EP0161739A2 - Emballage pour le chauffage à micro-ondes - Google Patents

Emballage pour le chauffage à micro-ondes Download PDF

Info

Publication number
EP0161739A2
EP0161739A2 EP85300915A EP85300915A EP0161739A2 EP 0161739 A2 EP0161739 A2 EP 0161739A2 EP 85300915 A EP85300915 A EP 85300915A EP 85300915 A EP85300915 A EP 85300915A EP 0161739 A2 EP0161739 A2 EP 0161739A2
Authority
EP
European Patent Office
Prior art keywords
foodstuff
cover
pan
further characterized
container
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.)
Granted
Application number
EP85300915A
Other languages
German (de)
English (en)
Other versions
EP0161739A3 (en
EP0161739B1 (fr
Inventor
Richard M. Keefer
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.)
Rio Tinto Alcan International Ltd
Original Assignee
Alcan International Ltd Canada
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 US06/662,992 external-priority patent/US4656325A/en
Application filed by Alcan International Ltd Canada filed Critical Alcan International Ltd Canada
Priority to AT85300915T priority Critical patent/ATE48504T1/de
Publication of EP0161739A2 publication Critical patent/EP0161739A2/fr
Publication of EP0161739A3 publication Critical patent/EP0161739A3/en
Application granted granted Critical
Publication of EP0161739B1 publication Critical patent/EP0161739B1/fr
Expired legal-status Critical Current

Links

Images

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
    • B65D81/3453—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
    • B65D2581/3437—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
    • B65D2581/3439—Means for affecting the heating or cooking properties
    • B65D2581/344—Geometry or shape factors influencing the microwave heating properties
    • 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
    • B65D2581/3439—Means for affecting the heating or cooking properties
    • B65D2581/344—Geometry or shape factors influencing the microwave heating properties
    • B65D2581/3441—3-D geometry or shape factors, e.g. depth-wise
    • 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
    • B65D2581/3463—Means for applying microwave reactive material to the package
    • B65D2581/3464—Microwave reactive material applied by ink printing
    • 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
    • B65D2581/3472—Aluminium or compounds thereof
    • 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
    • B65D2581/3479—Other metallic compounds, e.g. silver, gold, copper, nickel
    • 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

Definitions

  • the present invention relates to microwave energy cooking and more particularly to an improved package for foodstuffs to be heated or cooked with microwave energy.
  • U.S. Patent 4,190,757 describes a disposable microwave shipping, heating and serving package for food composed of a paperboard carton and a lossy microwave energy absorber which becomes hot when exposed to microwave radiation.
  • the absorber heats the adjacent surface of the food by conduction to a sufficiently high temperature to provide searing or browning while microwave exposure controlled by a shield heats the inside.
  • This is a very expensive structure compared with a metal foil pan and the energy absorber is wasteful of energy.
  • This prior art arrangement does not focus or increase the microwave energy acting on the food.
  • a food package which includes a flexible wrapping sheet of dielectric material capable of conforming to the shape of the food.
  • the dielectric wrapping sheet has a flexible metallic coating, such as aluminum, in the form of a film or foil, the coating being subdivided into a number of individual metallic islands separated by non-metallic gaps.
  • a part of the microwave energy is converted into heat by the metallic coating so as to brown or crispen the adjacent food.
  • the metallic coating is preferably contiguous to the food and the heat that develops is conducted directly into the surface of the food without having to be radiated through any intervening space.
  • the standard metal, e.g. aluminum, foil packaging containers can be used in microwave ovens provided they are used in association with a special cover which is spaced a distance from the surface of the foodstuff in the metal foil container.
  • the present invention relates to a cover for metal containers which in terms of microwave energy, does not transmit reflected energy.
  • the cover acts in a manner analogous with non-reflecting coatings in optics and permits passage of the microwave radiation into the container holding the foodstuff, while substantially preventing escape of microwave radiation reflected from the foodstuff surface and container bottom. In this manner the microwave energy is retained and concentrated within the container, resulting in more efficient and uniform heating of the foodstuff.
  • the novel reflected energy impenetrable cover referred to hereinafter as the "non-reflecting energy cover” or “cover” has a high effective dielectric constant and precipitates destructive interference with microwave radiation reflected from the foodstuff surface and container bottom. It is known that a high dielectric constant interface provides a reflection of energy at the interface. However, the present invention combines the use of a high dielectric constant interface with destructive interference so that the majority of microwave energy enters the container and the majority of microwave energy stays within the container and is absorbed by the foodstuff.
  • the cover may be comprised of substantially uniform dielectric materials having dielectric properties as described hereinafter, and for which the characteristics of reflectance and transmittance are functions of thickness.
  • the non-reflecting energy cover may also be in the form of an artificial dielectric comprised of metal powder or flakes dispersed in or on a dielectric substrate, for which the characteristics of reflectance and transmittance are at least equivalent to those obtained from the above uniform dielectric material.
  • the non-reflecting energy cover may be comprised of arrays of conductors, e.g. metal or metal foil shapes, on or embedded in a dielectric substrate, the reflectance and transmittance characteristics thereof being at least equivalent to those which are obtained from the above uniform dielectric material.
  • the non-reflecting energy cover must be spaced from the surface of the foodstuff in the container and the distance between the cover and the surface of the foodstuff is determined by the properties and structure of the cover and also by the conductivity and dielectric constant of the foodstuff. In general, as the conductivity of the foodstuff increases, the optimum distance between the cover and foodstuff decreases.
  • the distance between the cover and the surface of the foodstuff is usually in the range of about 0.8 to 2 cm., with the optimum being about 1.2 to 1.5 cm. at a microwave frequency of 2450 MHz.
  • the non-reflecting energy cover is preferably also flat and disposed substantially parallel to the foodstuff surface, although it may be contoured to improve uniformity of absorption of microwave energy by the foodstuff. If the surface of the foodstuff is curved, then the cover may also be provided with a similar curvature, so as to maintain a constant spacing from the foodstuff surface.
  • the substantially uniform dielectric materials used for the non-reflecting energy cover of this invention are dielectrics having dielectric constants greater than 10. These are exemplified by porous media containing labile water, the dielectric constants thereof being attributable to the presence of water, whose dielectric constant can approach 80.
  • Covers made of these substantially uniform dielectric materials must be quite thick, e.g. 0.4 to 1 cm. at an operating frequency of 2450 MHz., and also must be spaced from the foodstuff by a relatively small distance to be effective in blocking reflected energy. Because of the relatively small distance between the cover and the foodstuff surface, the effectiveness of this cover is very sensitive to unevenness in the foodstuff surface.
  • the metal powder or flakes dispersed in or on a dielectric substrate create an artificial dielectric meeting the required characteristics of the invention.
  • the metal powder or flakes may be applied in the form of paint or ink coatings having aluminum or bronze flakes dispersed therein.
  • the minimum thickness of the metallic islands is determined by the size of the current circulating in each of the metal islands and that current's associated ohmic heating. By dimensioning the size of the islands it has been found that metallized islands as thin as 600 Angstroms have been operable. On the other hand, thicknesses for the metallic islands in the neighborhood of 0.001" have been found to be convenient.
