JP3305712B2 - Food packaging - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION

The present invention relates to a microwave package, and more particularly to a package suitable for popping popcorn in an electronic oven.

[0002]

BACKGROUND OF THE INVENTION

United States patents US Pat. Nos. 4,861,958 and 4,678,882 describe cardboard cup-shaped popcorn containers. Microwave interaction sensitive material is attached to the bottom of the cup as a separate disk or stacked, and the lid has a hole for removing moisture generated during popcorn production. . Although microwave interaction sensitizers are intended to help pop the corn, the amount of popcorn produced and the percentage of grains left without popping is not what is required. Did not. The user is particularly aware of the particles that do not pop, ie, "old maize (old maize)
maids) "are embarrassed if a significant number of them remain after popping. Therefore, the book is to improve the amount of popcorn produced by the general style package described in the above patent and the amount of particles that do not pop. One object of the invention.

[0003] US Pat. No. 4,586,649 describes a popcorn package whose bottom is conveniently sloped towards a small central panel. The carton is bound at the bottom and supported by a separate platform in the form of a collapsible tube. It resembles two pyramids with a truncated tip. Since the bottom of the carton is inclined, the cones come together to form a single piece. In addition, the support stand must be manually operated. This requires extra care for the user, and in the current context of the development of this technology, it is considered unsatisfactory because of the extra time, effort, and care required to provide a popcorn package. Can be In addition, many users have difficulty following the instructions. The package also lacks a layer of microwave interaction sensitive material,
Corn popping doesn't go any further. Finally, the distance between the package and the oven floor varies from location to location due to the slope of the bottom of the package.

It is also known to provide a foil pan with an inflatable cover for producing popcorn on a stove. This package is not suitable for use in an electronic oven because the metal foil pan acts as a shield. U.S. Patents 3,519,439, 3,782,976, 3,969,535 are examples.

[0005] US Pat. No. 4,584,202 describes yet another popcorn package. The package includes a carton with a top panel having a removable portion that is torn off the package just before the cone pops. The cone that did not pop is placed in another sachet that is pushed out of the carton through the upper hole as it expands. The package does not include a layer of microwave interaction sensitive material. Thus, the popping of the cone may be fairly slow or incomplete. Such containers are more expensive because they use a separate child bag inside. So far, the technology has evolved to the extent that the removal of the panel prior to popping the corn is flawed that some users will not be able to accept the product. During the development of the present invention, the following has been found. That is, when the package is opened, fingers can be burned with large bubbles of heated steam that collect under the flexible cover. A plan was made to allow steam to escape from the vents. However, the presence of the vents will allow moisture to enter the cone and reduce its repelling performance. Moisture can also enter to some extent without vents. It was found that the change in moisture of the corn due to the increase and decrease of the humidity from the atmosphere is a troublesome obstacle to the good popping performance, not only in the amount of popcorn completed but also in the number of grains remaining without popping.

[0006] Therefore, popcorn can be eaten directly and stacked one after another without the need for tweaks prior to use,
It is a primary object of the present invention to provide an improved microwave popcorn package with significant improvements in the amount of popcorn produced and the number of grains that remain unblown.

[0007] Yet another object of the present invention is to provide a safe hermetic seal for the cone so that the cone will pop off, and to find a way to remove the vapor without allowing moisture to enter the cone through the vent. It is.

[0008]

The food package of the present invention for achieving the above object is a package for use in microwave heating of food, wherein (a) a first and a second partitioned inside. A container structure defining a space, and the container structure is sufficiently transparent to the microwave to enable the food material suitably placed therein to be heated by the microwave; (i) the container The structure has an upright side wall having an upper end and a lower end, and the upper end forms an upper opening of the container structure; (ii) the first partitioned space has a bottom wall; (2) the partitioned space has a vent communicating with the outside for releasing steam in response to the heating of the food in the container structure, and (b) storing the food material prior to the heating. Forming the first partitioned space Moisture blocking means for preventing the transmission of moisture between the inside and outside of the first partitioned space during storage; and (c) forming at least a part of the moisture blocking means, When the food held in the first partitioned space is provided between the partitioned space and the second partitioned space and is heated by being exposed to microwave energy, the ventilation is performed. A heat-releasable seal is provided for communicating the first partitioned space and the second partitioned space so as to allow moisture to escape to the outside through a mouth.

A food package according to another aspect of the present invention for achieving the above object is an inflatable package for popping popcorn in a microwave oven, comprising: (a) an upper opening; A container body having at least an upstanding side wall extending to a portion thereof, and a rigid body at least so as to be self-supporting; (b) a peripheral portion lined with the side wall and connected to the container body; and a center for horizontally covering popcorn before popping. A flexible cover having a portion and a flexible cover,
The heated steam generated by popping the corn separates the central portion within the container body and turns up from the side wall of the container body to accommodate the popped corn while the flexible cover flips up from the container body. (C) a second container disposed within the container body under the cover and forming a sealed space for accommodating the popcorn therein at least during storage. Is provided.

[0010] The foregoing objects, as well as other more specific specific objects, of the present invention will become better understood with reference to the following detailed description and drawings. In the detailed description and drawings, several examples of various embodiments of the invention are set forth within the scope of the appended claims.

[0011]

【Example】

This embodiment provides a package for making popcorn in an electronic oven. The main components are:
A wide open top container in the shape of a tub or bowl, made of a sheet-like material that is non-tipping, preferably rigid, microwave transparent, such as paper or cardboard. The tub includes a side wall that rises to an edge that forms a wide mouth at the top. The side walls are sloped outward so that multiple packages can be stacked on top of each other when transported or stored. The side walls have a lower end that rides on the floor of the electronic oven while popcorn is being made.

The tub also includes a flat bottom wall. Above the bottom wall is a first partitioned space containing unfluffed cones and vegetable oil or shortenings (such as lard, butter, etc.) if desired. The bottom wall is connected to the side wall at a point at a certain distance upward from the lower end of the side wall. This is for setting a second partitioned space having a uniform height space between the bottom wall of the package and the floor of the electronic oven in the package. A layer of microwave interaction sensitive material (hereinafter also referred to as a sensitive layer) is provided on the bottom wall. And
The entire sensitive layer is positioned at a constant distance from the bottom of the electronic oven to help generate popcorn. The uniform height of the space between the sensitive layer and the oven floor promotes efficient transfer of microwave energy to the cone through the sensitive layer to increase the popping power of the cone.

[0013] The lower end of the side wall of the tub is not cut so that it can be engaged with the oven floor and sealed to keep the air in the partitioned space under the package. As a result, the space between the sensitive layer and the oven floor is heated above the temperature of the oven air surrounding the package. This helps transfer microwave energy to the sensitive layer. The unbent cone in the upper partitioned space has a heat conducting relationship with the sensitive layer. Sealed over the tub with a flexible cover, which bulges upward as the grains pop.

The sensitive layer may be comprised of various materials that interact with microwaves, such as a thin metal layer, such as deposited metals, metal oxides, carbon, and the like, as are known in the art. Is also good. The sensitive layer may be attached directly to the bottom wall of the tub, or may be supported by paper or plastic that adheres to the bottom wall. A practically suitable sensitive layer is a thin layer of plastic or paper having a layer that has been dried by applying a liquid that interacts with the microwave. This layer comprises a microwave interacting component, such as a worm-like formation or substrate,
The microwave includes carbon particles bonded to transparent non-conductive attenuating particles. The sensitive layer may also comprise a non-peeling coating applied to the bottom wall. The coating comprises microwave interacting particles held within a storage binder or substrate, which storage binder or substrate holds the particles together,
The coating of the sensitive layer is bonded to the surface of the bottom wall. Such coatings are disclosed in U.S. Pat.
0, 4,190,757, and US Patent Application No. 456,159, filed December 22, 1989, or US Patent Application No. 261,380, filed October 24, 1988.

In another version of this embodiment, the cone is held in a sealed partition, ie, a hermetically sealed partition, and the venting means is separated from the partition by a releasable seal. It is provided in a partitioned space. In a preferred package, the cones are in a dish or tray that borders or forms a bottom wall with the bottom of the tub. The cover is a flexible, thin plastic that is cheaply attached to the edge of the dish. During heating, the seal breaks off and the flexible cover bulges upward. A circular lid may be placed on the plate below the cover.

Hereinafter, embodiments will be described in detail. As shown in each figure, package 10 comprises a tray or trough-shaped container having upstanding side walls 12 and bottom wall 16. 12
And 16 are both made of a rigid or semi-flexible material such as paper or cardboard. The side walls 12 are circular in this case, but other shapes are possible. As shown in FIGS. 1 and 2, the upper edge of the tub is bent outward at the edge 14 to secure a reinforcing lip that creates a circular wide mouth on the side wall 12. The circular bottom wall 16 is separated upward from the oven floor 18 by the collar 20. The bottom wall 16 is bonded to the side wall 12 above the lower end 21. The bottom wall 16 can be made of a rigid or flexible material such as cardboard or paper. As shown in the figure,
The outer edge is bent downward and adhered to the side wall 12. Above bottom wall 16 is a first partitioned space within the package. This partitioned space contains the contents 24 of corn mixed with cooking oil or other lard, butter, etc., as desired.

The cover 12 ′ is made of a circular microwave flexible transparent material with a fold 26 at the end (FIG. 3), which is glued to the rim 14 with an adhesive. The cover 12 'has a peripheral portion 28 that conforms to the inner surface of the side wall 12, and a central portion 30 that is positioned relative to the upper surface of the portion filled with non-popped corn and shortening contents 24. Pop 1 cover
2 'bulges to a point approximately at the top of the rim 14, or slightly higher. The size of the tub and the amount of popcorn contents 24 are balanced so that the popped corn almost fills or slightly exceeds the capacity of the tub. All that is required for the popcorn to be eaten is to simply tear off the cover 12 'from the edge 14 of the side wall 12. The pail functions as a dish or bowl into which popcorn can be eaten directly.

The tub side walls 12 are sloped outward so that the packages can be stacked on one another during transportation or storage.

A layer 22 of a suitable microwave interaction sensitive material (hereinafter “sensitive layer 22”) is adhered to the bottom wall 16 of the tub and is located at the center, but is folded down to the lower end of the side wall 12. It is not glued to the glued part. It can be seen that the bottom wall 16 and the sensitive layer 22 are both horizontal during use and parallel to the oven floor 18. In addition, the space between the bottom wall 16 and the lower end 21 of the side wall 12 is formed in the package below the bottom wall 16 so that a space is formed between the bottom wall 16 and the oven floor 18. You can also see the lower partition.
The space created by this partition is approximately the same height during pop. As a result, the sensitive layer 22 connected to the bottom wall is
The space G places the whole in a position that is substantially unchanged from the oven floor 18.

The lower end 21 of the side wall 12 is not cut so as to fit into the oven floor. As a result, the air in the lower partition is kept under the bottom wall 16 within the side wall 12. The air in the lower partition is heated above the air temperature in the oven during cooking. Since the height of the space G is unchanged, a heated air layer which acts as a height-invariant dielectric layer is provided throughout the lower portion of the sensitive layer 22 throughout cooking. It has been found that the dielectric constant of a material affects the distribution of microwave energy to the material. When the air in the space G is heated, its dielectric constant changes first as a result of the expansion due to heating and the reduced moisture in the heated air. Uniformity of the heated air layer in the space G (this uniformity serves to reduce the dielectric constant as the air is heated)
Will reliably transfer the maximum microwave energy to the sensitive layer 22.

As microwave energy reflects off the surface, an energy peak or node occurs at a predetermined distance from the surface. For example, there is an energy peak or node at a predetermined distance from the oven wall that partially or completely reflects microwave energy.

In one form of the invention, the bottom wall 16 and the sensitive layer 22 are
On the lower end 21 of the car at the technically necessary distance. This distance is determined in relation to the electrical properties of the microwave energy. For example, in this manner, when the oven has a wavelength of 12 cm (typical wavelength for almost all ovens), the space G is set to be about 1 cm to 1.5 cm, preferably about 1.25 cm. That is, the space G is about 1/8 of the microwave energy supplied to the oven.
Wavelength. In this manner, substantially the entirety of the sensitive layer 22 has a constant space G between itself and the oven floor 18;
That is, it has a space of about 1/8 of the microwave energy wavelength supplied to the oven. With respect to the microwave energy reflecting upwards towards the sensitive layer 22,
There is an energy augmentation zone or node, which is in the same space as the location of the sensitive layer 22, and which effectively transfers microwave energy to the popcorn.

The efficiency of the present invention is shown in the following comparative examples. In each case, the tub was made of food grade cardboard. The cover was made of a thin polyester that was glued to the edge of the tub.
The tubs each contained 56 grams of fresh corn and 23.5 grams of vegetable oil. In each case, popping was performed in a 700 watt Litton electronic oven for 2 minutes and 35 seconds.

Example 1-The present invention This example, as shown in the figures, illustrates the results achieved by the present invention. Bottom wall 16 and sensitive layer 22
It was placed about 7/16 inch (1.25 cm) above the lower end 21 of the wall side 12 so that a space 1.25 cm of 1.25 cm was formed between the oven floor 18 and the oven floor 18. The oven wavelength was 12 cm. The results obtained in all examples are shown in Table 1 below. Comparative Example 2 A package similar to that of Example 1 was prepared except that the portion of the side wall 12 extending below the bottom wall 16 was removed so that the bottom surface and the sensitive layer rest on the oven floor. COMPARATIVE EXAMPLE 3 The portion of the side wall 12 below the bottom wall 16 was cut away leaving four separately separated portions, and these four portions serve as legs for supporting the sensitive layer 22 at the same distance from the oven floor as in Example 1. A package similar to Example 1 was prepared, except that it allowed the air to circulate freely under the sensitive layer while functioning. Comparative Example 4 The same package as in Example 1 was prepared except that no sensitive layer was provided. The following table shows the results.

[0025]

As can be seen in the table, the amount of popcorn resulting from the present invention is 2100 ml, ie 150 ml more than in Examples 3 and 4,
200 ml more than in Example 2. This improvement will provide consumers with a larger volume of popcorn than ever before. Even more importantly, only a few particles can be repelled by the present invention.
1.9%. Compared with Example 1, in Examples 2, 3 and 4, the percentage of non-repellent grains was much higher, 13.3%, 7.2%,
8.6%. In other words, in Example 3, the number of unremoved grains is about 370% more than in the present invention, and in Reference 4, about 450% more than in the present invention.

In Example 1, the air in the compartment below the sensitive layer was heated to 198.4 ° C. after being heated for 2 minutes and 35 seconds. When the sensitive layer was not used, the air in the partition reached 128.7 ° C. During that time, the air inside the oven outside the package can be
9.5 ° C was reached. This indicates that the air in the compartment below the sensitive layer is about 195 ° C. higher than the air in the oven, about 70 ° C. higher than can be achieved with a similar package without the sensitive layer. This changes the dielectric constant of the air passing through the uniform height air between the sensitive layer and the oven floor. This uniform space helps the efficient transfer of microwave energy to the sensitive layer and cone.

Note that the package does not need to be manipulated at all prior to cooking. It also makes popcorn easy to eat directly. That is, an edible container is provided without having to be transferred to another container. In addition, cooking performance, as judged by the amount of popped grains and the reduction in the number of unpopulated grains, has been significantly improved.

