Patent US3678276A successfully refreshed from Google Patents.
US3678276A
Expired / Lapsed
US
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Infrared radiometric detection of seal defects
Assignee: United States Department of the Army
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Filing: 1971-07-01
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Granted: 1972-07-18
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Expires: 1991-07-01
Abstract
Abstract A rapid, non-destructive test for discovering seal defects in flexible packages wherein the package seal is passed between a narrow beam heat source and a detector sensitive to infrared energy, which detector senses variations in the radiant energy emitted from the seal, such variations resulting from a change in thermal conductivity due to the presence of voids, wrinkles, irregularities or occluded matter in the seal.
Inventors
- 👤 Rauno A Lampi
- 👤 Kwoh H Hu
- 👤 Richard F Osborne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:09
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/72
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
242 words
A method of detecting a defect present in the closure seal of a food-filled, flexible package, which comprises: a. placing the food-filled flexible package within a rigid package holder, said package holder having flat opposed plates bearing against and covering both sides of said closure seal to hold said seal in a flat plane, said plates having opposed narrow slots which coincide to expose a narrow portion of said closure seal along its entire length. b. applying heat energy at a uniform speed starting at one end and proceeding continuously to the opposite end, along the entire length of one side surface of the exposed portion of said closure seal, c. detecting the infrared radiant energy passing through said closure seal and emitted at the opposite side of said exposed portion of said closure seal by means of an infrared radiometric device which scans along the length of the exposed seal area at the same uniform speed at which the heat energy is applied, and d. moving said exposed portion of said closure seal between said heat energy source and said infrared radiometric device along a path so as to maintain a constant seal-to-heat energy distance and a seal-to-infrared radiometric device distance, whereby the presence of any defect in the exposed seal area is indicated by a change in the thermal radiation characteristics of said seal and any such anomaly in the thermal radiation characteristics is detected by the infrared radiometric device.
Claim 2
Independent Claim
242 words
A method of detecting a defect present in the closure seal of a food-filled, flexible package, which comprises: a. placing the food-filled flexible package within a rigid package holder, said package holder having flat opposed plates bearing against and covering both sides of said closure seal to hold said seal in a flat plane, said plates having opposed narrow slots which coincide to expose a narrow portion of said closure seal along its entire length. b. applying heat energy at a uniform speed starting at one end and proceeding continuously to the opposite end, along the entire length of one side surface of the exposed portion of said closure seal, c. detecting the infrared radiant energy passing through said closure seal and emitted at the opposite side of said exposed portion of said closure seal by means of an infrared radiometric device which scans along the length of the exposed seal area at the same uniform speed at which the heat energy is applied, and d. moving said exposed portion of said closure seal between said heat energy source and said infrared radiometric device along a path so as to maintain a constant seal-to-heat energy distance and a seal-to-infrared radiometric device distance, whereby the presence of any defect in the exposed seal area is indicated by a change in the thermal radiation characteristics of said seal and any such anomaly in the thermal radiation characteristics is detected by the infrared radiometric device.
Claim 3
Dependent Claim
22 words
A method according to claim 1 wherein the defects present in the closure seal may be either wrinkles, voids, or occluded matter.
Claim 4
Dependent Claim
34 words
A method according to claim 2 wherein the application of said heat energy to said seal leads the actual detection on the opposite side to permit the flow of heat through said seal thickness.
Claim 5
Dependent Claim
48 words
A method according to claim 3 wherein the means to apply said heat energy and the infrared radiometric device are stationary and the package seal is moved between said means and said device causing the length of the seal to be scanned by said means and said device.
Claim 6
Dependent Claim
21 words
A method according to claim 4 wherein neither said heat energy source nor said infrared radiometric device contact the closure seal.
Claim 7
Dependent Claim
24 words
A method according to claim 5 wherein said infrared radiometric device comprises optical means which focus said transmitted infrared energy on an infrared detector.
Claim 8
Dependent Claim
16 words
A method according to claim 6 wherein said infrared detector is a hyperhemispherically immersed tHermistor bolometer.
References Cited (Backward Citations)
US3210546A
Cited
US3206603A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |