EP0000797A1 - Mikrowellenenergiemoderator - Google Patents

Mikrowellenenergiemoderator Download PDF

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Publication number
EP0000797A1
EP0000797A1 EP78200114A EP78200114A EP0000797A1 EP 0000797 A1 EP0000797 A1 EP 0000797A1 EP 78200114 A EP78200114 A EP 78200114A EP 78200114 A EP78200114 A EP 78200114A EP 0000797 A1 EP0000797 A1 EP 0000797A1
Authority
EP
European Patent Office
Prior art keywords
microwave
microwave energy
moderator
layer
cooking
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP78200114A
Other languages
English (en)
French (fr)
Inventor
Thomas Joseph Flautt Jr.
Edward John Maguire Jr.
David Leroy Richardson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Procter and Gamble Co
Original Assignee
Procter and Gamble Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US05/854,941 external-priority patent/US4268738A/en
Application filed by Procter and Gamble Co filed Critical Procter and Gamble Co
Publication of EP0000797A1 publication Critical patent/EP0000797A1/de
Withdrawn legal-status Critical Current

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D81/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D81/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within the package
    • B65D81/3446Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within the package specially adapted to be heated by microwaves
    • B65D81/3461Flexible containers, e.g. bags, pouches, envelopes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2581/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D2581/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
    • B65D2581/3437Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within specially adapted to be heated by microwaves
    • B65D2581/3439Means for affecting the heating or cooking properties
    • B65D2581/344Geometry or shape factors influencing the microwave heating properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2581/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D2581/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
    • B65D2581/3437Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within specially adapted to be heated by microwaves
    • B65D2581/3439Means for affecting the heating or cooking properties
    • B65D2581/3452Packages having a plurality of microwave reactive layers, i.e. multiple or overlapping microwave reactive layers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2581/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D2581/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
    • B65D2581/3437Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within specially adapted to be heated by microwaves
    • B65D2581/3471Microwave reactive substances present in the packaging material
    • B65D2581/3472Aluminium or compounds thereof
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2581/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D2581/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
    • B65D2581/3437Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within specially adapted to be heated by microwaves
    • B65D2581/3486Dielectric characteristics of microwave reactive packaging
    • B65D2581/3487Reflection, Absorption and Transmission [RAT] properties of the microwave reactive package
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2581/00Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D2581/34Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
    • B65D2581/3437Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within specially adapted to be heated by microwaves
    • B65D2581/3486Dielectric characteristics of microwave reactive packaging
    • B65D2581/3489Microwave reflector, i.e. microwave shield

Definitions

  • the present invention pertains, in general, to providing means for moderating a field of microwave energy for instance, providing means for sufficiently enclosing and shielding comestible articles to be cooked in microwave ovens so that uniform cooking results.
  • the present invention also pertains to providing means for obviating the excessive loss of constituents such as water, fat, flavor, aromatics and the like during microwave cooking.
  • the invention still further pertains to providing means for reducing the criticality of timing microwave cooking as well as reducing the attention and activity associated with conventional microwave cooking. More particularly, the present invention enables cooking frozen foods in microwave ovens without having to initally thaw the food and/or without having to provide power level changes to sequentially effect thawing and then cooking.
  • Conventional microwave oven cooking generally involves having to periodically reposition an article being cooked and/or to adjust the oven power to lessen uneven cooking; or excessive weight loss and concomitant dryness of the article being cooked; or criticality of timing the cooking interval; or having to cook a plurality of articles (e.g.: meal components such as potatoes, vegetables, and meat) sequentially rather than simultaneously.
  • a plurality of articles e.g.: meal components such as potatoes, vegetables, and meat
  • frozen foods are much less effective than unfrozen foods with respect to converting microwave energy to heat
  • the cooking of frozen foods in microwave ovens conventionally requires either pre-cooking thawing and/or relatively elaborate control of and changes of microwave power. That is, low power or periodic power ON intervals to effect thawing, and relatively high continuous power to effect cooking.
  • the prior art further discloses a number of microwave cooking containers and the like which comprise selective shielding and/or microwave transparent apertures of various sizes in structures that are otherwise microwave reflective.
  • U.S. Patent No. 3,547,661 which issued December 15, 1970 to P.N. Stevenson discloses a container and food beating method wherein apertures of various sizes are provided in the top and bottom and are in registered relation. Such apertures may also be partially masked by microwave reflective material as indicated in Figures 1 and 3, areas 25 through 28.
  • the various sizes of apertures and partial masking ostensibly provide means for selectively heating different items to different temperatures simultaneously; reference Abstract Of The Disclosure.
  • a major object of the present invention is providing a microwave energy moderator which will, in effect, when disposed in a path of microwave energy, provide a substantially more uniform microwave energy filed downstream from the moderator than the uniformity of the field would be absent the moderator.
  • the moderator can be in the form of means for enclosing a comestible article and can further comprise means for obviating excessive.loss of volatile and liquid constituents of the article while it-is being cooked by microwave energy and means.for draining liquids from the enclosing means while the article.is being cooked in a microwave oven.
  • Another object of the present invention is providing a microwave moderating enclosure means which will shrink about an:article being cooked in a microwave'oven and, upon ceasing to shrink, provide a predetermined degree of doneness of the article.
  • An additional object of the invention is to provide an improved microwave oven having a passive liner or interior enclosure which sufficiently moderates the oven's microwave energy that there is a generally uniform field of microwave energy inside the liner or interior enclosure.
  • a microwave moderator which substantially fully comprises a predetermined array of alternately disposed portions of microwave reflective material and complemental-shape zones which are substantially transparent to microwave energy of a predetermined frequency.
  • the moderator can comprise a perforated sheet of microwave reflective material or a plurality of spaced microwave reflectors.
  • Such moderator embodiments can.further comprise means for causing the moderator to transition from being relatively transparent to.being substantially less transparent to microwave energy of a predetermined frequency range when the temperature of the moderator is increased through a predetermined temperature range.
  • Such a means for causing the moderator to be temperature responsive or activated may comprise heat shrinkable thermoplastic material.
  • the moderator can further comprise means for providing predetermined degrees of vapor and liquid permeability fcr venting and draining an article enclosed in such a moderator while the article is being cooked in a microwave oven.
  • a moderator can be made in the form of a bag, a wrap, a cooking vessel, a liner for a microwave oven or other microwave cooking device, or a package, or incorporated in other such articles which are otherwise substantially microwave reflective.
  • substantially fully comprised of a predetermined array means there are no relatively large areas of microwave reflective materials in moderator embodiments of the present invention, or in the walls of other microwave energy cooking structures or enclosures comprising such a moderator except for the microwave reflective portions of the "predetermined array and for unperforated border areas of perforated sheets of microwave reflective material incorporated in such a moderator or. such other structures.
  • a laminated, microwave moderating wrap 40 embodying the present invention is shown in Figures 1 through 4 with thicknesses greatly enlarged for clarity.
  • Wrap 40 comprises three laminae: a first thermoplastic film 41; a second thermoplastic film 42; and a sheet.43 of electrically conductive, microwave reflective material such as aluminum foil which sheet 43 has a multiplicity of apertures 44 through it.
  • Wrap 40 further comprises means such as adhesive layers 47 and 48, Figure 3, for bonding films 41 and 42 in face-to-face relation to the opposite surfaces of sheet 43.
  • adhesive layers 47, and 48, Figure 3, and adhesive layer 49, Figure 4, and spaced bonds such as weld lines, Figure 11, are exemplary bonding means. It is not intended, however, to thereby limit the present invention. Moreover, it is not intended to limit the present invention to laminated structures wherein a'plurality of discrete laminae are secured together as by adhesives, welding, and the like. Rather, the term laminated is intended to mean multi-layered. or multi-ply structures.in general and is specifically intended to include multi-layered structures of the type wherein a layer of material such as thermoplastic is cast or extruded directly onto a substrate such as a sheet of aluminum foil or a thermoplastic film. In the same vein, the terms lamina, ply, and layer are used alternatively herein unless specifically distinguished or otherwise restrictively defined.
  • the present invention may be incorporated in discrete microwave moderators as well as microwave moderating wraps, bags, vessels, microwave oven liners, and packages or containers and the like, the following descriptions are, in general, of wraps only. It is, however, not intended to thereby limit the present invention to wrap-type embodiments. Further more, it is believed that the present invention is.not limited to microwave cooking of comestible material. Accordingly, while it is understood that embodiments of the invention which are used for microwave cooking should be constructed exclusively of food approved materials, it is not intended to thereby limit the invention to constructions consisting exclusively of food approved materials.
  • the laminated wrap 40 is a microwave energy moderating wrap for enclosing an article to be heated (e.g.: cooked) in a field of microwave energy (i.e.: in a microwave oven) of a predetermined frequency range. That is, for instance, when an article (e.g.: a beef roast) to be cooked is enclosed in such a wrap and placed in a microwave oven, it is believed that the level or intensity and/or the uniformity of microwave energy inside the wrap may be somewhat attenuated and/or moderated as compared to the microwave energy intermediate the oven walls and the wrap-formed enclosure.
  • static and dynamic embodiments of the invention are disclosed: static embodiments being such that their relative degrees of transparency, transmissibility, attenuation, and/or moderation of microwave energy do not change substantially in use; and, dynamic embodiments being such that their relative degrees of transparency, transmissibility, attenuation and/or moderation of microwave energy do change substantially as the embodiments are heated. Therefore, as used herein, static embodiments of the present invention do not undergo.substantial structural changes during microwave cooking whereas dynamic embodiments do undergo substantial structural.changes as a result of temperature changes such as incurred during microwave cooking.
  • dynamic embodiments of the invention comprise means for undergoing sufficient structural changes to transition from being relatively transparent to being substantially less transparent to microwave energy of a predetermined frequency range as the temperature of the means is increased through a predetermined range of temperature.
  • such'means precipitate substantially reduced heating rates with respect to an enclosed article (e.g.: a beef roast) as the temperature increasess i.e., as the roast cooks.
  • the benefits provided by the present invention include more even cooking, reduced weight loss, reduced need for attention and/or handling, and/or reduced criticality of timing microwave oven cooking.
  • the dynamic wraps provide visually perceivable manifestations of when such beef roasts have achieved predetermined degrees of doneness.
  • the first thermoplastic film 41 and the second thermoplastic film 42 comprise materials which are. substantially transparent to microwave energy, have relatively low dielectric loss factors, and which are substantially impervious to many vapors and liquids encountered in cooking.
  • Exemplary such materials are, for example, polypropylene, polyethylene, fluorocarbons, and polyimides.
  • Sheet 43 of wrap 40 is made of microwave reflective material such as aluminum foil which is a good electrical conductor.
  • a predetermined array of apertures 44 is provided in sheet 43.
  • the array can be viewed as comprising three sets of. rows of apertures 44: one set of rows having their imaginary eenterlines extending generally horizontally, one set diagonally downwardly from left to right, and one set diagonally downwardly from right to left.
  • each of the three sets comprise the full field of apertures 44 and are simply used to enable visualizing that their imaginary centerlines form imaginary triangles having the center of an aperture 44 disposed at each apex (i.e., at each point) of each triangle.
  • the imaginary triangles are equilateral.
  • the array of apertures shown in Figure 2 is hereby designated an equilateral triangular, delta-shape array.
  • Apertures 44 are sufficiently large and sufficiently closely spaced to render the wrap substantially transparent to microwave energy of a predetermined frequency range yet sufficiently small and so spaced to cause microwave energy passing therethrough to be somewhat attenuated and/or moderated.
  • sheet 43 of wrap 20 its edges and the edges of apertures 44 are preferably smooth and absent any sharp corners because rough edges and sharp corners precipitate localized zones of high field intensity which may, under some circumstances, result in some electrical arcing when a sheet 43 is disposed in a field of microwave energy.
  • Holes 51, Figures 2 and 3, and holes. 52, Figure 2, . extend through the portions of films 41 and 42 which span apertures 44 and are nominally concentric with their associated apertures 44.
  • Holes 51 and/or 52 are provided as necessary to provide predetermined degrees of vapor and liquid permeability so that particular types of foods to be cooked therein are adequately vented and drained. For instance, if adequate venting is not provided, the enclosure (e.g., pouch) might become dangerously pressurized, or the cooked matter may be excessively moist. Also, if juices are not drained from some foods as they are being cooked, the portions of the foods which are immersed in such juices may not be cooked to the same extent as the portions not so immersed.
  • Figure 3 is a fragmentary sectional view of wrap 40 taken along line 3-3 of Figure 2.
  • the relative thicknesses are exaggerated.
  • apertures 44 have relatively large diameters (e.g., 3/4 inch) the portions of films 41 and 42 which span apertures 44 are bonded in face-to-face relation; not spaced as indicated in Figure 3.
  • Such electrical insulating can be achieved, for instance, by covering or encapsulating the conductive portions in such thermoplastic insulation materials as described hereinbefore (e.g, polypropylene) which are substantially transparent to microwave energy, have relatively low dielectric loss factors, and which have relatively good dielectric properties.
  • Such covering or encapsulating should be effected in such a manner that air pockets or bubbles do not form adjacent the microwave reflective material in order to obviate electrical arcing across air gaps. That is, in order to maximize the effectiveness of the covering and/or encapsulating materials.
  • such electrical insulating can be achieved by providing means for sufficiently spacing conductive portions to provide air-gap insulation, and which portions may also be covered or encapsulated with insulation material as described above.
  • films 41 and 42 are sixty (60) gauge polyethylene; sheet 43 is aluminum foil having a thickness of thirty-five-hundredths of a.mil (.00035 inch); apertures 44 are three-quarters (3/4) of an inch in diameter, and disposed in an equilateral triangular, delta-shape array spaced on one inch centers; and, holes 51 and 52 are about one-sixteenth (1/16) inch diameter and one-quarter (1/4 inch diameter, respectively.
  • Adhesives 47, 48 and 49 can be, for instance, spray adhesive type 3M-No. 77 which is available from The Minnesota Mining and Manufacturing Company, 3M Center, St. Paul, Minnesota 55101, and type Cascorez EA-7908 which is a water base, ethylene vinyl acetate (EVA) adhesive, and which is available from Borden Chemical, Division of Borden Inc., 180 East Broad Street, Columbus, Ohio 43215.
  • EVA ethylene vinyl acetate
  • Such exemplary warps 40 were used in the cooking experiments which are described hereinafter and were made up in sheets which were sixteen (16) inches wide, twenty (20) inches long (about 40.6 by 50.8 cm.), and had a total of two-hundred-eighty apertures 44 per sheet of wrap 40.
  • a centrally disposed group of thirty-six (36) apertures 44 was provided with drain holes 52, and the remaining two-hundred-forty-four (244) apertures 44 were provided with vent holes 51. But for their unperforated borders, these wraps had open areas of about fifty (50) percent.
  • a dynamic embodiment of wrap 40 is achieved by having film 41 and/or 42 comprised of heat shrinkable thermoplastic.
  • heat shrinkable thermoplastic For instance, biaxially oriented polyethylene such as sixty (60) gauge Clysar which is available from E. I. DuPont DeNemours and Co. (Inc.), Film Department, Wilmington, Delaware, 19898, and which has a nominal latent shrink capacity of about forty percent (40%).
  • dynamic embodiments of wrap 40 comprising a heat shrinkable thermoplastic film must further comprise means for securing the film to the perforated sheet 43 so that, when the film is shrunken, the effective sizes of apertures 44 in perforated sheet 43 are substantially reduced; for instance, as when sheet 43 is crumpled as shown in Figure 5 and as is described hereinbelow.
  • the adhesives identified . hereinbefore enable such crumpling by rendering the thermoplastic film(s) partially or selectively peelable from a sheet 43 of aluminum foil. That is, the film and foil will become sufficiently delaminated (partially peeled apart) by shrinkage induced forces to effect crumpling of the foil.
  • partial initial bonding such as lines of weld (rather than full face-to-face bonding) also enable sufficient shrink induced crumpling of the foil to occur that the effective sizes of apertures 44 are substantially reduced.
  • Figure 5 is an artistic rendition of a fragmentary plan view of a dynamic wrap 40, Figure 2, after it has been shrunken to about two-thirds (2/3) its original size by being used to enclose a beef roast while the roast was cooked in a microwave oven.
  • the shrunken wrap is designated 40s.
  • the other designators used for features of wrap 4 0 , Figure 2 are similarly converted to the designators in Figure 5 through the use of the suffix "s" (for shrunkeni.
  • shrinkage induces sufficient crumpling of the aluminum foil sheet 43 that the effective sizes of apertures 44 are sufficiently diminished that the relative degree of microwave transparency or transmissibility of wrap 40 is substantially reduced.
  • apertures 44 having.initial diameters of about nineteen millimeters (three-quarters-of-an-inch) and which were nominally spaced about twenty-five millimeters (one inch) between centers were diminished to having nominal mean diameters of about eleven millimeters (0.43 inches) and were nominally spaced about seventeen-and-one-half millimeters (0.69 inches) between centers as a beef roast was cooked as described above.
  • Figure 6 is a fragmentary, partially torn away view of an alternate wrap 140 embodying the present invention.
  • Alternate wrap 140 is substantially identical to wrap 4 0 but for the fact that apertures 44 of wrap 140 are disposed in an orthogonal-shape array comprising rows and columns of apertures which rows are perpendicular to the columns.
  • the corresponding features of wrap 40, Figure 2, and wrap 140, Figure 6, are identified by the same designators as are the corresponding features of the other alternate embodiments of the invention which are shown in the figures. But for their unperforated borders, wraps 140 having three-quarter-inch diameter apertures 44 spaced on one inch centers have open areas of about forty-four (44) percent.
  • Figure 7 is a perspective view of a pouch type package 240 which comprises a wrap 140, Figure 6, and which contains an article 65 such as a beef roast as shown in the sectional view.
  • Pouch 240 is formed from a sheet of wrap -140 by folding it and seaming it along a longitudinal seam 60 and end seams 61 and 62 as indicated in Figures 7 through 9 inclusive. Seam 60 is secured by an adhesive faced tape 63, Figure 8, and end seams 61 and 62 are secured by adhesive faced tapes 64, Figure 9.
  • Pouch 240 is shown in Figure 8 to be sufficiently large that it is, in fact, a very loosely fitted enclosure about roast 65.
  • the looseness of the apertured pouch is believed to provide a moderated (i.e.: substantially uniform density) field of microwave energy inside the pouch when the pouch is disposed in an ON microwave oven even though a non-uniformly dense field of microwave energy might otherwise surround the pouch or, absent the pouch, surround the roast.
  • the pouch is a microwave moderator comprising a predetermined array of alternately disposed portions of microwave reflective material (cummulatively, the perforated sheet 43, Figure 6) and complemental-shape zones (apertures 44 spanned by films 41 and 42, Figure 6) which are substantially transparent to microwave energy of a predetermined frequency range: for instance, nominally 2.45 CHz.
  • pouch 240 enables such a pouch which comprises a dynamic wrap as described hereinbefore to shrink about the article as it is being cooked.
  • FIG. 7 aad 8 holes 51 (vents are not shown because of their relatively small size. Howeve holes 52 are shown in Figure 8 disposed in the bottom wall portion of pouch 240. These holes 52 enable juices which issue, for instance, from a roast being cooked to drain from the pouch rather than accumulate inside the pouch. Thus, drain holes 52 are drain means for pouch 240.
  • Figure 10 shows an alternate, adhesively bonded end seam construction 62a for a pouch such as pouch 240 .which does not require the folding and taping shown in Figure 9. Oppositely disposed portions of film 42 are secured together by adhesive 49a to form seam 62a.
  • an alternate means for securing the films 41 and 42, and sheet 43 together to form an alternate, dynamically shrinkable three ply laminated structure 340 is shown to comprise lines 70 of securement such as weld lines, or lines of adhesive.
  • lines 70 of securement such as weld lines, or lines of adhesive.
  • Such lines of securament provide means for enabling the non-shrinkable sheet 43 of, for instance, aluminum foil to be crumpled when heated if either film 41 or film 42 or both comprise heat shrinkable thermoplastic material.
  • only film 42 is heat shrinkable thermoplastic.
  • lines 70 of securement intersect the edges of apertures 44 substantially perpendicularly at intersections 71 as indicated in Figure 11.
  • lines 70 appear as spaced areas of securement which areas are initially spaced a distance L apart.
  • Figure 13 shows the structure 340 of Figure 12 after film 42 has shrunk and has been redesignated 42s.
  • film 42 shrinks, the distance between adjacent lines 70 of securement is reduced from L, Figure 12, to LS, Figure 13.
  • This causes portions of the non-shrinkable film 41 and sheet 43 to hump as shown in Figure 13.
  • the 340s configuration appears to simply be corrugated, the macroscopic effects of the shrinkage and humping cause the structure 340 to crumple so that the effective size and the center-to-center spacing of apertures , 44 are reduced as described hereinbefore; reference discussibn with respect to Figure 5.
  • a closeable bag 440 embodying the present invention is shown in Figure 14 to strongly resemble pouch 240, Figure 7, and is intended to perform substantially the same functions (both static and dynamic) described in conjunction with pouch 240. Therefore, the corresponding portions are identified by the same designators.
  • bag 440 is provided with a closeable open end 74, and closure means 75 for securing the open end closed.
  • Closure means 75, Figures 14 and 15, comprises an extended tab portion 76 of the bag, a coating of adhesive 77, and a peelable strip 78.
  • strip 78 is peeled off; then, tab 76 is folded to overlie the front wall 79 of bag 440 and to be secured thereto by adhesive 77.
  • closure means as 75 is intended to merely be exemplary rather than exhaustive, it being contemplated that those skilled in the art will substitute other closure devices: for instance, zippers or quasi zippers such as zip-locks (i.e.: releasably interlooking ridge and channel in plastic articles) .
  • FIG. 33 Another closeable, microwave energycooking bag 740 embodying the present invention is shown in perspective in Figure 33 to comprise a front will 741, a back wall 742, side gussets 743 and 744, a bottom gusset 745, a strap 746, and an open top end 747.
  • the front wall 741 and the back wall 742 comprise . microwave moderators of the type described hereinbefore. That is, each is a three ply laminate having a perforated sheet, 748 of microwave reflective material such as aluminum foil disposed intermediate two laminae of thermoplastic films which films are selected from materials which are substantially transparent to microwave energy, and which have a low dielectric loss factor and which are relatively good electrical insulators.
  • the top edges of the front wall 741 and the back wall 742 are designated 750 and 749, respectively.
  • Figure 34 is a plan view of a partially assembled bag ' 740 which shows its three ply structure. comprising a top or outer lamina 751, a bottom or inside lamina 752, and two spaced sheets 748 of microwave reflective material.
  • An exemplary bag 740 comprises ninety (90) gauge (0.9 mil) polypropylene laminae 751 and 752, and one mil aluminum foil for'sheets 748.
  • the polypropylene film is provided with a copolymer coating of polyethylene and polypropylene to render it heat sealable.
  • Such a polypropylene film is Bicor OP-400S which is available from Mobil Chemical Company, Plastics Division, Commercial Films Dept., Cincinnati, New York 14502.
  • Sheets 748 of the exemplary bag 740 described above is one mil aluminum foil which is substantially fully perforated by apertures 44, Figure 34, which are preferably about twenty-five millimeters (25 mm.) in diameter and are spaced about thirty-one millimeters (31 mm.) between centers.
  • sheets 748 are about thirty centimeters (30 cm.) square with rounded corners (about 3 cm. radius) and are perforated with a nine-by-nine array of twenty-five millimeter (25 mm.) diameter apertures 44 spaced on thirty-one millimeter (31 mm.) centers. These sheets 748 are placed between the two thermoplastic laminae 751 and 752 so that the sheets 748 are spaced from each other and so that the peripheral portions of the thermoplastic laminae 751 and 752 extend beyond all of the edges of sheets 748. The sheets 748 and the films are then heat bonded in face-to-face relation in, for instance, a laminator such as Serial No. HD 25-111, Model No.
  • a laminator such as Serial No. HD 25-111, Model No.
  • thermoplastic laminae 751 and 752 which is available from Graphic Laminating, Inc., 5122 St. Clair Avenue, Cleveland, Ohio 44103. This tightly bonds face-to-face portions of the thermoplastic laminae 751 and 752 (i.e., the portions of laminae 751 and 752 spanning apertures 44, and'the border portions) but does not tightly bond the thermoplastic films to the aluminum foil sheets 748.
  • the partially assembled bag 740 is completed to the state shown in Figure 34 by placing a strap 746 (preferably comprised of substantially microwave transparent thermoplastic film) across the top portion of the partial assembly and then forming side bar seals 761 and 762, end bar seals-763 and 764, a transverse medial bar seal 765, and two transverse fold-line bar seals 766 and 767.
  • a suitable bar sealer is Model No. 24 PS/WC which is available from Vertrod Corporation, Thermal Impulse Heat Sealing Machinery, 2037 Utica Avenue, Brooklyn, New York 12234.
  • the partially assembled bag 740 shown in Figure 34 is converted into a finished bag 740, Figures 33, by U-folding it about the transverse medial bar seal 765 so that bar seal 766 overlies bar seal 767, and then bar sealing the juxtaposed portions of the side bar seals 761 and 762 together to form side seams 768 and 769, Figure 33.
  • the peripheral portions of the thermoplastic laminae which extend outwardly from the side and bottom edges of sheets 748 are then folded or tucked inwardly to form the side and bottom gussets shown in Figure 33.
  • Figure 35 is a frontal view of a bag 740a which is identical to bag 740, Figure 33 but for an alternate side seam construction having reduced bulk.
  • FIG. 36 shows the juxtaposed relation of the fold-line bar seals 766 and 767 in the open, completed bag 740a as shown in Figure 35.
  • Figure 37 is an enlarged scale, sectional view taken along line 37-37 of Figure 35 and shows a side seam and gusset construction wherein the gusset is primarily comprised of extended side-edge portions of only the outer thermoplastic lamina 751 to reduce the bulk of the gusset.
  • Figure 37a is an enlarged scale, sectional view of another alternate bag 740b having another alternate side seam and gusset construction,as compared to the constructions shown with respect to bag 740, Figures 33 and 34, and bag 740a, Figures 35 and 37.
  • the gusset is comprised of a discrete strip 780 of material such as thermoplastic film which is bar sealed to the edges of a discrete front wall 741b and a discrete back wall 742b along bar seals 762b and 762bb, respectively.
  • Figure 38 is a perspective view of bag 740, Figure 33, after it has been erected, and closed by folding the extended top portion of the bag about the juxtaposed fold-line bar seals 766 and 767 so that the top portion of the bag is tucked under strnp 746.
  • Figure 39 is a sectional view taken along line 39-39 of Figure 38 and which view shows the sheets 748 spaced apart by the extended portions of the thermoplastic laminae, and which shows an article 781 (such as a beef roast) in the bag to be cooked therein in a microwave energy field; e.g., in a microwave oven.
  • the discrete laminae of the laminated structure are not shown in Figure 39 in order to avoid unduly distorting the Figure with multiple laminae of exagerated thicknesses.
  • the extended peripheral portions of the thermoplastic laminae 751 and 752 of bag 740 provides means for spacing adjacent edge portions of sheets 748 apart so that electrical arcing therebetween is substantially obviated.
  • FIG 40 is a frontal view of another alternate bag 840 which embodies the present invention which will, because it comprises many identical or substantially identical features (which are identically designated) as bag 740, Figure 33, be described in terms of differences with respect to bag 740.
  • bag 840 is constructed without gusseted sides and bottom, and the front flap 855 is shorter than the back flap 856.
  • bag 840 comprises a strap 746, and a three ply laminate 850 which laminate is shown in the flat and partially peeled apart in Figure 41.
  • the laminate 850 comprises an outer-wall lamina 851, an inside-wall lamina 852 and two spaced and perforated sheets 748 of a microwave reflective material such as aluminum foil.
  • Laminae 851 and 852 are preferably comprised of substantially microwave transparent thermoplastic material having a relatively low dielectric loss factor.
  • An exemplary embodiment of laminate 850, Figure 41 comprises ninety (90) gauge polypropylene film having a polypropylene-polyethylene co-polymer coating for laminae 851 and 852, and one (1) mil aluminum foil for sheets 748.
