US3854653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum tight plastic sheet envelope
Assignee: Amcor Flexibles Viersen GmbH
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Filing: 1973-11-08
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Granted: 1974-12-17
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Expires: 1993-11-08
Abstract
Abstract A vacuum-tight, moisture impermeable envelope for food and the like consists of two laminar sheets or foils whose central portions bound a pocket and whose edge portions are sealed about the pocket by a weld integrally connecting the inner layers of the two sheets. Tearing lugs are constituted by respective parts of the two edge portions extending beyond the weld and movable relative to each other. The breaking strength and tear propagation resistance of the outer layer of one sheet are greater than the corresponding properties of the inner layer, and the latter is more brittle than the inner layer of the other sheet, both inner layers consisting of ethylene homo- or copolymers. The strength of the bond between the inner and outer layers of the one sheet is smaller than the breaking strength of the weld. This relationship of mechanical properties permits the sealed envelope to be opened conveniently.
Inventors
- 👤 H Engelsberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:49
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B7/00; B32B7/02; B32B7/022; B32B27/30; B32B27/306; B32B27/32; B32B27/34; B65; B65D; B65D75/00; B65D75/26; B65D75/52; B65D75/58; B65D75/5855; B32B2307/00; B32B2307/50; B32B2307/582; B32B2439/00; B32B2439/70; B65D75/28; B65D75/30; B65D75/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
210 words
A vacuum-tight envelope comprising: a. first and second laminar plastic sheets having each a central portion and an edge portion extending about the central portion in a closed loop; b. each shEet having an outer layer and an inner layer bonded to said outer layer; c. said central portions being spacedly superposed in such a manner that said inner layers of said central portions bound a pocket therebetween; d. said edge portions being contiguously superposed; e. an elongated weld integrally connecting said inner layers of said edge portions in a closed loop sealing said pocket; f. respective lug parts of said edge portions extending beyond said weld away from said pocket and being movable relative to each other; g. the breaking strength and tear propagation resistance of the outer layer of said first sheet being greater than the breaking strength and the tear propagation resistance of the inner layer of said first sheet; h. the inner layers of said first and second sheets consisting of ethylene polymers, the inner layer of said first sheet being more brittle than the inner layer of said second sheet; i. the strength of the bond between the inner and outer layers in said first sheet being smaller than the breaking strength of said weld.
Claim 2
Dependent Claim
210 words
A vacuum-tight envelope comprising: a. first and second laminar plastic sheets having each a central portion and an edge portion extending about the central portion in a closed loop; b. each shEet having an outer layer and an inner layer bonded to said outer layer; c. said central portions being spacedly superposed in such a manner that said inner layers of said central portions bound a pocket therebetween; d. said edge portions being contiguously superposed; e. an elongated weld integrally connecting said inner layers of said edge portions in a closed loop sealing said pocket; f. respective lug parts of said edge portions extending beyond said weld away from said pocket and being movable relative to each other; g. the breaking strength and tear propagation resistance of the outer layer of said first sheet being greater than the breaking strength and the tear propagation resistance of the inner layer of said first sheet; h. the inner layers of said first and second sheets consisting of ethylene polymers, the inner layer of said first sheet being more brittle than the inner layer of said second sheet; i. the strength of the bond between the inner and outer layers in said first sheet being smaller than the breaking strength of said weld.
Claim 3
Dependent Claim
54 words
An envelope as set forth in claim 1, wherein said outer layer of said first sheet consists of unstretched polyamide, and the ethylene polymer of the inner layer of said first sheet has a specific gravity of 0.928 to 0.940, and a melt index of 3 to 5 g/10min, corresponding to DIN35735 (MFJ 190/2,16)
Claim 4
Dependent Claim
28 words
An envelope as set forth in claim 2, wherein the inner layer of said second sheet consists of high-pressure polyethylene having a specific gravity of 0.918 to 0.924.
Claim 5
Dependent Claim
29 words
An envelope as set forth in claim 2, wherein the inner layer of said second sheet consists of high-pressure ethylene polymer having a specific gravity of 0.935 to 0.940.
Claim 6
Dependent Claim
32 words
An envelope as set forth in claim 1, wherein said weld includes a spur extending from said closed loop thereof in a direction away from said pocket and toward said lug parts.
Claim 7
Dependent Claim
30 words
An envelope as set forth in claim 1, wherein at least one longitudinal portion of said weld is of reduced width and more frangible than the remainder of said weld.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |