US20090175563A1

US20090175563A1 - Microwaveable steam pouch

Info

Publication number: US20090175563A1
Application number: US12/006,534
Authority: US
Inventors: Rodney M. Weaver
Original assignee: Sonoco Development Inc
Current assignee: Sonoco Development Inc
Priority date: 2008-01-03
Filing date: 2008-01-03
Publication date: 2009-07-09
Also published as: CA2648380A1

Abstract

A flexible pouch is provided having sidewalls sealed to form a internal pouch volume. A bottom wall is sealed to the sidewalls to form a bottom gusset and to create a stand-up pouch. A support wall is attached to the sidewalls, between the bottom gusset and the top end of the pouch. The support wall divides the interior of the pouch into a food compartment, adjacent the top end, and a liquid compartment, formed between the support wall and the bottom gusset. The food is positioned on the support wall and liquid is provided in the liquid compartment. The pouch is positioned within a microwave oven and the liquid in the liquid compartment is heated, creating steam, which flows through the porous support wall to heat the food supported thereon.

Description

FIELD OF THE INVENTION

The present invention relates to a pouch or the like for cooking or heating food within a microwave oven.

BACKGROUND

Contemporary consumers have created demand for products which prepare fresh or fresh-like food items. Also, there is a preference for preparing cooked food items in a short amount of time. One method of accelerated cooking is to use a microwave oven. Other cooking options including boiling, frying, baking, grilling and steaming.
One of the healthiest cooking options for many food items, and in particular fresh vegetables, is steam cooking. This method typically results in the maintenance of the highest level of nutrients within the cooked food. To steam food items, a consumer must typically use a vegetable steamer appliance or a cooking pot with a steamer insert therein. These items often require extending cooking times and leave several dishes to clean.
It is known to use flexible packaging for cooking and heating food within a microwave oven. For example, US 2007/0029314 to Rodgers et al. describes a microwavable bag having a steam source provided by an absorbent material having a liquid stored therein. The absorbent material is separated from a food compartment within the bag by a porous wall. When the bag is heated in a microwave oven, the liquid in the absorbent material vaporizes and moves into the food compartment via the holes in the porous wall. During heating, the absorbent material is positioned above the food in a separate compartment.
U.S. Pat. No. 4,596,713 to Burdette describes a gusseted microwavable bag having a cavity for storing food to be cooked and an interior package disposed within the cavity. The interior package contains a liquid to be mixed with the food. When the wall of the interior package reaches a predetermined temperature, it tears open and allows the additive to flow over the food.
U.S. Pat. No. 6,637,939 to Huffer describes a vented bag for microwave cooking of foods. The bag has a resealable opening for extracting food from the bag after cooking. A vent is provided within the sealing portion of the bag to exhaust steam created by the heating of the food.
In addition to the above, it is known to provide a vessel for use within a microwave oven for steam cooking of food. U.S. Pat. No. 4,481,392 to Nibbe et al. describes an enclosed rigid vessel having a microwave impermeable chamber located therein. Water is provided in the bottom of the rigid vessel and the chamber is positioned above the surface of the water. The chamber creates a radiation shield positioned over the food and therefore prevents the direct cooking of food by microwave energy. The microwave energy heats the water within the vessel to create steam which moves upwardly into the chamber through holes in the food support surface on the bottom of the chamber.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a flexible pouch having a front and rear panel or sidewalls which are sealed to one another along at least one edge to form an internal pouch volume. A bottom panel is sealed to the sidewalls and forms a bottom gusset. The bottom gusset and the sidewalls in cooperation with one another form a stand-up pouch. The bottom gusset creates the supporting surface for the pouch, with the sidewalls extending vertically upward from the bottom gusset. A support wall is attached internally to the sidewalls, between the bottom gusset and the top end of the pouch. The support wall divides the internal volume of the pouch into a liquid compartment positioned adjacent the bottom gusset and a food storage compartment positioned above the support wall. The support wall is preferably perforated and may have a V-shape for easy collapse when the pouch is not in use. A sealing means may be formed at the top end of the pouch for sealing the food therein and/or for controlled release of the steam created within the pouch during use.
In operation, the flexible pouch is formed and a liquid is placed within the liquid compartment. Preferably, the liquid is water, but other liquids, including sauces and flavorings, may be used. Food is provided on the perforated wall within the food compartment. The pouch is placed in the microwave oven with the gusset panel resting on a support surface, with the liquid in the liquid compartment positioned on the gusset panel, and with the food positioned on the perforated wall in the food compartment. Upon activating the microwave oven, the liquid within the pouch is heated to create steam, which flows into the food compartment, through the perforated wall and heats the food within the pouch. Upon completion of the heating or cooking process, the pouch can be opened and the food removed for serving.
It is contemplated that the pouch of the present invention may be separately provided from the food. Thus, the pouch may be purchased by the consumer and used with the food items of choice. Alternatively, the pouch may serve as the packaging for the food during shipment.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 shows an embodiment of the present invention in the form of stand-up pouch having a liquid provided in the bottom portion thereof.

FIG. 2 shows a side view of the embodiment shown in FIG. 1 with steam generated from the liquid in the bottom of the pouch and food provided in the food compartment.

FIG. 3 shows the embodiment of the present invention positioned within a microwave oven.

DETAILED DESCRIPTION OF THE DRAWINGS

In the drawings there is shown an embodiment of the present invention, with like numerals identifying like elements. In FIG. 1, there is shown a flexible pouch, which is generally designated by the numeral 10. The pouch or package 10, as illustrated, comprises a front wall 12 and rear wall 14 (FIG. 2) which are sealed to one another along side seams 16 and 18. A bottom panel 20 is formed between the sidewalls or panels 12, 14 and forms a gusset. The formation of the gusset between the sidewalls 12, 14 creates a stand-up pouch. The top end 22 of the pouch 10 includes an opening 24 which is resealable by a sealing means 26. The sealing means 26 may take any form as desired and is preferably selectably closeable in order to provide access to or seal the internal volume of the pouch 10. The sealing means 26 illustrated is formed in the manner disclosed in U.S. Pat. No. 6,637,939 to Huffer, which is commonly assigned with the present invention. This patent is herein incorporated by reference.
A perforated web 28 is provided within the interior of the pouch 10, between the top end 22 and the bottom wall 20. The web 28 is sealed to the side panels 12, 14 and/or the side seams 16, 18. As can be seen in FIG. 2, the web 28 has a generally V-shaped profile with the vertex pointing downwardly towards the bottom wall 20. It is contemplated that the web 28 will be substantially the same size as or slightly smaller than the bottom wall 20. Preferably the cross sectional area of the pouch at the position of the web 28 is less than that of the bottom gusset. Thus, the gusset will form a stable support for the pouch 10 in normal use.
In use, food is positioned on the web 28 in the upper portion of the interior of the pouch 10. This upper pouch portion serves as a food retaining compartment 30. A liquid is provided within the pouch and settles to the bottom, adjacent the bottom wall 20. The liquid is retained in a liquid retaining portion or compartment 32. The perforated web 28 forms a hammock between the two chambers 30 and 32 with the perforations in the web permitting the passage of steam and/or liquid there between. When the pouch 10 is positioned upright, the food in the food compartment 30 is separated from the liquid in the liquid compartment 32. As illustrated in FIG. 2, steam from the heated liquid rises through the perforated web 28 and across the food compartment 30. Steam is vented from the opening 24 in the top end 22 of the pouch 10 or its release is controlled by the sealing means 26.
As illustrated in FIG. 3, a microwave oven 34 includes a cooking chamber 36 with a support surface 38 therein. The flexible pouch 10 is filled with food in the food compartment 30 and with liquid, such as water, in the liquid compartment 32 at the bottom of the pouch. The microwave oven 34 is operated to heat the liquid, creating steam, which rises and heats the food in the food compartment 30. Excess steam can be vented through the top end 22 of the pouch, as illustrated in FIG. 2. The flexible pouch 10 is positioned on the support surface 38 and, because the pouch is a stand-up type pouch, is positioned upright on the bottom gusset 20.
Preferably, the pouch is formed from a laminate having, for example, an oriented polyethylene teraphalate (oriented PET) in the range of 48 to 92 gauge. A sealant layer is laminated to the outer web and is preferably cast polypropylene. The sealant layer is positioned on the inside surface of the sidewalls/ panels 12, 14. It is preferred that the outer web be relatively stiff in order to support the pouch during heating of the liquid. Also, cast polypropylene is preferred for the inside sealant layer, since it will more readily withstand the heat generated by the steam (and boiling water) within the pouch. Because the polypropylene sealant layer is positioned on the inside, the sidewalls 12,14 can be sealed to each other. Alternatively, the sidewalls of the pouch may be formed by a single web and a single seal be used. It is preferred that the laminate be formed using an adhesive, rather than being a mono web formed without an adhesive. The thickness of the sealant layer preferably falls between two to four mils. Again, added thickness of the material will help the pouch stand up during heating.
The perforated wall is preferably a 2 to 3 mil cast polypropylene film, which can be sealed to the sealant layer within the pouch laminate. The perforated wall is preferably compatible with the sealant layer within the laminate. The perforated wall may be sealed to the inside surface of the sidewalls of the pouch or may be separately sealed into the side seams. Alternative materials for the perforated web include a netting or other porous materials. It is contemplated that a cloth or woven fabric material may be sealed within the flexible pouch interior to form a food support.
Marketing of the present invention may include the separate division of food and pouches. The pouch may be stored in a box or the like in quantity, with each individual pouch removed for use when desired. Thus, fresh food can be placed into the pouch, and liquid supplied separately. Alternatively, the food may be shipped within the pouch with the liquid or the liquid may be added at cooking time. It may also be possible to provide the food in a fresh or frozen state. Medium density polyethylene and/or high density polyethylene may be used as part of the laminate if the food is shipped within the pouch, with cast propylene being used for the outside layer.
It is preferred that a barrier layer not be provided, since the application of microwave energy may cause undesirable emissions and/or prevent full application of the microwave energy to the liquid retained in the bottom of the pouch. Standard dimensions for a stand-up pouch to provide stability are contemplated. Preferably, the pouch is formed so that it does not significantly buckle during application of microwave energy or as a result of the heat generated by the liquid.
A variety of other modifications to the structure is particularly illustrated and described above will be apparent to those skilled in the art upon reviewing the disclosure provided herein. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.