  • the arrays of conductors on or in a dielectric substrate are exemplified by arrays of metal or metal foil squares or other geometrical shapes on a dielectric substrate, the dimensions of such squares or other shapes and the spacings therebetween being substantially less than one wavelength of the microwave energy.
  • the area of the metal foil shapes should be 50 to 80% of the total area of the non-reflecting energy cover.
  • the foil shapes are preferably arranged as islands, in that each shape is surrounded by a strip of dielectric. These shapes can vary quite widely in side dimensions, although it is desirable that each cover consist of a plurality of foil islands.
  • the dielectric substrates should be relatively low dielectric loss factor materials which are resistant to breakdown under microwave conditions. They are typically sheets or films of cellulosic or plastic resinous materials, and may, for example, include low dielectric loss papers, polyolefin film, such as polyethylene, polyester film, such as poly(ethylene terephthalate).
  • the microwave radiation enters the container through the novel non-reflecting energy cover.
  • the very high effective dielectric constant of the cover combined with the spacing of the cover from the surface of the foodstuff, creates a destructive interference with microwave radiation reflected from the foodstuff surface and container bottom. Since this results in the microwave energy being retained and concentrated within the container, energy is conserved in that the microwave energy is substantially all used to directly heat the foodstuff.
  • non-reflecting energy cover of this invention fields have been created in the space between the foodstuff surface and the cover which may be as much as 80 times the field within the foodstuff.
  • the result of this very high field is not only more uniform heating of the foodstuff, but also a highly desirable browning and/or crisping of the surface of the foodstuff.
  • the cover may also be used together with a microwave transparent container to obtain the benefit of its ability to brown and/or crisp the foodstuff surface.
  • Power output for a water load is found by converting the heat absorption so determined into Watt units [AT(OC)Xwt(gm.)x4.18400/t(sec)]. Determination of the power absorbed by foods is less straightforward, owing to the generally wide fluctuations of temperature-rise observed. Moreover, the use of calorimetry to circumvent this problem is prone to error because of wide variations of food heat capacity with temperature. Furthermore, IR methods only provide surface temperatures, which are not necessarily indicative of bulk temperature distributions.
  • conductivity In evaluating power absorption, conductivity and dielectric losses are grouped as a single loss term ("conductivity"). For many foods, it is found that both conductivity and dielectric properties are determined primarily by the presence of water, water being a major constitutent, and water conductivity and dielectric constant values being far greater than those of the other components present. Taking into account deviations of food properties from those of water, water power absorption measurements nevertheless provide a simple means of testing and simulating food performance in microwave ovens.
  • Alcan (trade mark) Catalogue No. 441-3 foil containers were used in this series of tests. This size of container is typical of many of the foil containers used in consumer frozen food applications (i.e. - the so-called "entree dish”). To best simulate performance with foods, these containers were filled with 310 gm of tap-water, it being felt that the electrolyte concentration of this water would give acceptably similar performance to that of a range of foods. In all cases, a Litton (trade mark) 80-08, 700 W commercial oven was used, this oven having similar wattage and a similar cavity size to a large portion of the consumer microwave oven market, with a microwave frequency of 2450 MHz.
  • Foil squares were carefully cut and mounted with adhesive on a dry paper. Squares were cut in 2 mm increments from 1 cm on a side to 2.4 cm, and were spaced in increments of 1 mm from 2 mm to 10 mm. Styrofoam spacers were cut in 1/4 0 increments from 1/4" to 1" in thickness, with a peripheral cross-section, so that the width of the resulting spacer frame was about 1/4" to minimize any effect from the presence of the styrofoam. Blank tests with water and only the frame indicated no change in power absorption by the water. The non-reflecting energy covers described above were mounted with adhesive tape on the styrofoam supports, and temperature-rises for runs with 310 g m of water and of 1 minute duration noted. Results were as follows:
  • FIG. 1 is an empirical representation of the effect of the present invention.
  • a cover having an effectively high dielectric constant is shown at 10.
  • This cover is comprised of a dielectric material lid 12 having a plurality of metallic islands 14 located thereon.
  • the combination forms a dielectric array top.
  • the metallic islands can be rectangular and have widths and lengths which are advantageously less than one-quarter wavelength of the microwave energy. It is preferred that they have dimensions which are less than one-half a wavelength in order to avoid the propagation of modes which yield high electric field voltages along the perimeters of the islands to prevent arcing. It has been found that a high effective dielectric constant can be achieved using many small islands which provide good initial transmission of the microwave energy into the volume defined by the pan and lid.
  • a ground plane 16 is provided either by using a metallic pan having a metallic bottom and sides or by a non-metallic pan having a conductive bottom intimately associated therewith. Such a bottom could be a metallic foil applied to a paper or plastic pan.
  • Figure 1 does not show the pan which is basically irrelevant to the invention as long as a metallic ground plane is provided. It should be noted that a ground plane is not essential to the operation of the invention since the foodstuff itself can be considered to be poor ground plane. However, optimum results are achieved using a ground plane as will be seen from Figure 1.
  • a foodstuff 18 to be heated is located directly on the ground plane 16 and spaced below the array dielectric top 10. As was mentioned above, this spacing ranges from between .8 and 2 cm. at the currently used microwave frequency of 2450 MHz. It should be noted that this range of spacing will change if the microwave frequency is altered and is more generally expressed as from X/15 to A/6 of a wavelength of the microwave energy used.
  • Fig. 1 The action of the combination of array dielectric top, foodstuff and ground plane is very schematically shown in Fig. 1.
  • Destructive interference in the plane of the high dielectric top accomplishes the desired effect.
  • Incident energy 20 arrives at the top plane and the majority of the energy enters air space 22 and foodstuff 18.
  • a small amount of the energy 24 is shown being reflected from the top plane.
  • the energy which passes through the top plane enters the foodstuff 18 which, because is it lossy, absorbs energy and is cooked.
  • Some of the energy passes through the foodstuff and is reflected from the ground plane 16 and is retransmitted through the foodstuff 18 where it is further absorbed.
  • Some of the energy 26, is reflected directly from the surface of the foodstuff.
  • the energy which was not absorbed by the foodstuff in its first reflection from the ground plane arrives, once again, at the top plane where the vast majority is reflected back into the foodstuff. This process is continued until all the energy is either absorbed by the foodstuff or transmitted back out into the general interior of the microwave oven through the top plane.
  • the ratio of energy absorbed by the foodstuff to the energy escaping from the top plane has been found to be very high. This process results in a very efficient concentration of energy within the container holding the foodstuff and the advantageous result of an even cooking of the foodstuff in the horizontal plane.
  • Figure 2 shows a generally rectangular container 30 containing a foodstuff which fills the container to approximately the top.
  • the container can be of a plastic material with a metallic ground plane (not shown) affixed to its bottom.
  • a more preferable embodiment, and the embodiment shown, utilizes a metallic container having a bottom 32 and sides 34.
  • a metallic lip 36 surrounds the top of the pan portion of the container.
  • the container is completed with a lid 38.
  • the lid is made of a dielectric material having a relatively low dielectric loss factor.
  • An example of a suitable material is polyethylene polyester film.
  • the top 40 of the lid is generally flat and is orientated so as to be generally parallel to the surface of the foodstuff.
  • a side region 42 is provided around the perimeter of the lid and mates with a circumferential step 44 which is designed to rest on lip 36 of the pan.
  • the side region 42 has a height dimension which locates the top surface 40 within the range above the surface of the foodstuff described above.
  • a preferred embodiment of the lid has a downwardly and outwardly sloping skirt 46 attached to the step 44. This skirt limits the proximity of the placement of the metallic pan to the microwave oven walls which effectively eliminates any possibility of arcing. The skirt also tends to lock or hold the lid on the pan by virtue of friction due to the lip of the pan.
  • Metallic islands 48 are placed on the top surface 40 and, as mentioned above, combine with the dielectric material of the lid to provide a region of effective high dielectric over virtually the entire surface area of the lid.
  • the surface area of the metallic islands should preferably be between 50 and 80 percent of the surface area of the top of the lid 40.
  • the array of islands 48 are shown in Fig. 2 as being rectangular islands forming a regular rectangular array. This particular configuration is not essential to the operation of the invention but has been found to function well.
  • FIG 3 is the circular embodiment.
  • elements which are the same as elements in Figure 2 bear like reference numerals.
  • the metallic islands 48 are arranged in two axially symmetrical rings.
  • the configuration shown provides a metallic surface area which is in the neighborhood of from 50 to 80 percent of the surface area of the top 40.
  • the configuration shown provides for an even heating of the foodstuff in the horizontal plane.
  • FIG. 4 is a perspective view of a multi-compartment container for use in heating, for example, a "TV" dinner (trade mark).
  • pan 30 includes outer side walls 34 and interior compartment walls which form compartments 50, 51, 52 and 53.
  • Compartments 50 and 53 contain foodstuffs requiring high heating as, for example, meat and potatoes.
  • an array dielectric consisting of dielectric material 40 and metallic islands 48 is located on the lid 38 directly over these compartments.
  • a high heat concentration and uniformity of heating is achieved in these compartments as was discussed above.
  • Compartment 52 requires medium heating to warm, for example, a frozen dessert, and therefore merely has the dielectric material directly over it. Compartment 52 is heated in the conventional manner.
  • Compartment 51 contains, for example, a green vegetable and requires little heating.
  • metallic shield 54 is affixed directly over this compartment. Sufficient microwave energy leaks around the shield to heat the contents of this compartment. In addition, the contents of the compartment are partially heated by conductive heating from the surrounding compartments.
  • any of the covers described above can be fitted with venting apertures to allow steam generated in the cooking process to escape without deforming either the pan or cover.
  • cover described herein could be used with a rigid reusable dish or permanent cooking container and that the cover itself could be reusable.
EP85300915A 1984-02-15 1985-02-12 Emballage pour le chauffage à micro-ondes Expired EP0161739B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85300915T ATE48504T1 (de) 1984-02-15 1985-02-12 Verpackung fuer mikrowellenheizung.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CA447471 1984-02-15
CA447471 1984-02-15
US06/662,992 US4656325A (en) 1984-02-15 1984-10-19 Microwave heating package and method
US662992 2003-09-15

Publications (3)

Publication Number Publication Date
EP0161739A2 true EP0161739A2 (fr) 1985-11-21
EP0161739A3 EP0161739A3 (en) 1986-08-13
EP0161739B1 EP0161739B1 (fr) 1989-12-06

Family

ID=25670292

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85300915A Expired EP0161739B1 (fr) 1984-02-15 1985-02-12 Emballage pour le chauffage à micro-ondes

Country Status (7)

Country Link
EP (1) EP0161739B1 (fr)
AU (1) AU577354B2 (fr)
BR (1) BR8500674A (fr)
DE (1) DE3574661D1 (fr)
DK (1) DK162492C (fr)
ES (4) ES8605962A1 (fr)
NZ (1) NZ210921A (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0206811A2 (fr) * 1985-06-25 1986-12-30 Alcan International Limited Récipient pour four à micro-ondes
EP0272089A2 (fr) * 1986-12-18 1988-06-22 Alcan International Limited Mesure d'échauffement de corps par micro-ondes
EP0271981A2 (fr) * 1986-05-09 1988-06-22 Alcan International Limited Récipient à micro-ondes
EP0336325A2 (fr) * 1988-04-06 1989-10-11 PACKAGING CORPORATION OF AMERICA (Corporation of Delaware) Emballage pour aliment à utiliser dans un four à micro-ondes
DE8912119U1 (fr) * 1989-10-11 1989-11-23 Alcan Deutschland Gmbh, 3400 Goettingen, De
EP0344574A1 (fr) * 1988-05-23 1989-12-06 The Pillsbury Company Suscepteurs ayant une couche métallisée déposée sur du papier pour le chauffage des aliments dans un four à micro-ondes
EP0364402A1 (fr) * 1988-10-12 1990-04-18 Alusuisse-Lonza Services Ag Dispositif pour empêcher l'amorçage d'etincelles dans des appareils à micro-ondes
WO1990005440A1 (fr) 1988-11-04 1990-05-17 The Pillsbury Company Support brunisseur pour le chauffage de produits alimentaires dans un four a micro-ondes dote d'une couche metallisee deposee sur du papier
WO1992012904A1 (fr) * 1991-01-24 1992-08-06 Alcan International Limited Recipient pour micro-ondes presentant une structure a rebords pour assujettir deux parois constituees d'un materiau different
EP0650905A2 (fr) * 1993-10-27 1995-05-03 James River Paper Company, Inc. Emballage pour four à micro-ondes avec fonction pour régler l'adaptation de l'impédance
US5416304A (en) * 1990-11-13 1995-05-16 Kraft General Foods, Inc. Microwave-reflective device and method of use
WO2004020310A1 (fr) 2002-08-27 2004-03-11 Christopher Paul Wedlock Dispositif de dispersion de micro-ondes
CN108800233A (zh) * 2018-06-23 2018-11-13 四川大学 一种可提高微波炉加热均匀性的托盘

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4126027A1 (de) * 1991-08-06 1993-02-11 Alcan Gmbh Recyclefaehiger behaelter zum erwaermen von lebensmitteln im mikrowellenofen

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3219460A (en) * 1962-11-20 1965-11-23 Lever Brothers Ltd Frozen food package and method for producing same
US3302632A (en) * 1963-12-06 1967-02-07 Wells Mfg Company Microwave cooking utensil
US3410700A (en) * 1965-10-25 1968-11-12 Marigold Foods Inc Package for frozen pizza and the like
US4081646A (en) * 1976-03-15 1978-03-28 Teckton, Inc. Device for microwave cooking
EP0001311A2 (fr) * 1977-09-28 1979-04-04 THE PROCTER & GAMBLE COMPANY Sachet modérant l'énergie à micro-ondes
US4190757A (en) * 1976-10-08 1980-02-26 The Pillsbury Company Microwave heating package and method
US4320924A (en) * 1980-05-16 1982-03-23 Elco International Reciprocated concrete surfacer member with shielded spring return
EP0063108A2 (fr) * 1981-04-10 1982-10-20 AB Akerlund & Rausing Matériau d'emballage

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4230924A (en) * 1978-10-12 1980-10-28 General Mills, Inc. Method and material for prepackaging food to achieve microwave browning

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3219460A (en) * 1962-11-20 1965-11-23 Lever Brothers Ltd Frozen food package and method for producing same
US3302632A (en) * 1963-12-06 1967-02-07 Wells Mfg Company Microwave cooking utensil
US3410700A (en) * 1965-10-25 1968-11-12 Marigold Foods Inc Package for frozen pizza and the like
US4081646A (en) * 1976-03-15 1978-03-28 Teckton, Inc. Device for microwave cooking
US4190757A (en) * 1976-10-08 1980-02-26 The Pillsbury Company Microwave heating package and method
EP0001311A2 (fr) * 1977-09-28 1979-04-04 THE PROCTER & GAMBLE COMPANY Sachet modérant l'énergie à micro-ondes
US4320924A (en) * 1980-05-16 1982-03-23 Elco International Reciprocated concrete surfacer member with shielded spring return
EP0063108A2 (fr) * 1981-04-10 1982-10-20 AB Akerlund & Rausing Matériau d'emballage

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0206811A3 (en) * 1985-06-25 1989-02-08 Alcan International Limited Microwave container
EP0206811A2 (fr) * 1985-06-25 1986-12-30 Alcan International Limited Récipient pour four à micro-ondes
EP0271981A2 (fr) * 1986-05-09 1988-06-22 Alcan International Limited Récipient à micro-ondes
EP0271981A3 (en) * 1986-05-09 1988-11-30 Alcan International Limited Microwave container and method of using same
EP0272089A2 (fr) * 1986-12-18 1988-06-22 Alcan International Limited Mesure d'échauffement de corps par micro-ondes
EP0272089A3 (en) * 1986-12-18 1989-09-13 Alcan International Limited Monitoring the heating of microwave-heated bodies
EP0336325A3 (fr) * 1988-04-06 1991-02-27 PACKAGING CORPORATION OF AMERICA (Corporation of Delaware) Emballage pour aliment à utiliser dans un four à micro-ondes
EP0336325A2 (fr) * 1988-04-06 1989-10-11 PACKAGING CORPORATION OF AMERICA (Corporation of Delaware) Emballage pour aliment à utiliser dans un four à micro-ondes
EP0344574A1 (fr) * 1988-05-23 1989-12-06 The Pillsbury Company Suscepteurs ayant une couche métallisée déposée sur du papier pour le chauffage des aliments dans un four à micro-ondes
CH676697A5 (fr) * 1988-10-12 1991-02-28 Alusuisse
EP0364402A1 (fr) * 1988-10-12 1990-04-18 Alusuisse-Lonza Services Ag Dispositif pour empêcher l'amorçage d'etincelles dans des appareils à micro-ondes
WO1990005440A1 (fr) 1988-11-04 1990-05-17 The Pillsbury Company Support brunisseur pour le chauffage de produits alimentaires dans un four a micro-ondes dote d'une couche metallisee deposee sur du papier
US4970360A (en) * 1988-11-04 1990-11-13 The Pillsbury Company Susceptor for heating foods in a microwave oven having metallized layer deposited on paper
DE8912119U1 (fr) * 1989-10-11 1989-11-23 Alcan Deutschland Gmbh, 3400 Goettingen, De
WO1991006196A1 (fr) * 1989-10-11 1991-05-02 Alcan Deutschland Gmbh Recipient a bord de securite pour micro-ondes
US5416304A (en) * 1990-11-13 1995-05-16 Kraft General Foods, Inc. Microwave-reflective device and method of use
WO1992012904A1 (fr) * 1991-01-24 1992-08-06 Alcan International Limited Recipient pour micro-ondes presentant une structure a rebords pour assujettir deux parois constituees d'un materiau different
EP0650905A2 (fr) * 1993-10-27 1995-05-03 James River Paper Company, Inc. Emballage pour four à micro-ondes avec fonction pour régler l'adaptation de l'impédance
EP0650905A3 (fr) * 1993-10-27 1995-08-23 James River Paper Co Emballage pour four à micro-ondes avec fonction pour régler l'adaptation de l'impédance.
WO2004020310A1 (fr) 2002-08-27 2004-03-11 Christopher Paul Wedlock Dispositif de dispersion de micro-ondes
CN108800233A (zh) * 2018-06-23 2018-11-13 四川大学 一种可提高微波炉加热均匀性的托盘
CN108800233B (zh) * 2018-06-23 2024-03-15 四川大学 一种可提高微波炉加热均匀性的托盘

