US3997677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High temperature resistant hermetically sealed plastic tray packages
Assignee: Standard Packaging Corp
•
Filing: 1975-02-07
•
Granted: 1976-12-14
•
Expires: 1995-02-07
Abstract
Abstract A package capable of withstanding prolonged exposure to temperatures in excess of 300° F is formed from a composite film which includes a thermostable, thermoplastic layer and a polyolefin layer having a softening point below 300° F. The package is hermetically sealed although it may include a weakened seal area which acts as a pressure relief valve, and may be employed as a serving dish as well as a heating container.
Inventors
- 👤 Arthur Hirsch
- 👤 Francis X. Spiegel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:46
CPC Classifications
B; B65; B65D; B65D75/00; B65D75/26; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B27/36; B32B27/365; B65D81/00; B65D81/34; B65D81/343; B32B2307/00; B32B2307/30; B32B2307/306; B32B2323/00; B32B2323/10; B32B2435/00; B32B2435/02; B32B2439/00; Y; Y10; Y10S; Y10S229/00; Y10S229/902; Y10S229/903; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31507; Y10T428/31533; Y10T428/31855
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
A hermetically sealed plastic package for use at temperatures above 300° F. comprising a semi-rigid tray member and a flexible lid member sealed together to form a cavity between them, an article to be heated to temperatures above 300° F. in said cavity, said tray member and said lid member each being formed from a laminate film and each member comprising an outer thermoplastic film layer selected from the group consisting of polycarbonate, polypentamethylene homo- and co-polymers and polysulfone films and an inner polyolefin film layer, said thermoplastic film layer being thermostable at temperatures above 300° F., said polyolefin film layer having a softening point greater than 180° F. but less than 300° F., a hermetic seal between the polyolefin film layer of said tray member and the polyolefin film layer of said lid member, said package being capable of withstanding exposure to a temperature in the range of 300° F. to 450° F. for a period of at least 15 minutes without losing its shape or its integrity.
Claim 2
Dependent Claim
169 words
A hermetically sealed plastic package for use at temperatures above 300° F. comprising a semi-rigid tray member and a flexible lid member sealed together to form a cavity between them, an article to be heated to temperatures above 300° F. in said cavity, said tray member and said lid member each being formed from a laminate film and each member comprising an outer thermoplastic film layer selected from the group consisting of polycarbonate, polypentamethylene homo- and co-polymers and polysulfone films and an inner polyolefin film layer, said thermoplastic film layer being thermostable at temperatures above 300° F., said polyolefin film layer having a softening point greater than 180° F. but less than 300° F., a hermetic seal between the polyolefin film layer of said tray member and the polyolefin film layer of said lid member, said package being capable of withstanding exposure to a temperature in the range of 300° F. to 450° F. for a period of at least 15 minutes without losing its shape or its integrity.
Claim 3
Dependent Claim
21 words
The package of claim 1 wherein said polyolefin film is a medium density polyethylene having a density greater than 0.925 gms./cc.
Claim 4
Dependent Claim
11 words
The package of claim 1 wherein said polyolefin film is polypropylene.
Claim 5
Dependent Claim
31 words
The package of claim 1 wherein the seal is formed between the polyolefin layer of said tray and the polyolefin layer of said lid around the outer periphery of said tray.
Claim 6
Dependent Claim
27 words
The package of claim 4 further including a pressure relief valve, said pressure relief valve comprising a seal area which is weaker than the surrounding seal area.
References Cited (Backward Citations)
US2951765A
Cited
US3017302A
Cited
US3298559A
Cited
US3615706A
Cited
US3531300A
Cited
US3570748A
Cited
US3550835A
Cited
US3547338A
Cited
US3454210A
Cited
US3619215A
Cited
US3637132A
Cited
US3750827A
Cited
US3890448A
Cited
UST915001I4
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-12-14 | 1980-06-14 | 1980-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-14 | 1984-06-14 | 1984-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-14 | 1988-06-14 | 1988-12-14 | $7700.00 | Window Closed / Lapsed |