  • This structure' is heat bonded or laminated with sheets 748 spaced apart as indicated, and sheets 748 are so sized and positioned with respect to laminae 851 and 852 that, when so U-folded that the two sheets 748 are juxtaposed, Figure 40, a relatively short front flap 855 and a relatively long back flap 856 extend upwardly from the top edges of sheets 748 as seen in Figure 40.
  • the laminae 851 and 852 are sufficiently wide to provide non-microwave reflective side border regions 858 and 859 disposed beyond outwardly from the side edges of sheets 748.
  • edges are bar-heat-sealed as described hereinbefore with respect to the partially assembled bag 740, Figure 34.
  • These bar seals are designated 861, 862, 863 and 864.
  • Figure'42 is an enlarged scale, fragmentary sectional view taken along line 42-42 of Figure 40 which view shows the side seam construction through the region where an end of strap 746 is secured to the side seam.
  • Figure 43 is a frontal view of bag 840, Figure 40, after its back flap 856 has been folded about the top edge of the front flap 855 and tucked under strap 746. As compared to the closure of bag 740 described hereinbefore, the closure of bag 840 vents mqre freely.
  • the extended edge or border portions of the theremoplastic laminae 851 and 852 provide means for all of the side edges of the sheet 748 disposed in the front wall of the bag to be spaced from the edges of the sheet 748 disposed in the back wall of the bag.
  • This spacing provides improved arc resistance to bag 840. The wider the spacing, the better the arc resistance. However, the greater the spacing, the greater the unattenuated microwave energy transmission into the bag. Thus, the optimum spacing will be great enough to substantially obviate arcing but small enough to obviate the transmission of sufficient microwave energy to vitiate the even cooking benefit available from such structures.
  • FIG 44 is a frontal view of another alternate bag 940 which embodies the present invention. As compared to bag 840 described above, bag 940 is virtually identical except it comprises a single integrated sheet 748a of microwave reflective material rather than two discrete sheets 748, Figure 41.
  • Figure 45 is a partially peeled apart plan view of a three-ply laminate 950 from which bag 940 is constructed.
  • the thermoplastic laminae of laminate 950 are identical to the thermoplastic laminae 851 and 852 of laminate 850, Figure 41, and are so identified in Figure 45, as are its bar-sealed edges 861,.through 864.
  • Laminate 950 is converted into bag 940, Figure 44, in the same manner described above with respect to converting laminate 850 into bag 840.
  • Figure 46 shows bag 940 after its front flap 855 andits back flap 856 have both been folded adjacent the top of sheet 748a, and tucked under the strap 746.
  • FIG 47 is a frontal view of yet another alternate bag 1.040 which embodies the present invention.
  • Bag 1040 is virtually identical to bag 940 described hereinabove except its closure flaps 855 and 856 are equal in length, and the single sheet 748a of microwave reflective material of bag 1040 is provided with oppositely disposed rounded notches 1070 and 1071, Figure 48, which span the medical fold line of laminate 1050, Figure 48.
  • the rounded edges of notches 1070 and 1071 tend to obviate or lessen the development of intense local electric fields when the bag 1040 is disposed in a microwave energy field. .
  • such bags can of course be made to be dynamic so that they become less transparent to microwave energy as they are heated by making one or both of the thermoplastic laminae of heat shrinkable thermoplastic and by bonding the structure together so that the effective sizes of the apertures in their perforated microwave reflective sheets are diminished as the heat shrinkable thermoplastic shrinks.
  • A.vessel 540 embodying the present invention is shown (partially torn away) in Figure 17 to comprise a box-shape bottom member 90 and a cover member 91.
  • the bottom member 90 and the cover member 91 are provided with predetermined arrays of apertures 44 which are so sized and spaced that they perform the microwave energy moderating function described hereinbefore with respect to pouch 240, Figures 7 and 8.
  • vessel 540 can comprise means for obviating arcing, and means for venting and draining (such as holes 51 and 52, Figure 2) as also described hereinbefore.
  • such a vessel can also be provided with means not shown for providing the vessel with predetermined .
  • vessel 540 can be made to be disposable (single use) or reuseable (durable cooking utensil). Furthermore, containers such as vessel 540 can be used as food packages and the like which would enable merchandising, freezing, storing, cooking, and serving foodstuffs in microwave energy moderating embodiments of the present invention.
  • Figure 18 is a perspective view of an alternate laminated wrap 640 embodying the present invention which wrap comprises an orthogonal-shape array of spaced microwave reflectors 100, three laminae or layers 101, 102, and I03 of substantially microwave transparent, thermoplastic material, and means for obviating arcing when said wrap is disposed in a field of microwave energy.
  • wrap comprises an orthogonal-shape array of spaced microwave reflectors 100, three laminae or layers 101, 102, and I03 of substantially microwave transparent, thermoplastic material, and means for obviating arcing when said wrap is disposed in a field of microwave energy.
  • Such materials and arc obviating means have been described hereinbefore.
  • the reflectors are so sized, configured, and initially spaced, and are so related to the latent shrink capacity of the heat shrinkable thermoplastic laminae that the wrap is initially substantially transparent to microwave energy of a predetermined frequency range and, when shrunken by increasing its temperature through a predetermined range of temperature, the wrap will become. substantially less transparent to the microwave energy because the reflectors move closer together; for instance, into overlapping positions.
  • This movement (rather than crumpling) is enabled by securing the reflectors 100 to the thermoplastic material at relatively small areas 170, Figures 20, 21, and 23.
  • reflector 100 is shown to comprise a four-lobe member 105 of a microwave reflective material such as aluminum foil, and an arc-obviating full sheath 106 (partially torn away) of electrical insulation material such as Teflon or Mylar (both registered trademarks of DuPont Company) having high, dielectric strength and a relatively low dielectric loss factor.
  • a microwave reflective material such as aluminum foil
  • an arc-obviating full sheath 106 (partially torn away) of electrical insulation material such as Teflon or Mylar (both registered trademarks of DuPont Company) having high, dielectric strength and a relatively low dielectric loss factor.
  • a four-lobe member 105 which is suitable for use in a wrap 640 in a field of microwave energy having a nominal frequency of 2.45 GHz is defined (in the plan view) in the following way. First, four ninety-degree arcs having radii RC of three-sixteenths of an inch (about 4.75 millimeters) are drawn in the four corners of an imaginary square having side edges of length SE, Figure 19. Those four arcs define the edge portions designated 111, 112, 113 and 114 in Figure 19.
  • the tip edges 115, 116, 117 and 118 of the lobes are defined by half ellipses having minor and major axes (collectively designated RE in Figure 19) of three-sixteenths-of-one-inch (about 4.75 millimeters) and three-eighths-of-one-inch (about 9.5 millimeters), respectively.
  • the imaginary center of the ellipses are disposed at the mid- points of the side. edges of. the imaginary square described above.
  • quasi apertures 144 having effective diameters of about three-eighths-of-one-inch (about 9.5 millimeters); sufficiently small to substantially reduce the relative transmissibility of microwave energy at 2.45 GHz with respect to the initial transmissibility of such microwave energy through the wrap.
  • wrap 640 is shown to have the row of reflectors 100 which extend diagonally upwardly from the lower left disposed intermediate layers 101 and 102 and, the row of reflectors 100 which extend diagonally downwardly from the upper left are disposed intermediate layers 102 and 103.
  • the upper reflectors as shown in Figures 20 and 21 have relatively heavier weight outlines in Figure 18 whereas the lower reflectors have relatively light weight outlines in Figure 18.
  • Tables I through IV are compilations of microwave oven cooking performance data derived from beef roasts enclosed in various embodiments of the present invention as well as corresponding data derived from similarly cooking unwrapped roasts, and roasts enclosed in oven bags: for instance, large-size (fourteen-by-twenty inch) BROWN-IN-BAGS (registered trademark of Reynolds Metals Company, Richmond, Virginia, 23261) which are believed to be made of Nylon 6 (registered trademark of DuPont Company).
  • Figures 24 through 29 are time vs. internal temperature graphs of some beef roast cooking experiments
  • Figures 29 through 32 are graphs of data derived from water heating experiments conducted in microwave ovens which graphs pictorially illustrate the effects of varying certain parameters of the present invention.
  • Example Series No. consisted of a plurality of discrete beef roast examples; that is, a series of discrete examples.
  • Each roast used in the cooking experiments was a lean sirloin tip roast having a nominal weight of one- thousand (1,000) grams.
  • the roasts had very little fat covering and little or no internal fat marbling.
  • the roasts were refrigerated at about forty degrees fahrenheit (40°F) .from about one to about three days prior to use.
  • Each roast . was trimmed to achieve the nominal one-thousand (1000) gram weight.
  • the roasts also had approximately the same shape: four-to-five inches (about 10 to about 13 centimeters) long and had about the same range of mean diameters.
  • Each roast i.e.: every unwrapped, bagged, and wrapped roast was placed on a microwave-oven-safe Tray Model No. 428 made by Plastics Inc., Saint Paul, Minnesota.
  • the tray was, in turn, placed in a nine-by-thirteen (9 x 13) inch (about 23 cm. by about 33 cm.) utility dish having a one-and-one-half quart capacity, namely Item Order No. M432 made by Anchor.Hocking, Lancaster, Ohio.
  • the combination of the tray and dish provided means for collecting liquids- which issued from the roasts so that such liquids were spaced from the roasts to obviate their shielding the undersides of the roasts.
  • roast-tray-dish combinations were then placed in a Litton Model 418 microwave oven having a nominal (100%) power of about G50 watts at a nominal microwave frequency of about 2.45 GHz., and a nominal wavelength of about twelve-and-two-tenths (12.2) centimeters (4.82 inches).
  • Example Series No. 1 through 5 inclusive were cooked to provide comparison (control) data with which to evaluate several static and dynamic embodiments of the invention.
  • Example Series No. 6 through 11 involved static embodiments of the present invention
  • Example Series No. 12 through 15 involved dynamic embodiments of the present invention. All rating scales indicated on the tables range from 1 (low or poor) to 10 (high or good).
  • palatability zone as used herein and on Table IV means, with respect to beef roasts, the temperature range from 125°F to 170°F.
  • oven ON time as well as standing time determine the doneness of the roast. For instance, if the'oven is turned OFF when the internal (core) temperature of the roast is 125°F and the roast is then wrapped in foil for ten (10) minutes before serving, its doneness will be rare. Without standing time, an internal temperature of 140°F must be reached to provide a doneness of rare. Similarly, an internal temperature of 155°F plus ten (10) minutes'standing time, or 170°F without standing time will provide well done beef roasts.
  • the temperature range of 125°F-170°F defines what is commonly accepted.as the palatability zone, especially with respect to conventional cooking, the zone is not absolute. Rather, roasts have been cooked through the use of the present invention to temperatures well above 170°F (to and above 200°F) and have not been overdone. That is, they were still quite palatable: juicy, and not hard- drusted or burned. Indeed, it appears that the present invention substantially extends the palatability zone upwardly and substantially obviates ruining a beef roast, for instance, by overcooking in a microwave oven unless it is grossly neglected.
  • Example Series No. 1 Table I indicates a moderate.improvement in evenness at 160°F and a substantial improvement in evenness at 170°F; Table II indicates a seven-to-nine percent (7-9%) higher retained weight; and Table IV indicates a reduced sensitivity to critical time inasmuch as time in the palatability zone increased from eight (8) to fourteen (14) minutes.
  • the unwrapped roasts of this series were cooked in what is believed to be the best contemporary manner for unwrapped roasts.
  • the first halves of their cooking intervals were at one-hundred percent (100%) power and their last halves were at seventy percent (70%) power, and they were repositioned four (4) times during the coating interval as indicated on Table III. 'These roasts had relatively high evenness ratings (Table I), and were comparable to Series 2 with respect to retained weight (Table II) and reduced time criticality (Table IV).
  • Example Series No. 1 through 5 achieving high evenness ratings required periodic repositioning of the roasts and/or reduced power levels and/or power level changes during the cooking interval.
  • the present invention generally provides improved evenness without repositioning and/or power level changes and, in general, reduces the criticality of timing the cooking interval by increasing the time in the palatability zone. This is believed to be a substantial benefit notwithstanding the fact that microwave cooking is slowed down and that such slowing down might be perceived to be a detriment rather than a benefit.
  • Example Series No. 6 through 15 were conducted by forming a pouch as described hereinbefore about the roast which pouch was of the configuration shown in Figure 7 and comprised varidus wrap embodiments (without recessed edges) of the present invention. All of these examples were cooked at one-hundred percent (100%) power and they were not repositioned during the cooking interval. Except for Example Series 7, the pouches were loosely fitted as shown in Figures 7 and 8.
  • each roast of this series was enclosed in a pouch comprising a static embodiment of the present invention comprised of only a sheet, of aluminum foil (.0007 inches thick) which was sixteen-by-twenty inchen; was porforated with an orthogonal array of three-quarter-inch-diameter apertures 44, Figure 6, which were spaced one inch between centers. But for the relatively narrow unperforated borders, such spacing provides a composite open area of about forty-four (44) percent. The number of apertures totaled two-hundred-fifty-two (252). The pouch was loosely fitted as shown in Figure 8. As compared to Series 1, this series provided improved evenness at 170°F (well done, Table I); improved weight retention (Table II); and a substantial increase in the time in the palatability zone (Table IV).
  • the wrap embodiment of the present invention which was used in this series was of the configuration identified 140 in Figure 6 except it had only one thermoplastic layer rather than two.
  • the thermoplastic layer was made from a BROWN-IN-BAG (registered trademark, Reynolds Metals Company which is believed to be one-hundred (100) gaugè Nylon 6 (registered trademark, DuPont).
  • the foil side was adjacent the roast during this series. As compared to no-wrap Series 1 and foil-only Series 6 and 7, these roasts exhibited improved evenne.
  • the wrap embodiment of the present invention which was used in this series was the three layer wrap 140, Figure 6.
  • Layers 41 and 42 were made from BROWN-IN-BAGS (registered trademark, Reynolds Metals Company) as described above (Series 8), and sheet 43 was aluminum foil (.00035 inches thick).