Also Published As

Publication number Publication date
ES540376A0 (es) 1986-04-16
EP0161739A3 (en) 1986-08-13
ES8701101A1 (es) 1986-11-16
DE3574661D1 (de) 1990-01-11
ES551320A0 (es) 1986-11-16
NZ210921A (en) 1988-07-28
ES551322A0 (es) 1986-11-16
EP0161739B1 (fr) 1989-12-06
DK62485D0 (da) 1985-02-11
BR8500674A (pt) 1985-10-01
DK62485A (da) 1985-08-16
ES8605962A1 (es) 1986-04-16
ES8701099A1 (es) 1986-11-16
AU577354B2 (en) 1988-09-22
ES551321A0 (es) 1986-11-16
DK162492B (da) 1991-11-04
AU3875285A (en) 1985-08-22
ES8701100A1 (es) 1986-11-16
DK162492C (da) 1992-03-30

Similar Documents

Publication Publication Date Title
US4656325A (en) Microwave heating package and method
CA2054671C (fr) Methode et dispositif pour cuisson aux micro-ondes
US4190757A (en) Microwave heating package and method
CA2251282C (fr) Capteur d'energie a motifs pour four micro-ondes
CA1297540C (fr) Propagation amelioree des ondes dans un contenant pour four a micro-ondes
US4560850A (en) Container with steam port for use in microwave ovens
EP0161739B1 (fr) Emballage pour le chauffage à micro-ondes
US4558198A (en) Metal container system for use in microwave ovens
US5910268A (en) Microwave packaging structures
US6229131B1 (en) Microwave cooking grill and steamer
CA1091305A (fr) Emballage pour chauffage aux microondes
CA2785965C (fr) Plateau de rechauffage aux microondes pour aliments surgeles a temperatures et textures multiples
EP0279659B1 (fr) Emballage et méthode pour chauffer des produits consommables dans un four à micro-ondes
US4948932A (en) Apertured microwave reactive package
US5593610A (en) Container for active microwave heating
FI93821C (fi) Pakkaus jäädytetyn piirakan tai vastaavan rekonstituoimiseksi
CA1339540C (fr) Methodes de cuisson au four a micro-ondes de produits alimentaires et autres, et dispositifs connexes
US5747086A (en) Method of cooking a food product using a mode filtering structure
EP0416026B1 (fr) Element de conditionnement a susceptance pour le chauffage d'un produit alimentaire unique.
CA2951481C (fr) Emballage pour micro-ondes
CA1228126A (fr) Contenant et methode de cuisson au four a micro-ondes
EP0344839A1 (fr) Matière d'emballage active bifonctionnelle pour produits alimentaires pour micro-ondes
CA2185179C (fr) Contenant a patisserie pour four a microondes
JPH0759651A (ja) マイクロ波加熱用治具及び容器

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

17P Request for examination filed

Effective date: 19861102

17Q First examination report despatched

Effective date: 19880803

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO MILANO S.P.A.

REF Corresponds to:

Ref document number: 48504

Country of ref document: AT

Date of ref document: 19891215

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3574661

Country of ref document: DE

Date of ref document: 19900111

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
EPTA Lu: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 19950101

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19950112

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19950116

Year of fee payment: 11

Ref country code: AT

Payment date: 19950116

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19950125

Year of fee payment: 11

EAL Se: european patent in force in sweden

Ref document number: 85300915.7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19950228

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19960212

Ref country code: AT

Effective date: 19960212

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19960213

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19960228

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19960228

Ref country code: BE

Effective date: 19960228

BERE Be: lapsed

Owner name: ALCAN INTERNATIONAL LTD

Effective date: 19960228

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19960901

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19960901

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20020117

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20020118

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20020121

Year of fee payment: 18

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030212

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030902

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031031

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST