EP0371739A2 - Artikel zum Heizen und dessen Erwärmungsverfahren - Google Patents

Artikel zum Heizen und dessen Erwärmungsverfahren Download PDF

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Publication number
EP0371739A2
EP0371739A2 EP89312307A EP89312307A EP0371739A2 EP 0371739 A2 EP0371739 A2 EP 0371739A2 EP 89312307 A EP89312307 A EP 89312307A EP 89312307 A EP89312307 A EP 89312307A EP 0371739 A2 EP0371739 A2 EP 0371739A2
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EP
European Patent Office
Prior art keywords
article
layer
microwave energy
stainless steel
substrate
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Withdrawn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
EP89312307A
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English (en)
French (fr)
Other versions
EP0371739A3 (de
Inventor
Donald Gregory Beckett
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.)
Beckett Industries Inc
Original Assignee
Beckett Industries Inc
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
Application filed by Beckett Industries Inc filed Critical Beckett Industries Inc
Publication of EP0371739A2 publication Critical patent/EP0371739A2/de
Publication of EP0371739A3 publication Critical patent/EP0371739A3/de
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS 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
    • B65D81/00—Containers, 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
    • B65D81/34—Containers, 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
    • B65D81/3446—Containers, 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
    • B65D81/3461—Flexible containers, e.g. bags, pouches, envelopes
    • B65D81/3469—Pop-corn bags
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS 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
    • B65D81/00—Containers, 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
    • B65D81/34—Containers, 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
    • B65D81/3446—Containers, 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
    • B65D81/3453—Rigid containers, e.g. trays, bottles, boxes, cups
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS 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
    • B65D2581/00—Containers, 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
    • B65D2581/34—Containers, 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
    • B65D2581/3401—Cooking or heating method specially adapted to the contents of the package
    • B65D2581/3402—Cooking or heating method specially adapted to the contents of the package characterised by the type of product to be heated or cooked
    • B65D2581/3421—Cooking pop-corn
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS 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
    • B65D2581/00—Containers, 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
    • B65D2581/34—Containers, 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
    • B65D2581/3437—Containers, 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
    • B65D2581/3471—Microwave reactive substances present in the packaging material
    • B65D2581/3477—Iron or compounds thereof
    • B65D2581/3478—Stainless steel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS 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
    • B65D2581/00—Containers, 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
    • B65D2581/34—Containers, 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
    • B65D2581/3437—Containers, 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
    • B65D2581/3486—Dielectric characteristics of microwave reactive packaging
    • B65D2581/3487—Reflection, Absorption and Transmission [RAT] properties of the microwave reactive package
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS 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
    • B65D2581/00—Containers, 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
    • B65D2581/34—Containers, 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
    • B65D2581/3437—Containers, 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
    • B65D2581/3486—Dielectric characteristics of microwave reactive packaging
    • B65D2581/3494—Microwave susceptor

Definitions

  • the present invention relates to novel heat susceptor structures for use in converting microwave energy to thermal energy.
  • the metal usually is supported on a polymeric substrate, such as a polyester, for example, that sold under trademark "Mylar".
  • a polymeric substrate such as a polyester, for example, that sold under trademark "Mylar”.
  • the thickness of the metal film required to achieve the generation of thermal energy varies depending on the electroconductive metal chosen.
  • the thickness may vary from about 0.1 to about 0.8 optical density, particularly about 0.2 to about 0.3 optical density.
  • Other metals which may be employed include copper and stainless steel.
  • the polymeric substrate In order to inhibit the polymeric substrate from distorting upon the application of microwave energy to the metal film, the polymeric substrate usually is laminated to a single sheet of relatively stiff paper or paperboard or sandwiched between two sheets of such material, using conventional laminating adhesives.
  • One typical prior art structure is shown in U.S. Patent no. 4,641,005.
  • U.S. Patent no. 4,210,124 describes a dish structure having a microwave-reflective metal foil coating and a microwave structure metal interactive metal oxide film.
  • the substrate is formed of porcelain, fired silica or similar material of construction of dishes.
  • U.S. Patent no. 4,351,997 discloses a tray structure in which a metal layer is described as foil and a reflector of microwave material.
  • U.S. Patent No. 4,364,995 is a general process for the formation of metal and metal oxide coatings on substrates.
  • U.S. Patent no. 4,592,914 describes the provision of a container including both a microwave absorptive layer, which is metallized plastic film, and microwave reflective layer, described as foil, coated on paper.
  • U.S. Patents Nos. 4,703,148 and 4,777,053 also describe a package for microwave heating including a microwave-reflective foil layer and a microwave susceptible metal film on polymeric substrate.
  • a novel heat susceptor structure in which an electroconductive material, such as a metal, for example, aluminum, copper or stainless steel, of heat susceptor thickness is directly supported on a paper or paperboard or other similar fibrous material substrate.
  • an electroconductive material such as a metal, for example, aluminum, copper or stainless steel
  • heat susceptor thickness is meant that the electroconductive metal is of a thickness such that it becomes semi-conductive, which results in the dissipation of the electrical resistance or heat when exposed to microwave energy.
  • an article of manufacture capable of conversion of a portion of microwave energy applied thereto to thermal energy consisting essentially of a substrate layer formed of structural fibrous stock material and a layer of electroconductive material directly engaging and being supported on one face of said fibrous material layer and having a thickness effective to convert a portion of incident microwave energy into thermal energy.
  • the present invention provides an article of manufacture comprising two elements, namely a substrate and a layer of electroconductive material supported on the substrate.
  • the structure is an extremely simple one and yet provides a very effective heat susceptor which can be incorporated directly into a wide variety of packaging structures for thermal heating of food products to achieve a variety of effects during microwave heating or reconstitution of such food products, for example, crisping and browning.
  • a second coating of electroconductive material of heat susceptor thickness may be provided on the opposite side of the substrate from the first layer of such material to achieve an enhanced heating effect from the two layers.
  • the electroconductive material layer usually is a metal layer, although carbon and certain metal oxides also may be employed.
  • the metal layer may comprise any electroconductive metallic material which is capable in the form of a thin film of a thickness effective to convert microwave energy to thermal energy.
  • Stainless steel is preferred for the reasons outlined below but other metals, such as aluminum or copper may be employed.
  • Other possibilities include lead, gold, silver and platinum.
  • Stainless steel for example 316 stainless steel, is a preferred metal in the structure of the present invention for a variety of reasons.
  • Stainless steel is inert to oxidation under normal room temperature conditions and hence maintains a stable sheet resistance over the storage and shelf life of the package.
  • Stainless steel as is well known, is an alloy containing iron, chromium and carbon as its essential components. Resistance to oxidation results from the chromium constituent migrating to the surface and being oxidized thereat to act as a barrier to oxidation of the subsurface iron.
  • the stainless steel layer in the structure of the invention heats up upon the application of microwave energy thereto. Since it is a resistive metal, there is a limit to the extent of a temperature rise which results, dictated by the temperature at which oxidation spontaneously occurs, which, for stainless steel, is around 425°F, a temperature ideal for the paper package environment in which the susceptor is to be employed. For aluminum, however, the self-oxidation upper limit is around 675°F, although this temperature varies widely depending on the pre-existing state of oxidation of the aluminum, so that continued application of microwave energy to an aluminum layer results in a continued rise in the temperature, which is often undesirable, since scorching or burning of the paper substrate should be avoided.
  • the metal layer should be capable of rapidly heating to a temperature of about 300° to about 400°F and of sustaining that temperature for the desired heating time for which microwave energy is to be applied to the food product, usually about 5 to 10 minutes.
  • a temperature of about 300° to about 400°F and of sustaining that temperature for the desired heating time for which microwave energy is to be applied to the food product, usually about 5 to 10 minutes.
  • the structure of the present invention it is possible with the structure of the present invention to achieve temperatures in the range of about 200° to about 420°F and to maintain such temperatures for as long as about 30 minutes, depending on the application.
  • microwave energy which is incident on a microwave susceptor structure is reflected off the surface, absorbed into the metal layer or transmitted through the structure. Only the energy absorbed into the metal layer can be converted to thermal energy.
  • the absorbed microwaves cause electrons in the metal to vibrate with the frequency of the oscillating microwave electric field.
  • the frequency is 2.45 GH Z .
  • the semiconductive thickness metal resists the movement of the electrons and the resulting energy is dissipated from the metal layer as heat.
  • the heat output obtained from the metal layer depends on the resistance of the metal layer, which may vary from about 50 to about 5000 ohms, preferably in the range of about 100 to about 2000 ohms.
  • the resistance is determined, to some extent, by the thickness of the metal layer, which may vary in depth across the face of the metal layer, depending on the nature of the substrate layer, as discussed in more detail below.
  • the thickness of the metal layer generally varies from about 10 to about 150 angstroms.
  • the sheet resistance is decreased from that of the maximum absorption and heat generation, corresponding to about 50% of the incident microwave energy, the absorption decreases, the reflection increases and the transmission decreases.
  • the sheet resistance is increased from that of the maximum absorption, the absorption decreases, the reflection decreases and the transmission increases.
  • the resistance of the layer In order to produce the maximum heat output from the metal layer, it is desirable for the resistance of the layer to be that which produces within about 5% of the peak absorption for the metal layer.
  • a sheet resistance which produces at least 45% absorption of microwave energy permits a wide range of balance of reflectance and transmission for the remainder of the microwave energy.
  • the degree of transmission of microwave energy by the novel structure may be determined by providing a microwave transmitter on one side of the structure and a microwave receiver on the other and determining the proportion of the incident microwave energy from the transmitter received by the receiver.
  • the metal layer of desired thickness may be applied to the substrate by any convenient substrate coating technique and the actual technique employed often depends on the metal employed.
  • the preferred metal is stainless steel and it is preferred to employ a sputtering process to effect the coating of the stainless steel layer on the substrate.
  • Sputtering is a well-known coating process and is described, for example, in "Electron Beam Evaporation and D.C. Magnetron Sputtering in Roll Coating" by J. Mattencci, Proc. 30th Tech. Conf., Society of Vacuum Coaters, April 28, 1987, p.2.
  • the electron beam coating process also described in that same article also may be employed.
  • the metal layer is directly applied to the substrate layer without the necessity for any intermediate layer, thereby eliminating the need for a polymeric film layer and a laminating adhesive, such as is required in the prior art.
  • the structure provided in accordance with this invention does not employ adhesives, polymers or other heat sensitive materials, the possibility of thermal breakdown of such materials in the structure of the invention is avoided, thereby overcoming environmental objections to the structures previously available.
  • a greater heat output is obtained by the structure of the present invention at the same thickness of metal on the substrate in comparison to structures wherein a thin metal layer is supported on a polymeric film laminated to paper.
  • paper or paperboard represents a much less expensive substrate material than polyester film.
  • a second thin metal layer may be provided on the face of the substrate opposite to that of the first layer, if desired, as noted earlier.
  • the substrate layer on which the metal layer(s) is provided may be formed of any suitable fibrous material, such as wood fibres or glass fibres, provided in sheet form.
  • the fibrous stock material functions to provide structural rigidity to the novel article of manufacture and to provide support for the metal layer when incorporated into a package structure.
  • the fibrous stock material is a low density material having a relatively high thermal insulating capacity and heat stability sufficient to withstand cooking temperatures generated by the metal layer.
  • the substrate layer most conveniently is formed from paper stock, although in other applications, paperboard or even wood sheet may be employed.
  • the substrate layer be capable of supporting a metal layer of an electrical resistance such that thermal energy is generated therefrom on the application of microwave energy thereto.
  • the substrate may be of any desired thickness consistent with the end use to which the structure may be put and the paperstock may vary from a thickness of about 12 lb/ream to about 20 points board, preferably from about 10 to about 40 mils.
  • the substrate sheet may comprise cellulosic material fibres, usually wood fibres, or glass fibres. In the latter case, the substrate sheet resists the burning which may occur in the case of substrates made from cellulosic fibrous material if excess heating occurs.
  • a substrate with a smooth surface it is preferred to employ a substrate with a smooth surface, since it is possible thereby to obtain a more uniform degree of heating from all portions of the surface of the metal layer.
  • Preferred forms of such smooth-surfaced paper are high-gloss calendered paper and grease-resistant paper.
  • the proportion of the incident microwave energy absorbed and hence the degree of heating obtained is dependent on the electrical resistance of the coating, which, in turn, is dependent, to some extent, on the thickness.
  • the electrical resistance of the metal layer decreases and the metal layer becomes thicker, absorption tends to decrease, so that less heat is generated. For this reason, providing the metal layer on a smooth substrate surface produces a more even heat generation from the metal layer and greater levels of such heat generation.
  • the metal layer is coextensive with the substrate layer as a result of the method of formation of the same.
  • Such an arrangement permits the article to be adhered to another surface by adhesive provided in the non thermal energy producing regions, with no danger of thermal breakdown of the adhesive.
  • One such procedure involves employing masks during the coating process to prevent deposition of a metal layer on the portions of the substrate where no metal is required to be present.
  • masking often is impractical in continuous production procedures.
  • Another procedure which may be employed is to print the substrate in a pattern of regions where heating is not desired with a suitable release material to which the metal does not adhere, such as a silicone release material, prior to metallizing the substrate surface.
  • a suitable release material to which the metal does not adhere such as a silicone release material
  • metal may be removed from the patterned regions by any suitable technique, such as by brushing away the metal or by removing the metal with an electromagnet.
  • the structure of the invention may be used for a variety of purposes where it is desired to convert a portion of incident microwave energy into thermal energy.
  • the major application of the novel structure is in the microwave heating and reconstitution of foodstuffs of a wide variety.
  • the parameters of the metal layer notably the electrical resistance, differing properties of energy absorbance, reflection and transmission of incident microwave energy and differing sustainable levels of heat generation can be achieved.
  • the particular choice of such properties depends on the application to which the structure of the present invention is put.
  • the novel structure is incorporated into the desired packaging structure by positioning the structure at the desired location or locations of the packaging material, usually a paper sheet, where the thermal heating is desired, generally by employing a convenient fastening means.
  • a suitable adhesive is employed, although mechanical bonding through interacting elements may be employed.
  • peripheral regions of the structure may be provided devoid of metal, by using one of the demetallization techniques described above, with the structure being adhesively bonded to the packaging material at such peripheral regions only. Since, in this arrangement there is no metal in the regions of location of the adhesive, no heating occurs in these regions and they remain cool, so that there is no possibility for thermal breakdown of the adhesive.
  • the novel structure Since the novel structure is not adhered to the packaging material, such as a paper sheet, in the region where the metal layer heats up when microwave energy is applied to the packaging structure, the air trapped between the novel structure and the adjacent face of the paper sheet expands as heat is generated by the metal layer, providing a degree of thermal insulation against heat passing from the heat susceptor to the exterior of the bag. In this way, a greater proportion of the heat generated by the metal layer as it is exposed to microwave energy is used to heat the food product.
  • the packaging material such as a paper sheet
