Microwave packaging and use of the packaging

····· · • · ·

ΡΑΉΑ * · MICROWAVE, MffTERlAL

MICROWAVE INSULATION, PACKAGING FOR A PRODUCT

M

FOOD WHICH MAY BE COOKED BY MICROWAVES, PACKING WITH INSULATING WALLS OF SELF-FORMATION, METHOD, METHOD OF CONTAINING FORMATION, METHOD OF PACKING A FOOD ITEM, PACKING FOR

INTENSIFY MICROWAVE HEATING OF A FOOD ITEM, AND METHOD TO INTENSIFY MICROWAVE HEATING OF A FOOD ITEM

FIELD OF THE INVENTION

The present invention relates to the technical area of ​​food preparation, and it particularly relates to materials and structures that can be used for preparing food in microwave ovens.

BACKGROUND OF THE INVENTION

Microwave ovens are normally used for preparing food quickly and effectively. To optimize the cooking performance of microwave ovens, several food packaging arrangements have been developed to block, augment, orient, or otherwise affect the interaction of microwaves with food.

If it is desired to darken or toast the exterior of the food item, the food item is arranged in a container that includes a susceptor. The susceptor typically includes a material that interacts with microwave energy, such as a metal, * '* cfúe ”aB5ofVe', * Vefífete, and transmits microwave energy in various proportions. The surface to be darkened is placed close to the susceptor. The susceptor absorbs microwave energy, and transmits heat to the food item to darken and toast its surface. In addition, a portion of the microwave energy is transmitted into the food item.

Numerous susceptor configurations, shapes and dimensions are known in the art. depending on the configuration of the susceptor, the time of exposure to microwave energy, the desired degree of browning or roasting, and other factors, the susceptor may be in close or close contact with the food item. Thus, a material or package including a susceptor can be used to cook a food item, and to darken or toast the surface of the food item in a manner similar to conventional operations used for frying, cooking or grilling food.

A specific food packaging configuration that may employ susceptors involves closed cells formed between layers of packaging material. When exposed to microwave energy, the cells expand to form inflated cells that isolate the food item contained in the packaging from the microwave oven environment. An example of a material from • · ·· ····· ··· * · ·· · ···· · · ·· ·· · ···· · · • ········ · ··· · microwave packaging that * prÔporci * õná * cêlul'as * 'irtPlávéis is described in the co-pending PCT patent application · «» with the present application, number PCT / US03 / 03779, entitled Insulating Microwave Interactive Packaging

Microwave Interactivity Insulation], which is incorporated here for reference.

Despite these advances, numerous challenges remain in the field of techniques for cooking food in microwaves. For example, removing large objects from a microwave oven, if such objects are not properly supported, can present difficulties. If a flat tray supporting a pizza is only grabbed on one side and lifted from the oven, the tray can deflect and slide the pizza out of the tray. In addition, many packages have a fixed shape and do not provide sufficient close or intimate contact with the food item to make it possible to darken or toast the surface of the food item. Some packages include partitions for increased contact with the food item, but in many cases the shape and dimensions of the partitions are adapted to a standard or nominal size of a food item that does not allow any variation in the size of the food item. For example, if the cross-sectional size of a portion of French fries on sticks varies, only a portion of the French fries will come in contact with the microwave interacting components of the package.

Thus, there remains a need to 'improve' the effectiveness of * emb'Jagged perfected interactive microwaves

SUMMARY OF THE INVENTION

The present invention relates in general to materials and packaging, and methods of manufacturing those materials and packaging, for use with food items that can be cooked in microwaves. In many respects an insulating material is used. In one aspect, the present invention involves a microwave foil with a self-sealing feature for providing a self-sealed food wrap after the foil is exposed to microwave energy. In another aspect, the present invention involves a sheet or package for use with microwaves that employs cells of varying size and variable expandability for use in transportation, for cooking food in microwaves, and for other uses. In another aspect, the present invention relates to a microwave tray with side walls that are formed when the tray is exposed to microwave energy. The present invention also relates to a microwave insulating material or other packaging material for use with microwaves providing an oxygen barrier. In addition, the present invention relates to a microwave insulating material or other microwave packaging material formed at least partially with a thermo-mechanical device. The present invention also includes a method for wrapping a food item in microwave insulating wrapping material * '* è' bpífiottalftieftTe, a protective wrap. Finally, the present invention includes a package with a lid that can be disposed under the package during microwave cooking to provide additional insulation and heating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. IA is a cross-sectional view of an insulating material for microwaves that can be used in accordance with the present invention;

<td>FIG.</td><td>1B is a</td><td>View</td><td>in perspective</td><td>of</td><td>material</td>

<td>insulating for</td><td>microwave</td><td>of FIG</td><td>. IA;</td><td></td><td></td>

<td>FIG.</td><td>1C is a</td><td>View</td><td>in perspective</td><td>of</td><td>material</td>

<td>insulating for</td><td colspan="2">microwave from</td><td>FIG. IA after</td><td colspan="2">exposure to</td>

microwave energy;

FIG. 1D is a cross-sectional view of an alternative microwave insulating material that can be used in accordance with the present invention;

FIG. 2 is a cross-sectional view of another alternative microwave insulating material in accordance with an aspect of the present invention, and which can be used in accordance with the present invention;

FIG. 3 is a cross-sectional view of another additional alternative microwave insulating material in accordance with an aspect of the present invention, and which can be used in accordance with the present invention;

FIG. 4 is a perspective view of a sheet of microwave material having an adhesive part • π ♦ · ···· · ·· «· · ·· · · · · · · · · 4 4 4 4 4 44 4 · 4 4 44444 ·· «φ 4 · · 4 that can be activated according to the present i * nvénçâ'o;

FIG. 5 is a perspective view of the leaf of the

FIG. 4 with a food item arranged on it;

FIG. 6 is a perspective view of the leaf of the

FIG. 5 with a portion of the sheet folded over the food item;

FIG. 7 is a perspective view of the leaf of the

FIG. 4 with a second part of the sheet folded over the first part of the sheet, thereby forming a glove;

<td colspan="2"></td><td>The</td><td>FIG.</td><td> 8</td><td>It is</td><td>another</td><td>vista.em</td><td>perspective</td><td>gives</td><td>sheet</td>

<td>gives</td><td>FIG.</td><td> 7;</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td></td><td></td><td>The</td><td>FIG.</td><td> 9</td><td>It is</td><td>a view</td><td>cutting</td><td>transversal</td><td>gives</td><td>sheet</td>

<td>gives</td><td>FIG.</td><td> 8</td><td colspan="2">outlet</td><td>to the</td><td>long of</td><td>a line</td><td> 9-9;</td><td></td><td></td>

FIG. 10 is a perspective view of the sheet and food item of FIG. 7 after exposure to microwave energy;

FIG. 11 is a cross-sectional view of the sheet of FIG. 10 taken along a line 11-11;

FIG. 12 is a perspective view of a sheet of microwave material including an activatable adhesive part in accordance with an aspect of the present.

<td rowspan="2">invention, The</td><td colspan="7">with a food item placed on it;</td>

<td colspan="2">FIG. 13</td><td>is</td><td>seen in</td><td>perspective</td><td>gives</td><td>sheet of</td>

<td>FIG. 12</td><td>with</td><td>one</td><td>part</td><td colspan="3">of the sheet folded over</td><td>the item</td>

<td colspan="2">food;</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>The</td><td>FIG</td><td> . 14</td><td>is</td><td>seen in</td><td>perspective</td><td>gives</td><td>sheet of</td>

FIG. 13 with a second part of the sheet folded over the food item for food;

formation üe JíttS ». * BckÍSa '* erft .fdrílo.

of the item to FIG. 15 is a perspective view of a sheet of microwave material including an activatable adhesive according to the present invention, with a food item placed on it;

FIG. 16 is a perspective view of the sheet of FIG. 15 with a portion of the sheet folded over the food item;

FIG. 17 is a perspective view of the sheet of FIG. 16 with a second part of the sheet folded over the food item to form a pouch around the food item;

FIG. 18 is a top plan view of a package employing a plurality of insulating expansion cell arrangements in variable arrangements, in accordance with the present invention;

FIG. 19 is a cross-sectional view of the package of FIG. 18 taken along a line 19-19;

FIG. 20 is a cross-sectional view of a package employing complementary arrangements of cells of variable expansion, in accordance with the present invention;

FIG. 21 is a perspective view of the package of FIG. 18;

FIG. 22A is a perspective view of a package having an insulating material on at least part of the interior of the package, in a closed position;

t · ··· · ····· ·· · • · ·· ·· ····· · • · · ·· ·· · FIG. 22B is a Vietnamese ·· * éoi '* .pe * 56pect.itz-a :. a package having an insulating material on at least part of the interior of the package, in an open position;

FIG. 23 is a perspective view of an exemplary microwave tray having four self-forming walls in the unfolded position;

FIG. 24 is a disintegrated view of the

FIG. 23;

FIG. 25 is a cross-sectional view of the tray of FIG. 23 prior to exposure to microwave energy;

FIG. 26 is a cross-sectional view of the tray of FIG. 23 after exposure to microwave energy;

FIG. 27 is a perspective view of an alternative microwave tray structure defining four self-forming tabs in the unfolded position;

FIG. 28 is a disintegrated view of the

FIG. 27;

FIG. 29 is a cross-sectional view of the tray of FIG. 27 prior to exposure to microwave energy;

FIG. 30 is a cross-sectional view of the sheet of FIG. 27 after exposure to microwave energy;

FIG. 31 is a cross-sectional view of an exemplary microwave insulating material with a barrier • · · · ···· · ···· · ·· · ··· · · · ···· · ···· · · Oxygen, according to the »V®» 'in »O-ê« Çã © *;' .. 'FIG. 32 is a cross-sectional view of another exemplary microwave insulating material with an oxygen barrier, in accordance with the present invention;

FIG. 33 is a cross-sectional view of another exemplary microwave insulating material with an oxygen barrier, in accordance with the present invention;

FIG. 34 is a cross-sectional view of the layers used to form an exemplary microwave insulating material;

FIG. 35 is a cross-sectional view of the layers of FIG. 34 with a plurality of thermo-mechanical devices configured to define a pattern of joints between the layers;

FIG. 36 is a cross-sectional view of the material and devices of FIG. 35, with the thermo-mechanical devices compressed into the layers defining closed cells;

FIG. 37 is a cross-sectional view of a microwave insulating material after processing with a thermo-mechanical device;

FIG. 38 is a detail of a section of FIG. 37 illustrating a union between layers;

FIG. 39 is a cross-sectional view of a tool adapted for pressing to form a container configuration, in an open position;

FIG. 40 is a cross-sectional view of the tool of FIG. 39 in the po &amp; i tion €&gt; «feòba'cfa ^ * FIG. 41 is a perspective view of the container formed by the tool of FIG. 39 and FIG. 40;

FIG. 42 is a cross-sectional view of the container of FIG. 41 taken along a line 42-42;

FIG. 43 is an enlarged view of a portion of the container of FIG. 42;

FIG. 44 is a perspective view of an alternative container shape shaped with a tool with integrated thermo-mechanical joining elements;

FIG. 45 is a perspective view of an exemplary process for forming a sheet of microwave insulating material around a food item according to the present invention;

FIG. 46 is a cross-sectional view of the heat seal and cutout tool of FIG. 45 taken along a line 46-46 in an open position;

FIG. 47 is a cross-sectional view of the heat seal and cutout tool of FIG. 45 taken along line 47-47 in an acted position;

FIG. 48 is a cross-sectional view of the wrapped food item of FIG. 45 taken along a line 48-48;

FIG. 49 is a cross-sectional view of a wrapped food item taken along a line

49-49 of FIG. 48;

FIG. 50 is a perspective view of a • · ·· ····· ····· ·· · · ··· · · · ·· ·· · ···· · · packaging with an Isolâífté cover *. £ fde / 'á * dôfcvràdã. under the package, in accordance with an aspect of the present invention;

<td>The</td><td>FIG.</td><td>51 is</td><td>one</td><td>another view in</td><td>perspective</td><td>gives</td>

<td>packing</td><td colspan="2">of FIG. 50</td><td>in a</td><td>open position;</td><td>and</td><td></td>

<td>The</td><td>FIG.</td><td>52 is</td><td>one</td><td>another view in</td><td>perspective</td><td>gives</td>

<td>packing</td><td>of</td><td>FIGS.</td><td>50 and</td><td>51 with the cover</td><td>folded under</td><td>The</td>

tray a.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to various aspects of materials and packaging for cooking food items by microwave, and methods for making such materials and packaging. Although several and different inventions, aspects, implementations, and configurations of the various inventions are provided, numerous interrelationships between, combinations of, and modifications of the various inventions, aspects, implementations and configurations of the inventions are contemplated here.

According to various aspects of the present invention, an insulating material is used to form numerous structures for microwave cooking and food packaging. As used herein, the term microwave insulating material refers to any layering of layers, such as layers of polyester, susceptor or layers interacting with microwaves, polymer layers, paper layers, continuous and batch adhesive layers, and adhesive layers with patterns formed on them, which provide an insulating effect. THE

9 99 · 9 9 9 · »99 9 9 9« 9 9 999 99 9 99 99 9 9999 9 9 sheet or packaging can incl5air.S_íi / h.òti.Wai * â..Su.st^,ep ^ 0Xes, one or more expandable insulating cells, or a combination of susceptors and expanding insulating cells. Examples of materials that can be suitable by themselves or in combination with one another include, without limitation, QwikWave® Susceptor, QwikWave® Focus, Micro-Rite®, MicroFlex® Q, and QuiltWave ™ susceptor materials, each of which is made available commercially by Graphic Packaging International, Inc.

An exemplary insulating material 10 is shown in FIGS. 1A-1D. In each of the examples illustrated here, it should be understood that the widths of the layers are not necessarily shown in perspective. In some cases, for example, the adhesive layers are very thin in relation to other layers, however they are still illustrated with a certain thickness for the purposes of clarity of illustration of the layer arrangement.

Referring to FIG. IA, material 10 may consist of a combination of several layers of different materials. A susceptor, which typically includes a thin layer of material 14 with microwave interactivity on a first plastic film 16, is joined, for example, by laminating with an adhesive (not shown) to a dimensionally stable substrate 20, for example paper. 0 substrate 20 is bonded to a second plastic film 22 using an adhesive 26 with patterns formed from the same or another material, of¹ closed cells 28 in material t3l * '^ Órwà' »that · * s&gt; ãb« formed

10. Closed cells 28 are substantially resistant to vapor migration.

Optionally, an additional substrate layer 24 should be adhered by an adhesive or otherwise to the first plastic film 16 at the location, opposite material 14 with interactivity with microwaves, as shown in FIG. 1D. The additional substrate layer 24 may consist of a layer of paper or other similar material, e.g. it may be provided to protect the food item (not shown) from any chips of susceptible film that form cracks and separate from the substrate during heating. The insulating material 10 provides a substantially flat multilayer sheet 30, as shown in

FIG. 1B.

FIG. 1C illustrates the exemplary insulating material 10 of FIGS. IA and 1B subjected to microwave energy from a microwave oven (not shown). When the susceptor film 12 is heated by the incidence of microwave energy, water vapor and other gases normally contained in the substrate 20, for example, paper, and any air trapped in the thin space between the second plastic film 22 and the substrate 20 in closed cells 28 they expand. The expansion of water vapor and air in the closed cells 28 puts pressure on the susceptor film 12 and the substrate 20 on one side and on the second plastic film 22 on the other side of the cells • · ·· ····· ·· ··· ·· · · ··· · · · ·· ·· · ···· · · • ········· ···· closed 28. Each side of the material 10 that forms the cells closed 28 reacts simultaneously, but in a unique way, to the heating and expansion of steam. Cells 28 expand or inflate to form a top and uneven surface 32 of pillows separated by channels (not shown) in the lamination of susceptor film 12 and substrate

20, which rises above a bottom surface 34 formed by the second plastic film 22. This expansion can occur in the space of 1 to 15 seconds in a microwave oven powered by energy, and in some cases it can occur in 2 to 10 seconds seconds.

FIGS. 2 and 3 illustrate exemplary alternative configurations of layers of microwave insulating material that may be suitable for use with any of the various sheets, packages, and other structures of the present invention. Referring first to FIG. 2, there is illustrated a microwave insulating material 40 with two symmetrical layer arrangements adhered to each other by an adhesive layer forming a pattern. The first arrangement of symmetrical layers, which begins at the top of the drawings, comprises a layer of PET film 42, a layer of metal 44, an adhesive layer 46, and a layer of paper or cardboard 48. The layer of metal 44 may comprise a metal, such as aluminum, deposited along part or all of the layer of PET film 42. The layers of metal 44 and PET film 42 together define a susceptor. The layer • · ······· ····· ·· · · ··· ·· · ·· · · ······ · · • ······ ··· ··· · Adhesive 4 6 joins the PET film * 42 ** and the metal layer 44 to the cardboard layer 48.

The second arrangement of symmetrical layers, illustrated starting at the bottom of the drawings, also comprises a layer of PET film 50, a layer of metal 52, an adhesive layer 54, and a layer of paper or cardboard 56. If desired, the two symmetrical arrangements can be formed by folding an arrangement of layers over themselves. The layers of the second symmetric layer arrangement are joined together. a shape similar to the layers of the first symmetrical arrangement. A layer of adhesive 58 forming a pattern is provided between the two layers of paper 48 and. 56, and defines a pattern of closed cells 60 configured to expand when exposed to microwave energy. In one aspect, an insulating material 10 having two layers of metal 44 and 52 according to the present invention generates more heat and a higher elevation of the cells.

Referring to FIG. 3, yet another microwave insulating material 40 is shown.

Material 40 may include a layer of PET film 42, a layer of metal 44, an adhesive layer 46, and a layer of paper 48. Additionally, material 40 may include a layer 50 of transparent PET film, an adhesive 54 , and a paper layer 56. The layers are adhered to or fixed by a standard shaped adhesive 58 defining a plurality of closed expandable cells 60.

• · ·· ····· ····· ·· · · ··· · · · ·· ·· · ···· · ·

The use of any of the exemplary insulating materials to pack and / or cook a food item provides several benefits before, during, and after heating in a microwave oven. First, the water and air vapor contained in the closed cells provides insulation between the food item and the internal surfaces of the microwave oven. The base of a microwave oven, for example, the glass tray found in most microwave ovens, acts as a large heat sink, absorbing a large part of the heat generated by the susceptor film or inside the food item itself. The steam bags on the cushions formed by the present invention can be used to insulate the food item and the susceptor film from the surfaces of the microwave oven and the ventilation air inside the microwave oven cavity, thereby increasing the amount of heat that remains inside the food item or is transferred to it.

Second, the formation of the cushions allows the material to conform more closely to the surface of the food item, with the susceptor film arranged in a closer proximity to the food item. This increases the ability of the susceptor film to darken and toast the surface of the food item by conducting heating, in addition to some convection heating, of the food item.

In addition, the insulating materials contemplated herein may be desirable as packaging materials as they add little volume to the finished packaging, however becoming a bulky insulating material without any preparation by the consumer before cooking the food.

I. Self-Sealing Sheet for Microwaves

In accordance with an aspect of the present invention, a sheet of packaging material for microwaves is provided with an activatable adhesive. As used herein, the term activatable adhesive refers to any bonding agent or adhesive that joins itself or a material when it is exposed to microwave heat or energy. The food item is wrapped in the foil and heated in a microwave oven, where it self-seals during microwave heating to cover all or part of the food item.

The type of adhesive that can be activated, the amount of adhesive applied to the microwave foil, and the coverage coverage and positioning of the foil on the foil may vary for a given application. Thus, the present invention contemplates numerous arrangements and configurations of the activation adhesive on the microwave sheet as needed or desired. In cases where a stronger union is desired, an adhesive may be selected and positioned correspondingly • · ·· ····· ····· ··· · ··· · · · ·· ·· · ·· ·· · · • ········· ···· specific. For a weaker bond, another specific adhesive can be selected and positioned accordingly. An example of an activable adhesive that may be suitable for use with the present invention is amorphous polyethylene terephthalate (Amorphous Polyethylene Terephthalate - APET). For example, an APET layer can be co-extruded with a transparent polyethylene terephthalate (PET). In a variant, the sheet or material includes a layer of DuPont PET Mylar ™ 850 with a heat-sealable APET layer. However, other adhesives that can be activated are contemplated by the present invention.

In one aspect, the activatable adhesive is not sticky or adhesive before being exposed to microwave heat or energy, making the sheet easier to handle. Alternatively, the adhesive may be slightly sticky or adhesive in such a way that the user can substantially wrap the food item prior to exposure to microwave energy. Depending on the activatable adhesive that is employed and / or the amount of heat generated during cooking, some implementations of the invention may employ a layer of susceptor under or adjacent to the activatable adhesive in order to concentrate a greater amount of heat in the adhesive area that can be activated and to optimize the bonding conditions.

In one aspect, a packaging or foil arrangement with an activatable adhesive may include a microwave insulating material. For example, according to one aspect of the present invention, the self-sealing package includes an insulating material having expandable closed cells. When exposed to microwave energy, the cells expand to form inflatable cells. Although a theoretical limitation is not desired, it is believed that the inflated cells allow to cook more efficiently in a microwave oven by reducing the heat loss to the environment surrounding the packaging. For example, it is believed that microwave packaging, a tray or the like with insulating cells disposed between the food item and the glass tray in most microwave ovens, will reduce the heat transfer between the food and the tray, allowing more efficient heating of the food. In addition, after the food is cooked, a package with inflated cells can be comfortable to touch, thus allowing a user to comfortably grasp the package to remove it from the microwave oven. Optionally, the sheet is provided with a susceptor material. In one aspect, the susceptor material is positioned in such a way that when the cells expand, the susceptor is pressed against the food item contained in the package to increase its heating, browning and / or roasting.

FIG. 4 is a perspective view of a leaf • «·· ····« «4 ···· · · · ·

999 9 Λ 9 9 9 9 9 9 999 9 9 9 9 999 90 99 99 9 »99 99 ·» · for exemplary microwaves 110 that employs and defines a region of activable adhesive 112 on a microwave insulating material 114 according to the present invention. The shape and size of sheet 110 and the location, size and shape of the activable adhesive region 112 can vary depending on numerous factors, such as the shape and size of the food item (preferably observable in FIGS. 5 and 6) intended to be heated with the sheet 110. The microwave sheet 110 defines one or more closed cells 116 that expand when exposed to microwave energy. Sheet 110 is provided in a rectangular shape, but any shapes or sizes can be used as needed or desired. In addition, the illustrated sheet 110 has insulating cells 116 of quadrangular shape, but other formats are contemplated.

Referring now to FIG. 5, a food item 118, for example, a pastel, is placed on the sheet 110. As shown in FIGS. 6 and 7, the user can center food item 118 on sheet 110, wrap a first portion 120 (without activable adhesive) of sheet 110 on food item 118 (FIG. 6), and then wrap a second portion 122 (with adhesive that can be activated) on food item 118 (FIG. 7) such that at least a portion of the activatable adhesive 112 contacts the first portion 120 of sheet 110. When folded in this manner, sheet 110 ·· · 444 »· ··« · · »·· ·· c · • 4 4 4 · 4 4 · 4 4 44 • 4 4 4 444 4 9 444 4 4 4 4 · * · 44 4 4 4 944 4 4 forms a sleeve 124 around • 44 44, f · 44, · ·. 44 ~ 9 fc. t food item 118.

To assist in joining and forming glove 124, the user can place the overlapping parts 120, 122 of sheet 110 under food item 118 in a manner illustrated in FIGS. 8 and 9 such that the wrapped sheet 110 is initially held together by the weight of food item 118. If desired, sheet 110 can be provided with a tray 128 in which wrapped food item 118 is placed to be cooked .

Food item 118 wrapped in sheet 110 is then placed in the microwave oven (not shown) and heated. During microwave heating, the microwave energy and / or the calof associated with it activates the adhesive, thus making the overlapping edges of the sheet join together. In this way, sheet 110 generally forms a sleeve 124 with two open ends 130,

132 around food item 118.

In addition, exposure to microwave energy causes cells 116 to expand, as shown in FIGS. 10 and 11. Expansion of cells 116 during heating provides an insulating function, as discussed above. The insulation around food item 118 provides more efficient heating by reducing the heat loss to the surrounding environment of the microwave oven (for example, the tray and the air contained in the microwave oven). In addition, the outer surface 134 of the self-formed sleeve 124 may be

<img src="BRPI0506901A_files/BRPI0506901A-1.png" style="width:381pt;height:37pt;" />

124. As such, a user can grasp the formed glove 124 and remove the food item from the microwave oven. If this is desired, the user will be able to eat food item 118 directly from the formed glove 124.

In addition, in cases where a susceptor material is used, the susceptor material is placed in substantially close and / or close contact with food item 118 to darken or toast its surface 136. Prior to cooking, a portion of the sheet 110 may not be in intimate contact with an irregularly shaped food item 118 wrapped in it. In this way, only some portions of the food item will be exposed to the susceptible material. The elevation or expansion of cells 116 of sheet 110 causes the susceptor layer to swell to meet the food item, providing greater contact with food item 118, and therefore heating, darkening and / or roasting it more efficiently. .

Exemplary sheet 110 illustrated in FIGS. 3-11 includes an activatable adhesive 112 that is positioned to facilitate self-formation of a glove 124 with two open ends 130, 132. In contrast, the

FIG. 12 illustrates another exemplary sheet 110 with an insulating material 114 and an activatable adhesive 112 provided along two adjacent edges 138, 140 of sheet 110. In this example, adhesive 112 is disposed. · · · · · ···· · ·· · • · · ··· · · contiguously along · ωη3 ·· 1) 0Ύά £ Vra'áefta ”138 * and a side edge 140 of sheet 110. The item 118 is' «&lt;

placed on sheet 110 between the regions of activable adhesive 112a and 112b. In FIG. 13, sheet 110 is wrapped around food item 118. In this example, a portion of sheet 110 is folded over the food item in such a way that the adhesive-free side edge 142 is first arranged over food item 118. The rear edge 138 is partially folded over itself to contact the back-activating adhesive strip 112a. FIG. 14 illustrates sheet 110 with expanded cells 116 fully wrapped around food item 118 after exposure to microwave energy. The overlapping edges adhered to form a pocket 148 with an open end 152 (shown in hidden line) and a closed end 146. The self-formed pocket 148 provides the same advantages discussed with respect to FIGS. 3-11 and additionally prevents excessive amounts of juices, cheese, sauce, and the like from dripping, provided that bag 148 is held with the open end 152 in an upright position while consuming food item 118. The open end 152 it also provides ventilation.

FIGS. 15-17 illustrate a microwave sheet

110 in which the activatable adhesive 112 is provided along at least a portion of three adjacent edges 138, 140, 144 of the sheet 110. In FIG. 15 is found • ······ ·· ·· ·· ·· • · · ··· · ·· · «···· · · · · · ··· · · · · · ·· · • · ···· · ···· · • ·· ·· ·· · * · a 114 sheet 110 microwave illustrated which nsmpr ^ g ^ vfrti ifiâtè'rih'1 'isôl * before and adhesive strips 112a, 112b, and 112c over a the rear edge portion 138, a front edge portion 144, and one of the side edges 140. FIG. 16 illustrates sheet 110 being folded over the food item

118. When folded in this way, the adhesive 112b along the leading edge 144 is aligned with itself or with a portion of the leading edge 144. Additionally, the adhesive 112a along the trailing edge 138 also aligns with itself or a portion. from the rear edge

138. FIG. 15 illustrates sheet 110 fully folded over food item 118 and defining a sealed cooking container 150. The side edge 140 provided with adhesive is folded over the corresponding opposite edge 142.

The front edge 144 is joined to itself and the rear edge

138 it is also attached to itself to form the container when exposed to heat or microwave energy. The configuration of FIG. 17 can be additionally provided with one or more ventilation openings, perforations, or holes (not shown), if necessary or desired.

Although several examples of self-sealing sheets for microwaves are illustrated and described herein, it should be understood that other arrangements and configurations are contemplated by the present invention. Thus, a microwave sheet may have a surface for contact with food, a surface that does not contact the food, or ·· ···· ·· · · »· · · · ·» ···· · · · · · Both, which is / are fully covered (s) • ········· ··· · partialmerit ^; · • Sub * et ^ ndial! NeKte, or by an activable sticker, for example, APET. In one aspect, the activatable adhesive, for example, APET, can substantially cover the food contact surface of the microwave foil. In this way, the food item can be placed on the sheet and the sheet can be folded over the food item in a variety of possible ways to form a glove, a bag, or some other container.

III. Heating and Transport of 'Microwave Interaction Sheet That Employs Cells of Dimensions and

Expandability Variables

Many food items have irregular shapes and small dimensions, making them difficult to insert into individual gloves with a microwave susceptor to be heated, darkened, and roasted. Thus, according to another aspect of the present invention, a packaging material and packaging formed therefrom provides improved contact between the material and a multiplicity of food items or a single food item having an irregular shape.

The material and its packaging include closed expandable cells that expand during exposure to microwave energy to conform to the shape and size of the food item. The cells may include one or more elements with interactivity for microwaves, or susceptors. The cells expand after being exposed to energy ·· ··· ·· «··· ··« · ·· ·· • · · · · · · · ·· · • · ······ · · «·· · · · · · · · ·· ·· · · ·· · · · · · ··· f - * d ^ · 'ifiícVootfdáS,' * d'e * ss * á * form bringing the susceptor material for greater proximity to the surface of the food item. In one aspect, individual food items are wrapped or packaged in an insulating material, for example, a material having cells of varying sizes and configurations that can expand to different degrees (hereinafter referred to as variable expansion cells or variable expandable cells). The material may consist of any suitable coriform expandable cell material that is desired, and in some cases, may include any of the materials described herein, any of the materials described in PCT / US Patent Application 03/03779, which is incorporated herein. reference title, or any combination thereof. Optionally, the material can be used to form a package that provides support and protection for fragile food items during transport and handling before they are cooked.

The variable expansion cells and their non-uniform arrangements provide several advantages over the microwave packaging materials currently available. First, the cells provide insulation along the bottom and the periphery of the food item, thereby preventing heat loss to the surrounding environment. Second, multiple arrangements and cells can be used to form a sheet intended for use in a package, of “· 4” ·· * 4 »··· ·· ·· ·· ·· ·« «· · · Ο «·· · ·· 4 4 4 • · ·· ·&gt; β 4 · · · · · 9 · 4 44 4 4 ·« · Ί · · «4 4 4 4 J · such that a multiplicity of“ iüéná · Ãlirttentícíos can be cooked in the same package. Thirdly, when a susceptor is included, the size, shape, and level of expansion can be standardized to suit any food item, thereby providing greater proximity to the susceptor material allowing it to darken and toast the food better during microwave heating .

The size, shape, and configuration of the expandable cells may vary for a specific application. Cells can be arranged in any pattern, including rows, concentric circles, sets of shapes or individual cells, or any other pattern as desired. Similarly, the size difference between the individual expandable cells may vary for a specific application. In one aspect, one or more cells range from about 5 to about 15% expanded volume, compared to the expanded volume of other cells. In another aspect, one or more cells range from about 15 to about 25% expanded volume compared to the volume of another cell. In another aspect, one or more cells range from about 25 to about 35%, from about 35 to about 45%, from about 45 to about 55%, from about 55 to about 65%, from about 65 to about 75%, from about 75 to about 85%, from about 85 to about 95%, from about 95 to about 105%, from about 105 to about 110%, from about 1L0. * to £ ê..éé.st * a.'de.'lA5% ;. from about 115 to about 85%, from about 85 to about 100%, from about 100 to about 125%, from about 125 to about 150%, from about 150 to about

175%, from about 175 to about 200%, from about

200 up to about 225%, from about 225 to about

250%, from about 250 to about 275%, from about

275 up to about 300%, from about 300 to about

325%, from about 325 to about 350%, from about

350 up to about 400%, from about 400 to about

450%, from about 450% to about 500%, from about

500 up to about 600%, from around 600 to about

700%, from about 700 to about 800%, from around

800 up to about 900%, from about 900 to about 1000%, or more than 1000% in expanded volume, compared to the expanded volume of another cell.

In another aspect, one or more cells range from about 5 to about 15% in unexpanded surface area, compared to the unexpanded surface area of ​​another cell. In one aspect, one or more cells range from about 15 to about 25% unexpanded surface area compared to the unexpanded surface area of ​​another cell. In another aspect, one or more cells range from about 25 to about 35%, from about 35 to about 45%, from about 45 to about 55%, from about 55 to about 65%, from about 65 to about 75%, from about • · ·· ····· ····· ·· · · up to about 85%, from &lt;5ercd. '&lt;de *' â5 * .áêé * select 95%, from about 95 to about 105%, from about 105 to about 110%, from about 110 to about 115%, from about 115 to about 85%, from about 85 to about 100%, from about 100 to about 125%, from about 125 to about 150%, from about 150 to about

175%, from about 175 to about 200%, from about

200 up to about 225%, from about 225 to about

250%, from about 250 to about 275%, from about

275 up to about 300%, from around 300 to about

325%, from about 325 to about 350%, from about

350 up to about 400%, from about 400 to about dé

450%, from about 450% to about 500%, from about

500 up to about 600%, from around 600 to about

700%, from about 700 to about 800%, from around

800 up to about 900%, from about 900 to about

1000%, or more than 1000% in unexpanded surface area, compared to the unexpanded surface area of ​​another cell.

In yet another aspect, the cells can be provided around the periphery of the food item such that during microwave heating, the cells expand along the periphery of the food item and darken the sides of the food item. In another aspect, cells are provided under and around the food product. The cells positioned under the food product can expand up to a certain height, and the cells adjacent to the pèriniêJbrü * .dô .. * ± Lem .. 'âJ.Ini6ntício can expand to a second height that is greater or less than the first height. In yet another aspect, the cells can be organized by forming one or more cavities that can contain the individual food items. In this and other aspects, the susceptor material is selectively placed in close or intimate contact with the surface of the food item during the expansion of the cells, thereby darkening and toasting it to a desired degree.

Additional examples are provided in FIGS. 18-22. For the sake of convenience, food items and packaging are described herein as having a top, bottom, and sides. In many cases, the top, bottom, and sides of a package or food item are relative to a surface on which the food item is placed and to the observer's perspective. It should be understood that the reference to a top, bottom, or side is not intended to confer any specific limitation on the scope of the invention, but merely to provide an easy form of reference for describing its characteristics.

Referring now to FIGS. 18-19, a sheet 200 of insulating material 210 including variable expansion cells 212 is provided. Sheet 200 defines four arrays 214 of variable expansion cells 212. Sheet 200 may include the same layer arrangement illustrated in FIGS. 1-3, however, the adhesive pattern that defines the cells • · ·· ····· ····· ·· · · ··· · · · ·· ·· ····· · · expandable 212 doesn't have a for2a5iiô '.. úfkifb £^Jtnefc **. í^,therein each array 214 of variable expansion cells 212, a first set 216 of cells 212 collectively defined in an approximately circular shape is surrounded by a second set 218 of cells 212 of larger size which collectively defines an approximate ring shape. 212 cells can have any desired shape, such as oval, square, or hexagonal.

Each of the four arrangements 214 of cells 212 of FIG. 18 can be used with a circular shaped food item 220, such as a pizza, pie, or any food item that is desirably darkened and roasted on the bottom and sides of it. For this purpose, food item 220 is disposed on sheet 200 in such a way that the bottom 224 of food item 220 is substantially centered on the first set 216 of cells 212. The periphery 226 of food item 220 is then aligned with the inner edge 222 of the second set 218 of cells 212. Four of these food items 220 can be arranged in each of the four arrays 214 of variable expansion cells 212 and may be desired. , be used to form a packaging or other structure. When the sheet 200 or a package employing the sheet 200 is exposed to microwave energy, the first inner set 216 of cells 212 rises upwardly against the bottom 224 of food item 220. The outer set 218 of cells 212 rises upwards. • • · · ··· · ·· ······ • · ······· ····· ·· · · ··· · · · ·· ·· · ··· · · · Distance greater than the first c4si '&gt; uh'td' ^ l ^. * D®.'óálulas 212 against the periphery 226 of food item 220.

If desired, a packaging that uses the foil

200 with variable cells 212 includes a cover 228 of cardboard or other type. Cover 228 may or may not include microwave-interacting material, such as a susceptor or antenna. In addition, vertical dividers (not shown) can be provided to maintain proper alignment of food items with cell arrangements.

In this and other respects, the sheet may include microwave or susceptible active elements. The susceptors can be flat, continuous, or patterned, and / or can be used in combination with protective or pseudo-protective elements, such as thicker aluminum plates. In addition, individual cells can be provided with patterns of interactive functionality with microwaves or susceptors, which can further assist in the individualized provision of means for heating, darkening and toasting the food item. Similarly, the area between the cell arrangements can include one or more of any of these elements as needed or desired to provide adequate heat distribution.

FIG. 20 illustrates an exemplary package employing two sheets 200a, 200b of material 210, each with the same array of variable cells 214 as illustrated in FIG. 18. The food item. 22disposed on the first sheet 200a in the same manner as discussed above with respect to FIGS. 18 and 19. The second sheet 200b is arranged on the food item in such a way that the generally circular shape of the first set 216b of cells 212 is basically centered on the top surface 230 of the food item 220, and the second set 218b of cells 212 is arranged on the adjacency of the periphery

226 of food item 220.

As shown in FIG. 20, after exposure to microwave energy, cells 212 on the first sheet 200a rise upwards in the same manner as discussed above with respect to FIGS. 18 and 19. As such, the first set 216a of cells 212 contacts the bottom 224 of food item 220 and the second set 218a of cells 212 swells to the outer periphery 226 of food item 220. The expanded cells 212 on the second sheet 200b substantially constitute a mirror image of the first sheet 200a, although other configurations are contemplated. The inner assembly 216b of cells 212 expands downwardly to contact the top surface 230 of food item 220 while outer cells 218b swell downwardly to contact outer periphery 226 of food item 220. The two sheets 200a and 200b thus work in concert to totally or almost totally involve the item • · · · ····· ····· ·· · · ··· · · ····· · ·· ·· · ·.

food 220. Thus: to &lt;ábá. * ôú..qtiay8. * t © dòe * ofc. sides of food item 220 are insulated by, and in contact with, expanded cells 212. Such a sheet or package may be used when it is desired to darken all surfaces of the food item.

Various packaging arrangements with cell sheets of variable expansion or with variable dimensions are contemplated by the present invention. In one aspect, a sheet of expandable cells is arranged on the bottom and top panels of a foldable packaging box. In another aspect, a sheet of expandable cells is adhered to a pouch or glove. In addition, a sheet with variable cells can be provided with an activatable adhesive as described herein.

According to another aspect of the present invention, a sheet or package with variable cell arrangements can be used to package and transport food items. Some food items are quite fragile, particularly in the frozen state, and can be damaged by normal distribution, transportation and handling efforts. It is known to provide thermo-formed plastic trays with compartments formed to better hold the product. These trays, however, are typically not capable of providing a susceptor functionality to darken and microwave the product. Thus, according to this aspect, the sheet or packaging is exposed to microwave energy for cell expansion and for immobilizing itdns.:. Ãl.? If! Êftt.íVií} s .. “sUráate transport. The sheet or packaging can be exposed with or without the food item (s) contained therein, for a period of 1 to about 15 seconds, for example, 2 to 10 seconds. In this way, the cells expand and provide support and protection for the food item (s) contained therein.

FIG. 21 illustrates an exemplary packaging or box 250 for transporting and cooking according to the present invention. Package 250. Includes a sheet 200 with variable cells 212 adhered to or otherwise inserted into the bottom part 252 of a package 250. Prior to filling with food items 220, package 250 including sheet 200 is briefly exposed to microwave energy , which causes an initial expansion of the variable cells 212. The food item (not shown) is then placed in it as discussed above and the package 250 is closed with the food items (not shown) contained and protected by the expanded variable cells 212. If desired, the package 250 can then be exposed again to microwave energy for further expansion of 212 cells and providing a more just conformation to the shape of the food item (not shown). Alternatively, the food item can be arranged in alignment on an unexpanded sheet or in a package, which is then briefly exposed to microwave energy for partial or full expansion of the cells. After " " " · ···· · ···· · ·· · · ··· · * · ·· ·· · "··· · · ,.

heating by the user, Ã emS ^ la ^ eiíi * .2 ^ C. * &amp;. 'a * fe ^ fia and the undamaged and properly cooked individual food items (not shown) are removed.

Another exemplary package is provided in FIGS. 22A and 22B. Package 260 includes a tray 262 and a lid 264 including a flap 266. Prior to opening (FIG. 22A), lid 264 covers tray 262 and the food item (not shown) contained therein, and the flap

266 can be removably attached to a front panel 268 of package 260. When the. food item (not shown) is ready to be heated, the packaging 260 is opened by a pull applied upwards to the flap 266. Ventilation holes 272 or other ventilation characteristics (not shown) can be provided in the front panel 268 if this necessary or desired.

If desired, the cap can be pulled along perforations (not shown) located along or in the vicinity of edges 274a and 274b. The inner surface 276 of the cap 264 can include an insulating material 278, with or without a susceptor layer, as described herein. Insulating material 278 may include an oxygen barrier layer, cells of varying dimensions and / or variable expansion, partially expanded cells, or numerous other features described or envisaged herein. To close the packaging 260 again after opening it, the flap 266 can contact and fit into a corresponding slot 280

However, to keep the lid 264 in position, other means of securing the flap 266 are contemplated here.

If desired, an additional insulating material 278 can be provided on one or more inner surfaces of the package, for example, on the inner surface 288 of the bottom to increase the heating, browning, and roasting effect of the food product or to provide additional insulation between the food item and the bottom of the tray and the floor of the microwave oven.

A package according to this aspect of the present invention can be suitable for packaging, transporting, and cooking numerous types of food items. For example, the packaging can be used for irregularly shaped items, such as French fries, and can incorporate other features disclosed herein, such as variable expansion cells, as discussed above, and pre-expanded cells, such as those that are discussed below.

IV. Insulating Material and Tray with Self-Forming Walls Formed with the Same

According to another aspect of the present invention, a microwave tray is provided. The tray is initially flat, but after exposure to microwave energy, one or more flaps or edges of the tray fold upward to form flaps substantially perpendicular to the tray. The flaps serve to reinforce and support the tray. Additionally, if they are combined with microwave active elements, the tabs can enhance the darkening and roasting of the sides of a food item in the tray.

FIGS. 23 and 24 illustrate an exemplary microwave tray 300 in accordance with the present invention.

Tray 300 includes a support 302 formed of cardboard, or other suitable material, having at least one layer of insulating material 304 partially adhered to or attached to it. The insulating material 304 is positioned in such a way that the susceptor film is oriented towards the food product (not shown) intended to be heated over it. Tray 300 includes four self-forming tabs 306a, 306b, 306c, and 306d in the unfolded position. The flaps 306a, 306b, 306c, and 306d can be integral with the support 302 or can be adhered or joined to it. The flaps 306a, 306b, 306c, and 306d can be defined by a cutout 318 at one or more corners 320 of the support 302. In one aspect, the insulating material 304a, 304b, 304c, and 304d aligned with the flaps 306a, 306b, 306c, and 306d is adhered thereto, and the remaining insulating material 304e is disposed on support 302 but is not adhered or otherwise attached to it.

FIG. 25 illustrates tray 300 of FIG. 23 with a food item 312 disposed on it. After exposure to microwave energy, the insulating cells 310 expand, thereby contracting the surface area in • · ·· ·········· ·· · · ·· * · · ··· · · · ···· · · • ······ ·· · ·· · · general insulating material 304. Hâ'mecfidâ * in which ”the insulating material 304 is adhered only to the flaps 306a, 306b, 306c, and. 306d of tray 300, the contraction of the insulating material 304 pulls the flaps 306a, 306b (not shown), 306c, and 306d (not shown) in the direction of food item 312, as shown in FIG. 26. In this way, tray 300 has self-forming walls 324 after exposure to microwave energy. The expanded cells 310 isolate food item 312 from the microwave environment, and if used with a susceptor layer, they darken and roast the bottom 314 and sides 316 of food item 312.

To facilitate the deflection of the flaps 306a, 306b,

306c, and 306d, it is also possible to provide a marking line 322, a depression, or a perforation in the desired fold line. The walls 324 are arranged substantially transversely with respect to the support 302, and serve to provide rigidity to the tray 300 and minimize its deflection. Thus, after removing tray 300 from the microwave oven, it becomes less likely that the food item will spill or fall from tray 300.

FIGS. 27 and 28 illustrate another exemplary tray 300 according to the present invention. Tray 300 includes a support 302 formed of cardboard, or other suitable material, having a first layer of insulating material 304 partially adhered to or attached to it, and a second layer of insulating material 308 partially adhered or fixed * ”to ** primè * ir * to fcaftfâda of insulating material 304. The insulating material 308 is positioned in such a way that the susceptor film is oriented towards the food product (not shown) to be heated over it. Tray 300 includes four self-formed tabs 306a, 306b, 306c, and 306d in the unfolded position. The flaps 306a, 306b, 306c, and 306d can be integral with the support 302 or can be adhered or joined to it. In one aspect, the insulating material 304a,

304b, 304c, and 304d aligned with .abas 306a, 306b, 306c, and

306d is adhered to them, and the remaining insulating material 304e is disposed on the support 302 but is not adhered or otherwise attached to it. Similarly, the insulating material 308a, 308b, 308c, and 308d aligned with the flaps 306a, 306b, 306c, and 306d is adhered to the corresponding portions 304a, 304b, 304c, and 304d of the first layer of insulating material 304, but is not adhered or otherwise fixed to them.

FIG. 29 illustrates tray 300 of FIG. 27 with a food item 312 disposed on it. After exposure to microwave energy, the insulating cells 310 expand, thereby contracting the general surface area of ​​the insulating material 304. Due to the fact that the insulating material 304 and 308 is adhered only to the flaps 306a, 306b, 306c, and 306d of the tray 300, the contraction of the insulating material 304 and 308 pulls the flaps 306a, 306b. (not shown), 306c, and 306d (not shown) in the direction of the item • ♦ * · ···· · ···· · ·· · · ··· ·· · ·· ·· ····· · · Food 312, as shown * found * ra'ilüst * radô ft'a FIG. 30. In this way, tray 300 has 324 autoVI walls formed upon exposure to microwave energy. The expanded cells 310 isolate food item 312 from the microwave environment, and if used with a susceptor layer, they darken and roast the bottom 314 and sides 316 of food item 312.

As discussed above, to facilitate the deflection of the flaps 306a, 306b, 306c, and 306d, it is also possible to provide a marking line 322, a depression, or a perforation in the desired fold line. The walls 324 are substantially transversal with respect to the support 302, and serve to make the tray 300 rigid and minimize its deflection. Thus, when tray 300 is removed from the microwave oven, the food item from tray 300 is less likely to spill or fall.

V. Microwave Insulating Material with Barrier

Oxygen

According to another aspect of the present invention, a microwave exposure material provided with an oxygen barrier and a package formed therefrom is provided. Such a material or packaging can extend the shelf life of a food item arranged in the packaging. In addition, the packaging can be used to contain and transport a food item. Numerous materials are contemplated here • · · · ···· · ···· · ·· · · ··· · · ·· ·· · ···· · · and packages with several layers * 'and *' f orbabies *.

Any suitable oxygen barrier material can be used in accordance with the present invention. Examples of materials that may be suitable include, without limitation, polyvinylidene chloride (PVdC), ethylene vinyl alcohol (EVOH), and DuPont's DARTEK ™ nylon 66 film, which can be applied in a variety of ways including the various configurations discussed in relation to PVdC and EVOH. DuPont Nylon 66 Dartek ™ has a high melting point and good oxygen barrier properties.

