Patent Publication Number: US-2019185239-A1

Title: Easy peel pouch

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of United Kingdom Patent Application Serial No. 1610432.5, filed on Jun. 15, 2016, which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     Pouches are becoming a popular packaging option for many different materials. In situations in which it is desirable to have a large opening for accessing the contents of the pouch, prior art solutions typically require that the pouch be cut or torn open to create a break in the walls of the pouch. In order for the cut or tear to provide direct access to the contents, the break in the walls must extend through the enclosed space. This can create an issue in that breaking the walls that form the enclosed space can cause the contents in the enclosed space to unintentionally escape during opening. 
     One pouch design exists in which a linear top seal is designed to be hand-peeled apart. This pouch is designed for dry foodstuffs, which do not need to be sterilized after packaging. In situations in which the contents of the pouch must be retorted (sterilizing the contents), however, the packaging must be able to maintain the seal of the enclosed space through the retort process. This creates a difficulty if a hand-peelable seal is desired, since the seal should be strong enough to withstand retorting while still being easy to peel apart by the consumer. 
     BRIEF DESCRIPTION 
     Embodiments described herein provide for a flexible package comprising: a first wall; a second wall opposing with the first wall, wherein the first wall and the second wall are flexible; one or more permanent seals sealing the first wall to the second wall; an easy-peel seal sealing the first wall to the second wall, and having an elongated shape with a first and second end; and a plurality of flaps extending outward from the easy-peel seal, wherein the one or more permanent seals and the easy-peel seal define edges of an enclosed space between the first wall and the second wall, wherein the easy-peel seal extends between portions of the one or more permanent seals forming a first intersection of the first end of the easy-peel seal and the one or more permanent seals and a second intersection of the second end of the easy-peel seal and the one or more permanent seals; wherein when opening the package by pulling apart the plurality of flaps, the effective peeling force increases at least 5 N as the package is opened to the first and second intersections of the easy-peel seal and the one or more permanent seals; wherein the elongated shape of the easy-peel seal defines a convex portion which projects away from the enclosed space. 
     Other embodiments described herein provide for a flexible package comprising: a first wall; a second wall opposing with the first wall, wherein the first wall and second wall are flexible, wherein the package is configured to be opened proximate a first edge thereof; one or more seals sealing the first wall to the second wall and defining one or more edges of an enclosed space between the first wall and the second wall, the one or more seals including: a first seal portion extending from the first edge of the package toward a distal edge of the package, wherein an internal edge of the first portion defines a first edge of the enclosed space and an external edge of the first portion defines a second edge of the package; a second seal portion extending from the first edge of the package toward the distal edge of the package, wherein an internal edge of the second portion defines a second edge of the enclosed space laterally opposite the first edge of the enclosed space and an external edge of the second portion defines a third edge of the package laterally opposite the second edge of the package, wherein the first and second seal portions increase in width from the first edge toward the distal edge, wherein the second edge of the package and the third edge of the package are substantially parallel with one another, and wherein the first edge and the second edge of the enclosed space are angled with respect to one another forming an enclosed space which increases in width from the distal edge toward the first edge thereof 
     Still other embodiments described herein provide for a flexible package comprising: a first wall; a second wall opposing with the first wall, wherein the first wall and second wall are flexible, wherein the first wall and the second wall define: one or more seals sealing the first wall to the second wall and defining one or more edges of an enclosed space between the first wall and the second wall; and a plurality of package edges including: a first longitudinal edge; a second longitudinal edge substantially parallel with the first longitudinal edge; a third edge substantially transverse to the first edge and the second edge; a fourth edge extending between the first edge and the second edge, wherein the packaged is configured to be opened proximate the fourth edge, wherein the first edge and the second edge include a concave portion disposed between adjacent linear portions. 
     Yet other embodiments described herein provide for a method of manufacturing a wall of a flexible package, the method comprising: cutting at least a first row and a second row of package walls out of a sheet of flexible material such that each wall of the first row and second row has a common geometry and defines; a first longitudinal edge; a second longitudinal edge substantially parallel with the first longitudinal edge; a third edge substantially transverse to the first edge and the second edge; a fourth edge extending between the first edge and the second edge, wherein the fourth edge has a convex shape, wherein the first longitudinal edge of each wall of the first row and second row abuts the second longitudinal edge of an adjacent wall, wherein the fourth edge of each wall of the first row is oriented in a first direction, wherein the fourth edge of each wall of the second row is oriented in a second direction, wherein a first row of package walls is oriented 180 degrees in relation to a second row of package walls such that the fourth edge of the walls in the first row are oriented towards the fourth edge of the walls in the second row, wherein the first row of package walls is offset from the second row of package walls such that the convex shapes of the first row extend into concave areas defined between adjacent convex shapes of the second row and the convex shapes of the second row extend into concave areas defined between adjacent convex shapes of the first row. 
    
    
     
       DRAWINGS 
       Understanding that the drawings depict only exemplary embodiments and are not therefore to be considered limiting in scope, the exemplary embodiments will be described with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG. 1A  is a front perspective view of an example filled pouch. 
         FIG. 1B  is an edge perspective view of the filled pouch of  FIG. 1A . 
         FIG. 2  is a front view of the pouch of  FIG. 1A . 
         FIG. 3  is an enlarged cut-away front view of the pouch of  FIG. 2  showing the easy-peel seal and flap. 
         FIG. 4  is a front view of another example pouch in a filled state. 
         FIGS. 5A, 5B, and 5C  are front views of the pouch of  FIG. 2  showing example coverage areas for application of thermal/ultrasonic energy to create the one or more permanent seals and the easy-peel seal. 
         FIG. 6  is a top view showing an example pattern in which walls for the pouch of  FIG. 1A  can be cutout of a sheet of material. 
         FIG. 7  is a top view showing another example pattern in which walls for a pouch can be cutout of a sheet of material. 
         FIG. 8A  is a graph showing an example effective peel force during opening of the pouch of  FIG. 1A . 
         FIG. 8B  is a cut-away front view of the pouch of  FIG. 1A  showing the areas of the seals that correspond to the graph of  FIG. 8A . 
     
    
    
     DETAILED DESCRIPTION 
     The terms “first”, “second”, and the like, as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Also, the terms “a” and “an” do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item, and the terms “front”, “back”, “bottom”, and/or “top”, unless otherwise noted, are merely used for convenience of description, and are not limited to any one position or spatial orientation. 
     Reference throughout the specification to “one example” or “an example” means that a particular feature, structure, or characteristic described in connection with an example is included in at least one embodiment. Thus, the appearance of the phrases “in one example” or “in an example” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. 
       FIG. 1A  is a front perspective view and  FIG. 1B  is an edge perspective view of an example flexible package  100  (also referred to herein as “pouch  100 ”) having contents therein. The pouch  100  has an easy-peel seal  102  that is both easy-to-open and maintains a sufficiently strong seal. The pouch  100  is composed of two walls  108 ,  110  that are sealed together at a plurality of locations to form an enclosed space. The two walls  108 ,  110  are disposed opposite one another and are sealed together to define the edges of the enclosed space. 
     The walls  108 ,  110  of the pouch  100  are flexible. As used herein, flexible means that the walls  108 ,  110  are configured to bend substantially and remain in a bent state in response to contents being inserted into the pouch  100 . In an example, the walls must also be suitable for retorting. To be suitable for retorting the walls must be able to maintain an airtight seal for the enclosed space through the retort process. Example plastics that can be included in the walls  108 ,  110  include polypropylene, polyester, polyethylene, polyamide and/or a bio-based/bio-degradable plastic. In many examples, the walls are a laminate (e.g., 2 ply, 3 ply, 4 ply) including at least one layer of plastic. In a particular example, the walls  108 ,  110  are a laminate including a layer of polyethylene terephthalate (PET) for the outside of the pouch, a layer of polypropylene for the inside of the pouch, and a layer of aluminum therebetween. Other examples are also possible. Examples of wall compositions that are not considered flexible and are not suitable for pouch  100  include cardboard, boxboard, and the like. 
     In the example shown in  FIGS. 1A and 1B , the two walls  108 ,  110  have an identical geometry and the two walls  108 ,  110  are superposed to form the pouch  100 . With the two walls  108 ,  110  superposed, all of the edges of the wall  108  are aligned with the edges of wall  110  and vice versa. In alternative examples, the two walls  108 ,  110  can have different respective geometries and/or can be disposed opposite one another such that some of the edges of wall  108  do not align with an edge of wall  110 . The two walls  108 ,  110  can be portions of a single piece of material or can be distinct pieces of material. 
     The areas of the two walls  108 ,  110  that are sealed together are referred to herein as seals. The seals define the edges of the enclosed space. The seals include one or more permanent seals  104  and an easy-peel seal  102 . The one or more permanent seals are formed in a manner that is not intended to be peeled apart by a consumer. Accordingly, the one or more permanent seals  104  are formed with a higher effective peel force. The easy-peel seal  102  is formed in a manner that is intended to be hand-peeled apart by a consumer in order to access the contents of the pouch  100 . Accordingly, the easy-peel seal  102  is formed with a lower effective peel force than the permanent seal(s)  104 . 
     The easy-peel seal  102  is disposed to form a first edge of the enclosed space, while other edges of the enclosed space are formed by the permanent seal(s)  104 . In the example shown herein, the enclosed space has a generally rectangular geometry although other shapes can also be used. 
     The pouch  100  also includes a plurality of flaps  106  that project outward from the easy-peel seal  102 . At least a first flap  106   a  is formed of a portion of the piece of material that forms the first wall  108 , and at least a second flap  106   b  is formed of a portion of the piece of material that forms the second wall  110 . This enables the first flap  106   a  to be grabbed by one hand of a consumer and the second flap  106   b  to be grabbed by the other hand of the consumer. The consumer can then pull the flaps away from one another to peel apart the easy-peel seal  102 , and thus open the pouch  100 . In the example shown in  FIG. 1 , two flaps  106   a ,  106   b  are shown, each having a single outward projection with a rounded profile. In other examples, however, one or more of the flaps  106  can have multiple outward projections and/or the outward projection(s) can have a profile other than rounded (e.g., triangular, square, etc.). Additionally, in the example shown in  FIG. 1 , the two flaps  106   a ,  106   b  have the same profile and are superposed over one another, however, in other examples, one or more of the flaps  106  can have a different profile than an opposing flap and/or can be offset from an opposing flap. 
     Advantageously, providing an easy-peel seal  102  on a first edge of the enclosed space that has a lower effective peel force than permanent seal(s)  104  forming other edges of the enclosed space enables a consumer to open one edge of the enclosed space by pulling apart the easy-peel seal  102 , without opening the other edges formed by the permanent seal(s)  104 . In particular, as the easy-peel seal  102  is pulled apart, when the pulled-apart seal reaches the junctions between the easy-peel seal  102  and the one or more permanent seals  104 , there is a substantial increase in effective force required to continue pulling apart the seal(s). This increase in force is a tactile signal to the consumer to stop pulling and provides resistance to pulling apart more than the easy-peel seal  102  (e.g., resistance to pulling apart the permanent seal(s)  104 ). 
     Since opening the easy-peel seal  102  results in only one edge of the enclosed space being opened, and the opening is via breaking of the seal, the enclosed space  102  can be opened with less risk of spilling the contents of the enclosed space. In particular, in conventional pouches in which a top portion is torn off to open the enclosed space, the tear necessarily tears portions of the wall defining the enclosed space. Thus, a portion of the contents may unintentionally spill out during opening. Opening with the easy-peel seal  102  described herein, however, does not tear the walls of the enclosed space. Thus, the risk of unintentionally spilling out the contents of the enclosed space is reduced. 
     In an example, a resin is used in between the walls in the area of the easy-peel seal  102  to aid in forming a suitable seal. In an example, the resin is disposed on the entire internal surface of at least one of the walls  108 ,  110 . In an alternative example, such resin is applied only to portions of at least one of the walls  108 ,  110  in and around the seals  102 ,  104  and is not applied to other portions of the walls  108 ,  110 . In either case, the resin can be applied to only one of the walls  108 ,  110  or to both walls  108 ,  110 . Notably, the same resin can be used to create both the easy-peel seal  102  and the one or more permanent seals  104 . The difference in strength between the easy-peel seal  102  and the permanent seals  104 , therefore, is not created by use of a different resin or wall material. Instead, the difference in peel force is created by using a different combination of sealing time, force/energy, and temperature for the different seals  102 ,  104  as discussed above. An example resin for use in creating the seals  102 ,  104  is the Sealution™ resin manufactured by The Dow Chemical Company of Midland Mich. Advantageously, the easy-peel seals  102  and permanent seal(s)  104  made with the Sealution™ resin are suitable for retorting. That is, the seals  102 ,  104  can maintain an airtight seal around the enclosed space through the retort process. Other resins may also be used. 
     In the example shown in  FIGS. 1A and 1B , the pouch  100  consists of the two planar walls  108 ,  110  and any resins thereon. No other walls or sections of material are included. In other examples, however, a gusset can be included between the planar walls  108 ,  110  in the area laterally opposite of the easy-peel seal  102  to form what is commonly referred to as a stand-up pouch. The gusset can be a portion of a common piece of material with one or both of the walls  108 ,  110  or can be distinct piece of material. Other flexible package constructions are also possible. 
       FIG. 2  is a front view of the pouch  100 . The one or more permanent seals  104  of the pouch  100  include a first portion  202  and a second portion  204 , each having an elongated shape that extend substantially parallel to one another in a first direction  208 . The easy-peel seal  102  has an elongated shape that extends in a direction substantially transverse to the first direction  208 . The easy-peel seal  102  extends between the first portion  202  and the second portion  204  of the one or more permanent seals  104 , forming a continuous seal including the first portion  202 , the easy-peel seal  102  and the second portion  202 . 
     In the example shown in  FIGS. 1A-2 , the two walls  108 ,  110  are formed from different pieces of material. Accordingly, the one or more permanent seals  104  also include a third portion  206  having an elongated shape that extends between the first portion  202  and the second portion  204 , laterally opposite the easy-peel seal  102 . Accordingly, the easy-peel seal  102 , along with the first portion  202 , the second portion  204 , and the third portion  206  of the one or more permanent seals  104  form a continuous seal defining the perimeter of the enclosed space of the pouch  100 . 
     The easy-peel seal  102  and the one or more permanent seals  104  form a substantially rectangular perimeter around the enclosed space. In the examples shown in  FIGS. 1A, 1B, and 2 , the long edges of rectangular perimeter are formed by the first portion  202  and the second portion  204  of the one or more permanent seals  104 , and the short edges of the rectangular shape are formed by the third portion  206  and the easy-peel seal  102 . In other examples, however, the seals  102 ,  104  can form a substantially square perimeter around the enclosed space or the long edges and short edges can be switched from that shown herein such that the long edges are formed by the easy-peel seal  102  and the third portion  206  and the short edges are formed by the first portion  202  and second portion  204 . 
     In the example shown in  FIGS. 1A, 1B, and 2 , the pouch  100  has a generally rectangular shape. The first portion  202  and second portion  204  of the permanent seal(s)  104  extend along and define two edges  212 ,  214  of the rectangular pouch  100 . In this example, the first portion  202  extends along a first edge  212  of the pouch  100  and the second portion  204  extends along a second edge  214  of the pouch  100 , wherein the first edge  212  of the pouch  100  is laterally opposite the second edge  214  of the pouch  100 . In this example, the third portion  206  extends along and defines a third edge  216  of the pouch  100 . In an alternative example in which the two walls  108 ,  110  are formed from a common piece of material, the third edge  216  of the pouch  100  can be formed by a fold in the common piece of material. In such an alternative example, the third portion  206  of the one or more permanent seals may not be used. In yet other examples, one or more of the first portion  202 , second portion  204 , or third portion  206  can be disposed inward of the respective edge of the pouch  100 . 
     The easy-peel seal  102  can be disposed proximate a fourth edge  218  of the pouch  100 . In the example shown in  FIG. 2 , the fourth edge  218  of the pouch  100  is defined by the flaps  106  that project outward from the easy-peel seal  102 . Thus, in the implementation shown in  FIGS. 1A, 1B, and 2 , the first edge  212 , second edge  214 , and third edge  216  of the pouch  100  are three sides of a hypothetical rectangle and the fourth side of the rectangle is replaced with the curved edge  216  of the flap  106 . 
     In the example shown in  FIG. 2 , the first portion  202 , second portion  204 , and third portion  206  of the permanent seal(s)  104  have straight internal and external edges with radiused intersections there between. In other examples, however, one or more of the edges of the permanent seal(s)  104  can have curved portions and/or the intersections are not radiused. The easy-peel seal  102  has a complex shape discussed in detail below. The intersections between the easy-peel seal  102  and the first portion  202  and second portion  204  can also be radiused. 
     The easy-peel seal  102  and the one or more permanent seals  104  can have any suitable width. In an example, the easy-peel seal  102  and the one or more permanent seals  104  can all have the same width  220 , for example, of 3 mm. Other widths can also be used. 
     In the example shown in  FIG. 2 , however, the width  220  of the first portion  202  and the second portion  204  of the one or more permanent seals  104  is not constant. Instead, the width  220  of the first portion  202  and the second portion  204  increases from the end proximate the easy-peel seal  102  at least a portion of the way to the end that is distal from the easy-peel seal  102 . The increase in width  220  can be gradual and even along the length of the first and second portions  202 ,  204  as shown in  FIG. 2  or the increase can be stepped or formed in some other manner. In the implementation of this example, the width  220  increases all the way from easy-peel seal  102  to the third edge  216 . 
     Advantageously, the increase in width  220  enables the respective outside edges  212 ,  214  of the pouch  100  formed by the first and second portions  202 ,  204  to be parallel to one another, while the internal edges  222 ,  224  of the first and second portions  202 ,  204  defining the enclosed space can be angled with respect to one another. This angled relationship of the internal edges  222 ,  224  of the first and second portions  202 ,  204  can advantageously form an internal space that increases in width  226  at least near the easy-peel seal  102 , and in the example shown in  FIG. 2  the enclosed space can increase in width  226  along the entire length from the third edge  216  toward the easy-peel seal  102 . 
     This increase in width  226  towards the opening end of the pouch  100  can aid in the release of the contents from the pouch  100  after opening. This can be particularly beneficial if the contents of the pouch  100  are wet and viscous, such as a gelatinous substance. In such a situation, the contents of the pouch  100  tend to be held in the pouch  100  due to the suction caused by the viscous materials blocking airflow into the pouch  100 . The increase in width  226  of the enclosed space toward the opening of the pouch  100  provided by the decreasing width  220  of the first and second seam portions  202 ,  204  can reduce this suction. Moreover, this increase in width  226  of the enclosed space is provided without having to form a package having a correspondingly tapered edges  212 ,  214 . This enables adjacent pouches  100  in the assembly process to be formed with a common exterior edge  212 ,  214  because the edges  212 ,  214  of the pouches  100  can be perpendicular to the sheets of material. 
     The first and second portions  202 ,  204  can increase in width  220  by at least 25 percent (i.e., 1.25 times) or at least 50 percent (i.e., 1.5 times) from the end proximate the easy-peel seal  102  to the distal end. In a particular example, the first and second portions  202 ,  204  increase in width  220  by at least 2 mm. In a more specific example, the first and second portions  202 ,  204  have a width  220  that is less than 3.5 mm proximate the easy-peel seal  102  and is at least 5.5 mm at the end distal of the easy-peel seal  102 . In the example shown in  FIG. 1 , the first and second portions  202 ,  204  are about 3 mm at the ends proximate the easy-peel seal  102  and are about 6 mm at the ends distal from the easy-peel seal  102 . 
     In other examples, the first portion  204  and second portion  202  can have other geometries such as having a constant width  220  (e.g., 3 mm) along their respective lengths. In such examples, the inside edge  222 ,  224  of the first portion  202  and second portion  204  can be straight and can define a constant width  226  for the enclosed space from the end distal to the easy-peel seal  102  to the easy-peel seal  102 . While such a constant width  226  may not provide as much suction relief as an increasing width  226  of the enclosed space as discussed above, it can provide some suction relief as compared to configuration in which the width  226  of the enclosed space decreases near or towards the opening portion. 
     In other examples, the easy-peel seal  102  and the one or more permanent seals  104  can form other shapes and/or the pouch  100  can have a different shape. In the example shown a single enclosed space is formed on the pouch  100 , however, in other examples multiple enclosed spaces can be disposed on a single pouch, each enclosed space having a respective easy-peel seal  102  and permanent seal(s)  104 . 
       FIG. 3  is an enlarged cut-away front view of a portion of the pouch  100 .  FIG. 3  shows the easy-peel seal  102  and flap  106  in greater detail. As shown, the elongated shape of the easy-peel seal  102  curves outward to form a two-dimensionally convex portion  302  that projects away from a center of the enclosed space. The easy-peel seal  102  also includes two linear portions  304 ,  306 . Each linear portion  304 ,  306  extends from one end of the convex portion  302 . The first linear portion  304  extends from the convex portion  302  and intersects with the first portion  202  of the permanent seal  104 . Likewise, the second linear portion  306  extends from the convex portion  302  and intersects with the second portion  204  of the permanent seal(s)  104 . The linear portions  304 ,  306  can intersect the respective portions  202 ,  204  of the permanent seal(s)  104  at equal longitudinal (along first direction  208 ) locations along the respective portions  202 ,  204 . A hypothetical line  308 , substantially perpendicular to the first portion  202  and the second portion  204 , can be defined between the intersection of the first portion  202  and the first linear portion  304  and the intersection of the second portion  204  and the second linear portion  306 . In this example, the linear portions  302 ,  304  extend along this hypothetical line  308 , and thus intersect the first portion  202  and second portion  204  of the permanent seal(s)  104  at approximately a right angle. In an alternative example, the entire easy-peel seal  102  consists of only the convex portion  302 , such that the easy-peel seal  102  begins projecting outward immediately from the intersections with the permanent seal(s)  104 , and no linear portions  202 ,  204  are included. 
     The convex portion  302  while being convex from a perspective outside of the enclosed space, is two-dimensionally concave from a perspective inside the enclosed space. In this example, the convex portion  302  has a chevron shape, however, in other examples, the convex portion  302  can have other shapes such as a smooth arc. In this example, the two linear portions  304 ,  306  are substantially equal in length such that the convex portion  302  is centered along the length of the easy-peel seal  102 . 
     The convex portion  302  can project outward at least 2 mm, such that the apex of the external edge of the convex portion  302  is at least 2 mm outward of the hypothetical line  308  extending between the locations in which the easy-peel seal  102  and permanent seal(s)  104  intersect. In the example shown in  FIG. 2 , the apex of the convex portion  302  is about 3 mm outward from the hypothetical line  308 . 
     The convex shape of the convex portion  302  focuses the peeling force applied to the flaps  106  onto the apex of the convex portion  302 . This enables a large portion of the peeling force applied by the consumer to be focused on a small portion of the easy-peel seal  102 . In turn, this enables a given magnitude of force to peel apart a seal having a comparatively higher peeling force than a straight (non-convex) seal. This affect can be utilized to construct a pouch  100  having an easy-peel seal  102  with a comparatively higher seal strength than a straight-edged pouch, which may reduce the likelihood of the easy-peel seal  102  opening unintentionally, such as during a retort process. Such a retort process can include heating the pouch  100  having contents enclosed therein at 130 degrees Celsius for 45 minutes. 
     In this example, the easy-peel seal  102  intersects the respective portions  202 ,  204  of the permanent seal(s)  104  at the respective ends thereof, such that neither the first portion  202  nor the second portion  204  extends past the intersection with the easy-peel seal  102 . Thus, the outer edge of the intersections between the easy-peel seal  102  and the respective portions  202 ,  204  of the permanent seal(s) can define the edge-corner of the pouch  100 . Additionally, having the intersection of the easy-peel seal  102  and the permanent seal(s)  104  at the end of the permanent seal(s)  104  enables the convex portion  302  of the easy-peel seal  102  to project further outward toward the fourth edge of the pouch  100  than the permanent seal(s)  104 . Thus, when opening the pouch  100  using the flaps  106 , the convex portion  302  is the first part of the seals  102 ,  104  to which force is applied, and the force can accordingly be focused on the convex portion  302 , and not on the permanent seal(s)  104 . 
     In the example shown in  FIG. 3 , the width  312  of the easy-peel seal  102  is constant through the first linear portion  304 , the convex portion  302 , and the second linear portion  306 , not including the radiused intersection with the permanent seal(s)  104 . In other examples, however, the width  312  of the easy-peel seal  102  can vary along its length. For instance, the width  312  of the easy-peel seal  102  could be greater near the intersections with the permanent seal(s)  104  and less at the apex of the convex portion  302 . In such an implementation, the width could vary gradually from the intersections with the permanent seal(s)  104  to the apex and/or could vary in a stepwise manner. Such a varied width may be beneficial to allow easy starting of the opening of the easy-peel seal  102  while providing more resistance to opening as the easy-peel seal  102  is further opened, closer to the permanent seal(s)  104 . The increased resistance to opening closer to the permanent seal(s)  104  can provide a tactile signal to the consumer that the end of the opening portion is being reached. The consumer can respond to this tactile signal by reducing the force applied, which can reduce the chances of the permanent seal(s)  104  also being broken and/or of the wall  108 ,  110  being torn after the easy-peel seal  102  is fully opened. 
     The flaps  106  shown in  FIGS. 1A, 1B, 2, and 3  have a curved outer edge forming a two-dimensionally convex shape that is aligned horizontally  314  with the convex portion  302  of the easy-peel seal  102  (i.e., the apex of the flap  106  is aligned horizontally  314  with apex of the convex portion  302 ). As discussed above with respect to  FIGS. 1A and 1B , other configurations for the flaps  106  can be used. 
     The flaps  106  also include one or more features  310  which are raised or sunken in the flap  106 . The one or more features  310  can aid in providing grip for a consumer when pulling the flaps  102  to open in the easy-peel seal. In the example shown in  FIG. 3 , the one or more features  310  includes a plurality of elongated features extending in a direction generally parallel to the easy-peel seal  102 . In particular, the plurality of elongated features can be chevrons or arcs that project in the same direction as the convex portion  302  of the easy-peel seal  102  and are aligned horizontally  314  with the convex shaped flap  106  and/or the convex portion  302  of the easy-peel seal  102 . In other examples, other geometries of features can be used such as dots. The one or more features  310  can be raised or sunken at least 0.5 mm or at least 1 mm with respect to the main surface of the flap  106 . The one or more features  310  can be formed in any suitable manner such as through embossing. 
     As used herein, the “effective peel force” of a seal  102 ,  104  is intended to correspond closely to the magnitude of force experienced by a consumer when opening the pouch  100 . That is, it is intended that the easy-peel seal  102  require a lower “real-life” (hand-peelable) force to open than the permanent seal(s)  104 . Accordingly, as used herein, the effective peel force of the easy-peel seal  102  is the magnitude of force measured with a Zwick™ sealed-seam tester for flexible packaging materials, set-up such that the tester opens the easy-peel seal  102  in the manner intended for opening by the consumer. Thus, to measure the effective peel force of the easy-peel seal  102 , the Zwick™ sealed-seam tester is secured to the flaps  106  of the pouch  100 , and pulls apart the flaps  106  to open the easy-peel seal  102  in a steady manner. The magnitude of force measured with the Zwicki™ sealed-seam tester while the easy-peel seal is being pulled apart, until the easy-peel seal  102  is fully opened, is the effective peel force for the easy-peel seal  102 . 
     The effective peel force of the permanent seal(s)  104  is the magnitude of force measured with a Zwick™ sealed-seam tester as the flaps  106  are pulled further apart, after the easy-peel seal  102  is fully opened, while pulling apart the permanent seal(s)  104 . Pulling the flaps  106  further apart after the easy-peel seal  102  is fully opened can cause the permanent seal(s)  104  to be opened. The magnitude of force measured by the tester during the opening of the permanent seal(s)  104  is the effective seal force thereof. 
       FIG. 8A  is an example graph  800  showing the effective peel force of an example pouch  100  after sterilization, as measured by pulling apart the flaps  106  as described herein.  FIG. 8B  illustrates the portions of the seals  102 ,  104  that correspond to the effective peel force in the graph  800 . In graph  800 , the vertical axis represents the effective peel force in Newtons (N) and the horizontal axis represents the distance the flaps  106  are pulled apart. 
     As shown, there is a starting period  802  representing the force required to initiate pulling apart of the easy-peel seal  102 . With reference to  FIG. 8B , the starting period  802  corresponds to the pulling apart of the apex  810  of the convex portion  302  of the easy-peel seal  102 . In this example, the starting period  802  peaks at about 11 N. Other examples can have other starting period  802  peaks of other values. In respective examples, the peak of the starting period  802  of the easy-peel seal  102  is in the range of 5 N to 20 N, 7.5 N to 15 N, or 7.5 N to 12.5 N. 
     Once pulling part of the easy-peel seal  102  has started, the effective peel force decreases as the easy-peel seal  102  is further pulled apart during period  804  of the graph  800 . This period  804  of the graph  800  corresponds to the pulling part of the easy-peel seal  102  in the regions shown at  812  of  FIG. 8B . Regions  812  correspond to the easy-peel seal  102  from the apex  810  of the convex portion  302  to the intersections with the portions  202 ,  204  of the permanent seal(s)  104 . In this example, the effective peel force during period  804  corresponds to about 30 mm of distance pulling the flaps  106  apart. This distance, however, will depend on the length of the easy-peel seal  102 . In respective examples, this period  804  of lower force than the peak of the starting period  802  corresponds to at least 20 mm, at least 30 mm, or at least 40 mm of distance pulling apart the flaps  106 . 
     In an example, the decrease in effective peel force as the easy-peel seal  102  is pulled apart during period  804  can be a generally smooth decrease, which provides a pleasant opening experience for the consumer. In this example, the effective peel force during period  804  decreases from the peak of the starting period  802  of around 11 N to around 4 N. In other examples, the effective peel force during period  804  can decrease to other values and/or at other rates. For example, the effective peel force during period  804  can decrease to a value of at least 2.5 N, or at least 5 N, less than the peak of the starting period  802 . In an example, the effective peel force during period  804  is less than the peak of the starting period  802  throughout the period  804 . 
     As shown, the peak of the starting period  802  is a substantially higher force than the effective peel force to continue opening the easy-peel seal  102  during period  804 . The convex shape of the convex portion  302  of the easy-peel seal  102  can reduce the peak of the starting period  802  as compared to a starting peak of a straight (non-convex) easy-peel seal. Keeping the peak of the starting period  802  low enables easier opening by a consumer. 
     As the easy-peel seal  102  is fully pulled apart, the pulled-apart seal reaches the intersection  814  with the permanent seal(s)  104 , causing a substantial increase in the effective peel force. This increase in effective peel force is shown at period  806  of graph  800  and corresponds generally to peeling apart the intersections  814  of the easy-peel seal  102  and the permanent seal(s)  102  shown in  FIG. 8B . In an example, this sharp increase is an increase of at least 5 N, at least 7.5 N, or at least 10 N. In an example, this sharp increase is experienced over a distance of less than 40 mm, less than 30 mm, or less than 20 mm of pulling the flaps  106  apart. In this example, the peak of this increase is around 17 N. In respective other examples, the peak of this increase is at least 10 N, at least 12.5 N, at least 15N, or at least 20 N. 
     Since the permanent seal(s) are not designed to be peeled apart, the effective peel force during further pulling apart of the permanent seal(s) can vary irregularly as shown by period  808  of graph  800  to the right of period  806 . Period  808  corresponds to further peeling apart of the portions  816  of the permanent seal(s)  102 . In this example, during further pulling apart of the portions  202 ,  204  of the permanent seal(s)  102 , the effective peel force does not drop substantially and is at least about 10 N throughout further pulling apart. 
     This effective peel force of the easy-peel seal  102  and the permanent seal(s)  104  is affected by the strength of the seal and the geometry of the seal. For example, for two seals having the same strength, where one seal is wider than the other, the wider seal will have a larger effective peel force than the narrower seal, because its increased width means there is more seal to pull apart even though both seals have equivalent strengths. Likewise, for two seals having the same geometry, where one seal has a lower strength, the seal having the lower strength will have a lower effective peel force. Accordingly, the easy-peel seal  102  can be configured to have a lower effective peel force than the permanent seal(s)  104  by appropriate configuration of the seal strengths and seal geometries. 
     In a first example, the easy-peel seal  102  has a lower strength than the permanent seal(s)  104 . As used herein the strength of a seal is the strength according to the DIN 55529 German national standard, using a 90 degree 15 mm test. Such a strength can be measured by a Zwick™ sealed-seam tester or an Instron® tester for example. Accordingly, the strength of the easy-peel seal  102  has the units of χ N/15 mm. 
     In respective examples, the one or more permanent seals  104  have a strength of at least 20 N/15 mm, at least 25 N/15 mm, at least 30 N/15 mm, at least 40 N/15 mm, or at least 50 N/15 mm. The easy-peel seal  102  can be formed with a strength that is less than 15 N/15 mm, less than 13 N/15 mm, less than 11 N/15 mm, less than 9 N/15 mm, or less than 7 N/15 mm. In respective examples, the easy-peel seal  102  is formed with a strength that is in the range of 5 to 7, 9, 11, 13, or 15 N/15 mm respectively. 
     In another example, the easy-peel seal  102  is configured to have a lower effective peel force than the permanent seal(s)  104  by having a smaller width  312  (shown in  FIG. 3 ) than the permanent seal(s)  104 . In such an example, the easy-peel seal  102  can have the same or a similar strength to the permanent seal(s)  104 , and the lower effective peel force can be achieved by a smaller width of the easy-peel seal  102 . In an implementation of this example, the easy-peel seal  102  has a width that is in the range of 1-2 mm and the permanent seal(s)  104  have a width that is in the range of 2.5 to 6 mm. In other examples, the easy-peel seal  102  can have both a lower strength and a smaller width  312  than the permanent seal(s)  104  to achieve the lower effective peel force. 
     The easy-peel seal  102  and the one or more permanent seals  104  can be formed in any suitable manner including by pressing the two walls  108 ,  110  together with a heated press or with ultrasonic sealing. The strength of such a seal can be set based on the length of time, magnitude of force, and temperature applied if heat pressing to create the seal, or the energy level and length of time if ultrasonic sealing to create the seal. In general, sealing for a longer time, applying more pressure/energy, and increasing the temperature all increase the strength of a resulting seal. Accordingly, the easy-peel seal  102  can be formed with a lesser strength than the one or more permanent seals  104  by sealing for one or more of a shorter length of time, a lower magnitude of pressure/energy, or a lower temperature than that used for the one or more permanent seals  104 . The particular length of time, pressure/energy, and temperature used to seal the one or more permanent seals  104  and the easy-peel seal  102  will depend on the particular implementation such as, contents of the pouch, size of the pouch, intended use of the pouch, whether the pouch will be sterilized, the material of the walls of the pouch, the properties of any resins used between the walls and other factors. Manners of determining these length of time, pressure/energy, and temperature parameters are known by those skilled in the art. 
       FIG. 4  is a front view of another example pouch  400  in a filled state (i.e., there are contents in the pouch  400 ). This pouch  400  is similar to the pouch  100  shown in  FIGS. 1A, 1B, 2, and 3  except that the pouch  400  shown in  FIG. 4  defines a two-dimensionally concave portion  406 ,  408  (from the perspective outside the pouch  400 ) on each of its longitudinal edges  402 ,  404 . The concave portions  406 ,  408  are inward curved portions of the otherwise linear longitudinal edges  402 ,  404 . Thus, the concave portions  406 ,  408  are disposed between two linear portions  410 ,  412 ,  414 ,  416  of their respective longitudinal edge  402 ,  404 . The linear portions  410 ,  412 ,  414 ,  416  extend from the respective concave portions  406 ,  408  to the intersection with the easy-peel seal  102  or with the third edge  418  of the pouch  400  respectively. The concave portions  406 ,  408  can provide a natural location to place a finger and a thumb respectively when holding the pouch  400 . Moreover, the concave portions  406 ,  408  can provide an aid to holding the pouch  400  when squeezing the pouch  400  to empty the contents therefrom. The concave portions  406 ,  408  can be disposed at substantially equal longitudinal locations on their respective edges  402 ,  404 , such that the two concave portions  406 ,  408  align. In an example, the concave portions  406 ,  408  (i.e., the centers thereof) are disposed at a location in the range of 30 percent to 70 percent along the longitudinal length (i.e., to the ends of the linear portion  410 ,  412 ,  414 ,  416 ) of their respective longitudinal edges  402 ,  404 . In an implementation of this example, the concave portions are disposed at a location in the range of 40-60 percent along the longitudinal length of their respective edges  402 ,  404 , such that the concave portions are generally centered along the pouch  100 . 
     In an example, the concave portions  406 ,  408  can indent at least 1 mm into the edge  402 ,  404  of the pouch  400 . In the example shown in  FIG. 4 , the concave portions  406 ,  408  indent about 2 mm into the edge  402 ,  404  of the pouch  400 . In an example, the concave portions can be an inward curving arc having a radius of at least 15 mm and an arc length of at least 20 mm. 
     In the example shown in  FIG. 4 , the permanent seals(s)  104  are disposed along and define the longitudinal edges  402 ,  404  and the third edge  418  of the pouch  400 . In other examples, however, the permanent seal(s)  104  can be disposed inward from one or more of the longitudinal edges  402 ,  404 , or the third edge  418 . 
     In the example shown in  FIG. 4 , the concave portions  406 ,  408  consist of an inward curving arc, however, in other examples, the concave portions  406 ,  408  can have other shapes such as a chevron, or a flat bottomed inward projection. 
       FIGS. 5A, 5B, and 5C  illustrate example coverage areas for sealing steps during the sealing of two walls  108 ,  110  to form the pouch  100 . In an example, the one or more permanent seal(s)  104  are created in multiple sealing steps.  FIG. 5A  illustrates an example coverage area  502  of a press or ultrasonic energy for a first of the multiple sealing steps. This first sealing step creates the first portion  202  and second portion  204  of the one or more permanent seal(s)  104 . The area  502  represents the area in which the press contacts the walls  108 ,  110  or the area in which the ultrasonic energy is applied to create the permanent seal(s)  104 . As discussed above with respect to  FIGS. 1A and 1B , the sealing step(s) to create the permanent seal(s)  104  can be conducted for an appropriate length of time, with an appropriate magnitude of force/energy, and at an appropriate temperature to create the permanent seal(s)  104  having the peeling force discussed above. Notably, at the intersection with the easy-peel seal  102 , the inside edge of the coverage area  502  of the sealing continues in a straight line from the area defining the enclosed space through the area of the easy-peel seal  102 . This straight line is the demarcation between the permanent seal(s)  104  and the easy-peel seal  102 . Thus, when the easy-peel seal  102  is fully opened, the inside edge of the resulting opening forms a substantially straight line with the inside edge of the formerly enclosed space. This straight line enables the contents of the pouch  100  to flow freely out through the opening of the pouch  100 . 
       FIG. 5B  illustrates an example coverage area  504  for creating the easy-peel seal  102 . The area  504  represents the area in which a press contacts the walls  108 ,  110  or the ultrasonic energy is applied to create the easy-peel seal  102 . As discussed above with respect to  FIGS. 1A and 1B , the sealing step to create the easy-peel seal  102  can be conducted for an appropriate length of time, an appropriate magnitude of force/energy, and at an appropriate temperature to create the easy-peel seal having the peeling force discussed above. Typically, the sealing step to create the easy-peel seal will be conducted for a shorter length of time, lower force/energy, and/or lower temperature than is used for the sealing step(s) to create the permanent seal(s)  104 . As shown, the coverage area  504  for creating the easy-peel seal  104  overlaps the coverage area  502  to create the permanent seal(s)  104 . This overlap ensures that a continuous seal is formed at the intersection of the permanent seal(s)  104  and the easy-peel seal  102 . 
       FIG. 5C  illustrates an example coverage area  506  for a second step of creating the one or more permanent seal(s)  104 . This second step creates the third portion  206  of the one or more permanent seal(s)  104 . The area  502  represents the area in which the press contacts the walls  108 ,  110  or the area in which the ultrasonic energy is applied to create the permanent seal(s)  104 . As discussed above with respect to  FIGS. 1A and 1B , the sealing step(s) to create the permanent seal(s)  104  can be conducted for an appropriate length of time, with an appropriate magnitude of force/energy, and at an appropriate temperature to create the permanent seal(s)  104  having the peeling force discussed above. As shown, the coverage area  506  for creating the third portion  206  of the permanent seal(s)  104  overlaps the coverage area  502  of the first portion  202  and second portion  204 . This overlap ensures that a continuous seal is formed at the intersection of the respective portions  202 ,  204 ,  206 . 
     To create a permanent seal  104  or easy-peel seal  102  having a desired shape (such as is shown herein) the sealing steps used to create the permanent seal(s)  104  and easy-peel seal  102  are conducted such that the areas in which the seal  102 ,  104  are contacted by the presses (or the area in which the ultrasonic energy is applied) are configured to have the desired shape of the seals  102 ,  104 . The areas in which no seal is desired are not contacted by the presses (or no ultrasonic energy is applied). For example, a vertical press having a contact surface with the desired shape of the resulting seal (e.g., an easy-peel seal with a convex portion) can be used to contact one or both walls  108 ,  110  to form the resulting seal as known to those in the art. 
     In an example, the first sealing step of the permanent seal(s)  104  and the sealing step for the easy-peel seal  102  are performed prior to filling the pouch  100 ,  400  with contents. After these sealing steps, three edges of the pouch  100 ,  400  are sealed and one edge remains open. The contents of the pouch can then be inserted into the pouch  100 ,  400 . After the contents are inserted into the pouch  100 ,  400 , the second sealing step for the permanent seal(s)  104  can be performed to complete the seal around the pouch  100 ,  400 . Leaving the third portion  206  of the permanent seal(s)  104  unsealed and using that edge to fill the pouch  100 ,  400  can be advantageous because this enables the easy-peel seal  102  to be created prior to filling the pouch  100 ,  400 . Creating the easy-peel seal  102  prior to filling the pouch can be advantageous, because there is less chance of an improper seal from contamination due to the contents of the pouch. This contamination issue is less likely for the permanent seal(s)  104 , since the permanent seal(s)  104  has a higher strength. Other numbers, orders, or configurations of sealing steps may also be used. 
     The pouches described herein can be constructed in any suitable manner. For example, the pouches can be constructed in a pre-made manner where the pouch walls are cut and assembled together with a first machine (e.g., in a first location) and the pouch is filled and finally sealed with a second machine(s) (e.g., in a second location). In other examples, the pouches can be constructed in a form, fill, and seal technique in which the pouch walls are formed (e.g., foil overlap), pockets are formed between two walls via one or more sealing steps. Once formed, the pockets can be filled with contents (e.g., pet food), and then enclosed via a second sealing step, before the pouches are cut to final shape. In many examples, the form, fill, and seal of the pouches can be performed all with a single machine. 