  • Figure 1 shows a perspective view of an article of manufacture 10 provided in accordance with one embodiment of the invention and consisting of a substrate layer 12 of paper supporting a metal layer 14 thereon.
  • the metal layer 14 is coextensive with the substrate layer 12.
  • FIGs 2 and 3 there is illustrated the application of the present invention to a microwave popcorn heating bag 20, which comprises overlying paper sheets 22,24 which are joined by gussets 26 to allow for expansion of the popcorn within the bag enclosure 28 during microwave popping.
  • a structure 30 in accordance with the present invention is provided adhered to the bottom paper sheet 24 internally of the bag by adhesive 32, preferably provided at the periphery only of the structure 30.
  • the metal layer 34 is the opposite side of the paper layer 36 from and hence out of contact with the popcorn 38.
  • the paper layer 36 usually is provided with a layer of some form of high heat resistant release material, such as a silicone, between the popcorn 38 and the paper 36.
  • the locations of the metal layer 34 and the paper layer 36 may be reversed. When such arrangement is employed, an overlying layer of a release material can be provided over the metal layer.
  • the structure 30 may be adhered external to the bag 20 at the location of the popcorn 38.
  • a peripheral region of the structure 30 where the adhesive 32 is provided is either free from metal or the metal has been de-activated by mechanically scuffing it, for example, with a pencil type eraser, so that no heating results in this region as a result of conversion of microwave energy into thermal energy, so that thermal breakdown of the adhesive does not occur.
  • the popcorn 38 As the bag 20 is exposed to microwave energy radiation, the popcorn 38 along with associated oil, heats up as a result both of the microwave energy to which it is exposed and the thermal energy generated by the metal layer 34, and is popped to fill the interior cavity 28 of the bag 20, as seen in Figure 3.
  • the bag When the popping is complete, the bag is opened to permit the popped corn to be consumed.
  • the pot pie dish 50 comprises a plurality of layers laminated together into the final structure.
  • An inner layer 52 adjacent the pot pie crust comprises a polymeric film to which is adhered a thin metallic layer 54 coextensive in dimension with the polymeric film layer and of a thickness effective to convert incident microwave energy to thermal energy.
  • a heat susceptor comprising a paper substrate layer 56 supporting a further thin metal layer 58 of thickness correspondingly sufficient to convert a portion of microwave energy incident thereon to thermal energy.
  • the combination of substrate layer 56 and thin metal layer 58 extends only for the region of base of the dish 50.
  • An outer layer 60 of cardboard completes the structure of the laminate.
  • Multi-Met As described in my copending United States patent application Serial No. 374,655 filed June 30, 1989 (“Multi-Met”), the disclosure of which is incorporated herein by reference, the provision of two metal layers in the base portion of the dish enables higher heat generation to be obtained than in the wall region where a single metal layer is present.
  • the arrangement permits heat from the thin metal layer to be generated during microwave cooking of the pot pie contained in the dish. Maximum heat is generated in the region at the bottom of the dish and a lesser amount of heat is generated in the region of the side walls.
  • the differential is chosen so that an even cooking of the pot pie occurs throughout the pie filling by a combination of the microwave energy and the heat generated from the metal film and an even browning effect to the crust is obtained.
  • the present invention provides a novel heat susceptor structure of a thin layer of metal or other electroconductive material of heat susceptor thickness directly engaging and supported on a paper or paperboard substrate which is useful in a variety of applications where it is desired to convert microwave energy to thermal energy and which does not produce decomposition vapors during microwave energy application. Improved heat production is achieved when compared with the conventional polyester substrate, as well as providing a much cheaper structure and an emission-decreased arrangement. Modifications are possible within the scope of this invention.
  • a heating element for microwave heating comprising a substrate layer of fibrous material, and a layer of electroconductive material directly engaging and supported on a face of the substrate layer and having a thickness effective to convert microwave energy into thermal energy.
  • a method of heating an item comprising placing the item in contact with or in proximity to a structure comprising a substrate layer of fibrous material, and a layer of electroconductive material directly engaging and supported on a face of the substrate layer and applying microwave energy to the structure to convert at least a portion of the incident microwave energy into thermal energy for heating the item.
EP19890312307 1988-11-28 1989-11-28 Artikel zum Heizen und dessen Erwärmungsverfahren Withdrawn EP0371739A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB888827708A GB8827708D0 (en) 1988-11-28 1988-11-28 Heat susceptor
GB8827708 1988-11-28

Publications (2)

Publication Number Publication Date
EP0371739A2 true EP0371739A2 (de) 1990-06-06
EP0371739A3 EP0371739A3 (de) 1991-12-27

Family

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Family Applications (1)

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EP19890312307 Withdrawn EP0371739A3 (de) 1988-11-28 1989-11-28 Artikel zum Heizen und dessen Erwärmungsverfahren

Country Status (5)

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EP (1) EP0371739A3 (de)
JP (1) JPH02184430A (de)
AU (1) AU619627B2 (de)
CA (1) CA2003470A1 (de)
GB (1) GB8827708D0 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0487166A1 (de) * 1990-11-21 1992-05-27 Koninklijke Emballage Industrie Van Leer B.V. Mehrschichtiger Suszeptor für niedrige Temperaturen
US5220140A (en) * 1991-06-17 1993-06-15 Alcan International Limited Susceptors for browning or crisping food in microwave ovens
WO2020047432A1 (en) * 2018-08-30 2020-03-05 Folia Water, Inc. Food packaging articles including substrates with metal nanoparticles

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2365929A4 (de) * 2008-09-17 2014-03-19 Graphic Packaging Int Inc Konstrukt zum goldbräunen und knusprigen aufbacken eines lebensmittels in einem mikrowellenherd
JP5810569B2 (ja) * 2011-03-17 2015-11-11 凸版印刷株式会社 電子レンジ調理用包装容器

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WO1987002334A1 (en) * 1985-10-17 1987-04-23 Beatrice/Hunt-Wesson, Inc. Microwave interactive package containing stainless steel and method of making same
EP0251445A2 (de) * 1986-06-25 1988-01-07 International Paper Company Kochbehälter für Mikrowellenofen mit kontrollierten thermischen Wirkungen
EP0287323A2 (de) * 1987-04-13 1988-10-19 E.I. Du Pont De Nemours And Company Faseriges, mikrowellenempfindliches Verpackungsmaterial
EP0344574A1 (de) * 1988-05-23 1989-12-06 The Pillsbury Company Suszeptoren mit einer auf Papier aufgebrachten metallisierten Schicht zum Heizen von Lebensmitteln in einem Mikrowellenofen

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AU7990987A (en) * 1987-10-19 1989-04-20 Golden Valley Microwave Foods, Inc. Flexible packaging sheets heatable by microwave radiation
US4927991A (en) * 1987-11-10 1990-05-22 The Pillsbury Company Susceptor in combination with grid for microwave oven package
CA1313231C (en) * 1987-11-18 1993-01-26 Richard M. Keefer Microwave heating

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1987002334A1 (en) * 1985-10-17 1987-04-23 Beatrice/Hunt-Wesson, Inc. Microwave interactive package containing stainless steel and method of making same
EP0251445A2 (de) * 1986-06-25 1988-01-07 International Paper Company Kochbehälter für Mikrowellenofen mit kontrollierten thermischen Wirkungen
EP0287323A2 (de) * 1987-04-13 1988-10-19 E.I. Du Pont De Nemours And Company Faseriges, mikrowellenempfindliches Verpackungsmaterial
EP0344574A1 (de) * 1988-05-23 1989-12-06 The Pillsbury Company Suszeptoren mit einer auf Papier aufgebrachten metallisierten Schicht zum Heizen von Lebensmitteln in einem Mikrowellenofen

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0487166A1 (de) * 1990-11-21 1992-05-27 Koninklijke Emballage Industrie Van Leer B.V. Mehrschichtiger Suszeptor für niedrige Temperaturen
US5220140A (en) * 1991-06-17 1993-06-15 Alcan International Limited Susceptors for browning or crisping food in microwave ovens
WO2020047432A1 (en) * 2018-08-30 2020-03-05 Folia Water, Inc. Food packaging articles including substrates with metal nanoparticles

Also Published As

Publication number Publication date
AU619627B2 (en) 1992-01-30
CA2003470A1 (en) 1990-05-28
JPH02184430A (ja) 1990-07-18
EP0371739A3 (de) 1991-12-27
GB8827708D0 (en) 1988-12-29
AU4563289A (en) 1990-05-31

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