The oxygen barrier material may be incorporated into any suitable insulating material including, without limitation, those described herein. Typically, the insulating material has several layers. For example, the microwave insulating material may include an outer layer of PET coated or otherwise provided with a layer of metal (such as aluminum), and a layer of paper or cardboard adhered to the layer of PET, such that the metallic layer is arranged between the PET layer and the paper layer. Typically, the food item is disposed on the material adjacent to the outer layer of PET. The insulating material includes expandable cells defined by an adhesive arrangement or pattern, such as in a grid pattern, between the paper layer and a second layer of PET. As discussed in detail above, the cells expand when exposed to microwave energy to provide a "^J* ristic 'isotant chafter and to bring the susceptor closer to the food item.

The oxygen barrier material can be incorporated into any of numerous possible 5 locations between layers of material. FIGS. 31-33 illustrate several exemplary arrangements of an insulating material 500 with an oxygen barrier 502. The exemplary microwave insulating material 500 includes a first layer of PET 504 and a layer of metal 506, which together define a 50.8 susceptor layer. The susceptor layer 508 is adhered to or attached to a layer of paper or cardboard

510 using a 518 adhesive, or otherwise. The paper layer 510 is adhered in a pattern using an adhesive 516, or is otherwise attached to a second layer of PET 512, thereby defining closed expandable cells 514. In FIG. 31, an oxygen barrier layer 502 is applied between the paper layer 510 and the second layer of PET 512. In FIG. 32, an oxygen barrier layer 502 is provided over the first layer of PET 504. In FIG. 33, an oxygen barrier layer 502 is positioned between the first layer of PET 504 and the paper layer 510. In another aspect (not shown), the oxygen barrier layer 502 can be provided on either side or both sides of the paper layer

510. Although several possible configurations are illustrated and described here, it should be understood that other arrangements are contemplated by the present invention and * * · · · «·· · ·« «« · «« «· • · · · · · · · · ····· · · possible configurations. ....... * '* * ........

A microwave insulating material with a barrier · »&lt;

of oxygen can be provided in a sealable structure or package. In such an exemplary structure, after the food item is inserted into the package, the package can be washed with a gas or a gas mixture, such as nitrogen and carbon dioxide, to displace oxygen from inside the package, and subsequently the package it is hermetically sealed. The oxygen barrier helps to delay or eliminate the re-entry of oxygen in the packaging. Such a package can help to reduce the oxidation and growth of aerobic bacteria in a food item contained therein, and can therefore reduce losses caused by spoiled food.

SAW. Formation of Microwave Isolating Structure using a Thermo-Mechanical Device

Various aspects of the present invention disclosed or anticipated herein involve the use of an insulating material having expandable closed cells. According to another aspect of the present invention, the closed cells of the insulating material are formed by thermo-mechanical joining of one or more layers of the insulating material.

Thermo-mechanical couplings can be formed using a thermo-mechanical device, an impulse sealing device, an ultrasonic coupling device, a heating bar, or any similar device, or any combination thereof. configured in the desired cell pattern. Typically, a pulse sealing device includes a nickel-chromium wire or a curved tube that is electrically pulsed to form a seal. 0 ultrasonic bonding device uses high frequency vibration, typically in the ultrasonic region, to create a thermomechanical bond. In one aspect, the bonding device is pressed against, or put into operation in the vicinity of, an arrangement of layers of material to form a bonding pattern between parts of the layers. The joining pattern defines a plurality of closed cells

<td>that expand</td><td>When</td><td>are</td><td>exposed to</td><td>energy</td><td>in</td>

<td>microwave, heat</td><td> generated</td><td>through the</td><td>same, and / or to</td><td>expansion</td><td>in</td>

<td>gases in cells</td><td>caused</td><td>through the</td><td>exposure to</td><td>energy</td><td>in</td>

microwave.

FIG. 34 illustrates the layers of an exemplary insulating material 600. In this example, the first layer 602 consists of a PET film and the second layer 604 consists of metal, and the layers together define a susceptor 606. The third layer 608 consists of paper or cardboard, which can be adhered to or attached to the susceptor using an adhesive or by another process. An example of a paper that may be suitable is a lightweight paper. dimensionally stable with some flexibility, such as paper with a basic weight of about 40 pounds / ream (18.14 kg / ream). The fourth layer

610 consists of film.:.de.·'P^T^tr^n^pauieriie with a coating of amorphous PET (APET) that can be heat sealed on one side, adjacent to the paper layer 608.

FIG. 35 illustrates the material of FIG. 34 with a plurality of joining elements 612. As used herein, the term joining elements includes thermo-mechanical devices, pulse sealing devices, ultrasonic or sonic joining elements, heated bars, or the like, capable of forming thermo joints -mechanics between layers of PET-susceptible film, transparent film, and paper, or other layers of microwave insulating material. Referring to FIG. 36, the joining elements 612 are sunk into the layers of material 600. At the points where the joining elements 612 contact the layers, a joint or seal 642 is formed by softening the APET between the layers of material. In the unconnected areas 644, the material layers define an open space 614 between the paper layer 608 and the layer 610 of transparent PET film, as shown in FIGS. 37 and 38. Thus, in this respect, closed cells are formed by selective sealing of the perimeter of the cells instead of being formed by applying an adhesive in a pattern, as discussed above.

FIGS. 39 and 40 illustrate a tool or stamp

620 comprising a plurality of joining elements 612 used for forming by pressing a container

632 including one or more: céJ: uÍaW..fêiGh ^ ctes.^,([Exhibited) that expand when exposed to microwave energy. Tool 620 includes a male or upper punch section 622 that forms the inner section or concave part of a container. Tool 620 additionally comprises a female section or lower cavity 624 which corresponds to the outside or convex part of a container. Both punch 622 and cavity 624 of tool 620 include joining elements 612. The connecting elements 612 are arranged in alignment with each other, such that when the tool 620 is closed to form the container, the connecting elements 612 in the upper punch section 622 align with the connecting elements 612 in the lower cavity section 624. Alternatively, the connecting elements 612 can be present only in the punching section 622 or in the cavity section 624 of the tool 620, and not in both sections. In yet another alternative, connecting elements 612 are used in the punching section 622 and in the cavity section 624, but they are not necessarily in alignment. The connecting elements 612 can be flush with the outer surface 628 of the punch 622 and with the outer surface 630 of the cavity 624, or the connecting elements 612 can be exposed in a slight protuberance to the outer surfaces 628 and 630 of the punch and the cavity , respectively. The arrangement of 612 connecting elements and the configuration of a tool

620 will depend on divesos • · · · ···· * ···· * ·· · ··· ·· · ·· ·· ····· ·. f aC Çxe è's. * t ai s .. tfoirto.

of the container and the shape, size, quantity, shape and arrangement of the insulating cells.

In one aspect, a container is formed of several layers of base material 600, such as those illustrated in FIG. 35. For this purpose, the layers are arranged between the upper punch 622 and the lower cavity

624. The 620 tool is then closed, thus forming the layers to obtain an insulating material having expandable cells. Simultaneously, the insulating material is formed in a 632 container.

In another aspect, a container is formed of a microwave insulating sheet having preformed expandable cells, such as those illustrated and described herein. The insulating material including the expandable cells is positioned between the upper punch 622 and the lower cavity 624. The tool is then closed, thus forming a container from the insulating material.

FIGS. 41-43 illustrate an exemplary container 632 that can be formed in accordance with the present invention. In the upper punch 622 and the lower cavity 624 of the tool 620, the joining elements 612 define a grid pattern for forming a closed cell pattern 634 on the plate 632. The cavity 624 is shaped to define the outer surface of the container 632 The punching section 622 is shaped to define the inner surface of the container 632.

FIG. 44 is an exetnpl® .dô * tuu ”Be * cíií3iôÃt.e * al» ternatívo

632 that can be formed according to the present invention.

In this example, the tool includes a generally square punch and cavity arrangement (not shown).

VII. Method of Packing a Food Item

According to another aspect of the present invention, a method and method for wrapping a food item in a glove of microwave insulating material is provided.