       FIG. 6  is a top view of an example sheet  600  of material from which the walls  108 ,  110  can be cut in order to construct a pre-made pouch. The example sheet  600  can be a sheet having the composition of the walls  108 ,  110 . For example, sheet  600  can include polypropylene, polyester, polyethylene, polyamide and/or a bio-based/bio-degradable plastic. In many examples, the sheet  600  is a laminate (e.g., 2 ply, 3 ply, 4 ply) including at least one layer of plastic. In a particular example, the sheet  600  is a laminate including a layer of polyethylene terephthalate (PET), a layer of polypropylene, and a layer of aluminum therebetween with a Sealution™ resin on the polypropylene layer. Other examples are also possible. 
       FIG. 6  illustrates an example cutting pattern used to cut the walls  108 ,  110  from the sheet  600 . In an example, at least two rows  602 ,  604  of walls  108 ,  110  are cut from a single sheet  600 . In the particular implementation shown in  FIG. 6 , four rows  602 ,  604 ,  606 ,  608  of walls  108 ,  110  are cut from a single sheet  600 . Moreover, in this example, both walls  108 ,  110  have a common shape, such that a single corresponding shape can be used for each cut and the resulting piece can be used for either wall  108  or wall  110 . In other example, each wall  108 ,  110  can have a different shape and the different shapes can be cut out of a common sheet of material or out of different sheets of material. In this example, a wall  108  from a first row  602  is sealed to a wall  110  from a second row  604  in a later processing step (not shown) to form the pouch  100 . 
     In the example shown in  FIG. 6 , each wall  108 ,  110  has a generally rectangular geometry corresponding to the geometry of the pouch  100  described above. The geometry includes a first longitudinal edge  610  and a second longitudinal edge  612  substantially parallel with the first longitudinal edge. Each wall  108 ,  110  also includes a third edge  614  substantially transverse to the first edge  610  and second edges  612 . Similar to the geometry described above with respect to pouch  100 , in the implementation shown in  FIG. 6 , the first edge  610 , second edge  612 , and third edge  614  of each wall  108 ,  110  are three sides of a hypothetical rectangle and the fourth side of the hypothetical rectangle is replaced with the outwardly curved fourth edge  616  which defines the flap  106 . 
     In the example shown in  FIG. 6 , each wall  108 ,  110  in a given row  602 ,  604 ,  606 ,  608  is oriented the same way. Thus, each wall  108  in the first row  602  is oriented with its fourth edge (defining the flap  106 ) pointing in a first direction  618 . Each wall  110  in the second row  604  is oriented with its fourth edge  616  pointing in a second direction  620 . Notably, the walls  108  in the first row  602  are oriented with their fourth edge  616  pointing towards the second row  604  and the walls  110  in the second row  604  are oriented with their fourth edge  616  pointing towards the first row  602 . That is, the first direction  618  is the opposite of the second direction  620  such that the walls  110  in the second row are rotated 180 degrees with respect to the walls  108  in the first row  602 . This 180-degree rotation orients the walls  108 ,  110  in the adjacent rows  602 ,  604  with their flaps  106  pointing towards the adjacent paired row. The walls  108 ,  110  in the respective adjacent rows  602 ,  604  are offset from each other in the horizontal direction  622  such that the flaps  106  of the first row  602  extend into concave areas defined between adjacent flaps  106  of the second row  604 . Likewise, the flaps  106  of the second row  604  extend into concave areas defined between adjacent flaps  106  of the first row  602 . Notably, the disposition of the walls  108 ,  110  on the sheet  600  described herein is the pattern in which the walls  108 ,  110  are cut from the sheet  600 . Cutting the walls  108 ,  110  out of the sheet  600  with the flaps  106  of the first row  602  interstitially positioned with the flaps  106  of the adjacent second row  604  reduces waste material in the sheet  600  as compared with other orientations of the walls  108 . Additional pairs of adjacent rows (e.g., the third row  606  and fourth row  608 ) can be oriented in the same relative manner. In the example shown in  FIG. 6 , the second row  604  is offset from the first row  602  by half a width of a wall  108 ,  110 , such that a centerline of the walls  108 ,  110  in one row  602 ,  604  is aligned with the edges of the walls  108 ,  110  in the other row  604 ,  602 . 
     In the example shown in  FIG. 6 , each wall  108 ,  110  is oriented with its longitudinal edges  610 ,  612  perpendicular to a longitudinal dimension (aligning with the horizontal direction  622  in this example) of the sheet  600 , however, other orientations are also possible. Additionally, although the walls  108 ,  110  having straight edges are shown in the example of  FIG. 6 , walls having other geometries (such as the walls of pouch  400 ) can also be cut out in the orientation described with respect to  FIG. 6 . The sheet  600  can be cut in any suitable manner such as with a rotary die, a flat die, a laser, or an air jet. 
       FIG. 7  is a top view of an alternative cutout pattern on a sheet  700  of material to form example walls  702 ,  704 . Sheet  700  can have the same composition described with respect to sheet  600 . In this alternative cutout pattern, each wall  702 ,  704  is oriented similarly to that described with respect to  FIG. 6 . The walls  702 ,  704 , however, have a slightly different geometry than the walls  108 ,  110  described above. The first longitudinal edge, second longitudinal edge, and third longitudinal edge can be the same as that described above with respect to walls  108 ,  110 . The flap  106  in the fourth edge, however, can have a shape configured such that a flap  106  from a first row  706  matches a concave area between flaps  106  of an adjacent second row  708 . Such a shape will further reduce the wasted material of the sheet  700  during cutting. 
     Advantageously, the flexible packages described herein can be used to enclose a food product such as a pet food. In a particular implementation, the flexible packages can be used to enclose a “wet” food product (e.g., pet food) such as a food product having a water activity at or above 0.6. 
     In an example, the flexible packages described herein can have a dimension that is suitable to be held in a single hand of a consumer. Accordingly, the flexible packages can have length and width dimensions in the range of 50 to 300 mm and can be configured to hold in the range of 25 to 200 grams of “wet” food product.