Claims

1. A flexible pouch comprising:

a front and rear panel sealed to one another along at least one edge thereof to form an internal pouch volume and an open top end;

a bottom panel sealed to the front an rear panels and forming a bottom gusset, the bottom gusset and front and rear panels forming a stand-up pouch, with the bottom gusset supporting the front and rear panels vertically when the pouch is standing,

a support wall attached to the front and rear panels between the open top end and the bottom gusset, the support wall forming the internal volume of the pouch into a food compartment adjacent the open top end and a liquid compartment formed between the bottom wall and the support wall.

2. The flexible pouch of claim 1, wherein the support wall comprises a perforated web.

3. The flexible pouch of claim 2, wherein the perforated web has a V-shape with the vertex thereof pointing toward the bottom panel.

4. The flexible pouch of claim 1, wherein the support wall is sealed to the inside surfaces of the front and rear panels.

5. The flexible pouch of claim 1, where in the support wall is a substantially porous web.

6. The flexible pouch of claim 1, where in the support wall is made from a cast polypropylene.

7. The flexible pouch of claim 1 further comprising sealing means formed at the top end for selective access to the food compartment.

8. The flexible pouch of claim 1 further comprising a steam vent for controlled discharge of steam during heating of liquid within the liquid compartment to steam cook food supported on the support wall in the food compartment.

9. The flexible packaging of claim 1 wherein the front and rear walls are formed of a laminate material comprising an oriented polyethylene teraphalate outer web and a cast polypropylene sealant web.

10. A package for storing food and cooking the food in a microwave oven, the pouch comprising:

a flexible laminate formed into a pouch having a series of side walls formed around a hollow interior and defining a top and bottom,

a gusset panel sealed to the side walls and closing the bottom of the hollow interior, the gusset panel in conjunction with the sidewalls forming a stand-up pouch,

a flexible perforated wall sealed to the side walls of the pouch within the hollow interior, between the bottom gusset and the top end, the perforated wall separating the hollow interior into a food compartment positioned above a liquid compartment formed adjacent the gusset panel,

a food access opening formed at the top of the sidewalls, the opening defining access to the food compartment, the opening being selectively closable, and

a steam vent for controlled discharge of steam during heating of liquid within the liquid compartment to steam food supported on the perforated wall in the food compartment.

11. A method of cooking food, comprising:

providing a flexible pouch formed from a flexible side walls around a hollow interior and a bottom gusset panel sealed to the side walls and closing the bottom of the hollow interior, the gusset panel in conjunction with the sidewalls forming a stand-up pouch,

providing a flexible perforated wall sealed to the side walls of the pouch within the hollow interior, the perforated wall spaced from the bottom gusset and separating the hollow interior into a food compartment and a liquid compartment,

providing a liquid in the liquid compartment,

providing food on the perforated wall within the food compartment,

placing the pouch within a microwave oven with the gusset panel resting on a support surface therein, and the liquid in the liquid compartment positioned vertically below the perforated wall and the food positioned in the food compartment,

activating the microwave oven to heat the liquid to create steam which flows into the food compartment and heats the food.