Turning now to FIG. 5, which illustrates a variation of the present invention. Here, parts corresponding to parts already described are denoted by the same reference numerals. As shown, the package, generally designated 40, includes circular sidewalls 12. This side wall 12
Has a tapered shape with a wide open mouth as in the previous embodiment. The top edge of the flexible cover 12 'is 43'
It can be seen that this is the first seal of the cover 12 'which is glued to the upper edge of the side wall 12. Package 40 also
It has a bottom wall 16 and further includes a downwardly bent collar 20 surrounding the bottom wall 16. The collar 20 is adhered to the lower end 21 of the side wall 12 to create a space G between the oven floor 18 and the bottom wall 16 of the package, thereby setting an air chamber of a uniform height. In this case, a dish 42 containing food, for example, a cone, is prepared in the package 40 with its lower surface resting on the bottom wall 16. The dish 42 may be made of any free-standing microwave transparent material, such as paper, cardboard or plastic. In one style shown, dish 42
Consists of a pair of inner and outer paper or cardboard layers 44,46. The outer paper layer 46 in this case is a 282 pound cardboard layer per series, while the inner paper layer 44 is 21 pound per series wax paper. Between the two layers (44 and 46) is a layer 48 of microwave interaction sensitive material (hereinafter "sensitive layer 48"), which in this case is a 0.48 mil metal coated thin polyester or the like. Made of thin plastic. The polyester is semiconducting and is adapted to absorb microwave energy and heat the contents (cones) designated by reference numeral 50.
Sensitive layer 48 may comprise any of the microwave interaction sensitizers described above or generally known to those skilled in the art. The appropriate sensitive layer is 2m
It consists of a semiconductive aluminum layer deposited by vacuum electrodeposition on one surface of a thin polyester polyester. The layers 44,46,48 forming the dish are made of a polyvinyl acetate milky adhesive such as Franklin International, Inc. of Colu, Columbus, Ohio.
mura, Ohio).

It can be seen that the dish 42 includes a side wall 52 that tapers outwardly of a bottom wall 53 and a horizontal circular edge 54.
In one preferred mode of the invention, only the bottom wall 53 and the rim 54 are provided with a microwave absorbing sensitizer, and the side walls 52 are coated with a microwave interaction sensitizer, such as, for example, metal. , The microwave interaction sensitive material is no longer present.

Between the lip 54 and the central portion 30 of the flexible cover 12 ′ is a second seal, in this case an annular heat releasable seal 56.
The adhesive seal 56 may be any thermoplastic adhesive that softens at high temperatures. A suitable adhesive is 3M from St. Paul, Minnesota that activates at high heat, meaning it melts in heat
Is an adhesive called Scotch Pack # 122 manufactured by The 3M Company of St, Paul, Minesota. The adhesive activates at about 225 ° F to 375 ° F.
It can also be seen that the seal 56 has been applied all around the mouth of the dish 42, i. Thus, the heat releasable seal 56 is a hermetic seal because the space containing the corn reduces the transfer of moisture to and from the popcorn 50. As a result, it has been found that the quality is maintained even after a considerably long storage.

The upper flexible cover 12 ′ of the dish 42 has an empty, in this case folded, partition space 51 (between the side wall 12 and the cover 12 ′) with a lot of 1/16 inch diameter vents 60. Is provided. Since the ventilation port 60 is located in the partition space 51 above the seal 56, the ventilation port 60 does not become a passage for entering and exiting the dish 42 in which moisture is sealed.

To use the package of FIG. 5, the package is placed in an electronic oven and exposed directly to microwave energy. Thereby, the cone 50 is heated and bursts. Additional heat is applied by the sensitive layer 48 of the dish 42 to facilitate cooking of the corn. The bottom of the dish 42 is typically heated from 300 ° F to 450 ° F by the sensitive layer 48. In addition, the responsive layer 48 in the rim 54 heats the heat releasable adhesive of the seal 56 so that during heating, as water vapor expands in the package, the cover 12 'lifts.

It should be noted that when the seal 56 is broken, the released matter easily exits the vent 60. However, prior to this, a hermetic seal 56 between the cover 28 and the perimeter of the cone containing the dish 42 prevents moisture from entering and exiting the popcorn 50 to ensure good cooking. In addition, the control of the package's vapor emissions by the vents 60 dissipates vapor bubbles that may occur within the package and cause the fingers to burn when the package is opened. Also, since the popcorn contents 50 are located between the central portion 30 of the cover 12 'and the plate 42, the side wall 12 of the tub need not be a steam barrier. Thus, the tub can be made of less expensive material.

