Patent Publication Number: US-2012024869-A1

Title: Pressurized, gusseted package, packaged products, and related methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. 119(e)(1) of a provisional patent application Ser. No. 61/369,382, filed Jul. 30, 2010, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to packages and packaged food and non-food products. 
     BACKGROUND 
     Products contained by commercial and consumer packages include food and non-food products. Food products include dough products, sometimes packaged in a manner to allow storage stability and convenience to a purchaser, e.g., ease of use of the product. 
     For food products, including raw dough products, packages can be designed to allow extended refrigerated or frozen storage, ease of opening, and general convenience of use. A wide variety of packaged dough products allow a user to “home bake” a raw dough to produce a desirable hot, fresh-baked item. Many such dough products are proofed prior to baking and for consumer convenience may be partially or fully proofed prior to purchase and prior to use by the consumer. Such products, sold after proofing or partial proofing, are examples of products referred to as “pre-proofed.” Examples of pre-proofed or partially proofed dough products include breads and bread-like products that generally contain a leavening ingredient that may be but are not limited to loaves of bread such as French bread, white or whole wheat bread, bread sticks, biscuits, rolls, pizza dough, and the like. Such products include dough formulations that can be, but are not necessarily, chemically-leavenable. 
     Various commercial dough products, including pre-proofed or partially proofed dough products, are sold in pressurized containers, which have a positive internal pressure, i.e., an internal pressure that is greater than atmospheric. One technique for preparing a pre-proofed dough product in a pressurized package is by placing an unproofed dough in a package and allowing the dough to proof and expand within the package. Such packages are sometimes referred to as self-sealing packages and include an interior space that is vented to the outside of the package to allow gas to be removed from the interior space through the vent by expansion of dough in the interior space, followed by the vent being sealed from the interior side of the package by the expanded dough. More specifically, after being placed in the package, the dough composition produces carbon dioxide and expands inside of the package. The expanding dough will replace gas from the space inside of the package; the gas is expelled through the vent and the expanded dough closes or seals the vent from the inside of the package. The dough can continue to produce carbon dioxide and produce an internal pressure inside the package. 
     Self-sealing packages sometimes used to contain raw dough can be in the form of a canister formed of composite paperboard spirally wound into a cylinder. The initial volume of dough packed into the canister is usually less than the canister volume and as the dough expands by proofing within the canister, the dough volume increases to force the dough to expel gas from the canister, eventually causing the dough to contact interior surfaces of the canister as well as channels, passages, or other openings (e.g., valves, near ends of the container); the dough contacts the channels, passages, or openings, to seal the canister from the interior side. Other packages are formed of flexible films, and may be referred to as pouches, chubs, form-filled-sealed packages, flow-wrap packages, etc. 
     There is continuing need for new types of packages useful for dough and non-dough products, including packaged pre-proofed dough products that may be refrigerator stable. Similarly, there is continuing need for new methods of packaging and preparing such products. 
     SUMMARY 
     Described packages can be used to contain any material desired, including food and non-food items, under pressure, meaning that the pressure at the interior is greater than ambient pressure. The present description relates in large part to applications for food, in particular dough products, but other food and non-food items may also be contained and stored in the described packages. 
     The package includes two opposing ends, and each end can be sealed after placing contents into the package. The seal at an end is prepared from opposing areas of film of the package, bonded together. One or more bonded area (alternately referred to as a “connection” or “fin”) can be shaped to include a directional component that is directed toward the opposite end of the package. Alternate types of connection to form a seal could extend along a straight line in a direction perpendicular to (at a 90 degree angle relative to) the length dimension of the package, also perpendicular to longitudinal edges, aligned with a width dimension of the package. According to certain embodiments of the invention, one or more seal is not a straight line perpendicular to the length dimension of the package but is a straight or curved line that includes a directional component in the direction of (directed toward) the opposite end; a single end of the package can be formed in this manner or both ends may be formed in this manner. 
     Advantage of a sealed end as described include useful and potentially improved pressure resistance at a sealed end. An end sealed with a non-square bond can withstand increased pressure, e.g., as measured by burst strength, compared to a similar gusseted package that includes an end seal that is aligned with a width dimension of the package, i.e., that extends in a direction perpendicular to the length of the package. 
     In one aspect the invention relates to a pressurized package having a longitudinal dimension, a width dimension, a left side, a right side, a top, and a bottom, a first package end, and a second package end. The package includes: a top side comprising a left longitudinal edge, a right longitudinal edge, a first end, and a second end; a bottom side comprising a left longitudinal edge, a right longitudinal edge, a first end, and a second end; a left folded side comprising an upper longitudinal edge, a lower longitudinal edge, a first end, and a second end; and a right folded side comprising an upper longitudinal edge, a lower longitudinal edge, a first end, and a second end. The left longitudinal edge of the top side meets the upper longitudinal edge of the left folded side at an upper-left longitudinal edge. The right longitudinal edge of the top side meets the upper longitudinal edge of the right folded side at an upper-right longitudinal edge. The left longitudinal edge of the bottom side meets the lower longitudinal edge of the left folded side at a lower-left longitudinal edge. And the right longitudinal edge of the bottom side meets the lower longitudinal edge of the right folded side at a lower-right longitudinal edge. An end of the package has a seal that includes: an upper-left connection formed between a left portion of an end of the top side and an end of an upper portion of the left folded side, the upper-left connection extending from the left fold to the upper-left longitudinal edge along a line that includes a directional component directed toward the second package end; an upper-right connection formed between a right portion of an end of the top side and an end of an upper portion of the right folded side, the upper-right connection extending from the right fold to the upper-right longitudinal edge along a line that includes a directional component in a direction toward the second package end; a lower-left connection formed between a left portion of an end of the bottom side and an end of a bottom portion of the left folded side, the lower-left connection extending from the left fold to the lower-left longitudinal edge along a line that includes a directional component in a direction toward the second package end, and a lower-right connection formed between a right portion of an end of the bottom side and an end of a bottom portion of the right folded side, the lower-right connection extending from the right fold to the lower-right longitudinal edge along a line that includes a directional component in a direction toward the second package end. 
     In another aspect the invention relates to a method of preparing a pressurized packaged dough product, including the following. Providing a package having a longitudinal dimension, a width dimension, a left side, a right side, a top, and a bottom, a first package end, and a second package end. The package includes: a top side comprising a left longitudinal edge, a right longitudinal edge, a first end, and a second end; a bottom side comprising a left longitudinal edge, a right longitudinal edge, a first end, and a second end; a left folded side comprising an upper longitudinal edge, a lower longitudinal edge, a first end, and a second end; and a right folded side comprising an upper longitudinal edge, a lower longitudinal edge, a first end, and a second end. The left longitudinal edge of the top side meets the upper longitudinal edge of the left folded side at an upper-left longitudinal edge. The right longitudinal edge of the top side meets the upper longitudinal edge of the right folded side at an upper-right longitudinal edge. The left longitudinal edge of the bottom side meets the lower longitudinal edge of the left folded side at a lower-left longitudinal edge. And the right longitudinal edge of the bottom side meets the lower longitudinal edge of the right folded side at a lower-right longitudinal edge. Placing a dough product in the package. Sealing one of the ends before or after the placing step. Sealing the other end after the placing step. One or two ends of the package has a seal that includes: an upper-left connection formed between a left portion of an end of the top side and an end of an upper portion of the left folded side, the upper-left connection extending from the left fold to the upper-left longitudinal edge along a line that includes a directional component directed toward the opposite package end; an upper-right connection formed between a right portion of an end of the top side and an end of an upper portion of the right folded side, the upper-right connection extending from the right fold to the upper-right longitudinal edge along a line that includes a directional component in a direction toward the opposite package end; a lower-left connection formed between a left portion of an end of the bottom side and an end of a bottom portion of the left folded side, the lower-left connection extending from the left fold to the lower-left longitudinal edge along a line that includes a directional component in a direction toward the opposite package end, and a lower-right connection formed between a right portion of an end of the bottom side and an end of a bottom portion of the right folded side, the lower-right connection extending from the right fold to the lower right longitudinal edge along a line that includes a directional component in a direction toward the opposite package end. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A ,  1 B, and  1 C, illustrate a side-perspective view, a top view, and an end view of a package that includes two opposing sealed ends, with the seals being “square” to the package. 
         FIGS. 2A and 2B  illustrate embodiments of packages that include a sealed end that includes a non-square seal. 
         FIGS. 3A and 3B  illustrate a top view of a package, and a sheet for preparing the package as described. 
         FIG. 3C  illustrates an embodiment of an end view of a package as described. 
         FIGS. 4A and 4B  illustrate a top view of a package, and a sheet for preparing the package as described. 
         FIG. 4C  illustrates an embodiment of an end perspective view of a package as described. 
         FIG. 4D  illustrates an embodiment of an end view of a package as described. 
         FIGS. 5A and 5B  illustrate a top view of a package, and a sheet for preparing the package as described. 
         FIGS. 6A and 6B  illustrate a top view of a package, and a sheet for preparing the package as described. 
         FIGS. 7A and 7B  illustrate a top view of a package, and a sheet for preparing the package as described. 
         FIGS. 8A and 8B  illustrate a top view of a package, and a sheet for preparing the package as described. 
         FIGS. 9 and 10  show burst strength data of exemplary sealed ends, as described. 
     
    
    
     All drawings are schematic and not to scale. 
     DETAILED DESCRIPTION 
     Described packages generally may be in any form consistent with the following description, for example a package sometimes referred to as any one of a form-filled-sealed package, a vertical form-filled-sealed package, a flowrap package, a horizontal form-filled-sealed package, a pouch, etc. The inventive packages can be pressurized (e.g., of an internal pressure of 15 psig or greater) for example at a low package pressure (e.g., having an internal pressure of less than 15 psig, preferably from 0 to 10 psig, e.g., 0 to 5 psig) during refrigerated or frozen storage, e.g., after placement of a product inside the container. 
     The package may made of flexible materials such as flexible film materials, including films known to be useful in packaging materials, e.g., for packaged food products. The package includes a dimension that can be referred to as a longitudinal dimension and another dimension that can be referred to as a width direction, generally perpendicular to the length dimension. The package also includes a side that can be referred to as a left side, a side that can be referred to as a right side, a top, a bottom, a first end, and a second end. The identity of one side as a right side, left side, top, bottom, etc., can be arbitrary. The package includes a top side and a bottom side, generally opposite of the top side. Connecting the top side and the bottom side, at left and right edges of the top and bottom sides, are a left folded side and a right folded side. These sides include a fold or bend longitudinally, between the ends. The package also includes four longitudinal edges running in the longitudinal (length) direction: an upper-left longitudinal edge at the location of the left longitudinal edge of the top side meeting the upper longitudinal edge of the left folded side; an upper-right longitudinal edge at the location of the right longitudinal edge of the top side meeting the upper longitudinal edge of the right folded side; a lower-left longitudinal edge at the location of the left longitudinal edge of the bottom side meeting the lower longitudinal edge of the left folded side; and a lower-right longitudinal edge at the location of the right longitudinal edge of the bottom side meeting the lower longitudinal edge of the right folded side. 
     Each longitudinal edge can be formed at edges of two separate pieces of package material, e.g., by bringing together and securing edges of two separate pieces of package material at an edge of each and securing by adhesive; welding (e.g., sonic welding); thermoforming by application of heat; combined application of heat and pressure; or any other useful bonding means. Alternately, a longitudinal edge may be formed by folding a single piece of package material, optionally with adhesive to form a two-layer bonded fold. 
     The package includes two opposing ends, and each end can be sealed after placing contents into the package. A seal at an end of the package can include: an upper-left connection formed between a left portion of an end of the top side and an end of an upper portion of the left folded side, an upper-right connection formed between a right portion of an end of the top side and an end of an upper portion of the right folded side, a lower-left connection formed between a left portion of an end of the bottom side and an end of a bottom portion of the left folded side, and a lower-right connection formed between a right portion of an end of the bottom side and an end of a bottom portion of the right folded side. 
     Connections to form an end seal (alternately a connection may be referred to a “fin seal”) can be between surfaces of the relevant package locations, as described herein, and at opposing surfaces of package materials located at and adjacent to ends of those materials, e.g., by bringing together and securing surfaces of two pieces of package material and securing by adhesive; welding (e.g., sonic welding); thermoforming by application of heat; combined application of heat and pressure; or any other useful bonding means. 
     According to the invention, one or more of the connections that forms a seal of an end can be shaped to include a directional component that is directed toward the opposite end of the package. For contrast, a different type of connection to form a seal could be a bond between surfaces, the bond (e.g., an edge or boundary of the bond) extending along a straight line in a direction perpendicular to (at a 90 degree angle relative to) the length dimension of the package, also perpendicular to the longitudinal edges, and aligned with a width dimension of the package. According to the invention, one or more seal includes an edge that is not a straight line perpendicular to the length dimension of the package and aligned with a width dimension, but is a straight or curved line that includes a directional component in a direction toward the opposite end; a single end of the package can be formed in this manner, or both ends may be formed in this manner. 
     Optionally, but not necessarily, the upper-left connection can be bonded to the lower-left connection and the upper-right connection can be bonded to the lower-right connection. In these versions of an end, one or more of the side pieces can include an aperture or hole at the location of the end seal to allow bonding between the end of the top side and the end of the bottom side. 
     The package can be prepared from one or more pieces of material suitable to contain a food or non-food product under pressure. Examples of useful materials include flexible films including flexible film materials known in the packaging arts, such as paper, polymeric or plastic materials. Specific examples include polyolefins such as polyethylene, and polypropylene, nylon, polyester, and the like. A film may be of a single or multiple materials including paper or polymeric base layer may be treated with a coating or film such as a metal foil layer, a plastic barrier or sealer layer added to a paper or cardboard (e.g., nylon, ethylene vinyl alcohol, polyethylene, polyvinyl chloride, polyvinylidene chloride, polypropylene, etc.), an adhesive or adhesive layer (e.g., thermoplastic polyolefin), a liner ply, tie-layer, or other functional layers or features. In certain preferred embodiments a flexible film material may be recyclable. As used herein, a recyclable material may be a recyclable metal, plastic, or a recyclable paper. A recyclable paper may be a paper or cardboard material that has a non-paper content that does not exceed 5 percent by weight. 
     Exemplary packages for dough compositions such as sweet rolls, breads, rolls, buns, biscuits, and others, may have exemplary dimensions that include an interior space volume in the range from 50 to 800 cubic centimeters, e.g., from 200 to 500 cubic centimeters. Stated differently, a hollow container may be sized and shaped to contain a desired volume (e.g., based on number or portions) of dough product, for example, for some retail-sale products, to contain from 1 to 10 chemically leavened biscuits dough pucks; volumes outside of this range may also be useful for biscuit or other dough products. 
     A package may be of any three-dimensional shape, generally including a length dimension, a width dimension, two opposing ends, and longitudinal edges. A shape may be as desired, with examples including a tube having a square or rectangular cross section. For a package designed for a retail-type product, an exemplary length-wise dimension may be in the range of from 2 to 10 inches, e.g., from 4 to 8 inches, and a width may be in the range from about 1 to about 5 inches, e.g., from about 2 to about 4 inches. 
     The package can optionally and preferably be vented. A useful vent can be any type of vent that allows gas to be expelled from the interior, optionally also being capable of being closed or covered from the interior, such as by a food (e.g., dough) product expanding within the interior space. A vent can be located at any desired location, such as at a surface of a top or bottom. A vent can be of any size or design, including mechanical vents, microvents (see, e.g., Patent Application 2010/0021591, the entirety of which is incorporated herein by reference), or any other type of passage, channel, or opening that may potentially be sealed from an interior of a package 
     A package as described can include a vent and a vent cover as described in Assignee&#39;s copending provisional patent application U.S. Ser. No. 61/369,406, entitled “PACKAGE WITH VENT AND PRESSURE-ACTIVATED ADHESIVE,” having a filing date of Jul. 30, 2010, the entirety of which is incorporated herein by reference. A vent cover is a structure of the package located to cover or close a vent or vent opening. Examples of vent covers can include a surface that is sized, shape, and positioned to cover an opening of a vent at an interior side of the package, also contacting a surface of the package that is adjacent to the vent opening. 
     An exemplary vent cover can include a pressure-activated adhesive coating. A pressure-activated adhesive coating can be useful to maintain a vent cover in a position that closes the vent and prevents subsequent gas or fluid from passing through the vent. As used herein, a pressure-activated adhesive coating is coating that contains an adhesive (e.g., a pressure sensitive adhesive), where the coating as a practical matter does not exhibit properties of a pressure sensitive adhesive (e.g., tack, adhesion (shear or peel)) but that can be caused to exhibit adhesive properties by application of a pressure, such as a minimum amount of pressure referred to as a threshold pressure. A threshold pressure can be an amount of pressure that causes a pressure-activated adhesive coating to display properties of a pressure-sensitive adhesive, such as tack, shear adhesion, peel adhesion, etc., and may be an amount of pressure that disrupts, fractures, or breaks a features or structure of the coating that then releases or exposes a pressure-sensitive adhesive, such feature or structure may be, e.g., a polymeric sphere (e.g., “microsphere”), a polymeric coating, a glass sphere (e.g., “glass bead”), non-spherical matrix, etc. 
     Prior to being exposed to a threshold pressure to activate the adhesive, a pressure-activated adhesive coating does not function as a pressure-sensitive adhesive; subsequent to being exposed to a threshold pressure, the pressure-activated adhesive coating behaves as a pressure-sensitive adhesive. The activation by exposure of the adhesive coating to pressure may be accomplished by known methods, such as by use of coatings that contain polymeric beads or microspheres, glass beads, or other matrixes, wherein the beads or matrixes may contain adhesive or components of adhesive (e.g., different components of a reactive adhesive such as an epoxy). Upon exposure of the beads, spheres, coating, microspheres, or matrix to pressure (e.g., a threshold pressure), the beads, spheres, coating, microspheres, or matrix become disrupted and release or expose the adhesive. 
     A pressure-activated adhesive coating can be any useful pressure-activated adhesive coating, and for use in a package for containing food can preferably be “generally recognized as safe,” (GRAS). In an “unactivated” condition, prior to a threshold pressure being applied to a pressure-activated adhesive coating, one or more properties of tack, peel adhesion, and shear adhesion can be below values for a pressure-sensitive adhesive, e.g.: for example, an unactivated pressure-activated adhesive coating can exhibit substantially no adhesive property measured as tack (measured by ASTM-D3121-06); peel adhesion (measured by ASTM-D1876-08); or shear adhesion (measured by ASTM-D3654 or Adhesion D-3330). Upon activation by application of a threshold pressure, the pressure-activated adhesive coating can exhibit one or more property of a pressure-sensitive adhesive, such as a useful level of tack (measured by ASTM-D3121-06); a property of peel adhesion (measured by ASTM-D1876-08) of at least 80 gm/in; or a property of shear adhesion (measured by ASTM-D-3330) of at least 2.0 N/10 mm. 
     An adhesive contained in a pressure-activated adhesive coating can be any adhesive or adhesive component, such as any adhesive known within adhesive arts as “pressure-sensitive adhesives” or “PSA.” Pressure-sensitive adhesives are known compositions that exhibit one or more adhesive properties of tack, peel adhesion, shear adhesion, that can adhere to an adherend surface based on contact and without the requirement of solvent, water, or heat to activate the adhesive. Examples of include poly olefins (e.g., poly-alpha olefins), polyacrylates, polystyrene and polystyrene block copolymers, vinyl ethers, ethylene-vinyl acetate, butyl rubber, nitriles, natural rubber, and the like. 
     A pressure-activated adhesive coating may be applied to a substrate by known methods, such as coating from solvent (e.g., organic or aqueous), hot-melt coating, etc., as desired. The amount can be an amount to provide desired adhesive properties before and after application of a threshold pressure. 
     A pressure-activated adhesive coating can be coated or otherwise placed on a surface of a vent cover or portion thereof. The vent cover or portion thereof such as a film or other substrate may be flexible and optionally elastic. A film substrate may be any material that is sufficiently flexible and optionally elastic or non-elastic, as desired, to be placed as described at a vent or vent opening of a package, and optionally capable of being bent, deflected, stretched, or otherwise pressured against the vent or vent opening to close or cover, and optionally seal the vent or vent opening. Materials can be known films made of and paper, polymeric, or metallic (e.g. foil) materials with specific examples including flexible polymeric film materials known to be useful for coated adhesive products such as adhesive tapes, or for food product packages. These can include acetate film, cellulose films, polyolefin films, polyester films, polyamide films, and the like. 
     In particular embodiments, a pressure-activated adhesive can be included on a vent cover that is in the form of a “patch,” i.e., a piece (generally small) of material sized to cover a vent or a vent opening and that can be affixed to a surface at an interior of a package in a manner to cover the vent or vent opening. The patch can include a substrate as described (e.g., a film), pressure-activated adhesive on a surface, and optionally pressure-sensitive adhesive on a surface. Some embodiments of vent covers can additional (optionally) include a structure that causes separation between the pressure-sensitive adhesive and a vent or vent opening, e.g., a separator, spacer, extension, or the like, that places a vent cover or a portion of a vent cover over a vent or vent opening, and a distance away from the vent or vent opening. The distance may be small, such as less than a millimeter. 
     In use, a vent cover that includes a pressure-activated adhesive allows fluid (e.g., gas or liquid) to escape from an interior space of the package by passing through a vent. For example, when a package contains a dough product that expands within the package, the expanding dough causes gas to be expelled from within the package through the vent. As pressure continues to increase within the package, such as by dough product continuing to expand, pressure builds within the package and the increased pressure can become applied against the vent cover and the surface of the vent cover that includes pressure-activated adhesive. At a threshold pressure the adhesive of the pressure-activated adhesive coating becomes activated and achieves adhesive properties (e.g., useful tack, and peel of 80 gm/in). Upon activation of the adhesive the surface of the vent cover, and an opposing surfaces at or adjacent to a vent or vent opening, become adhered together to close the vent and prevent further passage of fluid through the vent. 
     Optionally, a portion of a vent cover, e.g., a cover portion, can move between an open and a closed configuration. In an open configuration a vent cover may be separated from a vent opening and be positioned a distance away from the vent opening to allow unrestricted flow of fluid from the interior space of the package and out of the vent. In a closed configuration the cover portion can become repositioned to cover or close the vent opening, for example by pressure being exerted on the cover portion to cause the cover portion to move against the vent opening. The cover portion can be held in place by a support structure, if desired, that allows movement of the vent cover portion between the “open” and “closed” positions. 
       FIGS. 1A and 1B  illustrates a package that does not include an end seal of the invention, having an edge or boundary with a directional component in a direction toward the opposite end, but having a seal that includes a bond (edge or boundary) that extends in a direction aligned with the width of the package. Referring to  FIG. 1A , package  2  includes top side  4 , left folded side  6 , longitudinal edges  8 , and sealed ends  10 . Bottom side  14  and right folded side  16  are not shown. Optional valve  12  is on top side. Each of folded sides  6  and  16  and top and bottom sides  4  and  14  can be made of one sheet of flexible film folded and formed into package  2 , optionally with adhesive to form each longitudinal edge  8 . Alternately, each of folded sides  6  and  16  and top and bottom sides  4  and  14  can be made of a separate sheet of flexible film folded and formed into package  2 , with adhesive to secure edges at each longitudinal edge  8 . Sealed ends  10  each include a bond that extends along a line  18 , in a direction along the width dimension (designated w) and perpendicular to the length direction ( 1 ). Fold line  3 , dashed, indicates the location of a fold in each of left folded side  6  and right folded side  16  at a medial location of end  10  relative the width dimension. 
       FIG. 1B  shows a top view, again illustrating that line  18  is in the direction of the width dimension of package  2 , perpendicular to the length dimension. 
       FIG. 1C  is an end view that shows upper-left connection  20  between a left portion of an end of top side  4  and an upper portion of an end of left folded side  6 , upper-right connection  22  between a right portion of an end of top side  4  and an upper portion of an end of right folded side  16 , lower-left connection  24  between a left portion of an end of bottom side  14  and a lower portion of an end of left folded side  6 , and lower-right connection  26  between a right portion of an end of bottom side  14  and a lower portion of an end of right folded side  16 . As illustrated at  FIG. 1C , upper-left connection  20  is not bonded to lower-left connection  24 , and upper-right connection  22  is not bonded to lower-right connection  26 . Optionally, in alternate versions, upper-left connection  20  is bonded to lower-left connection  24 , and upper-right connection  22  is bonded to lower-right connection  26 . Apex  5  is a location at which medial ends of each of connections  20 ,  22 ,  24 , and  26  meet, and is also adjacent to two opposing folds of left folded side  6  and right folded side  16 . At this location (apex  5 ) converge sealed end  10  and folds of the opposing left folded side  6  and right folded side  16 , creating a pressure point and potential locus of failure. 
     According to packages of the invention, in contrast to the squared sealed ends of package  2 , a seal (e.g., an edge, border, or boundary of a seal) at an end of an inventive package is shaped to be non-perpendicular to a width dimension of the package, i.e., the seal (edge, border, or boundary) is shaped to extend from a medial location (e.g., apex at which connections of the seal meet) in a width direction and also in a direction toward the opposite end of the package.  FIG. 2A  shows package  32  that includes sealed end  41 , sealed by adhesive and pressure. Package  32  also includes left longitudinal edge  40 , right longitudinal edge  42 , top side  44 , and optional valve  46 . Fold line  43 , dashed, indicates the location of a fold in each of a left folded side and right folded side at a medial location of end  41  relative the width dimension. Sealed end  41  includes left sealed area  34  extending along straight line  37  (edge, border, or boundary of sealed area  34 ) angled away from apex  38  and end edge  47  in a direction toward a second end (not shown) of package  32 . Right sealed area  36  extends along straight line  50  angled away from apex  38  and end edge  47  in a direction toward a second end (not shown) of package  32 . Also designated at  FIG. 2A  is angle alpha (α), which is an angle between a line ( 9 ) extending away from apex  38  in a width dimension, and line  50  along the boundary of sealed area  36  (alternately referred to as the miter angle).  FIG. 2B  is similar, but straight lines  37  and  50  are replaced by curved lines  29  and  51  (edges, borders, or boundaries of sealed areas  34  and  36 ). 
     Package  32  includes upper-left connection  31  between a left portion of an end of top side  44  and an upper portion of an end of a left folded side (not shown), and upper-right connection  33  between a right portion of an end of top side  44  and an upper portion of an end of a right folded side (not shown). Also included in package  32  but not shown are a lower-left connection between a left portion of an end of a bottom side and a lower portion of an end of a left folded side, and a lower-right connection between a right portion of an end of a bottom side and a lower portion of an end of a right folded side. Optionally, upper-left connection  31  can be bonded or need not be bonded to the lower-left connection. Also optionally, upper-right connection  33  can be or need not be bonded to the lower-right connection. 
     A package of the invention can be formed by any means and method, from one sheet of flexible film material or from multiple pieces of flexible material. For example, multiple pieces may include a piece for a top side, a piece for a bottom side, a piece for a folded left side, and a piece for a folded right side, held together by any means such as adhesive along longitudinal edges. 
       FIGS. 3A  (top view) and  3 B illustrate the use of a single piece of flexible film material, sheet  90 , to prepare a package as described, e.g., as illustrated at  FIG. 2A  or  2 B. Package  32  includes top side  44  (visible at top view  3 A), sealed end  41 , sealed end  60 , upper-left longitudinal edge  40 , and upper-right longitudinal edge  42 . (Features not shown at  FIG. 3A  include bottom side  82 , right folded side  80 , left folded side  84 , lower-left longitudinal edge  88 , and lower-right longitudinal edge  86 .) Sealed end  41  includes sealed left area  34  and sealed right area  48 , including areas between end edge  47  and lines  37  and  50  (which areas also meet at apex  38  and fold line  43 ; fold lines  43  and  71  at ends  41  and  60 , respectively, corresponds to portions of fold lines  81  and  83  of  FIG. 3B ). Sealed end  60  includes sealed left area  64  and sealed right area  68 , including the areas between end edge  67  and lines  66  and  70  (which lines meet at apex  69 ). 
     Package  32  can be prepared from sheet  90  shown at  FIG. 3B . Sheet  90  may be any useful flexible package film such as polyester, which may be one or multiple layers such as a base layer and a coated metal layer. Sheet  90  can be a uniform, flat flexible film that can be folded and processed to produce package  32 .  FIG. 3B  schematically illustrates areas and lines for processing (e.g., folding and bonding) sheet  90  into package  32 , as follows; the recited features are not necessarily physical features of sheet  90 . 
     Sheet  90  is designated to include four package “sides”: top side  44 , right folded side  80 , bottom side  82 , and left folded side  84 . Between top side  44  and right folded side  80  are two relatively long and narrow areas  42 , which can be folded onto each other and bonded (e.g., by adhesive) to produce upper-right longitudinal edge  42 . Between right folded side  80  and bottom side  82  are two relatively long and narrow areas  86 , which can be folded onto each other and bonded (e.g., by adhesive) to produce lower-right longitudinal edge  86 . Between bottom side  82  and left folded side  84  are two relatively long and narrow areas  88 , which can be folded onto each other and bonded (e.g., by adhesive) to produce lower-left longitudinal edge  88 . At opposing length-wise edges of sheet  31  are long and narrow areas  40 , which can be bonded together to produce upper-left longitudinal edge  40 . 
     Fold lines  81  and  83 , are shown as dashed lines extending longitudinally between opposing ends of sheet  90 . Fold lines  81  and  83  represent a location of a potential fold. A fold can exist along each of fold lines  81  and  83 , from end to end and along the entire length of a package  32  prepared from sheet  90 , e.g., while a package  32  is empty. Upon placement of contents into package  32 , folded left and right sides  80  and  84  become unfolded at locations between ends  41  and  60 . To produce sealed ends  41  and  60 , folded left and right sides  80  and  84  are folded at locations of sealed ends  41  and  60 , and folded left and right sides  80  and  84  may become partially or fully un-folded between sealed ends  41  and  60  upon placement of contents into package  32 . 
     Still referring to  FIG. 3B , the designated areas and lines are placed in the illustrated order to allow sheet  31  to be folded along lines in the length dimension to produce package  32 . In specific, a longitudinal fold can be made to fold and bond together areas  42  at opposing surfaces (of these areas) to produce upper-right longitudinal edge  42 . Likewise, longitudinal folds can be made to fold and bond together areas  86  at their opposing surfaces, and areas  88  their at opposing surfaces, to produce lower-right longitudinal edge  86 , and lower-left longitudinal edge  88 , respectively. Areas  40  can be bonded together at opposing surfaces to produce upper-left longitudinal edge  40 . 
     After folding to produce the four recited longitudinal edges  40 ,  42 ,  86 , and  88 , sheet  90  can form an elongate tube with two opposing open ends. A desired content can be placed into the package, which will expand the package and cause folds of the two opposing folded sides to become at least partially unfolded. One end can optionally be sealed before placing contents into the package. Alternately, contents can be placed into the package, a first end can be sealed to produce sealed end  41 , and the opposing end can be sealed to produce sealed end  60 . 
       FIG. 3C  is an end view of package  32  in a longitudinal direction toward sealed end  41 . As illustrated, sealed end  41  includes four connections that can be surfaces of various areas of sheet  90 , bonded by adhesive or other bonding means (e.g., heat, pressure, welding, or a combination of two or more of these). Upper-left connection  31  is formed between a surface of a left portion of an end of top side  44  and a surface of an upper portion of an end of left folded side  84 . Upper-right connection  33  is formed between a surface of a right portion of an end of top side  44  and an upper portion of an end of right folded side  80 . Lower-left connection  94  is formed between a left portion of an end of bottom side  82  and a lower portion of an end of left folded side  84 . Lower-right connection  96  is formed between a right portion of an end of bottom side  82  and a lower portion of an end of right folded side  80 . As illustrated at  FIG. 3C , upper-left connection  31  is not bonded to lower-left connection  94 , and upper-right connection  33  is not bonded to lower-right connection  96 . Optionally, in alternate embodiments, upper-left connection  31  is bonded (e.g., by adhesive) to lower-left connection  94 , and upper-right connection  33  is bonded (e.g., by adhesive) to lower-right connection  96 . 
       FIGS. 4A  (top view),  4 B,  4 C, and  4 D show alternate embodiments of package  32  and sheet  90 , which are similar to those of  FIGS. 3A ,  3 B, and  3 C, with the addition of apertures  100  at ends of folded right side  80  and folded left side  84 . Apertures  100  are located at surfaces at ends of left folded side  84  and right folded side  80  so that when sheet  90  is folded to produce a tube with two opposing open ends (by producing longitudinal edges  40 ,  42 ,  86 , and  88 ), and right folded side  80  and left folded side  84  are folded along fold lines  81  and  83 , apertures  100  align to allow contact between a surface at an end of top side  44  and a surface at an end of bottom side  82 . 
       FIG. 4C  shows an end-perspective view of sheet  90  folded into a tube with an open end capable of being sealed to form sealed end  41 . Apertures  100  are located at ends of left folded side  84  and right folded side  80 .  FIG. 4D  shows an end cross-sectional view of sealed end  41  of package  32  of  FIG. 4A . As illustrated, sealed end  41  includes four connections formed between surfaces of sheet  90 , bonded by adhesive or other bonding means. Upper-left connection  31  is formed between a surface of a left portion of an end of top side  44  and a surface of an upper portion of an end of left folded side  84 . Upper-right connection  33  is formed between a surface of a right portion of an end of top side  44  and an upper portion of an end of right folded side  80 . Lower-left connection  94  is formed between a left portion of an end of bottom side  82  and a lower portion of an end of left folded side  84 . Lower-right connection  96  is formed between a right portion of an end of bottom side  82  and a lower portion of an end of right folded side  80 . As illustrated at  FIG. 4D , upper-left connection  31  is bonded to lower-left connection  94 , and upper-right connection  33  is bonded to lower-right connection  96 . Apertures  100  are shown to align as left folded side  84  and right folded side  80  are each in a folded configuration, to allow contact between surface  102  of top side  44  and opposing surface  104  of bottom side  82 , resulting in added strength of sealed end  41 . 
     Apertures  100  of  FIGS. 4C and 4D  are exemplary and illustrated, and can be sized and shaped to provide a desired bond between top side  44  and bottom side  82 , extending between right and left folded sides.  FIGS. 5A  (top view),  5 B,  6 A (top view),  6 B,  7 A (top view),  7 B, and  8 A (top view) and  8 B illustrate alternate apertures  100  as part of packages  32 . At  FIGS. 4A ,  4 B,  4 C,  4 D,  5 A  5 B,  7 A  7 B,  8 A, and  8 B, apertures  100  are further designated as aperture  100 R associated with right folded side  80 , and aperture  100 L associated with left folded side  84 . 
     A package as described can be used to contain any type of food or non-food product, e.g., under pressure (at an interior pressure that is above atmospheric pressure). Particular embodiments of packages can be used to contain raw dough. A dough contained by a package as described may be of any formulation, with preferred doughs being capable of expanding within the package to contact a vent to seal the package from within. The dough generally will have a rheology, formulation (e.g., water content), and texture to allow expansion of the dough inside the package, against the package interior, optionally and preferably to contact and close a vent from the package interior. The dough may be yeast or chemically leavened, and for use according to the invention may desirably include a leavening system that provides predictable leavening and expansion after packaging and during refrigerated storage. 
     Examples of useful dough types include developed and non-developed chemically leavened doughs such as bread doughs, pizza doughs, sweet rolls, rolls, etc. Specific formulations of dough compositions that may be useful as doughs within the present description, include chemically leavenable dough formulations, yeast-leavened dough formulations, combinations of yeast and chemically leavened dough formulations. The dough may be a developed dough formulation or a non-developed dough, such as one of those described in any of the following patent applications: U.S. Ser. No. 09/945,204, filed Aug. 31, 2001, titled “CHEMICAL LEAVENED DOUGHS AND RELATED METHODS,” (now U.S. Patent Publication No. 2003/0049358); U.S. Ser. No. 10/446,481, filed May 28, 2003, titled “PACKAGED DOUGH PRODUCT IN FLEXIBLE PACKAGE, AND RELATED METHODS,” (now U.S. Patent Publication No. 2004/0241292); U.S. Ser. No. 10/273,668, filed Oct. 16, 2002, titled “DOUGH COMPOSITION PACKAGED IN FLEXIBLE PACKAGING WITH CARBON DIOXIDE SCAVENGER AND METHOD OF PREPARING,” (now U.S. Pat. No. 7,235,274); U.S. Ser. No. 11/132,831, filed May 19, 2005, titled “PACKAGED, NON-DEVELOPED DOUGH PRODUCT IN LOW PRESSURE PACKAGE, AND RELATED COMPOSITIONS AND METHODS,” (now U.S. Patent Publication No. 2005/0271773); U.S. Ser. No. 11/132,826, filed May 19, 2005, titled “PACKAGED, DEVELOPED DOUGH PRODUCTION IN LOW PRESSURE PACKAGE, AND RELATED METHODS,” (now U.S. Patent Publication No. 2005/0281922); U.S. Ser. No. 12/306,745, filed Aug. 24, 2009, titled “DOUGH PRODUCT AND VENTED PACKAGE,” (now U.S. Patent Publication No. 2010/0021591); and U.S. Ser. No. 11/334,301, filed Jan. 18, 2006, titled “REFRIGERATED DOUGH AND PRODUCT IN LOW PRESSURE CONTAINER,” (now U.S. Patent Publication No. 2006/0177558); the entireties of each of these being incorporated herein by reference. 
     As stated, the packaged dough product can include any type or formulation of yeast or chemically-leavenable dough composition that expands, such as by production of carbon dioxide, after packaging and optionally during refrigerated storage. Many if not all formulations of (pre-proofed or unproofed) yeast and chemically-leavenable dough compositions evolve an amount of carbon dioxide prior to or during refrigerated storage, causing expansion of the dough as presented in this description, within a package having vents. 