  • the wraps were sixteen-by-twenty inches and had an orthogonal-shape array of three-quarter-inch diameter apertures 44 (totaling 252) spaced one inch between centers.
  • Series 10 provided a still further improved evenness (Table I).
  • the wrap embodiment of this series was the three layer wrap 40, Figures 1 and 2, having an equilateral triangular, delta-shape array of one inch diameter apertures 44 spaced one inch between centers (totaling 280). But for the unperforated borders, such spacing provides an open area of about fifty (50) (totaling 280).
  • the wraps comprised the same materials of construction as described above with respect to Series 10.
  • wrap 40 provides a somewhat faster cooking rate than No. 10 (orthogonal-shape aperture array) and comprises about twelve percent (12%) less aluminum; a substantial benefit with respect to the conservation of such microwave reflective materials as aluminum foil.
  • the dynamic wraps substantially obviate overcooking/overdoneness of, for example, beef roasts cooked in microwave ovens except under extreme conditions: i.e., a grossly miscalculated cooking interval or simply being turned ON and forgotten for an extended period of time.
  • the dynamic embodiments of the present invention shrink about the article (e.g., beef roast) being cooked so that, when shrunken the wrap is drawn in closely about the article.
  • the shrihkage reduces the effective areas of the apertures 44 and slows cooking.
  • the cessation of shrinkage is a visually perceivable manifestation that the roast has a doneness of about rare and, if the oven is then turned OFF and the roast is given ten (10) minutes of standing time, it will have a doneness of about medium.
  • the present invention provides means for cooking an article (e.g.: a beef roast) to a pre-determined degree of doneness without monitoring the internal temperature of the roast and/or without having to control cooking as a function of the internal temperature of the article. This is believed to be a great benefit to microwave oven users whose ovens are not equipped with such sensors and/or control means.
  • an article e.g.: a beef roast
  • Figures 24 through 28 are graphs of. data generated by cooking beef roasts in microwave ovens under various conditions and/or which were enclosed in various embodiments of the present invention as described hereinbefore. Some but not all of the graphed data were obtained from the fifteen (15) aforementioned Example Series which were run and upon which Tables I through IV are based.
  • Figure 24 is a graph showing the time vs internal temperature relations among roasts which were: not wrapped, Example Series No. 1, curve 201; enclosed in oven bags, Example Series No. 4, curve 202; loosely wrapped (pouched) in a three ply static embodiment .
  • Figure 2 of the present invention Example Series No. 11, curve 203; and loosely wrapped (pouched) in a dynamic (heat shrinkable) three ply embodiment ( Figure 2) of the present .
  • invention Example Series No. 15, curve 204.
  • the-curves on the graph, Figure 24, show that both the static (curve 203) and dynamic (curve 204), wrap embodiments of the invention, Figure 2, cook more slowly than unwrapped roasts (curve 201) and the oven bag enclosed roasts (curve 202).
  • This extra time especially in the palatability zone, facilitates achieving a predetermined degree of doneness through the use of.the invention than without it. That is, the roast can be periodically checked with, for instance, a meat thermometer at less critically timed intervals through the use of the present invention.
  • the cessation of shrinkage of the dynamic embodiments provides a visually perceivable manifestation of a predetermined degree of doneness without the use of a meat thermometer and/or' a temperature (end point) control system.
  • Figure 25 is a graph showing time vs. internal temperature of roasts which were cooked using a variety of static embodiments of the present invention. Curves 201, (no-wrap) and 202 (oven bag) are repeated to facilitate comparisons. Curves 206 through 209 resulted from tests involving the following static embodiments of the present invention: curve 206, 2 ply embodiment of Series 9; curve 207, 3 ply wrap 140 of Series 10; curve 208, loosely fitted foil of Series 6; and curve 209, closely fitted foil only of Series 7.
  • Figure 26 shows curves 201, 207 and 212 which involved, respectively: no-wrap; static three ply wrap 140, Figure 6, Series 10; and dynamic three ply wrap 140, Figure . 6, Series 14.
  • Figure 27 is a graph which shows the time vs temperature relations among roasts which were cooked as follows: curve 212 was developed through the use of a dynamic wrap 140, Figure 6, Series 14; curve 213 was developed through the use of a dynamic wrap 140 which had been pre-shrunk with hot air to approximate its ultimate degree of closure prior to beginning the cooking of that particular roast; and curve 214 was developed through the re-use of a dynamic wrap 140, Figure.6, Series 14. These curves illustrate the reduced rate of cooking which is precipitated by the shrinkage of the dynamic embodiments of the invention.
  • curves 212 through 214 have approximately equal slopes through the palatability zone, each would provide about equal criticality of timing through the palatability zone but, because the dynamic cooks faster and provides substantial benefits (Series 10, Tables I through IV), it is believed to be obviously superior to pre-shrunken wraps and/or to similar wraps having smaller holes which are static (non-shrinking).
  • Figure 28 is a graph which illustrates the criticality with respect to where vent/drain holes are positioned.
  • Layers 41 and 42 were sixty (60) gauge, biaxially oriented polyethylene, and layer 43 was aluminum foil having a thickness of about thirty-five hundred-thousandths inch (about 0.009 mm).
  • one-quarter inch (about 6.35 mm) diameter vent/drain holes were centrally located in the thermoplastic spanning each of the two-hundred-fiftytwo (252) apertures 44.
  • two-hundred-twenty-one (221) one-quarter-inch vent/drain holes were provided in the central portions-of the cross-shape lands defined by each two-by-two sub-array of apertures 44.
  • Figures 29 through 32 are graphs showing time vs. temperature rise relations which illustrate the effects of varying some of the parameters of the present invention.
  • Figures 29 through 32 were derived by placing forty (40) milliliters of water in .a microwave transparent inner container inside an-internally insulated, cubical-shape (having six inch square sides), microwave reflective quasi-calorimeter having a five inch (about 12.7 mm.) square opening in its top wall.
  • the calorimeter was then provided with a variety of six inch (about 15.2 mm.) square, microwave moderator tops of microwave reflective material which each had a sub-array of nine (9) holes through it.
  • the variety of tops resulted in generating curves 221 and 222, Figure 29; curves 224 through 228, Figure 30; curves 231 through 235, Figure 31; and curves 237 through 239, Figure 32.
  • Figure.29 illustrates the relative microwave energy (2.45 GHz) transmissibility difference between a moderator top comprising a nine-aperture portion of static wrap 140, Example Series No. 10, curve 221, and a moderator top comprising a nine-aperture portion of an activated (shrunken) dynamic wrap 140, Example Series No. 14, curve 222.
  • Figure 30 illustrates that the relative microwave energy transmissibility of such microwave moderators is directly related to the diameter of the holes when the spacing between holes is constant.
  • the calorimeter-top moderators used to generate the curves of Figure 30 comprised nine- hole delta-shape aperture sub-arrays in which the holes were spaced one-quarter inch (about 6.35 mm) apart and in which the holes had, with respect to curves 224 through 22 8 , diameters of one-quarter-inch (about 6.35 mm), three-eighths-inch (about 9.5 mm), one-half-inch (about 12.7 mm), three-quarters-inch (about 19 mm), and one inch (25.4 mm), respectively.