Turning now to FIG. The package of FIG. 6 is generally similar to FIG. 5 except that the bottom wall 16 has been removed by applying a downward collar 64 to the outer edge of the rim 54. In FIG. 6, the dishes are indicated by 43. Furthermore, a circular lid 66 made of a suitable barrier material such as a plastic flake, for example, a polyester flake coated with polyvinyl adenine, is covered by a heat-releasable seal made of a suitable thermoplastic adhesive. Adhered to edge 54. To reduce the ingress and egress of water vapor into the popcorn contents 50, the lid 66 can be made of any other plastic known for its low moisture and water vapor transmission rates. However, a less expensive plastic that does not need to have vapor barrier properties can be used for the cover 12 '. Flexible cover, not necessary
12 'is desirably adhered to the edge or other portion of the lid 66, for example, by an adhesive 67.

The package of FIG. 6 behaves the same as described in FIG. When microwave energy heats the package and the pressure rises in the room containing the popcorn,
The seal 56 breaks and the expansion of the heated air and vapor in the package causes the cover 12 'to lift upward. As the cover 12 'lifts in response to the popping cone expansion, water vapor exits the vent 60. However, before the corn pops, the popcorn 50 in the dish 43 is sealed to ensure good quality cooking.

Although the embodiment of FIG. 5 requires some more material than the embodiment of FIG. 6, it can be more easily assembled from a pre-made tub and the bottom wall 16 It is somewhat harder than usual to be. However, the embodiment of FIG. 6 requires less constituent materials and is therefore less expensive.

It will be apparent to those skilled in the art that various modifications can be made in the present invention within the scope of the appended claims if the principle described herein is understood. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of the present invention with one portion cut away.

FIG. 2 is a vertical sectional view of a part of a side wall and a bottom wall of the package.

FIG. 3 is a vertical sectional view of a central portion of the package shown in FIG. 1;

FIG. 4 is an enlarged vertical sectional view of a part of the central part of the package.

FIG. 5 is an alternative vertical cross-sectional view of the present invention.

FIG. 6 is a partial vertical cross-sectional view of another aspect of the present invention.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Watkins, James Dee. 55373 Praia Lake, Mushtown Road, Minnesota, USA 18591 (72) Inventor Brandberg, Lawrence Sea. 55427, Minnesota, USA Crystal, 36T Avenue North 7710 (72) Inventor Watkins, Jeffrey T. 55104, Minnesota, United States Estee. Paul, Charles Avenue 1039 (72) Inventor Hanson, Dennis E. Minnesota, USA 55330 Elk River, Lander Street, Northwest 19824 (72) Inventor Tarpin, Charles H. Minnesota, USA 55410 Minneapolis, Queen Avenue South 4932 (56) References JP-A-1-199881 (JP, A) JP-A-2-152679 (JP, A) JP-A 60-179668 (JP, U) JP-A 62-139294 (JP, U) JP-A 63 -156978 (JP, U) JP-A-1-134081 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65D 81/00 A23L 1/00

Claims (20)

