapsed CA ⏱️ 0.0 years remaining

Seal for self-welding bag

Assignee: WR Grace and Co Conn
•
Filing: 1977-04-14
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Granted: 1980-07-22
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Expires: 1997-04-14
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Abstract

Abstract SEAL FOR SELF-WELDING BAG Abstract of The Disclosure The invention relates to a self-welding bag or pouch of heat-shrinkable material having a novel seal configuration composed of a complete end or outer heat seal and at least one perforated inner heat seal adjacent and parallel to said outer seal so that air can be removed from the space between seals as the bag is evacuated and shrunk thereby providing an area seal between said inner and outer seals as the bag walls adhere to each other. This seal configuration overcomes the problem of seal delamination which occurs in prior art self-welding bag and pouch structures.

Inventors

  • 👤 Joseph Z. Sun

Bibliographic Details

Application Number —
Jurisdiction CA
Data Source google_patents
Last Synchronized 2026-11-08 07:58
CPC Classifications
—

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 116 words
In an evacuated package including a product enclosed within a bag made of a single sheet of heat shrunken self-welding thermoplastic material and said bag having a hermetic closure at one end, the improved seal configur-ation at the other end of said bag which comprises: (a) a complete outer seal closing the other end of said bag; (b) at least one inner seal spaced apart from said outer seal, each inner seal being located between said outer seal and said product; and, (c) an area seal between said inner and outer seals, said area seal being formed by the self-welding bag walls having ad-hered to each other in the space between said inner and outer seals.
Claim 2
Dependent Claim 116 words
In an evacuated package including a product enclosed within a bag made of a single sheet of heat shrunken self-welding thermoplastic material and said bag having a hermetic closure at one end, the improved seal configur-ation at the other end of said bag which comprises: (a) a complete outer seal closing the other end of said bag; (b) at least one inner seal spaced apart from said outer seal, each inner seal being located between said outer seal and said product; and, (c) an area seal between said inner and outer seals, said area seal being formed by the self-welding bag walls having ad-hered to each other in the space between said inner and outer seals.
Claim 3
Dependent Claim 12 words
The package of claim 1 including a multiplicity of perforated inner seals.
Claim 4
Dependent Claim 27 words
The package of claim 1 wherein the heat shrinkable, self-welding material is a film laminate comprising layers of vinylidene chloride/vinyl chloride copolymer and, ethylene vinyl acetate copolymer.

References Cited (Backward Citations)

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