  • Figure 31 is a graph of data which were generated. in the same manner as for Figure 30 except that the nine- hole sub-arrays of apertures were delta-shape (Figure 2) for Figure 30, and were orthogonal-shape ( Figure 6) for Figure 31.
  • Curves 231 through 235 were generated using moderators having hole diameters of one-quarter-inch (about 6.35 mm), three-eighths-inch (about 9.5 mm), one-half-inch (about 12.7 mm), three-quarters-inch (about 19 mm), and one-inch (25.4 mm), respectively. Comparing the curves of Figure 31 with the corresponding curves of Figure 30 confirms that the delta-shape array provides greater microwave transmissibility (higher heating rates) than the orthogonal-shape array; all . other things being equal.
  • curves 237 through 239 illustrate the effect of varying the inter-hole spacing in fixed arrays of holes of a given diameter, to wit: the apparent relative microwave energy transmissibility of a calorimeter-top type microwave moderator having a fixed number (nine in the example) of holes of a given diameter varies inversely with respect to the spacing of the holes.
  • the six-by-six inch moderators had nine hole, orthogonal-shape sub-arrays of three-quarter-inch (about 19 mm) diameters and were spaced, center-to-center, seven-eighths-inch (about 22.2 mm), one-inch (25.4 mm), and one-and-one-half-inch (38.1 mm), respectively.
  • Figure 29 illustrates the effectiveness of dynamic microwave energy moderators-such as wrap 140, Figure 6, to reduce the rate of cooking from an initially high rate (curve 221) to a substantially diminished rate (curve 222) as the temperature is increased through the indicated range of temperature.
  • Figures 30 through 32 show that relative microwave energy transmissibility of such moderators is directly related to hole diameter and inversely related to hole spacing. This is confirmed by the fact that, on the average, apertures 44 are more closely spaced in the delta-shape array ( Figure 2) than in the orthogonal-shape array ( Figure 6), and the evidence discussed hereinbefore that cooking is faster with embodiments of the invention having delta-shape aperture arrays as compared to orthogonal-shape aperture arrays.

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  • Food Science & Technology (AREA)
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EP78200114A 1977-08-04 1978-07-20 Mikrowellenenergiemoderator Withdrawn EP0000797A1 (de)

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US82193477A 1977-08-04 1977-08-04
US821934 1977-08-04
US83707477A 1977-09-28 1977-09-28
US837074 1977-09-28
US05/854,941 US4268738A (en) 1977-09-28 1977-11-25 Microwave energy moderator
US854941 1997-05-13

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US4518651A (en) * 1983-02-16 1985-05-21 E. I. Du Pont De Nemours And Company Microwave absorber
WO1989008373A1 (en) * 1988-02-29 1989-09-08 The Pillsbury Company Method and apparatus for adjusting the temperature profile of food products during microwave heating
EP0344839A1 (de) * 1988-06-01 1989-12-06 Koninklijke Emballage Industrie Van Leer B.V. Bifunktionelles aktives Verpackungsmaterial für Mikrowellenlebensmittelprodukte
FR2635089A1 (fr) * 1988-08-05 1990-02-09 Sp Metal Sa Complexe brunisseur pour la cuisson au four a micro-ondes
WO1991006195A1 (en) * 1989-10-23 1991-05-02 Beckett Industries Inc. Microwave heating intensifier
EP0451144A1 (de) * 1988-12-28 1991-10-16 Du Pont Schrumpfbare, modellierbare mikrowellenverpackung.
WO1992014864A3 (en) * 1991-02-14 1993-04-01 Beckett Ind Inc Selective demetallization method and apparatus and products obtained by this method
WO1996035626A1 (en) * 1995-05-12 1996-11-14 United Biscuits (Uk) Limited Shrinkable microwave package
WO1999019224A1 (en) * 1997-10-09 1999-04-22 Heather Janet Davies Reusable packaging
WO2004020310A1 (en) 2002-08-27 2004-03-11 Christopher Paul Wedlock Microwave dispersing device
EP2082973A1 (de) * 2008-01-23 2009-07-29 Nestec S.A. Verpackung mit einer wärmeschrumpfenden Folie
CN108709202A (zh) * 2018-07-31 2018-10-26 雷子墨 一种减小微波泄漏的微波炉

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FR2119478A5 (de) * 1970-12-21 1972-08-04 Philips Nv
US3835281A (en) * 1973-07-05 1974-09-10 F Mannix Differential microwave heating container
FR2251497A1 (de) * 1973-11-15 1975-06-13 Trans World Services
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Cited By (18)

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US4518651A (en) * 1983-02-16 1985-05-21 E. I. Du Pont De Nemours And Company Microwave absorber
WO1989008373A1 (en) * 1988-02-29 1989-09-08 The Pillsbury Company Method and apparatus for adjusting the temperature profile of food products during microwave heating
US4972059A (en) * 1988-02-29 1990-11-20 The Pillsbury Company Method and apparatus for adjusting the temperature profile of food products during microwave heating
EP0344839A1 (de) * 1988-06-01 1989-12-06 Koninklijke Emballage Industrie Van Leer B.V. Bifunktionelles aktives Verpackungsmaterial für Mikrowellenlebensmittelprodukte
FR2635089A1 (fr) * 1988-08-05 1990-02-09 Sp Metal Sa Complexe brunisseur pour la cuisson au four a micro-ondes
EP0451144A1 (de) * 1988-12-28 1991-10-16 Du Pont Schrumpfbare, modellierbare mikrowellenverpackung.
EP0451144A4 (en) * 1988-12-28 1991-12-04 E.I. Du Pont De Nemours And Company Shrinkable, conformable microwave wrap
US5310976A (en) * 1989-08-23 1994-05-10 Beckett Industries Inc. Microwave heating intensifier
WO1991006195A1 (en) * 1989-10-23 1991-05-02 Beckett Industries Inc. Microwave heating intensifier
WO1992014864A3 (en) * 1991-02-14 1993-04-01 Beckett Ind Inc Selective demetallization method and apparatus and products obtained by this method
EP0936286A1 (de) * 1991-02-14 1999-08-18 Beckett Industries Inc. Selektive Entmetallisierung von Aluminium
WO1996035626A1 (en) * 1995-05-12 1996-11-14 United Biscuits (Uk) Limited Shrinkable microwave package
WO1999019224A1 (en) * 1997-10-09 1999-04-22 Heather Janet Davies Reusable packaging
WO2004020310A1 (en) 2002-08-27 2004-03-11 Christopher Paul Wedlock Microwave dispersing device
EP2082973A1 (de) * 2008-01-23 2009-07-29 Nestec S.A. Verpackung mit einer wärmeschrumpfenden Folie
WO2009092622A1 (en) * 2008-01-23 2009-07-30 Nestec S.A. Packaging comprising a heat shrinking film
US8425958B2 (en) 2008-01-23 2013-04-23 Nestec S.A. Packaging comprising a heat shrinking film
CN108709202A (zh) * 2018-07-31 2018-10-26 雷子墨 一种减小微波泄漏的微波炉

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AU3861378A (en) 1980-02-07
ES472317A1 (es) 1979-10-16
ES480290A1 (es) 1979-12-16
BR7805017A (pt) 1979-05-02
IT7826457A0 (it) 1978-08-03

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