(57) [Claims] 1. A package for microwave heating of food, comprising: (a) a container structure forming first and second partitioned spaces therein; and the container structure has therein: (I) the container structure is upright with side walls having an upper end and a lower end; The upper end forms an upper opening of the container structure; (ii) the first partitioned space has a bottom wall, and the second partitioned space heats food in the container structure. And (b) forming said first partitioned space to store food material prior to heating, during storage, Humidity between the inside and the outside of the first partitioned space (C) forming at least a part of the moisture blocking means, provided between the first partitioned space and the second partitioned space, and When the food held in the first partitioned space is heated by being exposed to microwave energy, the first partitioned space and the second partitioned space are configured to release moisture to the outside through the vent. 2. A food package comprising: a heat-releasable seal that communicates with the partitioned space of (2). 2. The food package according to claim 1, further comprising a food material disposed in the first partitioned space, wherein the food material includes popcorn before popping. 3. A microwave interaction responsive material disposed in heat transfer relationship with said first partitioned space and exposed to microwaves for heating. Food package. 4. The (a) first partitioned space comprises: (i) a dish-shaped sheet made of a package material; and (ii) a seal formed on the dish-shaped sheet. The food package of claim 3, further comprising a cover that closes, wherein the heat releasable seal has a portion that seals the cover to the dish-shaped sheet. 5. The method according to claim 1, wherein the cover is a first side and a second side.
(B) a first side of the cover is sealed to the dish-shaped sheet by the heat-releasable seal; and (c) a second side of the cover is the second partition. The food package according to claim 4, wherein the package is sealed in a part of the space provided. 6. The cover comprises a flexible material, the flexible material comprising: (i) a top opening of the container structure; and (ii) a food product in the first partitioned space. (Iii) including a central portion that is sealed to the dish-shaped sheet so as to close the dish-shaped sheet so that the second partitioned space can expand as the material expands. The food package according to claim 4, wherein 7. The first partitioned space includes: (i) a sheet made of a package material having a bottom and an upper edge; and (ii) a sheet sealed to the upper edge of the sheet. (B) at least a part of the heat-releasable seal seals the cover to the sheet; (c) the package comprises: (i) a bottom portion of the sheet; A microwave interaction responsive material that is exposed to and heated by the microwave, the microwave interaction sensitive material being arranged to have a heat transfer relationship; The package for food according to claim 1, further comprising a microwave interaction responsive material that is heated by being exposed to the air. 8. The flexible sheet is provided so that the second partitioned space can be expanded by expansion of food material inside the first partitioned space. The food package according to claim 7, wherein the package covers a space. 9. The apparatus according to claim 1, further comprising exhaust means for discharging heated air or steam from said second partitioned space when said package is exposed to microwave energy. Food package as described. 10. The container according to claim 9, wherein said exhaust means comprises at least one vent in a part of said container structure between said heat-releasable seal and said upper opening of said container structure. Food package as described. 11. The container structure according to claim 2, wherein said second partitioned space is expandable with expansion of a food material in said first partitioned space. The food package according to claim 1, further comprising a flexible sheet including a space. 12. The food according to claim 1, wherein the bottom wall of the first partitioned space is arranged with a predetermined space upward from a lower end of the side wall. package. 13. An inflatable package for popping popcorn in a microwave oven, comprising: (a) a container body having upstanding side walls extending to an upper opening and at least as self-supporting as possible. (B) a flexible cover having a peripheral portion lined with the side wall and connected to the container body, and a central portion for covering the popcorn before popping in a horizontal direction;
The heated steam generated by popping the corn separates the central portion within the container body and turns up from the side wall of the container body to accommodate the popped corn while the flexible cover flips up from the container body. (C) a second container disposed within the container body under the cover and forming a sealed space for accommodating the popcorn therein at least during storage. A food package comprising: 14. The second container typically holds popcorn therein and has a heated release as a temporary seal to allow the container to open when heated in a microwave oven. The second container is opened by being separated from the cover at the temporary seal by the heat generated in the microwave oven, and the cover is flipped up in the container body to open popcorn. 14. The food package according to claim 13, wherein the food package can enter a space formed under the cover. 15. The food package according to claim 14, wherein the second container has a lid member coupled to the cover. 16. The food package according to claim 14, wherein the heat-releasing seal is a peripheral seal along an outer periphery of an end portion of the second container. 17. The microwave absorbing and heating microwaves arranged in heat transfer relationship with the popcorn in the package and for heating the popcorn to promote popping of the popcorn when exposed to microwave energy. 14. The food package according to claim 13, further comprising a microwave interaction sensitive material. 18. The microwave interaction responsive material has a horizontal central bottom and an upstanding peripheral side wall extending from the central bottom, and is disposed inside the second container so as to surround the popcorn before popping. 18. The food package according to claim 17, wherein: 19. The food package according to claim 13, wherein the second container has a dish shape. 20. The food package according to claim 13, wherein the second container is connected to the container body.