Patent US4904836A successfully refreshed from Google Patents.
US4904836A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave heater and method of manufacture
Assignee: General Mills Marketing Inc
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Filing: 1988-05-23
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Granted: 1990-02-27
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Expires: 2008-05-23
Abstract
Abstract A microwave food package with a heater and method of manufacture are provided. The heater includes a substrate coated with a microwave lossy material having a thickness in the range of between about 0.001 cm and about 0.025 cm and an inverse penetration depth greater than about 0.01 cm -1 . The layer of lossy material is preferably in liquid form when applied to the substrate and is non-liquid when used. The lossy material can have electric field loss properties alone or magnetic loss properties and combination thereof.
Inventors
- 👤 Charles H. Turpin
- 👤 Michael R. Perry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:50
CPC Classifications
B; B65; B65D; B65D81/00; B65D81/34; B65D81/3446; B65D2581/00; B65D2581/34; B65D2581/3437; B65D2581/3439; B65D2581/344; B65D2581/3443; B65D2581/3447; B65D2581/3448; B65D2581/3463; B65D2581/3464; B65D2581/3471; B65D2581/3477; B65D2581/3483; B65D2581/3486; B65D2581/3487; Y; Y10; Y10S; Y10S99/00; Y10S99/14
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
73 words
A microwave heater for use for heating or cooking food in a microwave oven, said heater comprising: (a) a thermally stable substrate having a first surface; and (b) a lossy layer on at least a portion of said substrate first surface, said loosy layer having at least one region thereof with thickness and inverse power penetration depth which have values within the ranges of about the values within Area A of FIG. 34.
Claim 2
Dependent Claim
73 words
A microwave heater for use for heating or cooking food in a microwave oven, said heater comprising: (a) a thermally stable substrate having a first surface; and (b) a lossy layer on at least a portion of said substrate first surface, said loosy layer having at least one region thereof with thickness and inverse power penetration depth which have values within the ranges of about the values within Area A of FIG. 34.
Claim 3
Dependent Claim
33 words
A microwave heater as set forth in claim 1 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area B of FIG. 35.
Claim 4
Dependent Claim
33 words
A microwave heater as set forth in claim 1 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area C of FIG. 36.
Claim 5
Dependent Claim
33 words
A microwave heater as set forth in claim 1 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area D of FIG. 37.
Claim 6
Dependent Claim
42 words
A microwave heater as set forth in claim 1, 2, 3 or 4 wherein: (a) said lossy layer has at least one preselected nonuniformity in at least one characteristic thereof in a preselected pattern across a major surface of said lossy layer.
Claim 7
Dependent Claim
31 words
A microwave heater as set forth in claim 5 wherein: (a) said nonuniformity includes a plurality of different sized regions of lossy layer portions having electrical disruptions between said regions thereof.
Claim 8
Dependent Claim
26 words
A microwave heater as set forth in claim 6 wherein: (a) said different sized regions are positioned in preselected locations across said lossy layer major surface.
Claim 9
Dependent Claim
44 words
A microwave heater as set forth in claim 6 wherein: (a) at least a portion of said regions each have major and minor axial dimensions and the major and minor axial dimensions of said portion of said regions is less than about 1.6 cm.
Claim 10
Dependent Claim
63 words
A microwave heater as set forth in claim 6 wherein: (a) at least a portion of said regions each have major and minor axes and the size of the major and minor axes of said portion of said regions is less than about the size wherein a further increase in the size does not result in an appreciable increase in microwave power absorbed.
Claim 11
Dependent Claim
28 words
A microwave heater as set forth in claim 5 wherein: (a) said nonuniformity includes preselected regions having different inverse power penetration depths across said lossy layer major surface.
Claim 12
Dependent Claim
30 words
A microwave heater as set forth in claim 10 wherein: (a) said regions having different inverse power penetration depths are positioned in preselected locations across said lossy layer major surface.
Claim 13
Dependent Claim
26 words
A microwave heater as set forth in claim 5 wherein: (a) said nonuniformity includes preselected regions having different materials therein across the lossy layer major surface.
Claim 14
Dependent Claim
25 words
A microwave heater as set forth in claim 12 wherein: (a) said different materials are positioned in preselected locations across said lossy layer major surface.
Claim 15
Dependent Claim
50 words
A microwave heater as set forth in claim 1, 2, 3 or 4 wherein: (a) said lossy layer has a ratio of its thickness to the wavelength of microwaves in the lossy layer in at least a portion of said lossy layer of less than or equal to about 0.15.
Claim 16
Dependent Claim
25 words
A microwave heater as set forth in claim 1 wherein: (a) said nonuniformity includes preselected regions having different thicknesses across said lossy layer major surface.
Claim 17
Dependent Claim
26 words
A microwave heater as set forth in claim 15 wherein: (a) said regions having different thicknesses are in preselected locations across said lossy layer major surface.
Claim 18
Independent Claim
86 words
A method of making a microwave heater for use for heating or cooking food in a microwave oven, said method comprising: (a) applying a mixture of microwave absorptive material and vehicle to a first surface of a thermally stable substrate; (b) curing said mixture to form a lossy layer which is solid; and (c) said lossy layer having at least one region thereof with thickness and inverse power penetration depth which have values within the ranges of about the values within Area A of FIG. 34.
