[0001] Microwave cooking packages, and, in particular, microwave popcorn packages in current commercial use, typically employ two-ply paper constructions in which inner and outer flexible paper sheets or plies are laminated to one another, typically with a microwave interactive sheet, typically referred to as a microwave susceptor, encapsulated between the two flexible paper sheets. The resulting microwave popcorn packages can be provided in a bag form that may be collapsed and folded when stored before use (e.g., when packaged for shipping, sale, and storage by a consumer). During popping, when a popcorn charge within the packages is exposed to microwave energy in a microwave oven, the bags unfold and expand. When the popping operation is completed, the bag is opened and the contents emptied into a container such as a bowl or basket for consumption. The microwave popcorn package may then be collapsed for disposal. When a container is not available, the consumer may instead reach into the bag to obtain the contents.

SUMMARY

[0002] Microwave cooking packages such as microwave popcorn packages are disclosed. In implementations, the microwave popcorn packages comprise a sidewall construction and a flexible bag construction. The sidewall construction is formed of a vertically rigid material and configured to be expandable between a collapsed configuration and an expanded configuration. The flexible bag construction includes a portion that is secured to the interior of the sidewall construction, and is also configured to be expandable between the collapsed configuration and the expanded configuration. In the expanded configuration, the flexible bag construction and the sidewall construction form a container having vertically rigid sidewalls. In one or more embodiments, the flexible bag construction may be generally transparent (e.g., transparent or translucent to visible light) so that contents of the bag may be visible during popping, after popping in the expanded configuration, and so on.

[0003] A vent assembly for a microwave cooking package is also disclosed. The microwave cooking package includes a bag construction configured to contain a food product. The bag construction is formed of at least one sheet of polyester film material and configured to expand from a collapsed configuration to an expanded configuration when the food product is heated in a microwave oven. The vent assembly includes a first portion of bag construction and a second portion of a bag construction that is configured to be folded against the first portion. The second portion includes a venting structure formed in the sheet of polyester adhesive is configured to adhere the first portion to the second portion so that the vent is at least partially sealed while the bag construction is in the collapsed configuration and to release the first portion from the second portion as the bag construction expands to the expanded configuration to allow the vent to at least partially open. In one or more implementations, the microwave cooking package may comprise a microwave popcorn package. In such implementations, the bag construction may be secured to an interior of a sidewall construction and may contain a popcorn charge as the food product.

[0004] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

DRAWINGS

[0005] The detailed description is described with reference to the accompanying figures. In the figures, the use of the same reference numbers in different instances in the description and the figures may indicate similar or identical items.

FIGS. 1A and IB are schematic, perspective views illustrating example microwave popcorn packages according to the present disclosure after popcorn popping in a microwave oven and after package opening.

FIGS. 2A and 2B are schematic, plan views of example microwave popcorn packages according to the present disclosure, prior to microwave popcorn popping.

FIGS. 3A and 3B are cross-sectional views of the microwave popcorn packages shown in FIGS. 2A and 2B, respectively, taken generally along line 3A-3A and 3B-3B thereof.

FIGS. 4A and 4B are schematic, perspective views of the microwave popcorn packages of FIGS. 2A and 2B and FIGS. 3 A and 3B, respectively, depicted after microwave popcorn popping but while the packages are lying on a side, as the packages would during and immediately after popping.

FIG. 5A is a depiction of the microwave popcorn package of FIG. 4A, after microwave popcorn popping, but shown stood up on the package's base.

FIG. 5B is a depiction of an example microwave popcorn package after microwave popcorn popping, but shown stood up on its base, wherein the microwave popcorn package employs a tear strip. microwave popcorn popping, but shown stood up on the package's base.

FIG. 6A is a depiction of microwave popcorn package according to FIG. 5A, depicted during opening of the package.

FIG. 6B is a depiction of a microwave popcorn package according to FIG. 5C, depicted during opening of the package.

FIG. 7 is a depiction of an example microwave popcorn package that includes a window disposed in a sidewall of the package so that the contents of the package are visible through the window.

FIG. 8 A is a plan view of an example flexible blank usable to form an internal bag component of the microwave popcorn package of FIGS. 2A, 3 A, 4A, 5 A, and 6A.

FIG. 8B is a plan view of an example blank usable to form an internal bag of the microwave popcorn package of FIG. 5B.

FIG. 8C is a plan view of an example blank usable to form an internal bag component of the microwave popcorn package of FIGS. 2B, 3B, 4B, 5C, and 6B.

FIG. 9A is a view of FIG. 8A, showing example dimensions and angles for a particular implementation of the microwave popcorn package.

FIG. 9B is a view of FIG. 8C, showing example dimensions and angles for a particular implementation of the microwave popcorn package.

FIG. 10A is a plan view of an example sidewall panel suitable for use in the microwave popcorn package of FIGS. 2 A, 3 A, 4 A, 5 A, and 6 A.

FIG. 10B is a plan view of an example sidewall panel suitable for use in the microwave popcorn package of FIGS. 2B, 3B, 4B, 5C, and 6B.

FIG. IOC is a plan view of an example sidewall panel suitable for use in the microwave popcorn package of FIG. 7.

FIG. 11A is a view of FIG. 10A, showing example dimensions and angles for a particular implementation of the microwave popcorn package.

FIG. 11B is a view of FIG. 10B, showing example dimensions for a particular implementation of the microwave popcorn package.

FIG. 12 is an isometric view illustrating an example microwave cooking package, in particular, a microwave popcorn package, having a vent assembly in accordance with the present disclosure.

FIG. 13 is an isometric view of the microwave popcorn package shown in FIG. 12, wherein the package is shown in a collapsed configuration prior to popping. wherein the package is shown in an expanded configuration following popping.

FIG. 15 is a cross-sectional view of the microwave popcorn package shown in FIG.

12.

FIG. 16 is a plan view illustrating an example blank that may be folded into the bag construction of the microwave popcorn package shown in FIG. 12.

FIG. 17 is a plan view illustrating the application of adhesive to polyester film material stock to form the blank shown in FIG. 16.

FIG. 18 is a plan view illustrating the application of paper stock to the polyester film material stock shown in FIG. 17.

FIGS. 19A and 19B are partial side elevation views of the microwave popcorn package shown in FIG. 12, further illustrating the vent assembly prior to venting.

FIGS. 19C and 19D are partial side elevation views of the microwave popcorn package shown in FIG. 12, further illustrating the vent assembly following venting.

DETAILED DESCRIPTION

Overview

[0006] Microwave cooking packages may be used to facilitate cooking of a variety of food products in a microwave oven. In particular, in some implementations, microwave cooking packages may be configured as microwave popcorn packages used to pop popcorn. An example microwave cooking package (e.g., microwave popcorn package) is described. The microwave popcorn package includes a sidewall construction and a flexible bag construction. Together, the sidewall construction and the flexible bag construction provide for an arrangement that: (a) contains unpopped microwaveable popcorn in a convenient container; (b) can expand upon exposure to microwave energy as the popcorn pops; and (c) can be stood up and used as a rigid walled bowl, for access to the popped popcorn.

[0007] The microwave popcorn package generally has a collapsed configuration and an expanded configuration. The collapsed configuration is the configuration of the popcorn package prior to exposure to microwave energy in a microwave oven, to pop a contained, unpopped, microwaveable popcorn charge. The microwave popcorn package is comprised of microwave transparent materials, except for a microwave interactive construction used as described herein. This structure provides for efficient utilization of microwave energy to cause microwave popcorn popping. configuration. In general the sidewalls are "vertically rigid" meaning the sidewalls are resistant to collapse when stood vertically during normal use. However the sidewalls are flexible and can be deformed from a flat to an expanded generally convex configuration, as described. The sidewall construction may be fabricated of a semi-rigid material such as a paperboard material, a paper material, a film material, a plastic material, or the like.

[0009] The sidewall construction comprises first and second panels. The panels may be formed from a single piece, or can be two pieces adhered to one another. Each of the panels may have opposite side ends or edge portions, and each may include a plurality of fold lines (e.g., score lines, crease lines, etc.) extending generally parallel to the side edge portions. The fold lines facilitate flexing of the sidewall construction into a generally convex arrangement, such as, for example a curved (e.g., ring) arrangement, a faceted (e.g., polygonal) arrangement, an irregular curved arrangement, and so on) when the microwave popcorn package is in the expanded configuration. The first and second panels are generally rectangular, although other shapes can be used.

[0010] The flexible bag construction is positioned between, and may be secured to the panels of, the sidewall construction. Thus, the bag construction is positioned internally of (e.g., inside) the sidewall construction. In examples, the flexible bag construction is surrounded by, or circumscribed by, the sidewall configuration. Other configurations are possible.

[0011] The flexible bag construction includes a central portion in which an unpopped popcorn charge is positioned prior to popping. A microwave interactive construction is positioned in thermoconductive relation to the central portion so the heat from the microwave interactive construction is transferred to the vicinity of the unpopped popcorn during a microwave popping operation.

[0012] The flexible bag construction may comprise a paper construction, a film construction such as a polyester film (e.g., a biaxially-oriented polyethylene terephthalate [PET]) construction, and so on, and may be single-ply or multiple (e.g., double) ply. In one example, the flexible bag construction may be generally transparent (e.g., transparent or translucent) to allow the contents (e.g., popped popcorn) of the package to be viewed.

[0013] In one or more implementations, the flexible bag construction has first and second side panels, a bottom, and a top. In implementations, the bottom of the flexible bag construction may comprise a base gusset. The flexible bag construction is positioned such that a base gusset thereof is located inside of the sidewall construction. In other implementations, the bottom of the flexible bag construction may comprise a collapsed flat possible. The bottom (e.g., the base gusset, collapsed flat bottom, etc.) when expanded, forms a bottom of the bowl, inside the upwardly standing sidewall construction. Thus, the bottom of the bowl is not rigid. Rather, the bottom is a flexible bag material.

[0014] A top of the flexible bag construction may be removed to provide access to the contents of the flexible bag construction when the microwave popcorn package is in the expanded configuration. For example, the top may include a top portion of the flexible bag construction that may project outwardly from inside of the sidewall construction. The top may also include a top gusset that is directed inwardly. The top portion or top gusset is removed when the package is opened for use. The top of the flexible bag construction may further be configured to vent during a popping operation, thereby relieving pressure from the flexible bag construction during and after popping. For example, in one or more implementations, the flexible bag construction may be configured to vent near the end of the popping operation. In this manner, the flexible bag construction may be inflated during popping so that visibility of the popping popcorn is enhanced.

[0015] The flexible bag construction may thus be characterized as having: a first collapsed configuration in which the bottom (e.g., a base gusset, a collapsed flat bottom, etc.) is (and, if present, a portion of the first and second side panels are) positioned folded collapsed and positioned inside or folded over the sidewall construction; and, as having a second expanded configuration in which the bottom is expanded when inside of the bowl or ring configuration of the sidewall construction, to form a bowl having a vertically rigid sidewall and a flexible bottom.

[0016] The flexible bag construction may be folded from a single (e.g., one-piece) package blank. The terms "single" and "one-piece" in this context are meant to refer to a package blank that is a single unit. It may comprise various layers secured to one another. The package blank may comprise a single-ply or multi-ply construction.

[0017] Furthermore, during popping, the bag construction is expanded from a collapsed configuration to an expanded configuration by steam generated during popping and/or the expanded volume of the popped popcorn. This expansion of the bag construction due to increased pressure therein places stress on the seals of the bag construction, which, in some instances, could cause the seals to open spilling the contents (e.g., unpopped popcorn kernels, oils, seasonings, popped popcorn, and so on) from the package.

[0018] Accordingly, a vent assembly is disclosed for a microwave cooking package that comprises a bag construction formed of polyester film material such as a PET film, or the the bag construction and a second portion of the bag construction that is configured to be folded against the first portion. For example, in one implementation, the vent assembly may be formed near a fold of a gusset the bag construction so that the first portion and the second portion are positioned on either side of the fold. The second portion includes a venting structure formed in the sheet of polyester (e.g., PET) film material from which the bag construction is fabricated.

[0019] An adhesive is applied to at least one of the first portion or the second portion of the bag construction. While the bag construction is in the collapsed configuration (i.e. prior to popping), the adhesive adheres the first portion to the second portion so that the vent is at least partially sealed. However, as the bag construction expands to the expanded configuration during popping, the adhesive is configured to release the first portion from the second portion to allow the vent to at least partially open venting the bag construction.

[0020] In an implementation, the vent is comprised of one or more generally curved scores formed in the second portion that at least partially open when the first portion is released from the second portion. For example, the vent may comprise a first semi-circular score and a second semi-circular score, in mirrored relation to the first semi-circular score. The mirrored first and second semi-circular scores may be spaced apart from one another to form a land area there between.

Example Microwave Popcorn Packages

[0021] Example microwave cooking packages are now described. The microwave cooking packages may be configured as microwave popcorn packages or the like. In the figures described herein below, some relative material thicknesses and component sizes may be shown exaggerated, to facilitate an understanding of the disclosure. Additionally, as used herein, the terms "top" and "bottom" are used to refer to components, with reference to relative location after the package is configured in an expanded configuration and is stood up, for normal use. Thus, the terms "top" and "bottom" may be used to identify components even when those components are in the collapsed configuration, but with reference to eventual relative locations once the package is expanded and positioned stood on its bottom or base, for normal use.

[0022] FIGS. 1A and IB depict example microwave popcorn packages 1 after: (a) popping microwave poppable popcorn upon exposure of microwave energy in a microwave oven to convert the microwave popcorn package from a collapsed configuration to an expanded popped popcorn therein. In FIGS. 1A and IB, a portion of package 1 is depicted. The portion includes an open or expanded package bowl 2 that remains to be stood upright, for normal use, after a top portion is removed to open the package 1 and provide access to the package contents (e.g., popped popcorn) 4 through open top 5.

[0023] The microwave popcorn package 1 includes a sidewall construction 8. In general, the sidewall construction 8 is vertically rigid. By the term "vertically rigid" and variants thereof, in this context, it is meant that the sidewall construction 8 is resistant to collapse when stood up in the orientation shown in FIGS. 1A and IB, in the vertical direction. The term "vertically rigid" is not meant to suggest the microwave popcorn package 1 cannot be collapsed, but rather that the package 1 is resistant to collapse under ordinary use conditions, and is more resistant to collapse than would be a flexible paper bag construction alone.

[0024] The example sidewall construction 8 depicted defines the bowl 2 as having an upper or top edge 9a and lower or bottom edge 9b, and includes first and second panels 10, 11 extending between side ends 15, 16. The first and second panels 10, 11 may comprise separate pieces of material secured to one another, or, the panels 10, 11 may be folded from a single piece of material. For the particular sidewall construction 8 shown, each of the first and second panels 10 and 11 may be fabricated of a vertically rigid material that is adapted to be curved or configured from a flat or collapsed configuration into an expanded configuration having a generally a generally convex arrangement, such as, for example a curved (e.g., ring) arrangement, a faceted (e.g., polygonal) arrangement, an irregular curved arrangement, and so on) to define the open top 5 depicted in FIGS. 1 A and IB.

[0025] In FIG. 1A, the first and second panels 10, 11 illustrated may be fabricated from a semi-rigid material such as a paperboard material, a paper material, a film material, a plastic material, or the like. The use of a semi-rigid material allows the panels 10, 11 to have substantial vertical rigidity in the direction from top edge 23a to bottom edge 23b. Thus, the sidewall construction 8 of FIG. 1A may operate as, and define, a sidewall of a bowl configuration 2, when stood up as shown in FIG. 1.

[0026] In implementations, the first and second panels 10, 11 may be fabricated of a paper or paperboard material. Herein, the term "paperboard" is meant to include various materials, including various forms of fiber board and cardboard provided the material selected is sufficiently vertically rigid to resist vertical collapse under conditions of normal use, when positioned as shown. A variety of paper and paperboard materials may be used provided the materials have sufficient vertical rigidity to function as an end container. For instance, the material of at least 8 points, for example, within the range of 8-15 points (e.g., 10-12 points). Typically, 1 point is equal to 0.001 inch or 0.025 mm thickness. Paper and/or paperboard materials useable may have a variety of weights. For instance, in example implementations, a paper material useable may have a weight of as little as 45-50 lbs. per ream or less provided the paper material provides sufficient vertical rigidity as discussed above. In other implementations, paperboard materials useable include those having a weight of 75 lbs. per ream or more. In such implementations, paperboard materials used may have a weight of at least 85 lbs. per ream, for example 90 lbs. per ream or more. However, lightweight paper or paperboard materials having weights less than 75 lbs. per ream may be used. As noted, other materials such as film materials, plastic materials, and so on, may also be used to form first and second panels 10, 11.

[0027] As shown in FIG. 1A, the vertically rigid material of first panel 10 may be modified by fold lines (e.g., creases or scores) 18 to allow for, and to facilitate, curvature. The second panel 11 may include analogous fold lines (e.g., creases or scores), not shown. The fold lines 18 may extend across the sidewall construction 8, and may help the first and second panels 10, 11 to be flexed into a generally convex configuration analogous to the one shown. Fold lines 21, 22 adjacent to side ends 15, 16, respectively, facilitate flexing of first panel 10 at these locations. The second panel 11 may include analogous fold lines to fold lines 21, 22, shown.

[0028] The fold lines 18 may generally be viewed as vertical scores or creases, since they extend vertically when the sidewall construction 8 is in its expanded, upright, position as shown in FIG. 1A. Herein, when the fold lines extend completely between the top edge 9a and the bottom edge 9b, the fold lines 18, 21, 22 may be characterized as "vertically complete." When the fold lines 18, 21, 22 are continuous and not segmented, the lines may be characterized as "continuous" or by variants thereof. In general terms, the fold lines 18 may be oriented to be generally parallel to the side ends 15, 16.

[0029] In general, as shown in FIG. 1A, the fold lines 18, 21, 22 are not cuts through or partway through the first and second panels 10, 11, although such is possible. Rather, the fold lines 18, 21, 22 shown are package creases or scores of the type used on paperboard packaging containers, to create separate panels and tabs. Such creases or scores are generally formed by creaser equipment that compresses the material along a defined line creating a region of weakness that can be easily folded or manipulated. Thus, the fold lines 18, 21, 22, can be formed with standard packaging equipment for paperboard or cardboard containers. another, positioned as mirror images in the microwave popcorn package 1. Each defines an upper or top edge 23a and an opposite lower or bottom edge 23b, corresponding to top and bottom edges 9a, 9b, respectively. The fold lines 18, 21, 22 provide for weakness in portions or segments of the first and second panels 10, 11 to allow easy adaptation from flat (e.g., non- expanded) to the expanded form depicted in FIG. 1A. The fold lines 18, 21, 22 may be continuous or discontinuous (segmented). The number of fold lines 18 between side ends 15, 16 is a matter of choice, depending upon the amount of curvature desired. For example, fold lines between opposite edges 23a, 23b may be spaced at intervals ranging from 15 to 35 mm (e.g., at 19 to 30 mm intervals).

[0031] In FIG. IB, the first and second panels 10, 11 are fabricated from a paper material. In implementations, the paper material may be of sufficient weight (e.g., gauge) to allow the panels 10, 11 to have substantial vertical rigidity in the direction from top edge 23a to bottom edge 23b. Thus, like the sidewall construction 8 shown in FIG. 1 A, the sidewall construction 8 of FIG. IB may operate as, and define, a sidewall of a bowl configuration 2, when stood up as shown. In one example, the material used in fabrication of first and second panels 10, 11 may comprise a paper material having a weight of at least 60 lbs. per ream. However, paper materials having weights lighter than 60 lbs. per ream may also be used. Additionally, other materials such film materials, plastic materials, and the like, may be used.

[0032] In the example shown in FIG. IB, the first and second panels 10, 11 are again generally identical to one another, positioned as mirror images in the microwave popcorn package 1. However, the vertically rigid material of the first and second panels 10, 11 is sufficiently flexible in the horizontal direction to allow easy adaptation from flat (e.g., non- expanded) to the expanded form depicted. Thus, the vertically rigid material of the panels 10, 11 is not modified by fold lines. In FIG. IB, as in FIG. 1A, each panel 10, 11 defines an upper or top edge 23a and an opposite lower or bottom edge 23b, corresponding to top and bottom edges 9a, 9b, respectively.

[0033] FIGS. 1A and IB are schematic. For the examples shown, the first and second panels 10, 11, are joined at side ends (e.g., tabs) 15, 16 with portions of the flexible bag construction 25 (in particular, portions of side seams) captured therebetween. The amount of curvature obtained in the first and second panels 10, 11 may depend upon such factors as: the thickness of the first and second panels 10, 11; the length of the first and second panels 10, 11 between the side ends 15, 16; the presence, number, configuration, and spacing of fold lines 18; and consumer.

[0034] In general, for microwave popcorn package 1 , the sidewall construction 8 defines an interior 24 in which the flexible bag construction 25 is received. The contents 4 are contained within an interior 27 of the flexible bag construction 25. The flexible bag construction 25 may comprise a paper construction, a film construction such as a polyester film (e.g., a biaxially-oriented polyethylene terephthalate [PET]) construction, and so on, and may be single-ply or multiple (e.g., two) ply. In one or more implementations, the flexible bag construction may be generally transparent to allow the contents (e.g., popped popcorn) 4 of the package 1 to be viewed. As used herein, the flexible bag construction 25 may be "generally transparent" if the contents 4 of the bag 25 are visible through the bag 25. Thus, the flexible bag construction 25 may be generally transparent if the bag 25 is completely transparent, translucent, transparent or translucent with opaque regions, transparent or translucent with printed indicia, tinted, and so on.

[0035] The flexible bag construction 25 provides an enclosure for the microwave poppable popcorn charge during storage of the package 1 and popping; and a bottom for the resulting bowl arrangement. Thus, the flexible bag construction 25 has an expanded configuration and a collapsed configuration. The flexible bag construction 25 occupies a collapsed configuration prior to popping, and the expanded configuration after popping.

[0036] Referring now to FIGS. 2A, 2B, 3 A, and 3B, example microwave popcorn packages 1 are depicted in a collapsed form, e.g., as the packages 1 would appear before a popping operation, for example, after the package 1 has been placed in (e.g., on the floor or turntable of) a microwave oven for a popping operation, and before the top of the flexible bag construction 25 has been removed to open the package 1 as discussed in reference to FIGS. 6A and 6B below.

[0037] In FIGS. 3A and 3B, the sidewall construction 8 is shown in the collapsed form including first and second panels 10, 11 defining top and bottom edges 23a and 23b, respectively. The internal flexible bag construction 25 is viewable in a collapsed form and defining interior 27 in which an unpopped popcorn charge 30 is positioned. The unpopped popcorn charge 30 may include various components or additives such as fat/oil, salt, seasonings, nutrients, and so on, as are commonly used for microwave popcorn products. In one or more implementations, various components used as part of the charge 30, for example a fat, oil or other components, can be included within an internal pouch structure, for example incorporated herein by reference.

[0038] Referring to FIG. 3A, an example flexible bag construction 25 is shown that comprises a two-ply bag arrangement 32 having an outer ply 33 and an inner ply 34. The flexible bag construction 25 may be folded from a single (e.g., one-piece panel) blank 36 to define first and second opposite sides 37 and 38, with a bottom comprised of a base gusset 39 positioned there between. The base gusset 39 is "inwardly directed." By this, it is meant that a center fold line 39a of the gusset 39 is directed inwardly between sides 37, 38, from edges 39b.

[0039] A portion of side 37 may be secured to the first panel 10 with an end portion 37a of side 37 projecting outwardly from between the first and second panels 10, 11 beyond the top edge 9a. By use of the term "beyond" in this context, it is meant that the extension is out from between the first and second panels 10, 11 in a direction from edge 9a. Similarly, side 38 is secured to second panel 11 with a portion 38a projecting outwardly from between the first and second panels 10, 11 beyond the top edge 9a.

[0040] Extension 40 of the flexible bag construction 25, which comprises the portions 37a, 38a extending outwardly from between the first and second panels 10, 11, beyond the top edges 9a, is configured to be torn from a remainder 26 of the package 1 during an opening step, as discussed herein below.

[0041] In FIG. 3A, microwave interactive construction (e.g., a microwave susceptor) 45 is shown positioned in thermoconductive relation to a central region 50 of the flexible bag construction 25 adjacent to the second panel 11. In FIG. 2A, phantom lines 45a indicate the approximate position of microwave interactive construction 45. In the implementation shown, the microwave interactive construction 45 may be positioned between the plies 33, 34 of the flexible bag construction 25. However, other configurations are possible. For example, the microwave interactive construction may be positioned between the outer ply 34 and the second panel 11 , on the outer surface of the second panel 11 (e.g., covered by a patch), and so on. Herein, the term "microwave interactive construction" is meant to refer to a construction which, upon exposure to microwave energy in a microwave oven, generates heat. A variety of microwave interactive constructions may be used, example ones comprising a metalized (e.g., aluminized) polyester film.

[0042] The unpopped popcorn charge 30 is shown positioned within interior 27 of the flexible bag construction 25 in the central region 50, over, and in thermoconductive contact with, microwave interactive construction 45. When the arrangement of FIG. 3 A is placed in microwave energy, heat and generated steam or vapor will cause expansion of the flexible bag construction 25 and thus the package 1. During popping, the flexible bag construction 25 may vent along top seam 60. As shown, top seam 60 may be constructed to have at least a central portion 61 (FIG. 2A) thereof that comprises a heat releasable material to allow and facilitate venting. In addition, as the flexible bag construction 25 expands during popping, the first and second panels 10, 11 are pushed away from one another and the base gusset 39 is opened.

[0043] Referring to FIG. 3B, a flexible bag construction 25 is shown that comprises a single- ply bag arrangement 32a having ply 33a. Like the flexible bag construction 25 of FIG. 3A, the flexible bag construction 25 shown in FIG. 3B may be folded from a single (e.g., one- piece) panel blank 36. Folding of the blank 36 defines first and second opposite sides 37 and 38, with a base gusset 39 and a top gusset 39c positioned there between. The bottom and top gussets 39 and 39c may be longitudinal gussets that are "inwardly directed" so that center fold lines 39a, 39c of the gussets 39, 39c are directed inwardly between sides 37, 38, from edges 39b, 39e, respectively. In one or more examples, the base gusset 39 may be larger (e.g., deeper) than the top gusset 39c since the base gusset 39 is configured to form the bottom of the bowl structure, while the top gusset 39c is configured to be removed following popping. For example, the base gusset 39 may be a 4-inch gusset while the top gusset may be a 3-inch gusset. Other configurations are possible.

[0044] In FIG. 3B, the microwave interactive construction 45 is shown positioned in thermoconductive relation to a central region 50 of the flexible bag construction 25. In FIG. 2B, phantom lines 45a indicate the approximate position of microwave interactive construction 45 adjacent to the second panel. In one or more implementations, the microwave interactive construction 45 is affixed (e.g., adhered) directly to ply 33a. The second panel 11 is then adhered to the ply 33a over the microwave interactive construction 45. In other implementations, the microwave interactive construction 45 may be affixed to the second panel 11 so that the second panel 11 and microwave interactive construction 45 are affixed to the ply 33 a. A paper insulator may be provided between the microwave interactive construction 45 and the ply 33a to limit the heat applied to the ply 33a by the microwave interactive construction 45 during the popping operation. The paper insulator may be affixed to the ply 33 a, the microwave interactive construction 45, the second panel 11, combinations thereof, and so on. In one or more further implementations, the microwave covered by a paper insulator.

[0045] In the example illustrated in FIGS. 2B and 3B, the microwave interactive construction 45 may comprise a low optical density microwave susceptor, a patterned microwave susceptor, and so on. Herein, the terms "low optical density microwave susceptor" and "patterned microwave susceptor" are meant to refer to constructions, which, upon exposure to microwave energy in a microwave oven, generate an amount of heat that is sufficient to provide popping, but do not cause excessive damage (e.g., melting, softening, scorching) to the adjacent portions of the flexible bag construction 25. For instance, in implementations where the flexible bag construction 25 is formed of a polyester film such as PET, the microwave interactive construction 45 may be configured so that the temperature of the ply 33a adjacent to the microwave interactive construction 45 does not exceed a predetermined limit (e.g., the softening point and/or the melting point of the film, and so on). In one example, the microwave interactive construction 45 may be configured as a low optical density microwave susceptor that has an optical density of 0.10 so that the temperature of the ply 33a adjacent to the microwave interactive construction 45 does not exceed approximately 425-450 °F (approximately 218-232 C).

[0046] In FIG. 3B, the unpopped popcorn charge 30 is shown positioned within interior 27 of the flexible bag construction 25 in the central region 50, over, and in thermoconductive contact with, microwave interactive construction 45. When the arrangement of FIG. 3B is placed in a microwave oven in the general orientation shown, and is exposed to an adequate level of microwave energy, heat and generated steam or vapor will cause expansion of the flexible bag construction 25 and thus the package 1. During popping, the flexible bag construction 25 may vent along top gusset 39c. For example, top gusset 39c may include a plurality of vent slots 60a that may open to facilitate venting. Example vent slots 60a are further described in the discussion of FIGS. 8C and 8D. In one or more implementations, the flexible bag construction 25 may include vent slots 60a that are configured to vent near the end of the popping operation. In this manner, the flexible bag construction 25 may be inflated during popping so that visibility of the popping popcorn within the bag 25 is enhanced.

[0047] In addition, as the flexible bag construction 25 expands during popping, the first and second panels 10, 11 are pushed away from one another and the base gusset 39 and top gusset 39c are opened. In the implementation shown, the first and second panels 10, 11 may have about the same width as the flexible bag construction 25 so that the first and second panels other embodiments, the first and second panels 10, 11 may have a width that is narrower than the bag flexible construction 25 so that portions of the flexible bag construction 25 (e.g., portions of the top gusset 39c and the base gusset 39) project outwardly from between the first and second panels 10, 11 beyond the top edge 9a and the bottom edge 9b. For example, the first and second panels 10, 11 may have a width that allows the top gusset 39c and the base gusset 39 of the flexible bag construction 25 to extend beyond top edge 9a and bottom edge 9b by about 2.54 cm, respectively.

[0048] In example implementations, each of the first and second panels 10, 11 for a microwave package of the type depicted in FIGS. 1 through 3B may be configured to provide outer dimensions of at least about 20 cm (e.g., 20-40 cm) long (wide) by at least about 10 cm (e.g., 10 to 22 cm) high to contain 25 to 80 g unpopped popcorn kernels, when collapsed. Referring to FIGS. 2A and 2B, the package 1, prior to popping operation, can be conveniently stored within a moisture barrier outer package or wrap, such as a polyethylene or oriented polypropylene wrap, for storage, shipment, and display. In addition, the surfaces of the first and second panels 10, 11, as well as the flexible bag construction 25, for example in region 40, may be used for printing to display graphics or information. Moreover, in implementations, the interior surface of the second panel 11 (and the first panel 10) may be treated to be grease resistant (e.g., with a film forming starch treatment, an alginate treatment, an acrylic resin treatment, a fluorochemical treatment, or the like).

[0049] The appropriate orientation for the package 1 , when placed in a microwave oven for popping, as shown in FIG. 3A and 3B, is generally with: the second panel 11 adjacent to microwave interactive construction 45, positioned down; and, with the unpopped popcorn kernels positioned above the microwave interactive construction 45. In this manner, the heat generated at the microwave interactive construction 45 is underneath the popcorn.

[0050] Turning now to FIGS. 4A and 4B, the microwave popcorn packages 1 are depicted in an expanded, vented orientation after microwave popping prior to opening (e.g., before tearing extension 40 [FIG. 4A] or top gusset 39c [FIG. 4B] from a remainder 26 of the package 1). In FIG. 4A, the flexible bag construction 25 is illustrated as being formed of opaque paper. In FIG. 4B, flexible bag construction 25 is illustrated as being generally transparent (e.g., formed of a generally transparent polyester [PET] film) to allow the contents (e.g., popped popcorn) 4 of the package 1 to be viewed through the base gusset 39. Further, the first and second panels 10, 11 are shown expanded apart, but secured together at side ends 15, 16. The flexible bag constructions 25 are shown positioned between the first FIG. 4A, the fold lines 18 facilitate curving of the first and second panels 10, 11 into the configuration shown. Further facilitation of curving of the first and second panels 10, 11 can be caused by the consumer, upon grasping and pressing side ends 15, 16 toward one another, i.e., in the directions indicated generally at arrows 80, 81 respectively.

[0051] Turning now to FIGS. 5A, 5B, 5C, and 5D, the vented, expanded, packages 1 of FIGS. 4A and 4B are depicted standing upright. As noted above, it may be convenient for the consumer to apply pressure against the side ends 15, 16 in the direction of arrows 80, 81 after popping to facilitate formation of the package into the generally convex arrangement shown. Also, the consumer may shake the package 1 or tap it (e.g., against a surface), to facilitate settling the popcorn before opening.

[0052] FIGS. 5 A and 5B illustrate a flexible bag construction 25 that includes extension 40, as shown in FIGS. 2 A and 3 A, in the expanded configuration. A variety of techniques may be used to facilitate removal of the extension 40 from the remainder of the flexible bag construction 25. For example, the flexible bag construction 25 may be scored or perforated along a line extending around the flexible bag construction 25 to facilitate removal of extension 40. Tear tape may be provided in place of or in addition to scoring or perforations formed in the bag construction 25. In embodiments, tear tape may comprise a strip of material that reinforces the base substrate and provides a way to tear the base substrate cleanly along a line extending around the bag construction 25 (such as the line of scoring or perforations) without ripping of the substrate at angles to the line. In FIG. 5A, an implementation of the flexible bag construction 25 is illustrated that includes a tear line (e.g., a cut or notch) 83 provided in the flexible bag construction 25 to facilitate opening of the bag by removal of extension 40.

[0053] In FIG. 5B, implementation of the flexible bag construction 25 is illustrated that includes a tear strip 84. As shown, the tear strip 84 is disposed on an exterior surface of the first and second opposite sides 37, 38 (shown in FIG. 3A) of the flexible bag construction 25. The tear strip 84 may extend from a first edge 85 of each of the first and second opposite sides 37, 38 to an oppositely disposed second edge 86 of each of the first and second opposite sides 37, 38. In one example, the tear strip 84 is disposed on the flexible bag construction 25 such that the tear strip 84 is adjacent to the top edge 9a of the sidewall construction 8 when the package 1 is in the expanded configuration. In another example, the tear strip 84 is disposed on an interior surface of the first and second opposite sides 37, 38 of the flexible bag construction 25. A notch 87 (shown in FIG. 7A) may be disposed in the flexible bag extends into the notch 87. The notch 87 provides a location at which the grip projection 88 of the tear strip 84 to be grasped and pulled to expose the content (e.g., popped popcorn) 4. The tear strip 84 may be made from a high-temperature polyester material having a width in a range of about 1/8 inch to about 1 inch (e.g., about 1/4 inch to about 3/4 inch). In one example, the width of the tear strip 84 may be at least 1/4 inch.

[0054] FIG. 5C illustrates a microwave popcorn package 1 that includes a flexible bag construction 25 having a top gusset 39c, as shown in FIGS. 2B and 3B, wherein the package 1 is shown in the expanded configuration. A variety of techniques may be used to facilitate removal of the top gusset 39c from the remainder of the flexible bag construction 25. For example, in FIG. 5C, a tear line (e.g., a cut or notch) may be provided in the flexible bag construction 25 at 83a to facilitate opening of the bag 25 by removal of top gusset 39c. In the example shown, the tear line 83a is positioned above the adhesive line at the base of the top gusset 49 where the flexible bag construction 25 attaches to the sidewall construction 8. Thus, the tear line 83a is below the top edge 9a of the sidewall construction 8 when the package 1 is in the expanded configuration.

[0055] In one or more implementations, the flexible bag construction 25 may employ tear tape 84a affixed to the ply 33a to facilitate tearing of the top gusset 39c from the flexible bag construction 25. As shown, the tear tape 84a extends along and is generally parallel to the adhesive line at the base of the top gusset 39c where the flexible bag construction 25 attaches to the sidewall construction 8. Thus, the tear tape 84a is positioned below the top edge 9a of the sidewall construction 8 when the package 1 is in the expanded configuration. For example, the tear tape 84a is disposed on an exterior surface of the first and second opposite sides 37, 38 (shown in FIG. 3B) of the flexible bag construction 25. The tear tape 84a may extend from a first edge 85 of each of the first and second opposite sides 37, 38 to an oppositely disposed second edge 86 of each of the first and second opposite sides 37, 38. In one example, the tear tape 84a may be made from a high-temperature polyester material having a width of about 1/4 inch. The tear tape and/or the underlying ply 33a may be scored to facilitate tearing. Scoring of the tear tape 84a and/or the underlying ply 33a is further described in the discussion of FIGS. 8C and 8D.

[0056] In FIGS. 6A and 6B, opening of the packages 1 shown in FIGS. 4A, 4B, 5A, 5B and 5C is illustrated. In FIG. 6A, the region 40 is removed (e.g., torn) from the remainder 26 of the package 1 at top edges 9a to expose the contents 4 of the package 1. After the region 40 is removed from the package 1, the bowl arrangement shown in FIG. 1A results. Removal of pulling the tear strip 84 (shown in FIG. 5B).

[0057] In FIG. 6B, the top gusset 39c is torn from the remainder 26 of the microwave popcorn package 1 to expose the contents 4 of the package 1. After the top gusset 39c is removed from the package 1, the bowl arrangement of FIG. IB results. The tearing of the top gusset 39c from the package 1 may be initiated at tear line 83 (shown in FIG. 5C).

[0058] In some instances, after the top portion 40 or top gusset 39C is removed, the consumer may increase the curvature to the sidewall construction 8 by pressing the side ends 15 and 16 of the first and second panels 10, 11 of the sidewall construction 8 together.

[0059] In one or more implementations, the microwave popcorn package 1 may include a window formed in the sidewall construction 8 of the package 1. For instance, as shown in FIG. 7, a window 10a may comprise an opening formed in the first panel 10 so that the flexible bag construction 25 is exposed there through. In the example shown, the flexible bag construction 25 is fabricated from a film material such as a polyester film material (PET) that is generally transparent to allow the contents 4 of the package to be viewed through the window 10a. In FIG. 7, the window is illustrated as being rectangular. However, it is contemplated that the window 10a may have a variety of shapes (e.g., square, round, oval, triangular, irregular, and so on). Additionally, it is contemplated that microwave popcorn packages need not employ the configuration described herein to employ a window. Thus, a conventional microwave popcorn bag may have a window provided therein. For example, a microwave popcorn bag having a conventional two-ply configuration may employ a generally transparent material (e.g., polyester film material (PET) as an inner ply). A window 10a may be provided in the outer ply allowing contents of the bag to be viewed. Similarly, a conventional bag (either single-ply or multi-ply) may employ a patch of generally transparent material (e.g., applied to an interior of the bag, laminated between plies of the bag, and so on) that is in registration with the window provided in the bag. Other examples are possible.

[0060] In FIGS. 2A, 3 A, 4A, 5 A, 5B and 6A, the flexible bag construction 25 illustrated is fabricated from an opaque paper. Consequently, the package 1 does not facilitate viewing of the contents 4. In FIGS. 2B, 3B, 4B, 5C, 5D, 6B and 7, the flexible bag construction 25 is illustrated as being fabricated from a film material such as a polyester film material (e.g., PET) that is generally transparent (e.g., transparent, translucent, and so on). Consequently, the contents (e.g., popped popcorn) 4, may be viewed through the base and top gussets 39, 39c, particularly, during popping and when the microwave popcorn package 1 is in the popcorn packages 1 fabricated in accordance with the present disclosure are not limited to the specific examples illustrated. For example, it is contemplated that the flexible bag construction 25 illustrated in FIGS. 4A, 5 A, 5B, and 6A could be fabricated of a film material (e.g., PET), which may be generally transparent to allow the contents 4 of the package 1 to be viewed (e.g., through the base gusset 49 and/or the extension 40). Similarly, it is contemplated that the flexible bag construction 25 illustrated in FIGS. 4B, 5C, 5D, and 6B could be fabricated of opaque paper so that the contents 4 of the package 1 are no viewed prior to opening of the package 1.

[0061] In the next section, the features of the flexible bag construction 25 are described in greater detail.

Example Flexible Bag Constructions

[0062] The flexible bag construction 25 may have a variety of configurations. For example, the flexible bag construction 25 may be a single-ply arrangement, or a multi-ply arrangement, such as a two-ply arrangement, and may be formed of paper, a polyester film, and so on. As previously discussed, the depicted examples in FIGS. 1 A, 2A, 3A, 4A, 5A, 5B, and 6A utilize a flexible bag construction 25 that is two-ply and formed of paper. An example blank suitable for use in fabricating this flexible bag construction 25 is described herein in reference to FIGS. 8A, 8B and 9A in greater detail. Similarly, the depicted examples in FIGS. 2B, 3B, 4B, 5C, 5D, and 6B utilize a flexible bag construction 25 that is single-ply, formed of a polyester film (e.g., PET), which may be generally transparent. An example blank suitable for use in fabricating this flexible bag construction 25 is described herein in reference to FIGS. 8C, 9B and 10 in greater detail.

[0063] Referring now to FIGS. 8A and 8B, example blanks 36 suitable for use in fabricating the flexible bag constructions 25 described herein in reference to FIGS. 1A, 2 A, 3 A, 4 A, 5 A, 5B, and 6A is illustrated. In FIG. 8A, a foldable one-piece (e.g., single piece) bag blank 90 having a two-ply construction 91 with a susceptor 92 positioned between plies is shown. The particular bag blank 90 depicted is rectangular. However, other shapes can be used. Various notations described below in relation to FIG. 8 A indicate: locations of fold lines; locations of seal or seam material; and, a location between the plies for a susceptor 92. Three folds along lines 93, 94, 95 are used to form bottom or base gusset 39 and side panels 73, 74 (shown in FIG. 4A). The resulting base gusset 39 is an internally directed base gusset with two side panels. Opposite sides 37, 38 of the flexible bag construction 25 are formed by regions 96 the two panels to one another along the panels' outer edges. Seal dots 101 are used to provide a diagonal seam and thus an example top configuration of the flexible bag construction 25. In region 102, a heat releasable seam 70a is provided between panels 37, 38 (shown in FIG. 5A).

[0064] Spot seals are also indicated at 103. In the completed flexible bag construction 25, adhesive at spot seals 103 close the gusset 96 against panel 73 to inhibit popcorn from entering this region during a filling and handling operation. This occurs by spot seals 103 a being folded, around fold line 93, over and into engagement with spot seals 103b.

[0065] In region 108, adhesive is also provided on the back side (i.e., opposite side from the view of FIG. 8 A) to provide an example base gusset configuration.

[0066] As the gussets are folded around fold line 93, diagonal seams 109a overlap and seal to diagonal seams 109b, and diagonal seams 109c are folded over fold line 95, into engagement with diagonal seams 109d. This arrangement helps form a convenient stand-up base gusset 39, in the resulting product. The resulting side edges of the flexible bag construction 25 formed from folding the blank of FIG. 8 A may be positioned between the panels 10, 11, and secured into and along end seams 15, 16 (FIG. 3A).

[0067] In FIG. 8B, the bag blank 90 is illustrated as including an adhesive region 110 disposed on the backside (i.e., opposite side from the view of FIG. 8B) of the bag blank 90. The adhesive region 110 provides a location at which the flexible bag construction 25 can be secured to the interior of the sidewall construction 8. In the depicted example, the adhesive region 110 includes generally horizontal sections 110a that extend along the first and second edges 85, 86 of the flexible bag construction 25 and generally vertical sections 110b that extend between the first and second edges 85, 86 such that the adhesive region 110 outlines a generally rectangular shape. In the depicted example, the adhesive region 110 is symmetrically disposed about the center fold line 39a.

[0068] Within the adhesive region 110 are adhesive areas 112a, 112b that are disposed on the backsides (i.e., opposite side from the view of FIG. 8B) of the first and second sides 37, 38, respectively. The adhesive areas 112 further secure the first and second sides 37, 38 of the flexible bag construction 25 to the interior of the sidewall construction 8. In the depicted example, each of the adhesive areas 112a, 112b includes an adhesive-free zone 114. In the depicted example, the adhesive-free zone is generally semi-circular in shape. The adhesive- free zone 114 allows the flexible bag construction 25 to pull away from the sidewall expanded configuration.

[0069] In the depicted example of FIG. 8B, the susceptor 92 is surrounded by a susceptor adhesive overlap region 116. In the depicted example, the susceptor adhesive overlap region 116 has a width greater than the width of the susceptor 92 by at least 0.25 inches and a length greater than the length of the susceptor 92 by at least 0.25 inches. Exemplary adhesive patterning for the susceptor overlap region 116 has been disclosed in U.S. Pat. No. 5,753,895, entitled "MICROWAVE POPCORN PACKAGE WITH ADHESIVE PATTERN", filed on January 16, 1996.

[0070] In one or more embodiments, the flexible bag constructions 25 shown in FIGS. 8 A and 8B may comprise structural materials that, in conglomerate, have a weight of no more than 60 lbs. per ream (e.g., no more than 50 lbs. per ream), and, in part as a result, are quite flexible. An example sealant for all seals on the blank of FIGS. 8A and 8B, and as a laminating adhesive between the plies, is a polyvinyl acetate adhesive, such as Duracet 12 from Franklin, Intl. of Columbus, OH.

[0071] Referring now to FIG. 8C, an example blank 36 suitable for use in fabricating the flexible bag construction 25 described herein in reference to FIGS. IB, 2B, 3B, 4B, 5C, and 6B is shown. In FIG. 8C, the example blank 36 comprises a foldable one-piece (e.g., single piece) bag blank 90a having a single-ply construction 91a with a susceptor 92a affixed to the back side of the blank 90a (i.e., opposite side from the view of FIG. 8C). As described herein, the bag blank 90a may comprise a polyester film (e.g., PET) material, and may be generally transparent as described herein. For instance, in a specific example, the blank 90a may be formed of transparent 92 gauge PET film. However, the use of blanks 90a formed of other materials is contemplated. Additionally, the particular bag blank 90a depicted is rectangular. However, it is contemplated that the bag blank 90a may have other shapes.

[0072] As in FIGS. 8A and 8B, the notations described below in relation to FIG. 8C indicate: locations of fold lines; locations of seal or seam material; score lines; and a location for attachment of the susceptor 92a. Three folds along lines 93a, 94a, 95a are used to form base gusset 39c and side panels 73a, 74a (shown in FIG. 4B). Similarly, three folds along lines 93b, 94b, 95b are used to form top gusset 39c and side panels 73b, 74b (shown in FIG. 5C). The resulting base gusset 39 and top gusset 39c are longitudinal, internally directed gussets with two side panels.

[0073] Opposite sides 37, 38 of the flexible bag construction 25 are formed by regions 96a and 97a, respectively. Adhesive in areas 101b is used to seal the edges of sides 37, 38 construction 25 formed from folding the blank 90a may be positioned between the panels 10, 11, and secured into and along end seams 15, 16 (FIG. 2B). In regions 108a, 108b, adhesive is also provided on the back side (i.e., opposite side from the view of FIG. 8C) to provide the respective bottom and top gusset 39, 39c. Adhesive in region 108c is further provided on the back side (i.e., opposite side from the view of FIG. 8C) to seal the flexible bag construction 25 closed along the top gusset 39c. Indicia, such as a tinted (e.g., red) bar, or the like, may be applied to areas 101c, for example, to aide in providing instruction to direct a consumer in opening of the package 1 following popping.

[0074] As shown, the bag blank 90a includes adhesive areas 112a, 112b that are disposed on the back sides (i.e., opposite side from the view of FIG. 8C) of the first and second sides 37, 38, respectively. The adhesive areas 112a, 112b secure the first and second sides 37, 38 of the flexible bag construction 25 to the interior of the sidewall construction 8. In FIG. 8C, the microwave interactive construction 92a is affixed to the back side of the second side 38. Adhesive within adhesive areas 112a, 112b is then applied over the microwave interactive construction 45. An example adhesive suitable to adhere the flexible bag construction 25 to the interior of sidewall construction 8 (e.g., for use in adhesive areas 112a, 112b of FIG. 8C) is adhesive no. 45675-2N from Forbo Bonding Systems, Baar, Switzerland.

[0075] Tear tape 84a may be applied to the blank 90a to facilitate tearing of the top gusset 39c from the remainder 26 of the flexible bag construction (FIG. 6B). As shown, the tear tape 84a may extend along the edges of adhesive areas 112a, 112b, respectively. The tear tape and/or the underlying blank 90a may further be scored to facilitate tearing. For instance, in the example illustrated, score lines 84b may be applied to the polyester film material used in the fabrication of the blank 90a beneath the tear tape 84a.

[0076] As shown, the blank 90a may be scored to provide a plurality of vent slots 60a that may open during popping to facilitate venting. In the example illustrated, the vent slots 60a may comprise short, linearly spaced lines 60b scored into the polyester film from which the blank 90a is fabricated. During popping, pressure within the flexible bag construction 25 may cause the lines 60b to open providing vent slots 60a to vent pressure from the bag construction 25. FIG. 8D illustrates scoring of polyester film material (e.g., PET) 90b used in the fabrication of bag blank 90a of FIG. 8C. As shown, the polyester film material 90a may be provided in a roll 90b having a width that corresponds to the width of the blank 90 (e.g., equal to dimension 250A in FIG. 9B). Score lines 84b and vent slots 60a are formed via laser etching. In one or more examples, the score lines 84b and/or the vent slots 60a extend only and/or the vent slots 60a may comprise perforations of the polyester film material 90a. In one or more implementation, the lines 60b may be configured to open to provide vent slots 60a near the end of the popping operation. In this manner, the flexible bag construction 25 may be inflated during popping so that visibility of the popping popcorn within the bag 25 is enhanced.

[0077] In FIG. 9A, the example blank 90 of FIG. 8A is depicted with various dimensions and angles indicated. The following table provides example values and ranges for those dimensions and angles.

TABLE 1 A - Example Dimensions and Angles for FIG. 8A

¹ A wide range, not limited to the values in the table, can be used. In this category, example ranges for arrangements like those depicted are provided. indicated. The following table provides example values and ranges for those dimensions.

TABLE IB - Example Dimensions for FIG. 8C

[0079] A variety of other bag blank configurations are possible.

Example Sidewall Construction

[0080] In FIGS. 10A and 10B, first and second panels 10, 11 of the sidewall constructions 8 described in reference to FIGS. 1A, 2A, 3A, 4A, 5A and 6A or FIGS. IB, 2B, 3B, 4B, 5B, and 6B, respectively, are illustrated. In particular, the first panels 10 are depicted. It is noted, however, that the first and second panels 10, 11 may be structurally identical to one another, positioned as mirror images.

[0081] In FIG. 10A, the panel 10 illustrated includes a surface 119 that forms a surface against the flexible bag construction 25 of FIG. 8 A or 8B. An example adhesive pattern between the flexible bag construction 25 and the first panel 10 is also depicted. In particular, no adhesive would be positioned along bottom edge strip 120 between side edges 121, 122. Edge strip 120 will be positioned in package 1 to form the bottom edge 23b adjacent base gusset 39. A no adhesive (adhesive-free) region or strip 120 extends adjacent to and upwardly from bottom edge 23b, a distance of about 2 to 6 mm. This region of no adhesive helps allow the flexible bag construction 25 to pull away from the first and second panels 10, stand up.

[0082] In central region 130, adjacent to, and joining, edge strip 120, a second region 131 of no adhesive (or adhesive-free region) is provided. No adhesive in this region allows the flexible bag construction 25 to pull away from the first and second panels 10, 11, in the bottom center, during popping and expansion. This facilitates the package 1 being stood up.

[0083] In general, region 130 should be a region containing no adhesive that is located centrally between side ends 121, 122. The region 130 may have a total area of at least 9.5 sq. cm (e.g., an area of 12 to 19 sq. cm). The region may extend away from edge 23b a distance of at least 2.5 cm, for example 3 to 4 cm. At its widest extension, in the direction along the direction of edge 23b, the region extends over a distance of at least 6 cm (e.g., 8.5 to 9.5 cm). For example, the widest extension may be a bottom region located adjacent edge strip 120 and narrowest region is an opposite top region 132. A typical configuration is a triangular shape, centered along central line 135 of the first panel 10, with the central line 135 extending generally parallel to opposite edges 121 , 122, centrally positioned there between. The central line 135 could also be a crease or score line 18. It is noted that although shapes other than triangular can be used, the triangular shape provided helps provide for a symmetrical pulling away of gusset 39 from first panel 10 in this region, to create a convenient base gusset 39 for the flexible bag construction 25.

[0084] In regions 140, 141, adhesive patterns are located. The adhesive coverage in region 140 may be continuous. Thus, along top edge 23a a continuous extension of adhesive may be provided, as well as along side edges 121, 122. Region 140 extends at least 1.8 cm (e.g., 2 to 3 cm), inwardly from adjacent ones of edges 121, 122, and 23a.

[0085] Region 141 generally occupies a central portion 146 of panel 10, except for the region occupied by no adhesive regions 120, 130. It is not necessary that there be a complete adhesive coverage in region 141, although complete adhesive coverage could be used. An adhesive coverage created in a pattern that provides for no more than 60% (e.g., no more than 50%) of adhesive coverage in the region can be used, for example, by providing the adhesive in a dot pattern or in a line pattern, and so on. Patterns in accord with those shown as laminating adhesive patterns in patents 5,753,895; 5,928,554; 5,049,072; and 6,396,036, i.e., as patterns for laminate adhesive between plies could be adapted. These patterns can be used to secure the bag to the sidewall.

[0086] The second panel 11 may be configured identically to first panel 10, with respect to shape and adhesive/no adhesive regions. The flexible bag construction 25 is secured to the are positioned in overlap with regions 150 and 151 (shown in FIG. 10A). It is noted that the adhesive pattern discussed with respect to FIG. 9 could be provided on the outside of the flexible bag construction 25 in addition to, or as an alternative to, being provided on the first and second panels 10, 11.

[0087] In FIG. 10B, a panel 10 is illustrated that includes a surface 119a that forms a surface against the flexible bag construction 25 of FIG. 8C. An example adhesive pattern between the flexible bag construction 25 and the panel 10s, 11 is also depicted. Adhesive-free regions (e.g., strips) 120a, 120b extend along the top and bottom edges 23a, 23b. These regions 120a, 120b allow the flexible bag construction 25 to pull away from the first and second panels 10, 11 adjacent to edges 23a, 23b, so the base gusset 39 and the top gusset 39c, FIG. 4B and 5C, can open during popping and facilitate the package 1 being stood up. The adhesive-free region 120b further allows the side panels 10, 11 to be folded apart adjacent to the top gusset 39c, so that the top gusset 39c to be grasped and removed from the remainder 26 of the package 1.

[0088] As shown, adhesive is positioned along a center region (e.g., strip) 141a of the surface 119a. Region 141 generally occupies a central portion 146 of panel 10, except for the region occupied by no adhesive regions 120a, 120b. In an example, complete adhesive coverage may be used in region 141. In other examples, an adhesive coverage created in a pattern that provides for less than complete coverage may be used. For example, a pattern that provides for adhesive coverage of no more than 60% (e.g., 50%) in region 141a can be used, for example, by providing the adhesive in a dot pattern or in a line pattern, and so on.

[0089] The second panel 11 may be configured identically to first panel 10, with respect to shape and adhesive/no adhesive regions. In implementations, the at least a portion of the surface 1 19a (e.g., region 141a) of the second panel 11 (and the first panel 10) may be treated to be grease resistant (e.g., with a film forming starch treatment, an alginate treatment, an acrylic resin treatment, a fluorochemical treatment, or the like). The flexible bag construction 25 is secured to the adhesive on each panel, between the panels. It is noted that the adhesive pattern discussed with respect to FIG. 10B may be provided on the outside of the flexible bag construction 25 in addition to, or as an alternative to, being provided on the first and second panels 10, 11.

[0090] FIG. IOC illustrates an example sidewall panel 10 suitable for use in the microwave popcorn package of FIG. 7. As in FIG. 10B, adhesive-free regions (e.g., strips) 120a, 120b extend along the top and bottom edges 23a, 23b, while adhesive is positioned along a center so that the flexible bag construction 25 (FIG. 7) is exposed there through. In implementations, the second panel 11 may not include window 141b due to the positioning of the microwave interactive construction 45.

[0091] Attention is now directed to FIGS. 11A and 11B. In FIG. 11A, the first panel 10 is depicted analogously to FIG. 10A. Similarly, in FIG. 11B, the first panel 10 is depicted analogously to FIG. 10B.

[0092] In FIG. 11 A various dimensions of an operable example are indicated, by reference to the following table. A perimeter area for the panel is defined by Dimension 300H by Dimension 300B. A height is Dimension 300B. A width is Dimension 300H.

TABLE 2 A - Example Dimensions and Angles for FIG. 10A

¹ A wide range, not limited to the values in the table, can be used. In this category, typical values for arrangements like those depicted are provided.

[0093] In FIG. 11B various dimensions of an example side panel 10 are indicated, by reference to the following table. A width is Dimension 350A. A height is Dimension 350B. A perimeter area for the panel is defined by Dimension 350A by Dimension 350B.

TABLE 2B - Example Dimensions and Angles for FIG. 10B

Example Fabrication Techniques and Use

[0094] Assembly of the microwave popcorn packages 1 described herein may be accomplished in a number of ways. For example, assembly of the example microwave popcorn package 1 shown in FIG. 2A may generally involve providing the bag blank 90 of FIGS. 8A and 9A, and folding it into a bag construction with sealing as indicated. The resulting folded arrangement may then be positioned between two panels 10, 11, adhered where indicated by the sealant fields of FIGS. 10A and 11 A. The popcorn charge may then be distributed into the flexible bag construction 25 into the region adjacent the susceptor 45. Distribution of the popcorn charge into the region 160, FIG. 3 A, may be inhibited due to the seals 103, FIG. 8A. The flexible bag construction 25 is next sealed along edge 60, FIG. 5A. Region 40 may then folded over panel 10 along fold line 70.

[0095] Assembly of the example microwave popcorn package 1 shown in FIG. 2B may similarly involve providing the bag blank 90a of FIGS. 8C and 9B. However, panels 10, 11, and microwave interactive element 45 may be adhered to the bag blank 90a where indicated by the sealant fields of FIGS. 10B and 1 IB before folding. The assembly is then folded into a bag construction 25 and sealed with sealing as indicated. In one example, bag blanks 90a and panels 10, 11 may be provided in one or more rolls, which are unrolled and adhered together. Microwave interactive element 45 may likewise be provided in a roll or strip, registered with the bag blank 90a (and/or panels 10, 11) and adhered thereto. The assembly may then be cut and folded. The popcorn charge may then be distributed into the flexible bag construction 25 into the region adjacent the microwave interactive element 45, and the flexible bag construction 25 sealed.

[0096] The microwave popcorn packages 1 described above may be sealed within a moisture protective outer barrier once assembled, for storage, shipping, and/or display. In use, the package 1 is removed from the moisture barrier outer wrap (in some examples, region 40 [FIG. 3A] may be allowed to unfold or partially unfold) and the package is laid in a microwave oven, with second panel 11 down. A typical construction may be configured to yield full popping within a period of about 2 to 5 minutes, in a typical household microwave oven, on high setting. After popping, the microwave popcorn package 1 may be positioned as shown in FIGS. 5A and 5B, and region 40 (FIG. 6A) or top gusset 39c (FIG. 6B) may then be torn from the remainder 26 of the package 1, to yield bowl construction 2, FIGS. 1A and IB. [0097] An example microwave cooking package that employs a bag construction formed of polyester film material such as a PET film, which may be provided with a vent assembly in accordance with the present disclosure, is now described. In the figures discussed herein below, some relative material thicknesses and component sizes may be shown exaggerated, to facilitate an understanding of the disclosure. Additionally, as used herein, the terms "top" and "bottom" are used to refer to components, with reference to relative location after the package is configured in an expanded configuration and is stood up, for normal use. Thus, the terms "top" and "bottom" may be used to identify components even when those components are in the collapsed configuration, but with reference to eventual relative locations once the package is expanded and positioned stood on its bottom or base, for normal use.

[0098] FIGS. 12 through 15 illustrate an example microwave cooking package that is configured as a microwave popcorn package 410 suitable for use in popping popcorn in a microwave oven. As shown, the microwave popcorn package 410 includes a sidewall construction 412 and a flexible bag construction 414. The example sidewall construction 412 depicted includes first and second panels 416, 418 extending between ends 420, 422. The first and second panels 416, 418 may comprise separate pieces of material secured to one another, or, the panels 416, 418 may be folded from a single piece of material. For the particular sidewall construction 412 shown, each of the first and second panels 416 and 418 may be fabricated of a material that is adapted to be curved or configured from a flat or collapsed configuration into an expanded configuration having a generally convex arrangement, such as, for example a curved (e.g., ring) arrangement, a faceted (e.g., polygonal) arrangement, an irregular curved arrangement, and so on, to define the open top 424 depicted in FIG. 14. In the example shown, the first and second panels 416, 418 are generally identical to one another, positioned as mirror images in the microwave popcorn package 410.

[0099] In general, the sidewall construction 412 may be vertically rigid. By the term "vertically rigid" and variants thereof, in this context, it is meant that the sidewall construction 412 is resistant to collapse when stood up in the orientation shown in FIG. 14, in the vertical direction. However, the term "vertically rigid" is not necessarily meant to suggest the microwave popcorn package 410 cannot be collapsed, but rather that the package 410 is resistant to collapse under ordinary use conditions, and is more resistant to collapse than would be a flexible paper bag construction alone. [0100] In implementations, the first and second panels 416, 418 may be fabricated of a paper or paperboard material. Herein, the term "paperboard" is meant to include various materials, including various forms of fiber board and cardboard provided the material selected is sufficiently vertically rigid to resist vertical collapse under conditions of normal use, when positioned as shown. A variety of paper and paperboard materials may be used provided the materials have sufficient vertical rigidity to function as an end container. For example, in an implementation, the first and second panels 416, 418 may be fabricated from a paper material of sufficient weight (e.g., gauge) to allow the panels 416, 418 to have substantial vertical rigidity in the direction from top edge 426 to bottom edge 428. In one example, the material used in fabrication of first and second panels 416, 418 may comprise a paper material having a weight of at least 60 lbs. per ream. However, paper materials having weights lighter than 60 lbs. per ream may also be used to fabricate the first and second panels 416, 418. Additionally, other materials such film materials, plastic materials, and the like, may be used.

[0101] As shown, the sidewall construction 412 defines an interior 430 in which the flexible bag construction 414 is received. A food product, in this case, a microwave poppable popcorn charge 432, is contained within an interior 434 of the flexible bag construction 414. The first and second panels 416, 418, are joined at side ends 420, 422 with portions of the flexible bag construction 414 (in particular, portions of side seams formed in the bag construction 414) captured there between. The amount of curvature obtained in the first and second panels 416, 418 may depend upon such factors as: the thickness of the first and second panels 416, 418; the length of the first and second panels 416, 418 between the side ends 420, 422; the extent to which the package 410 is manipulated into the generally convex construction by the consumer; and so on.

[0102] As noted, the flexible bag construction 414 is comprised of a film material such as a polyester film material (e.g., a biaxially-oriented polyethylene terephthalate (PET) material, and so on), and may be single-ply or multiple (e.g., two) ply. In one or more implementations, the flexible bag construction may be generally transparent to allow the contents of the package 410 (e.g., popped popcorn) to be viewed. As used herein, the flexible bag construction 414 may be "generally transparent" if the contents of the bag construction 414 are at least partially visible through the bag construction 414. Thus, the flexible bag construction 414 may be generally transparent if the polyester film material from which the flexible bag construction 414 is constructed is completely transparent, translucent, transparent or translucent with opaque regions, transparent or translucent with printed indicia, tinted, and so on.

[0103] The flexible bag construction 414 provides an enclosure for the microwave poppable popcorn charge 432 during storage of the package 410 and popping. The unpopped microwave poppable popcorn charge 432 may include various components or additives such as fat/oil, salt, seasonings, nutrients, and so on, as are commonly used for microwave popcorn products. In one or more implementations, various components used as part of the charge 432, for example a fat, oil or other components, can be included within an internal pouch structure, for example the type described in the U.S. patent application having serial number 10/299,537, incorporated herein by reference.

[0104] The flexible bag construction 414 may generally be viewed as having a collapsed configuration and an expanded configuration. The flexible bag construction 414 occupies the collapsed configuration prior to popping, and the expanded configuration after popping. In FIGS. 12 and 13 microwave popcorn package 410 is depicted in a collapsed configuration, e.g., as the package 410 appears before a popping operation, for example, after the package 410 has been placed in (e.g., on the floor or turntable of) a microwave oven for a popping operation.

[0105] In implementations, the flexible bag construction 414 may be folded from a single (e.g., one-piece) panel blank 436 (see FIG. 17). Folding of the blank 436 defines first and second opposite sides 438 and 440, with a bottom gusset 442 and a top gusset 444 positioned there between. The bottom and top gussets 442 and 444 may be longitudinal gussets that are "inwardly directed" so that center fold lines 446, 448 of the gussets 442, 444 are directed inwardly between sides 438, 440, from edges 450, 452, respectively. In one or more examples, the bottom gusset 442 may be larger (e.g., deeper) than the top gusset 444 since the bottom gusset 442 is configured to form the bottom of the bowl structure, while the top gusset 442 is configured to be removed following popping.

[0106] Following popping, the top gusset 444 is torn from the remainder of the microwave popcorn package 410 to expose the contents of the package 410 (e.g., popped popcorn) for consumption. When top gusset 444 is removed from the package 410, a bowl arrangement is provided from which the popped popcorn may be consumed. In some instances, after the top gusset 444 is removed, the consumer may increase the curvature to the sidewall construction 412 by pressing the side ends 420 and 422 of the first and second panels 416, 418 of the sidewall construction 412 together.

[0107] A variety of techniques may be used to facilitate removal of the top gusset 444 from the remainder of the flexible bag construction 414. For example, in the implementation illustrated, a tear line (e.g., a cut or notch) may be provided in the flexible bag construction 414 to facilitate opening of the bag construction 414 by removal of top gusset 444. The tear line may, for example, be positioned along an adhesive line at the base of the top gusset 444 where the flexible bag construction 414 attaches to the sidewall construction 412. Thus, the tear line is located below the top edge 426 of the sidewall construction 412 when the package 410 is in the expanded configuration. In other implementations, the flexible bag construction 414 may employ tear tape affixed to the bag construction 412 to facilitate tearing of the top gusset 44 from the remainder of the flexible bag construction 414. In such implementations, the tear tape may extend along and be generally parallel to the adhesive line at the base of the top gusset 444 where the flexible bag construction 414 attaches to the sidewall construction 412. Thus, the tear tape is likewise positioned below the top edge 426 of the sidewall construction 412 when the package 10 is in the expanded configuration. In one example, the tear tape may be fabricated from a high-temperature polyester material having a width of about 0.25 in. The tear tape and/or the underlying polyester film material may further be scored (e.g., using a laser) to facilitate tearing.

[0108] In FIG. 15, the microwave popcorn package 410 is illustrated as including a microwave susceptor 454, which is shown positioned in thermoconductive relation to a central region 456 of the flexible bag construction 414. In the implementation illustrated, the microwave susceptor 454 is attached (e.g., adhered) directly to the side 440 of the flexible bag construction 414. The second panel 418 is then adhered to the side 440 over the microwave susceptor 454. In other implementations, the microwave susceptor 454 may be affixed to the second panel 418, and the second panel 418 and microwave susceptor 454 affixed to the side 440 of the flexible bag construction 414. The microwave susceptor 454 may comprise a low optical density microwave susceptor, a patterned microwave susceptor, and so on. Herein, the terms "low optical density microwave susceptor" and "patterned microwave susceptor" are meant to refer to constructions, which, upon exposure to microwave energy in a microwave oven, generate an amount of heat that is sufficient to provide popping, but do not cause excessive damage (e.g., melting, softening, scorching) to the adjacent portions of the flexible bag construction 414. For instance, in implementations where the flexible bag construction 414 is formed of a polyester film such as PET, the microwave susceptor 454 may be configured so that the temperature of the polyester film adjacent to the microwave susceptor 454 does not exceed a predetermined limit (e.g., the softening point of the film, the melting point of the film, and so on). In one example, the microwave susceptor 454 may be configured as a low optical density microwave susceptor that has an optical density of 0.10 so that the temperature of the polyester material adjacent to the microwave susceptor 454 does not exceed approximately 425-450 °F (approximately 218-232 C).

[0109] In FIG. 15, the unpopped popcorn charge 432 is shown positioned within the interior 434 of the flexible bag construction 414 in the central region 456 over, and in thermoconductive contact with, microwave susceptor 454. When the microwave popcorn package 410 is placed in a microwave oven in the general orientation shown in FIGS. 13 and 15, and is exposed to an adequate level of microwave energy, heat and generated steam and/or vapor will cause expansion of the flexible bag construction 414 and thus the package 410. As the flexible bag construction 414 expands during popping, the first and second panels 416, 418 are pushed away from one another and the bottom gusset 442 and top gusset 444 are opened. In the implementation shown, the first and second panels 416, 418 may have a width that is narrower than the flexible bag construction 414 so that at least part of the flexible bag construction 414 (e.g., part of the top gusset 444) project outwardly from between the first and second panels 416, 418 beyond the top edge 426. However, in other implementations, the first and second panels 416, 418 may have about the same width as the flexible bag construction 414 so that the first and second panels 416, 418 enclose the flexible bag construction 414 prior to popping.

[0110] In example implementations, the microwave popcorn package 410 may be configured to provide outer dimensions of at least about 20 cm (e.g., 20-40 cm) long (wide) by at least about 10 cm (e.g., 10 to 22 cm) high, when collapsed, and to contain 25 to 80 g unpopped popcorn kernels. The package 410, prior to a popping operation, can be conveniently folded in thirds (as shown in FIG. 12) and stored within a moisture barrier outer package or wrap, such as a polyethylene or oriented polypropylene wrap, for storage, shipment, and display. Several such wrapped packages 410 may be stored in a cardboard box, or like container, for shipping, sale, and storage. In addition, indicia (e.g., graphics, text, etc.) may be printed on the surfaces of the first and second panels 416, 418, as well as the flexible bag construction 414. Moreover, in implementations, the interior surface of the second panel 418 (and the first panel 416) may be treated to be grease resistant (e.g., with a film forming starch treatment, an alginate treatment, an acrylic resin treatment, a fluorochemical treatment, or the like).

Example Fabrication Techniques

[0111] Turning now to FIGS. 16, 17, and 18, example techniques for fabricating the microwave popcorn package 410. FIG. 16 illustrates an example blank 436 suitable for use in fabrication of the flexible bag construction 14 described herein in reference to FIGS. 12 through 15. In FIG. 16, the example blank 436 comprises a foldable one-piece (e.g., single piece) bag blank 460 having a single-ply construction 462 with the susceptor 454 affixed to the back side of the blank 460 (i.e., opposite side from the view of FIG. 16). As described herein, the bag blank 460 may comprise a polyester film (e.g., PET) material, and may be generally transparent as described above. For instance, in a specific example, the blank 460 may be formed of transparent 492 gauge PET film. However, the use of blanks 460 formed of other materials is contemplated. Additionally, the particular bag blank 460 depicted is rectangular. However, it is contemplated that the bag blank 460 may have other shapes.

[0112] The notations described below in relation to FIG. 16 indicate: locations of fold lines; locations of seal or seam material; score lines; and a location for attachment of the susceptor 454. Three folds along lines 464, 466, 468 are used to form the bottom gusset 442 with interior panels 470, 472 (see FIG. 15). Similarly, three folds along lines 474, 476, 478 are used to form the top gusset 444 with interior panels 480, 482 (see FIG. 15). The resulting bottom gusset 442 and top gusset 444 are longitudinal, internally directed gussets as described in the discussion of FIGS. 12 through 15.

[0113] Opposite first and second sides 438, 440 of the flexible bag construction 414 are formed by regions 484 and 486, respectively. Adhesive in area 488 is used to seal the edges of sides 438, 440 together, thereby forming a bag configuration. The resulting side edges of the flexible bag construction 414 formed from folding the blank 460 may be positioned between the panels 416, 418 and secured into and along the end seams (FIG. 14). In regions 490, adhesive is also provided on the back side (i.e., opposite side from the view of FIG. 16) to provide the respective bottom and top gussets 442, 444. Adhesive in region 492 is further provided on the back side (i.e., opposite side from the view of FIG. 16) to seal the flexible bag construction 14 closed along the top gusset 444. Indicia, such as a tinted (e.g., red) bar, or the like, may be applied to areas to the blank 460, for example, to aide in providing instruction to direct a consumer in opening of the package 410 following popping.

[0114] As shown, the bag blank 460 includes adhesive areas 494 that are disposed on the back sides (i.e., opposite side from the view of FIG. 16) of the first and second sides 438, 440, respectively. The adhesive areas 494 secure the first and second sides 438, 440 of the flexible bag construction 414 to the interior of the sidewall construction 412. In FIGS. 15 and 16, the microwave susceptor 454 is affixed to the back side of the second side 440. Adhesive within adhesive areas 494 is then applied over the microwave susceptor 454.

[0115] Tear tape 498 may be applied to the blank 460 to facilitate tearing of the top gusset 444 from the remainder of the flexible bag construction 414. As shown, the tear tape 498 may extend along the edges of adhesive areas 494. The tear tape and/or the underlying blank 460 may further be scored to facilitate removal of the top gusset 444.

[0116] Assembly of the microwave popcorn package 410 described herein may be accomplished in a number of ways. For example, a bag blank 460 as shown in FIG. 16 may be provided. Adhesive may be applied to the bag blank 460. FIG. 17 illustrates the application of adhesive to polyester film material stock to form the blank 436 shown in FIG. 16. Panels 416, 418 and microwave susceptor 454 may be adhered to the bag blank 460 where indicated by the sealant fields of FIG. 16 before folding. The assembly is then folded into a bag construction 414 and sealed as indicated. In one example, bag blanks 436 and panels 416, 418 may be provided in one or more rolls of stock, which are unrolled and adhered together. For example, the polyester film material stock shown in FIG. 17 is illustrated as having a width of two or more blanks 436. Similarly, FIG. 18 illustrates the alignment of paper stock for application of panels 416, 418 to the polyester film material stock shown in FIG. 17. Microwave interactive element 454 may likewise be provided in a roll or strip, registered with the bag blank 460 (and/or panels 416, 418) and adhered thereto. The assembly may then be cut and folded. The popcorn charge may then be distributed into the flexible bag construction 425 into the region adjacent the microwave interactive element 445, and the flexible bag construction 425 sealed. Example Vent Assembly

[0117] During popping, the flexible bag construction 414 is expanded from a collapsed configuration, shown in FIGS. 12 and 13, to an expanded configuration, shown in FIG. 14, by steam (and other gases) generated during popping and/or the expanded volume of the popped popcorn of the popcorn charge 432. This expansion places stress on the various seals of the bag construction 414 (e.g., seals along ends 420, 422), which, in some instances, could cause the seals to fail (open) spilling contents such as unpopped popcorn kernels, oils, seasonings, popped popcorn, and so on from the package 410.

[0118] Accordingly, the flexible bag construction 414 includes a vent assembly 500 configured to vent pressure within the bag construction 414 during popping. In the illustrated implementation, the vent assembly 500 is formed within the top gusset 444 of the flexible bag construction 414 and is spaced away from an end (e.g., end 422) of the package 410. For instance, in one example, the vent assembly 500 may be provided in the top gusset 444 so that the center of the vent assembly 500 is approximately 3 in. from an end (e.g., end 420 or end 422) of the microwave popcorn package 410. In this location, the vent assembly 500 is positioned away from the seals of the flexible bag construction 414 located at ends 420, 422. The consumer may thus grip the package 410 (e.g., at ends 420, 422) away from the vent 500 when removing the package 410 from a microwave oven following popping. Moreover, this location allows the vent assembly 500 to be spaced away from the popcorn charge 432 when the microwave popcorn package 410 is folded in thirds for storage and shipping as shown in FIG. 12; helping to prevent the wicking of oils, seasonings and so forth through the vent assembly 500.

[0119] FIGS. 19A, 19B, 19C, and 19D illustrate the vent assembly 500 in greater detail. In the illustrated implementation, the vent assembly 500 is comprised of a first portion 502 of the bag construction 414 and a second portion 504 of the bag construction 414. As shown, the first portion 502 is comprised of a section of the side 438 of the bag construction 414 adjacent to the fold line 474 at edge 452 within a strip of the bag construction 414 that extends beyond the top edge 426 of the first panel 416. Similarly, the second portion 504 comprises a section of an interior panel 480 of the gusset 444 adjacent to the fold line 474 at edge 452. The first portion 502 and the second portion 504 are thus in mirrored relation to one another so that the second portion 504 is configured to be folded against the first portion 502 when the gusset 444 is formed. In FIGS. 19A through 19D, the first portion 502 and the second portion 504 are illustrated as being generally rectangular in shape and of at least approximately the same size. However, it is contemplated that the first portion 502 and the second portion 504 may have other shapes (e.g., square, circular, oval, triangular, polygonal, irregular, and so on), and thus are not necessarily limited to the illustrated shape. Moreover, it is contemplated that the first and second portions 502, 504 may be of different sizes.

[0120] The second portion 504 includes a venting structure 506 formed in the sheet of polyester film material from which the bag construction 414 is fabricated. As shown in FIG. 19 A, the venting structure 506 is comprised one or more scores 508 formed within the second portion 504. In the example shown, the scores 508 extend only partially through the polyester film material and form a weakened area within the second portion 504. However, it is contemplated that, due to manufacturing variations, at least some portion of one or more of the scores 508 may extend completely through the polyester film material. Moreover, it is contemplated that in some implementations of the vent assembly 500, the venting structure 506 may include apertures forming in the polyester film material in place of, or, in addition to, the scores 508 illustrated in FIG. 19A. A variety of fabrication techniques may be used to form the scores 508 in the polyester film material. For example, in the illustrated example, the scores 508 may be stamped into the polyester film material during fabrication of the microwave popcorn package. However, it is contemplated that the scores 508 may be formed prior to fabrication and/or may be formed using other techniques such as laser scoring, and so forth.

[0121] The scores 508 of the venting structure 506 may have a variety of shapes. In one or more implementations, at least one of the one or more scores 508 may have a generally curved shape. For example, in FIGS. 19A and 19B, the venting structure 506 illustrated comprises a butterfly vent 510 that includes a first semi-circular score 512 and a second semi-circular score 514 formed in the polyester film material. As shown, the second semi-circular score 514 is arranged in mirrored relation to the first semi-circular score 512, and is spaced apart from the first semicircular score 512 to form a land area 516 there between that separates the scores 512, 514.

[0122] An adhesive 518 is applied to at least one of the first portion 502 or the second portion 504 of the bag construction 414. While the bag construction 414 is in the collapsed configuration, as shown in FIGS. 19A and 19B, the first portion 502 is folded against the second portion 504. Thus, in the collapsed configuration, the adhesive 518 causes the first portion 502 to be adhered to the second portion 504 to form a seal 520 around the venting structure 506. For example, in the illustrated example, the adhesive 518 may be applied to both the first portion 502 and the second portion 504 to provide an adhesive -to-adhesive contact seal 520 when the first portion 502 is folded against the second portion 504. Prior to venting, the seal 520 at least partially seals the venting structure 506 so that the contents of the bag construction 414 (e.g., unpopped popcorn kernels, oils, seasonings, and so on) are prevented from spilling from the bag construction 414 through the venting structure 506.

[0123] In the implementation shown in FIGS. 19A and 19B, the seal 520 comprises a region of the first and second portions 502, 504 surrounding the venting structure 506 in which the adhesive 518 is further activated to join the first portion 502 to the second portion 504. The seal 520 may, for example, include a region around the venting structure 506 wherein heat sealing is used to cause the adhesive 518 to secure the first portion 502 to the second portion 504 within the region. In FIGS. 19A and 19B, the activated (e.g., heat sealed) region is generally circular in shape. However, it is contemplated that the region may have other shapes (e.g., oval, square, rectangular, polygonal, irregular, and so on) without departing from the scope and spirit of this disclosure. Moreover, it is contemplated that adhesive 518 applied to the first and second portions 502, 504 outside of the seal region may function to further seal the venting structure 506, thereby preventing contents of the bag construction 414 (e.g., unpopped popcorn kernels, oils, seasonings, and so on) from migrating into the seal region around the venting structure 506.

[0124] As the flexible bag construction 414 expands to the expanded configuration during popping (FIG. 14), the gusset 444 is opened causing the interior panel 462 of the gusset 444 to be pulled away from the side 438 of the bag construction 414 about the fold line 458. Thus, during expansion of the flexible bag construction 414, the second portion 504 tends to be pulled away from the first portion 502. As the first and second portions 502, 504 are pulled apart; the adhesive 518 is configured to release the first portion 502 from the second portion 504 to allow the venting structure 506 to at least partially open, venting the bag construction 414. For instance, as shown in FIGS. 19C and 19D, the first and second semi-circular scores 512, 514 of the butterfly vent 510 may be configured to at least partially open when the first portion 502 is released from the second portion 504. The first and second semi-circular scores 512, 514 define a first flap 522 and a second flap 524, respectively. When the first portion 502 is pulled away from the second portion 414 (e.g., due to expansion of the bag construction 414), at least part of either or both of the first and second flaps 522, 524 remain adhered to the first portion 502. Thus, the first and second flaps 522, 524 are pulled away from the remainder of the second portion 504 creating one or more vent apertures 526, 528 in the second portion 504 through which steam (and other gases) may vent from the bag construction 414. In some implementations, the parts of the first and second flaps 522, 524 that are pulled away from the second portion 504 may remain adhered to the first portion 502 by the adhesive 518 after the first portion 502 is released from the second portion 504, and thus may detach from the second portion 504. Moreover, in some instances it is contemplated that portions of the second portion 502 other than the first and second flaps 522, 524 may pull from the second portion 504, and may remain adhered to the first portion 502, creating vent apertures 526, 528 that are irregular in shape.

[0125] The vent assembly 500 is configured to provide efficient venting of steam and other gases from the flexible bag construction 414 during popping. For example, the vent assembly 500 may include a venting structure 506 that is sufficiently large to vent the bag construction prior to failure (opening) of seals within the bag construction 414 (e.g., seals along ends 420, 422) due to pressure within the bag construction 414 during popping. In examples, the venting structure 506 may comprise a butterfly vent 510 that includes a first semi-circular score 512 and a second semi-circular score 514 having diameters of between about 0.1875 in. and about 0.3125 in. In one specific example, the first semi-circular score 512 and the second semi-circular score 514 may have diameters of about 0.25 in., while the land 516 has a width of about .04 in. When opened, each semi-circular score 512, 514 may provide a vent aperture 526, 528 having an area of at least about 0.02 in ² if fully opened. Moreover, while the microwave package assembly 410 is illustrated as including one vent assembly 500, it is contemplated that two or more vent assemblies 500 may be provided in the flexible bag assembly 414 without departing from the scope and spirit of the present disclosure.

[0126] In implementations, the vent assembly 500 may be configured to vent (open) at an approximate, predetermined time during the popping operation (e.g., near the end of a popping operation). In this manner, the flexible bag construction 414 may be allowed to inflate during popping so that visibility of the popping popcorn within the bag construction 414 is enhanced and/or a desired pressure within the bag construction 414 is maintained to enhance popping of the popcorn. For example, the seal strength provided by the adhesive 518 may be selected to prevent separation of the first portion 502 from the second portion 504, and thus, venting of the venting structure 506, until the bag construction 414 has reached a desired degree of expansion (inflation), but to allow separation of the first portion 502 from the second portion 504, and thus venting by the venting structure 506, prior to failure of seals within the bag construction 414.

[0127] A variety of adhesives 518 may be employed to adhere the first portion 502 to the second portion 504. In one example, the adhesive 518 may be a water-based adhesive providing approximately a 0.5 lb seal. In this example, the seals of the flexible bag construction 414 may also be made using a water-based adhesive. However, the adhesive used may provide seals having strengths greater than that of the adhesive 518 (e.g., providing approximately a 1 lb. to 2 lb. seal). The adhesive 518 of the vent assembly 500 may, for example have a different composition than the adhesive used in the seals of the flexible bag construction 414, and/or may be applied to the polyester film material in a lesser concentration. Solvent-based adhesives may also be used.

[0128] As shown in FIG. 5, the adhesive 516 may be applied to the bag blank 436 as an adhesive field 530. Scores 508 (e.g., semi-circular scores 512, 514) may be stamped into the polyester film material within the adhesive field 530 prior to, or during, folding of the bag blank 436 to form the flexible bag construction 414. As the top gusset 444 is folded, the first and second portions 502, 504 are folded together as described above, providing an adhesive-on-adhesive contact. The first and second portions 502, 504 may then be heat sealed to form seal 520 around the venting structure 510 (e.g., around scores 508 stamped into the polyester film material). Folding and sealing of the blank 436 to form the microwave popcorn package is then completed. A popcorn charge 436 inserted into the bag construction 414 as shown in FIG. 12. Adhesive applied at areas 532 helps to maintain the shape of the bag construction 414 as the popcorn charge 432 is inserted and prevents inadvertent opening of the vent assembly 500.

Example Use

[0129] The microwave popcorn packages 410 described above may be sealed within a moisture protective outer barrier once assembled. In some instances, the microwave popcorn packages 410 may further be packaged into boxes for storage, shipping, and/or display. In use, the package 410 is removed from the moisture barrier outer wrap and placed in a microwave oven with the second panel 418 down. A typical microwave popcorn package 410 may be configured to yield full popping within a period of about 2 to 5 minutes in a typical household microwave oven, on high setting. After popping, top gusset 444 is removed to allow the microwave popcorn package 410 to function is a container (e.g., a bowl) for consumption of the popped popcorn.

Conclusion

[0130] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.