If desired, the wrapped food item can be

<td>additionally</td><td>wrapped in a top wrapping film</td>

<td>printed.</td><td></td>

<td>Making</td><td>now reference to FIG. 45, is found</td>

<td colspan="2">illustrated an exemplary process according to the</td>

present invention. A movable surface 700 includes one or more continuous belts 702 and 704 supported at each end by rollers 706. A first continuous roll of microwave insulating material 708 is unrolled on the surface 700 of the belt. Food items 710 are placed on the 708 web of the microwave insulating material. A second continuous roll of microwave insulating material 712 is unrolled on the food items 710 supported on the first continuous web of material 708. Thus, the insulating material is provided along the bottom and top surfaces of the food item 710. In one aspect, the two webs of material 708 and 712 have an approximately equal width that is less than the width of food item 710 (measured across the • 4 4 · »··· 4 4 4 14 · 9 4 9 9 949 D 4 9 4 4 9 4 4 444 9 4 9 direction of transport). This jfèí &amp; çâo * 'dimeíísi »ôr&gt; al» 5: «facilitates the formation of a glove 714 having two ends

Open M 716a and 716b, with a small portion of the ends 718a and 718b of food item 710 being on display. It is possible, however, to provide any frame sizes of microwave insulating material or other material. For example, it is possible to provide an arrangement for forming a bag with an open end, or for providing a bag fully capable of wrapping the bag.

food item.

Referring now to FIGS. 46 and 47, the wrapped food item 710 goes to an integrated thermal sealing and cutting station 720. The thermal sealing and cutting tool 722 comprises an external thermal sealing tool 724 and an internal blade 726 coaxially aligned with it. The thermal sealing device 724 and the cutting tool 726 are illustrated integrated with each other. However, the heat seal and cutout functions can be separated if desired. A plate 728 is provided to support the food item 710 during the actuation of the heat seal and cutout tool 722. The food items 710 are moved in increments on the flat plate 728 in such a way that the front edge 730 of the food item 710 is arranged adjacent to the heat seal tool and cut out 722 but not directly under it. As shown in FIG. 45, the material plots 708 and 712 are • · · · · · ···· · ·· · • · ·· ·· ····· · suspended between food items * ci^,® * s **^;7ÍO * â &lt;3ljaee^,nt'esí »

Referring now to FIG. 47, the thermal seal and cutout tool 722 is shown in the actuated position. When actuated, the heat sealing part 724 is pressed against the upper web of material 712, pushing it downwards against the lower web of material 708. The heat sealing tool 724 also exerts downward pressure on plate 728 . When in contact with the plate 728, the thermal sealing tool 724 is energized to create a seal 732, such as a thermo-mechanical connection, between the first web of insulating material 708 and the second web of insulating material 712. It is also possible to provide an amorphous or activable adhesive (not shown) in the region where the thermal sealing tool will create the seal between the wefts.

In an alternative configuration (not shown), the 728 plate can be replaced with a second heat seal tool. In such a configuration, the second thermal sealing tool may be arranged in opposition to the first thermal tool of the thermal sealing and cutting tool, in such a way that at the time of performance, the two thermal sealing tools work in concert to form a seal between the first and second wefts of insulating materials. In one aspect, the face of the heat sealing tool can be shaped to accommodate the heat seal, which will make direct contact with the second heat sealing tool. For example, the face of the second heat seal tool can be curved, notched, slit, or otherwise configured to accommodate the part of the blade that extends beyond the interface between the first and second heat seal tools. If desired, the blade can travel from the heat seal tool housing and cutout during operation.

Referring again to FIG. 46, when the heat seal and cutout tool 722 is in the upper position, the cutout part of tool 726 can be retracted into tool 722. In contrast, when tool 722 is actuated, blade 726 extends from tool 722. When blade 726 is pressed downwardly against joined webs 708 and 712, as shown in FIG. 47, a separation line 760 is formed between food items 710. Separation line 760 is located substantially along the center line of the thermally sealed area, such that the wrap around each food item remains intact.

It can be seen in FIG. 47 that a first food item 710a is located on the arrival part 734 of the plate 728 at the end of the first belt 730, and a second food item 710b is located on the exit part 736 of the plate 728 at the end of the second belt 704. Ο proceed to the first item •• 'âJíimehfeí ^ iZ · • 710a will locate the second food item

710b in the subsequent movement of belts 702 and 704. The front part 740 of wefts 708 and 712 on the second food item 710b was cut and subjected to heat sealing during the previous actuation of the heat sealing and cutting tool 722. thermal seal and cutout 722 in the current position, the front parts 742 of wefts 708 and 712 for the first food item 710a are subjected to. thermal seal, and the rear parts 744 of wefts 708 and 712 for the second food item 710b are subjected to thermal seal. When blade 726 separates wefts 708 and 712, the first food item 710a is fully processed with a glove 714 of microwave insulating material. If desired, food items 710 with sheets of microwave insulating material 714 can be sent along the second belt 704 to a wrapping station 746 (FIG. 45) for the provision of an upper sealing package formed with a printed film. FIGS. 48 and 49 illustrate a food item 710 with a glove 714 and an upper wrap 748.

VIII. Package with Reconfigurable Insulating Lid

According to yet another aspect of the present invention, illustrated in FIGS. 50-52, a package 800 is provided having an insulating lid 802 that can be folded under the package. The cover 802 includes a folding line 804 along the length of the / *0 * 6 tuna tongue

808 or other closure or sealing means along the side

Opposite method 810. The cover 802 has an internal surface 820 that can include an insulating material 832, with or without a susceptor layer, such as those described herein. The insulating material may include an oxygen barrier layer, cells of varying dimensions and / or variable expansion, cells partially expanded, or numerous other characteristics described or envisaged herein.

Before opening (FIG. 50), cover 802 covers tray 812 and the food item (not shown) contained therein, and tongue 808 can be attached in a removable seal to the front panel 822 of package 800. To close again the package 800 after it is opened, the tab 808 can fit into a corresponding slot 816 to hold the cover 802 in place. However, other means of securing the 808 tongue are contemplated here.

As shown in FIGS. 51 and 52, when food item 814 is ready to be heated, package 800 is opened, and lid 802 is folded under tray 802. Latch 808 fits into a second slot (not shown) or other frame located along the outside of the bottom surface 818. In this way, cover 802 forms an insulating layer between the bottom 818 of tray 812 and the floor or glass tray of a microwave oven (not shown). The additional insulation provided by cover 802 intensifies the cooking of the

W w -w ww w V w VV WVVVV V «food item 814 na 6andêga« * 8l »2 '» me'di'a&gt; i «€ ê ·· prevention of heat loss to the surrounding environment.

If desired, an additional insulating material 830 may be provided on one or more internal surfaces of the package to provide additional insulation between the food item and the bottom of the tray and the floor of the microwave oven. Spacers can also be provided along the surface of the lid to provide additional separation between the lid and the bottom of the tray in the folded position under it. Ventilation holes 824 can also be provided.

It will be readily understood by those skilled in the art that in view of the detailed description of the invention that has been made above, the present invention is amenable to wide utility and application. Many adaptations of the present invention other than those described herein, as well as many variations, modifications, and equivalent arrangements will be apparent from the present invention, or will be suggested by the same and its detailed description as given above, without departing from the substance or scope of the present invention.

Although the present invention is described here in detail with respect to specific aspects, it should be understood that this detailed description is merely illustrative and exemplary of the present invention and is given merely for the purpose of providing full disclosure and subject to practical use of the present invention. . The retired description * Líffdá »« * 'aqúi ·' «retired is not intended to be and should not be construed as constituting a limitation of the present invention or in any other way excluding any other configurations, adaptations, variations, modifications, and equivalent arrangements of the present invention . In this way, all directional references (for example, top, bottom, ascending, descending, left, right, left, right, top, bottom, up, down, vertical, horizontal, clockwise. And counterclockwise) are used for identification purposes only to assist the reader in understanding the present invention, and not to create limitations, particularly with regard to the position, orientation, or use of the invention. Coupling references (for example, coupled, fixed, connected, and the like) should be interpreted broadly and may include intermediate elements between a connection of elements and relative movement between elements. As such, these coupling references do not necessarily imply that two elements are directly connected and in a fixed relationship with each other. Accordingly, the present invention is limited only by the appended claims and their equivalences.