     Preferred dough compositions can be formulated, in combination with selection of a size of an internal volume of a package and an amount (e.g., volume) of dough to be contained within the package, such that upon expansion of the dough within the package a desired internal pressure is achieved. An exemplary pressure can be a positive pressure (gauge) such as greater than one atmosphere (0 psig), such as a pressure in the range from 1 to 30 pounds per square inch, gauge (psig), such as within the range from 5 to 25 psig. The dough can be placed in the package at a specific volume that is below the specific volume to which the dough will expand in the package, e.g., a specific volume of less than 2.0 cubic centimeters per gram (cc/g), such as below 1.5 cc/g, or a specific volume in the range from 0.9 to 1.1 or 1.2 cc/g. After being placed in the package, and after the package is closed (e.g., a closure is placed on an opening) the dough can expand to partially proof or proof within the package to a desired raw specific volume. An example of a partially-proofed or pre-proofed dough may be a dough having an expanded raw specific volume in the range from 1.5 to 2.0 cubic centimeters per gram (as measured after removal from the package). 
     Yeast and chemically-leavened dough compositions can be prepared from ingredients generally known in the dough and bread-making arts, typically including flour, a liquid component such as oil or water, a leavening agent such as yeast or chemical leavening agents, and optionally additional ingredients such as shortening, salt, sweeteners, dairy products, egg products, processing aids, emulsifiers, particulates, dough conditioners, yeast as a flavorant, flavorings, and the like. 
     As an example, unproofed doughs generally have a raw specific volume within the approximate range of 0.9 to 1.1 cubic centimeters per gram (cc/g). An amount of dough having predictable refrigerated leavening properties can be expected to expand to a desired raw specific volume during refrigerated storage, when allowed to expand within a fixed-volume container. A relevant parameter is the amount of unleavened raw dough volume compared to internal package volume (meaning a fixed or a maximum or “expanded” package volume). According to embodiments of the invention, a volume of unproofed dough per package volume (e.g., having a raw specific volume in the range from 0.9 to 1.1) can be about 50 to 31 percent dough volume per package volume, such as from 80 to 85 percent dough volume to package volume. With certain doughs of the invention, having predictable refrigerated leavening properties, this ratio of non-expanded dough to maximum package volume has been identified as useful to produce a packaged dough product having an internal pressure of 1 to 30 psig, e.g., 5 to 25 psig, or 8 to 15 psig, after allowing the dough to expand inside of the package to a raw specific volume in the range from 1.5 to 2.0 cc/g, e.g., 1.6 to 1.9 cc/g (measured after removal from the package). 
     Dough compositions that exhibit predictable refrigerated leavening properties can include various types of dough, including doughs formulated with yeast for leavening, chemical leavening systems, or a combination of yeast and chemical leavening systems used for leavening. Doughs may be developed or non-developed types of doughs and dough products. Yeast-leavened doughs can exhibit predictable refrigerated leavening properties based on selection of a yeast that has predictable behavior such as a substrate-limited yeast (in combination with selected substrates), a cold-temperature sensitive yeast, combinations of these types of yeasts, and combinations of these types of yeasts with other ingredients such as a cold-temperature sensitive yeast used in combination with ethanol. Examples of these types of predictable yeasts are described in U.S. Pat. Nos. 5,939,109, 5,798,256, 5,759,596, 5,650,183, the entireties of which are incorporated herein by reference. 
     Other examples dough formulations having predictable refrigerated leavening properties can be certain types of chemical leavened doughs, such as those formulated with acidic or basic chemical leavening agents that are specifically chosen to produce a desired effect on the timing or amount of leavening during refrigerated storage. 
     Chemically-leavenable (also referred to as “chemically-leavened”) dough compositions are dough compositions that leaven to a substantial extent by the action of chemical ingredients that react to produce a leavening gas. Typically the ingredients include a basic chemical leavening agent and an acidic chemical leavening agent that react to produce carbon dioxide, which, when retained by the dough matrix, causes the dough to expand. 
     Acidic chemical leavening agents are generally known in the dough and bread-making arts, with examples including sodium aluminum phosphate (SALP), sodium acid pyrophosphate (SAPP), monosodium phosphate, monocalcium phosphate monohydrate (MCP), anhydrous monocalcium phosphate (AMCP), dicalcium phosphate dihydrate (DCPD), glucono-delta-lactone (GDL), as well as a variety of others. Commercially available acidic chemical leavening agents include those sold under the trade names: Levn-Lite® (SALP), Pan-O-Lite® (SALP+MCP), STABIL-9® (SALP+AMCP), PY-RAN® (AMCP), and HT® MCP (MCP). Optionally, an acidic chemical leavening agent can be encapsulated. Optionally, a combination of acidic agents can be useful to produce desired leavening properties; e.g., a dough formulation may include a soluble acidic agent to produce a desired (predictable) amount of leavening and expansion of a dough during refrigerated storage, and an amount of low solubility acidic agent can be included to produce additional expansion during baking. 
     Soluble acidic chemical leavening agent is considered to be soluble in a liquid (e.g., aqueous) component of the dough composition, at a temperature used during processing (e.g., from 40 to about 72 degrees Fahrenheit) or refrigerated storage (e.g. from about 32 to about 55 degrees Fahrenheit). A soluble acidic chemical leavening agent is an acidic agent that is sufficiently soluble to dissolve in a dough composition at a temperature within processing and refrigerated storage ranges to react with a basic chemical agent if available, e.g., is freely soluble or will substantially entirely dissolve. Particularly useful soluble acidic chemical leavening agents include glucono-delta-lactone and sodium acid pyrophosphate (SAPP) of a moderate to high solubility e.g., SAPP 60, SAPP 80, as well as other acidic chemical leavening agents that exhibit similar solubility behavior. 
     Soluble acidic chemical leavening agent can be present in an amount that provides refrigerated stability, desired refrigerated raw specific volume, and desired baked leavening properties following refrigerated storage. Exemplary amounts of soluble acidic agent can be included to provide a raw specific volume in the range from 1.5 to 2.0 grams per cubic centimeter upon expansion during refrigerated storage, as well as a desired baked specific volume upon baking, such as a baked specific volume in the range from 3.0 to 4.5. 
     Insoluble acidic chemical leavening agent refers to acidic chemical leavening agents that are not substantially soluble at a processing or refrigeration temperature, but are insoluble or only slightly soluble at processing and refrigerated storage temperatures, and that are substantially soluble at temperatures that a dough reaches during baking (e.g., early baking). Insoluble acidic chemical leavening agents include sodium aluminum phosphate (SALP) and other acidic chemical leavening agents that have solubility properties that are similar to SALP. 
     A combination of soluble and insoluble acidic agents may be useful to produce a combination of desired raw and baked specific volumes. A desired raw specific volume can result from the soluble acidic agent reacting to produce a desired amount of leavening gas during processing or refrigerated storage. A desired baked specific volume can result from the insoluble acidic agent reacting to produce an amount of leavening gas during baking. 
     The total amount of acidic chemical leavening agent included in a dough composition can be an amount that is useful to prepare a dough composition having desired raw and baked specific volumes, and desirable expansion properties for use within a package of this description. An amount of acidic agent that is stoichiometric to the amount of basic agent can be useful, as well as amounts that are above and below a stoichiometric amount. Amounts of acid or base leavening agents are sometimes used in amounts based on neutralization value, which is the amount of base (by weight) neutralized by 100 parts by weight leavening acid. Amounts of soluble and insoluble acidic agents can be in the range from 40:60 to 60:40, based on neutralization values. Specific exemplary ranges of useful amounts of total acidic chemical leavening agent (e.g., soluble acidic agent, insoluble acidic agent, or a combination of these), can be in the range from about 0.5 to about 2.75 weight percent based on the total weight of a dough composition, including the range from about 0.75 to about 2.25 weight percent, based on total weight of a dough composition. 
     The dough composition also includes basic chemical leavening agent, such as an encapsulated basic chemical leavening agent. Useful basic chemical leavening agents are generally known in the dough and baking arts, and include soda, i.e., sodium bicarbonate (NaHCO 3 ), potassium bicarbonate (KHCO 3 ), ammonium bicarbonate (NH 4 HCO 3 ), etc. These and similar types of basic chemical leavening agents are generally freely soluble in an aqueous component of a dough composition at processing and refrigerated storage temperatures. 
     The amount of basic chemical leavening agent used in a dough composition may be sufficient to react with the included acidic chemical leavening agent to release a desired amount of gas for leavening, thereby causing a desired degree of expansion of the dough product. Exemplary amounts of basic chemical leavening agent such as sodium bicarbonate may be in the range from about 0.2 or 0.25 to about 1.5 weight percent based on the total weight of a dough composition, including the range from about 0.75 to about 1.25 weight percent based on total weight of a dough composition. (As used throughout this description and claims, unless otherwise noted, amounts of basic chemical leavening agents and encapsulated basic chemical leavening agents are given in terms of the amount of active basic agent, not including the weight of any encapsulant or barrier material.) 
     Encapsulated basic chemical leavening agents are generally known, and can be prepared by methods known in the baking and encapsulation arts. An example of a method for producing enrobed particles is the use of a fluidized bed. 
     A dough for use according to this description, whether chemically or yeast-leavened, developed, or non-developed, can contain other ingredients generally known in the dough and bread-making arts, typically including flour, a liquid component such as oil or water, sugar (e.g., glucose), chemical leavening agents as described, and optionally additional ingredients such as shortening, salt, dairy products, egg products, processing aids, emulsifiers, particulates, dough conditioners, yeast as a flavorant, other flavorings, etc. Many dough formulations are known to those skilled in the dough and baking arts and are readily available to the public in commercial cookbooks. 
     A flour component can be any suitable flour or combination of flours, including glutenous and nonglutenous flours, and combinations thereof. The flour or flours can be whole grain flour, flour with the bran and/or germ removed, or combinations thereof. Typically, a dough composition can include between about 30 and about 50 weight percent flour, e.g., from about 35 to about 45 weight percent flour, based on the total weight of a dough composition. 
     Examples of liquid components include water, milk, eggs, and oil, or any combination of these, as will be understood to be useful in chemically-leavened, non-developed dough compositions. Water from these components and similar ingredients is available to hydrate flour or protein, and is understood to be “available water.” For example, liquid components may provide available water (added as an ingredient and as part of other ingredients), e.g., in an amount in the range from about 15 to 40 weight percent, e.g., from 25 to 35 weight percent, although amounts outside of this range may also be useful. Water may be added during processing in the form of ice, to control the dough temperature in-process; the amount of any such water used is included in the amount of liquid components. The amount of liquid components included in any particular dough composition can depend on a variety of factors including the desired moisture content of the dough composition. 
     A dough composition can optionally include fat ingredients such as oils and shortenings. Examples of suitable oils include soybean oil, corn oil, canola oil, sunflower oil, and other vegetable oils. Examples of suitable shortenings include animal fats and hydrogenated vegetable oils. Fat may be used in an amount less than about 20 percent by weight, often in a range from 5 or 10 weight percent to 20 weight percent fat, based on total weight of a dough composition. 
     Dough compositions described herein can be prepared according to methods and steps that are known in the dough and dough product arts. These can include steps of mixing or blending ingredients, folding, lapping with and without fat or oil, forming, shaping, cutting, rolling, filling, etc., which are steps well known in the dough and baking arts. 
     Example packages were prepared and tested.
 
Two main end seal features contributed to unexpectedly high burst test values on the Mocon Skye Burst seal tester:
 
     1) Radiused or Mitered (straight-line, angled) end seal geometry (see  FIGS. 2B and 2A , respectively). 
     2) “Tacked end” seal flaps (see  FIGS. 4A-4D ,  5 A,  5 B,  6 A,  6 B,  7 A,  7 B,  8 A, and  8 B, showing embodiments with holes located at one or more of right folded side and left folded side portions of an end seal). 
     The tested packages include end seals prepared according to the following materials and seal settings:
         48 ga polyethylene terephthalate (PET)/1.5# adh/48 ga met PET/1.5# adh/2.5 mils Coex—linear low density polyethylene (LLDPE).   Serrated Heat Sealer: 260°, 60 pounds per square inch (psi), 1.5 seconds.
 
 FIGS. 9 and 10  show values of burst strength (pounds per square inch) of an end seal as described, having a “mitered” (angled) end seal, a “tacked end,” or both.
 
In other testing, the type (e.g., strength) of film material used to produce an end seal has been found to affect the strength of end seals. Stronger materials (Printpack met and Bemis met) result in stronger endseals at a mitered angle, relative to less strong materials (Printpack clear).
       

                                             burst average (psi) at   Psi burst average at miter           miter angle = 0 degrees   angle = 45 degrees                                                Printpack clear   2.1   7.1       Printpack met   2.4   12.0       Bemis met   3.8   12.9                    
Overall, failures at low pressure (1-2 psi) were observed at the gusset/seal apex (see  FIG. 1B ) on pouches made with the same dimensions using various materials, but that did not have a “radiused” or “mitered” end seal geometry or “tacked” end seals. Packages having various versions of “radiused” and “tacked end” seal profiles were prepared and tested. The modified sealed ends mitigated the pouch gusset stress points and showed unexpectedly high burst test values (up to 18 psi) on the Mocon Skye seal tester.