Claim 19
Independent Claim
86 words
A method of making a microwave heater for use for heating or cooking food in a microwave oven, said method comprising: (a) applying a mixture of microwave absorptive material and vehicle to a first surface of a thermally stable substrate; (b) curing said mixture to form a lossy layer which is solid; and (c) said lossy layer having at least one region thereof with thickness and inverse power penetration depth which have values within the ranges of about the values within Area A of FIG. 34.
Claim 20
Dependent Claim
37 words
A method of making a microwave heater as set forth in claim 17 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area B of FIG. 35.
Claim 21
Dependent Claim
37 words
A method of making a microwave heater as set forth in claim 17 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area C of FIG. 36.
Claim 22
Dependent Claim
37 words
A method of making a microwave heater as set forth in claim 17 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area D of FIG. 37.
Claim 23
Dependent Claim
46 words
A method of making a microwave heater as set forth in claim 17, 18, 19 or 20 wherein: (a) said lossy layer has at least one preselected nonuniformity in at least one characteristic thereof in a preselected pattern across a major surface of said lossy layer.
Claim 24
Dependent Claim
35 words
A method of making a microwave heater as set forth in claim 21 wherein: (a) said nonuniformity includes a plurality of different sized regions of lossy layer portions having electrical disruptions between said regions thereof.
Claim 25
Dependent Claim
30 words
A method of making a microwave heater as set forth in claim 22 wherein: (a) said different sized regions are positioned in preselected locations across said lossy layer major surface.
Claim 26
Dependent Claim
48 words
A method of making a microwave heater as set forth in claim 22 wherein: (a) at least a portion of said regions each have major and minor axial dimensions and the major and minor axial dimensions of said portion of said regions is less than about 1.6 cm.
Claim 27
Dependent Claim
67 words
A method of making a microwave heater as set forth in claim 22 wherein: (a) at least a portion of said regions each have major and minor axes and the size of the major and minor axes of said portion of said regions is less than about the size wherein a further increase in the size does not result in an appreciable increase in microwave power absorbed.
Claim 28
Dependent Claim
29 words
A method of making a microwave heater as set forth in claim 21 wherein: (a) said nonuniformity includes preselected regions having different thicknesses across said lossy layer major surface.
Claim 29
Dependent Claim
30 words
A method of making a microwave heater as set forth in claim 26 wherein: (a) said regions having different thicknesses are in preselected locations across said lossy layer major surface.
Claim 30
Dependent Claim
32 words
A method of making a microwave heater as set forth in claim 21 wherein: (a) said nonuniformity includes preselected regions having different inverse power penetration depths across said lossy layer major surface.
Claim 31
Dependent Claim
34 words
A method of making a microwave heater as set forth in claim 28 wherein: (a) said regions having different inverse power penetration depths are positioned in preselected locations across said lossy layer major surface.
Claim 32
Dependent Claim
30 words
A method of making a microwave heater as set forth in claim 21 wherein: (a) said nonuniformity includes preselected regions having different materials therein across the lossy layer major surface.
Claim 33
Dependent Claim
29 words
A method of making a microwave heater as set forth in claim 30 wherein: (a) said different materials are positioned in preselected locations across said lossy layer major surface.
Claim 34
Dependent Claim
54 words
A method of making a microwave heater as set forth in claim 17, 18, 19 or 20 wherein: (a) said lossy layer has a ratio of its thickness to the wavelength of microwaves in the lossy layer in at least a portion of said lossy layer of less than or equal to about 0.15.
Claim 35
Independent Claim
102 words
A method of making a microwave heater for use for heating or cooking food in a microwave oven, said method comprising: (a) forming a liquid mixture of vehicle and microwave lossy material; (b) applying said liquid mixture to a surface of a thermally stable substrate to form a layer of said liquid mixture; and (c) curing said liquid mixture to thereby change the liquid into a solid lossy layer with said lossy layer having at least one region thereof with thickness and inverse power penetration depth which have values within the ranges of about the values within Area A of FIG. 34.
Claim 36
Independent Claim
102 words
A method of making a microwave heater for use for heating or cooking food in a microwave oven, said method comprising: (a) forming a liquid mixture of vehicle and microwave lossy material; (b) applying said liquid mixture to a surface of a thermally stable substrate to form a layer of said liquid mixture; and (c) curing said liquid mixture to thereby change the liquid into a solid lossy layer with said lossy layer having at least one region thereof with thickness and inverse power penetration depth which have values within the ranges of about the values within Area A of FIG. 34.
Claim 37
Dependent Claim
37 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area B of FIG. 35.
Claim 38
Dependent Claim
37 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area C of FIG. 36.
Claim 39
Dependent Claim
37 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said thickness and inverse power penetration depth values are within the ranges of about the values within Area D of FIG. 37.
Claim 40
Dependent Claim
31 words
A method of making a microwave heater setforth in claim 33 wherein: (a) a said vehicle including a solvent which at least partially evaporates from the liquid mixture during curing thereof.
Claim 41
Dependent Claim
25 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said vehicle includes a binder material which cures by co-reacting.
Claim 42
Dependent Claim
27 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said liquid mixture is applied to said substrate by a printing technique.
Claim 43
Dependent Claim
28 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said liquid mixture is applied to said substrate by a silk screen process.
Claim 44
Dependent Claim
27 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said liquid mixture is applied to said substrate by a spraying process.
Claim 45
Dependent Claim
27 words
A method of making a microwave heater as set forth in claim 33 wherein: (a) said liquid mixture is applied to said substrate by a coating process.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |