Abstract:
A pouch includes first and second pouch walls that define an interior of the pouch, and an opening to the interior of the pouch is provided in at least one of the first and second pouch walls. A flow channel profile is disposed on an inner surface of the first pouch wall, and a complementary groove is disposed on an inner surface of the second pouch wall. The complementary groove releasably engages the flow channel profile so as to define a flow channel between the first and second pouch walls. The flow channel profile extends between the opening and a portion of an interior of the pouch that is spaced from the opening. When the flow channel profile is releasably engaged with the complementary groove, a tip of the flow channel profile contacts a surface the complementary groove, and a surface of the flow channel profile that is adjacent to the tip also contacts a surface of the complementary groove.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 11/818,584, filed Jun. 15, 2007, which issued as U.S. Pat. No. 7,887,238 on Feb. 15, 2011, and which is hereby incorporated by reference herein in its entirety. 
    
    
     REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH FOR DEVELOPMENT 
     Not applicable. 
     SEQUENTIAL LISTING 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to pouches, and particularly, to a flow channel that may be used to evacuate a pouch. 
     2. Description of the Background of the Invention 
     Pouches are typically used for storage and preservation of perishable contents such as food. Perishable contents may be made to last longer with less degradation if stored under a vacuum. Evacuable thermoplastic pouches have been designed to work with a vacuum source to allow storage of contents under a vacuum. However, a problem with evacuating a thermoplastic pouch is that the pouch has flexible walls that are forced together into contact with one another as a result of the evacuation. Regions of the pouch interior may thus be blocked from the vacuum source by the contacting walls, making those regions difficult or impossible to evacuate. In response to this problem, evacuable thermoplastic pouches have been designed with various flow channels that function to prevent the pouch walls from coming into contact and blocking off regions of the pouch from the vacuum source. 
     One such pouch has a thick textured porous sheet that is affixed to an inner surface of a pouch wall over an aperture in the pouch wall. The sheet has dimensions similar to the pouch wall and functions to prevent the pouch walls from adhering to one another during evacuation. The sheet provides flow paths from the pouch interior to the aperture to prevent the pouch walls from adhering, thus preventing evacuation of the pouch. Another pouch has a strip of mesh or woven material that extends from the pouch interior to a mouth of the pouch. The strip of mesh may be inserted by a user or affixed to the pouch interior during manufacture. The strip may alternatively be comprised of a plurality of tubes held together to form the strip. 
     A further pouch has a strip of flexible plastic material attached to an interior of the pouch. The pouch has an aperture that extends through a wall of the pouch proximate to an end of the pouch. The strip has a flat base and a plurality of ribs disposed lengthwise on one side of the base. A first end of the strip is attached to the interior of the pouch opposite to the aperture. A second end of the strip is attached to a region of the interior that is at an opposite end of the pouch from the aperture. The ribs provide fluid communication between the aperture and the entire length of the strip. 
     Other pouches have protuberances that are extruded integrally with a sidewall or embossed onto a sidewall of the pouch between an interior of the pouch and an evacuation aperture. Each protuberance has a body that extends away from the sidewall between a base end and a distal end. The body has parallel side walls or is generally tapered from the base end to the smaller distal end. The protuberances may take the form of discrete shapes or may be joined to form ridges. The protuberances may also be arranged irregularly or formed into patterns. Channels formed between the protuberances provide fluid communication between the evacuation aperture and the interior of the pouch. 
     Yet another pouch has one or more wall panels that are formed from a material that is pressed between rollers to impart a corrugated cross section to the material. Grooves and ridges formed by the rollers are imparted on an angle with respect to the direction of forming. The material is folded upon itself to form the pouch with the wall panels, wherein the pouch has grooves and ridges in each wall panel that intersect with grooves and ridges on an opposing wall panel. The intersecting grooves and ridges prevent the wall material from flattening under evacuation, thereby creating air channels throughout the pouch. 
     Still another pouch has a pattern of channels on a sidewall that is created by pressing a melt-extruded resin between rollers. The channels have baffles that allow gases to escape from the pouch, yet trap liquid within the pouch. Another pouch has at least one sidewall that has a zigzag pattern of channels or ridges formed therein or thereon, respectively. 
     Pouches that have flow channels may have regions of the pouch interior blocked from a vacuum source by an opposing sidewall that has entirely collapsed into a channel due to the inherent flexibility of the opposing sidewall material. Narrower flow channels can lessen blockage caused by the collapsed opposite sidewall, but also have decreased flow volume. Sidewalls made of a more rigid material can also lessen blockage by limiting collapse, but necessarily have less flexibility. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a pouch includes first and second opposing pouch walls and a plurality of flow channel protuberances that defines a flow channel between the first and second pouch walls and is disposed on an inner surface of at least one of the first and second pouch walls. At least one of the plurality of protuberances includes a first component that extends from the at least one of the first or second pouch walls and a second component that extends at a non-zero angle from the first component. The flow channel extends between an opening of the pouch and a portion of an interior of the pouch that is spaced from the opening. 
     According another aspect of the present invention, a pouch includes first and second opposing pouch walls. A flow channel profile is disposed on an inner surface of the first pouch wall, and a complementary groove is disposed on an inner surface of the second pouch wall to releasably engage with the flow channel profile, to define a flow channel between the first and second pouch walls. The flow channel extends between an opening of the pouch and a portion of an interior of the pouch that is spaced from the opening. 
     According to yet another aspect of the invention, a pouch includes a pouch wall and a flow channel profile, wherein the flow channel profile includes a first component extending from the pouch wall and a second component extending at a non-zero angle from the first component. The flow channel profile is disposed on an inner surface of the pouch wall to define a flow channel disposed between the pouch wall and an opposing surface, and that extends between an opening of the pouch and a portion of an interior of the pouch that is spaced from the opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric partial cutaway view of a pouch illustrating a plurality of flow channel protuberances extending from an inner surface of a first pouch wall; 
         FIG. 2  is a fragmentary cross-sectional view of a first embodiment of flow channels, taken generally along the lines  2 - 2  of  FIG. 1 , with portions behind the plane of the cross section omitted for clarity; 
         FIG. 3  is a fragmentary cross-sectional view illustrating other embodiments of flow channels, taken generally along the lines  2 - 2  of  FIG. 1 , with portions behind the plane of the cross section omitted for clarity; 
         FIG. 4  is an isometric partial cutaway view of a pouch illustrating a further embodiment of flow channels; 
         FIG. 5  is a fragmentary cross-sectional view, taken generally along the lines  5 - 5  of  FIG. 4 , with portions behind the plane of the cross section omitted for clarity. 
         FIG. 6  is a plan view of yet another embodiment of flow channels illustrating segmented flow channel profiles; 
         FIG. 7  is an isometric partial cutaway view illustrating a still further embodiment of flow channels; 
         FIG. 8  is a fragmentary cross-sectional view similar to the views of  FIGS. 2 ,  3 , and  5 , and illustrating still further embodiments of flow channels; and 
         FIG. 9  is a cross-sectional view similar to the views of  FIGS. 2 ,  3 ,  5 , and  8 , and illustrating still other embodiments of flow channels. 
     
    
    
     Other aspects and advantages of the present invention will become apparent upon a consideration of the following detailed description, wherein similar structures have similar reference numerals. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a reclosable pouch  50  has a first sidewall  52  and a second sidewall  54 . Illustratively, the first and second sidewalls  52 ,  54  may be made of one or more thermoplastic materials or resins, such as polyolefin, including, for example, polyethylene and polypropylene. The first and second sidewalls  52 ,  54  are joined at three edges  56   a - 56   c  by heat sealing or any other sealing method known in the art to define a mouth  58  leading to an interior  60 . The edge  56   b  may also be a fold line separating a single piece of material into the first and second sidewalls  52 ,  54 . The first sidewall  52  includes an inner surface  72  and the second sidewall  54  includes an inner surface  84 . 
     A closure mechanism  62  extends across the pouch  50  proximate to the mouth  58 . The closure mechanism  62  allows the pouch  50  to be repeatedly opened and closed. When occluded, the closure mechanism  62  provides an airtight seal such that a vacuum may be maintained in the pouch interior  60  for a desired period of time, such as days, months, or year, when the closure mechanism is sealed fully across the mouth  58 . The closure mechanism  62  comprises first and second closure elements (not shown) that are attached, respectively, to the inner surfaces  72  and  84  of the first and second sidewalls  52 ,  54 . The first closure element includes one or more interlocking closure profiles (not shown), and the second closure element also includes one or more interlocking closure profiles (not shown). The first and second interlocking closure profiles may be male and female closure profiles, respectively. However, the configuration and geometry of the interlocking profiles or closure elements disclosed herein may vary. 
     In a further embodiment, one or both of the first and second closure elements (not shown) may include one or more textured portions, such as a bump or crosswise groove in one or more of the first and second closure profiles, in order to provide a tactile sensation, such as a series of clicks, as a user draws the fingers along the closure mechanism  62 , to seal the closure elements across the mouth  58 . In another embodiment, the first and second interlocking closure profiles (not shown) include textured portions along the length of each profile to provide tactile and/or audible sensations when closing the closure mechanism  62 . In addition, protuberances, for example, ridges (not shown), may be disposed on the inner surfaces  72 ,  84  of the respective first and second sidewalls  52 ,  54  proximate to the mouth  58 , to provide increased traction in a convenient area for a user to grip, such as a gripping flange, when trying to open the sealed pouch  50 . Further, in some embodiments, a sealing material, such as a polyolefin material or a caulking composition, such as silicone grease, may be disposed on or in the interlocking profiles or closure elements to fill in any gaps or spaces therein when occluded. The ends of the interlocking profiles or closure elements may also be welded or sealed by ultrasonic vibrations, as is known in the art. Illustrative interlocking profiles, closure elements, sealing materials, tactile or audible closure elements, and/or end seals useful in the present invention include those disclosed in, for example, Pawloski U.S. Pat. No. 4,927,474, Dais et al. U.S. Pat. No. 5,070,584, U.S. Pat. No. 5,478,228, and U.S. Pat. No. 6,021,557, Tomic et al. U.S. Pat. No. 5,655,273, Sprehe U.S. Pat. No. 6,954,969, Kasai et al. U.S. Pat. No. 5,689,866, Ausnit U.S. Pat. No. 6,185,796, Wright et al. U.S. Pat. No. 7,041,249, Pawloski et al. U.S. Pat. No. 7,137,736, Anderson U.S. Patent Application Publication No. 2004/0091179, now U.S. Pat. No. 7,305,742, Pawloski U.S. Patent Application Publication No. 2004/0234172, now U.S. Pat. No. 7,410,298, Tilman et al. U.S. Patent Application Publication No. 2006/0048483, now U.S. Pat. No. 7,290,660, and Anzini et al. U.S. Patent Application Publication No. 2006/0093242 and No. 2006/0111226, now U.S. Pat. No. 7,527,585. Other interlocking profiles and closure elements useful in the present invention include those disclosed in, for example, U.S. patent application Ser. No. 11/725,120, filed Mar. 16, 2007, now U.S. Pat. No. 7,886,412, and U.S. patent application Ser. No. 11/818,585, now U.S. Pat. No. 7,857,515, Ser. No. 11/818,593, now U.S. Pat. No. 7,784,160, and Ser. No. 11/818,586, now U.S. Pat. No. 7,946,766, each of which was filed on Jun. 15, 2007. It is further appreciated that the interlocking profiles or closure elements disclosed herein may be operated by hand, or a slider (not shown) may be used to assist in occluding and de-occluding the interlocking profiles and closure elements. 
     An exterior  64  of the pouch  50  is also shown in  FIG. 1 . An opening  66   a ,  66   b , or  66   c  allows fluid communication between the interior  60  and the exterior  64  of the pouch  50 . The opening  66   a  may extend through or around the closure mechanism  62 . Alternatively, the opening  66   b  may extend through either the first or second sidewall  52 ,  54 . The opening  66   c  may also extend through a side edge  56   a - 56   c , for example, through the bottom edge  56   b . A valve  68  may optionally be disposed in or cover the opening  66   a - 66   c  to allow air to be evacuated from the pouch interior  60  and to maintain a vacuum when the closure mechanism  62  has been sealed. As shown in  FIG. 1 , the valve  68  may be disposed on the second sidewall  54 , spaced from the closure mechanism  62 . The valve  68  provides a fluid path with fluid communication between the pouch interior  60  and the exterior  64  of the pouch. Illustrative valves useful in the present invention include those disclosed in, for example, Newrones et al. U.S. Patent Application Publication No. 2006/0228057, now U.S. Pat. No. 7,837,387. Other valves useful in the present invention include those disclosed in, for example, U.S. patent application Ser. No. 11/818,592, now U.S. Pat. No. 7,967,509, Ser. No. 11/818,586, now U.S. Pat. No. 7,946,766, and Ser. No. 11/818,591, now U.S. Pat. No. 7,874,731, each of which was filed on Jun. 15, 2007. 
     Although not shown, in some embodiments, an evacuation pump or device may be used to evacuate fluid from the pouch  50  through, for example, the valve  68  disposed in one of the sidewalls  52 ,  54 , or in the closure mechanism  62  or one of the side edges  56   a - 56   c  of the pouch. Illustrative evacuation pumps or devices useful in the present invention include those disclosed in, for example, U.S. patent application Ser. No. 11/818,703, filed on Jun. 15, 2007, now U.S. Pat. No. 8,096,329. 
     In a first embodiment shown in  FIGS. 1 and 2 , a plurality of flow channel protuberances  70  is arranged regularly or irregularly on the inner surface  72  of the first sidewall  52 . The protuberances  70  define flow channels  74  between the first and second sidewalls  52 ,  54  as depicted, for example, by the lines and arrows in  FIGS. 1 and 2 , and that extend from the interior  60  to the opening  66   a - 66   c  of the pouch  50 . Illustratively, the flow channel  74  provides fluid communication between the opening  66   a - 66   c  and a portion of the interior  60  that is spaced from the opening  66   a - 66   c . For example, an embodiment including the opening  66   b  that extends through a first sidewall  52  includes a flow channel  74  that extends from directly opposite to the opening to a portion of the interior  60  that is spaced from the opening. Alternatively, embodiments including either of the openings  66   a  or  66   c  include a flow channel  74  that extends from directly adjacent to the opening to a portion of the interior  60  that is spaced from the opening. The flow channels  74  defined by the protuberances  70  may be straight or curved. The flow channels  74  defined by the protuberances  70  may be parallel to one another, or, in other embodiments (not shown), may extend radially away from the opening  66   a - 66   c  in, for example, an expanding sunburst configuration, or may have any other configuration, such that the flow channels  74  provide fluid communication between the opening  66   a - 66   c  and a portion of the pouch interior  60  spaced from the opening when the pouch  50  is under vacuum pressure. 
     Referring to  FIG. 2 , the protuberances  70  may be integral with the first sidewall  52 . Each of the protuberances  70  includes a first component  76  that extends from the first sidewall  52 . Each protuberance  70  also includes a second component  78  that extends laterally away from the first component  76  proximate to a distal end  80  thereof. The second component  78  may be round or square, or any convenient shape, and may extend laterally away from the first component  76  at any non-zero angle with respect to the first component  76  around a portion of or an entire periphery thereof. The second component  78  provides increased surface area  82  on a distal end  90  of each protuberance  70 . 
     Further, a solid material that includes fixed or supported portions is displaced at an unsupported portion in response to a force being applied to the unsupported portion. The amount of displacement depends upon, for example, the span of the unsupported portion, the amount and distribution of force applied thereto, and/or a material property of the solid material, called the flex modulus. For example, in the pouch  50  being evacuated, unsupported portions of each of the first and second sidewall  52 ,  54  may sag into the flow channel  74  by an amount that depends upon spacing between respective ends of the protuberances  70 , the flex modulus for the material in each of the first and second sidewall, and/or the level of vacuum drawn on the pouch. Assuming a given composition for the first and second sidewalls  52 ,  54 , and a given level of vacuum drawn on the pouch, the amount of sag of each of the first and second sidewalls, therefore, depends on the spacing between respective ends of the protuberances  70 . The increased surface area  82  makes contact over an increased area of the inner surface  84  of the second sidewall  54 , thereby leaving less of the second sidewall  54  disposed over the flow channel  74  unsupported during evacuation of the pouch  50 . Inhibiting sag of the first and second sidewalls  52 ,  54  into the flow channels  74  allows the flow channels to remain open for a longer period of time while fluid is being evacuated therefrom and from the pouch. 
     Referring next to  FIG. 3 , the second component  78  of each flow channel protuberance  70  may also extend from an intermediate region  86  that may be at any position on the first component  76  between a base  88  and the distal end  80  thereof. The second component  78  may again be any convenient shape and may extend laterally away from the first component  76  at any non-zero angle with respect to the first component  76  around a portion of or the entire periphery thereof. The second component  78  extends from the intermediate region  86  to increase the effective surface area  92  at the distal end  90  of the protuberance  70 . Similar to the above, increased surface area  92  in contact with the inner surface of the second sidewall  54  leaves less of the second sidewall  54  unsupported during evacuation of the pouch  50 . 
     The flow channel protuberances  70  may also depend from a first side  94  of a base member  96 , as illustrated in  FIG. 3 . A second side  98  of the base member  96  is affixed to the inner surface  72  of the first sidewall  52 . The base member  96  may be affixed to the first sidewall  52  by a thermoplastic weld layer  210 , a heat seal, an adhesive, or any other method known in the art. In each of the embodiments included therein, the flow channel protuberances  70  or profiles  100  (shown in  FIGS. 4-9 ) may either be integral with the first sidewall  52 , as described with respect to  FIG. 2 , or may depend from the first side  95  of the base member  96 , as described with respect to  FIG. 3 . The flow channel protuberances  70  or profiles  100  may be extruded integrally with the base member  96  to form a three-dimensional tape structure that may be fastened to the inner surfaces  72 ,  84  of the respective first and second sidewalls  52 ,  54  of the pouch  50 , to create the flow channels  74 . 
     Referring next to  FIGS. 4 and 5 , in a further embodiment, flow channel profiles  100  define flow channels  74  between the first and second sidewalls  52 ,  54 , as depicted, for example, by the lines and arrows in  FIG. 4 , and that extend from the interior  60  to the opening  66   a - 66   c  of the pouch  50 . Grooves  102  are provided on the inner surface  84  of the second sidewall  54 . The grooves  102  align and engage with the flow channel profiles  100  when the pouch  50  is brought under vacuum pressure. The engaged profiles and grooves  100 ,  102  may reduce or limit lateral displacement of the second sidewall  54  across the profiles  100 . The engaged profiles and grooves  100 ,  102  may also reduce or limit bowing of the profiles  100  in response to vacuum pressure. Therefore, the engaged profiles and grooves  100 ,  102  may provide increased effective structural rigidity for sections of the second sidewall  54  between the grooves  102 . The engaged profiles  100 ,  102 , therefore, may lessen blockage of the flow channels  74  by limiting collapse of the second sidewall  54  during evacuation of the pouch  50 . The flow channel profiles  100  of this embodiment may also be integral with the first sidewall  52 , as disclosed in detail above with respect to  FIG. 2 , or may depend from the base member  96  that is affixed to the inner surface  72  of the first sidewall  52 , as disclosed in detail above with respect to  FIG. 3 . 
     Referring now to  FIG. 6 , the flow channel profiles  100  may also be cut into segments  104 . The segmented flow channel profiles  100  define flow channels  74  between the first and second sidewalls  52 ,  56  as depicted, for example, by the lines and arrows in  FIG. 6 , and that extend from a portion of the interior  60  to the opening  66   a - 66   c  of the pouch  50 . The flow channel profiles  100  and corresponding grooves  102  may be straight or curved. The profiles  100  may be parallel to one another, or in other embodiments (not shown), may extend radially away from the opening  66   a - 66   c  in an expanding sunburst configuration, or may have any other configuration, such that the continuous flow channels  74  provide fluid communication between the opening  66   a - 66   c  and a portion of the pouch interior  60  spaced from the opening, when the pouch  50  is under vacuum pressure. 
     Referring next to  FIGS. 7 and 8 , the flow channel profiles  100   a - 100   c  each have a first component  106  that extends from the inner surface  72  of the first sidewall  52  or from the first side  94  of the base member  96  that is affixed to the inner surface  72  of the first sidewall  52 , as disclosed in detail above with respect to  FIG. 3 . Each profile  100   a - 100   c  also includes a second component  108  that extends laterally away from the first component  106  proximate to a distal end  110  thereof. The second component  108  may have a straight or curved cross section and may extend laterally away from one side of the first component  106 , as illustrated in left-most profile  100   a  in  FIG. 8 , or may extend laterally away from both sides of the first component  106 , as illustrated in right-most profile  100   e  in  FIG. 8 . 
     Illustratively, the second component  108  may extend laterally away from the first component  106  perpendicular to the first component  106 , as shown in profiles  100   a  and  100   e  in  FIG. 8 . In another embodiment, the second component  108  may extend laterally away from the first component  106  at an obtuse angle, as illustrated in profiles  100   b  and  100   c  in  FIG. 8 . In a further embodiment, the second component  108  may extend laterally away from the first component  106  at an acute angle, as illustrated in profile  100   d  in  FIG. 8 . The second component  108  provides increased surface area  112  on a distal end  114  of each profile  100   a - 100   e , and as discussed above, provides additional support area for the second sidewall  54 , to assist in preventing collapse thereof into the channel  74  when the pouch  50  is being evacuated. 
     Referring next to  FIG. 9 , in still other embodiments, the second component  108  of each of the flow channel profiles  200   a - 200   c  may also extend from an intermediate region  116  of the first component  106  between a base end  118  and the distal end  110  thereof. In one embodiment, the second component  108  may have a straight or curved cross section and may extend laterally away from both sides of the first component  106 , as illustrated in left-most profile  200   a  in  FIG. 8 , or in other embodiments, may extend laterally away from one side of the first component  106 , as illustrated in profiles  200   b  and  200   c  in  FIG. 9 . The second component  108  may extend laterally away from the first component  106  at any non-zero angle with respect to the first component  106 , for example, an acute angle, an obtuse angle, or a ninety degree angle. The second component  108  may extend from both sides of the first component  106  and away from the base member  96 , as illustrated by left-most flow channel profile  200   a  in  FIG. 9 , because such a configuration may provide an increased effective surface area  112  across the distal end  114  of the profile  200   a.    
     The flow channel profiles  100   a - 100   e  and  200   a - 200   c  may be straight or curved. The profiles  100   a - 100   e  and  200   a - 200   c  may be parallel to one another, or in other embodiments (not shown), may extend radially away from the opening  66   a - 66   c  in an expanding sunburst configuration, or may have any other configuration, such that the continuous flow channels  74  provide fluid communication between the opening  66   a - 66   c  and a portion of the pouch interior  60  spaced form the opening when the pouch  50  is under vacuum pressure. 
     Although not shown, one or both sidewalls, such as the second sidewall  54 , may also be embossed or otherwise textured with a pattern, such as a diamond pattern, on one or both surfaces spaced between the bottom edge  56   b  and the closure mechanism  62 , or a separate textured and embossed pattern wall may be used to provide additional flow channels (not shown) within the pouch interior  64 . Illustrative flow channels useful in the present invention include those disclosed in Zimmerman et al. U.S. Patent Application Publication No. 2005/0286808, now U.S. Pat. No. 7,726,880, and Tilman et al. U.S. Patent Application Publication No. 2006/0048483, now U.S. Pat. No. 7,290,660. 
     In one embodiment, the first and second sidewalls  52 ,  54  and/or the closure mechanism  62  are formed from thermoplastic resins by known extrusion methods. For example, the sidewalls  52 ,  54  may be independently extruded of a thermoplastic material as a single continuous or multi-ply web, and the closure mechanism  62  may be extruded of the same or different thermoplastic material(s) separately as continuous lengths or strands. Illustrative thermoplastic materials include polypropylene (PP), polyethylene (PE), metallocene-polyethylene (mPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ultra low density polyethylene (ULDPE), biaxially-oriented polyethylene terephthalate (BPET), high density polyethylene (HDPE), polyethylene terephthalate (PET), among other polyolefin plastomers and combinations and blends thereof. Further, the inner surfaces  152 ,  154  of the respective sidewalls  52 ,  54  or a portion or area thereof may, for example, be composed of a polyolefin plastomer, such as an AFFINITY™ resin manufactured by Dow Plastics. Such portions or areas include, for example, the area of one or both of the sidewalls  52 ,  54  proximate to and parallel to the closure mechanism  60 , to provide an additional cohesive seal between the sidewalls when the pouch  50  is evacuated of fluid. One or more of the sidewalls  52 ,  54  in other embodiments may also be formed of an air-impermeable film. An example of an air-impermeable film includes a film having one or more barrier layers, such as an ethylene-vinyl alcohol copolymer (EVOH) ply or a nylon ply, disposed between or on one or more of the plies of the sidewalls  52 ,  54 . The barrier layer may be, for example, adhesively secured between the PP and/or LDPE plies to provide a multilayer film. Other additives, such as colorants, slip agents, and antioxidants, including, for example, talc, oleamide or hydroxyl hydrocinnamate, may also be added as desired. In another embodiment, the closure mechanism  62  may be extruded primarily of molten PE with various amounts of slip component, colorant, and talc additives in a separate process. The fully formed closure mechanism  62  may be attached to the pouch body using a strip of molten thermoplastic weld material, or by an adhesive known by those skilled in the art, for example. Other thermoplastic resins and air-impermeable films useful in the present invention include those disclosed in, for example, Tilman et al. U.S. Patent Application Publication No. 2006/0048483, now U.S. Pat. No. 7,290,660. 
     The protuberances  70 , and flow channel profiles  100 ,  100   a - 1003 , and  200   a - 200   c  as disclosed herein may be composed of any thermoplastic material, such as would be used for the first and second sidewalls  52  and  54  of the pouch  50 , as disclosed herein. Illustratively, the protuberances  70 , and flow channel profiles  100 ,  100   a - 100   e , and  200   a - 200   c  may, for example, be composed of a polyolefin plastomer, such as an AFFINITY™ resin manufactured by Dow Plastics. 
     The resealable pouch  50  described herein can be made by various techniques known to those skilled in the art, including those described in, for example, Geiger, et al., U.S. Pat. No. 4,755,248. Other useful techniques to make a resealable pouch include those described in, for example, Zieke et al., U.S. Pat. No. 4,741,789. Additional techniques to make a resealable pouch include those described in, for example, Porchia et al., U.S. Pat. No. 5,012,561. Additional examples of making a resealable pouch as described herein include, for example, a cast post applied process, a cast integral process, and/or a blown process. 
     INDUSTRIAL APPLICABILITY 
     Flow channels within a pouch may be used to evacuate fluid from the pouch, thereby allowing pouch contents, such as food, to remain fresher for extended periods of time. Flow channels allow a vacuum source to reach interior regions of the pouch that are spaced from the vacuum source. The flow channels herein are defined by structures having first and second components that together provide an increased surface area that prevents collapse of an opposing pouch wall when the pouch is subjected to vacuum evacuation. 
     Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and to use the invention, and to teach the best mode of carrying out the same. The exclusive rights to all modifications that come within the scope of the appended claims are reserved. All patents, patent publications and applications, and other references cited herein are incorporated by reference herein in their entirety.