Flow channels for a pouch

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 or second pouch walls. At least one of the plurality of protuberances includes a first component extending from the at least one of the first or second pouch walls and a second component extending 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.

CROSS REFERENCE TO RELATED APPLICATIONS

Not applicable

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 vacuum. Evacuable thermoplastic pouches have been designed to work with a vacuum source to allow storage of contents under 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 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 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 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 or 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 to another aspect of the 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.

Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description, wherein similar structures have similar reference numerals.

DETAILED DESCRIPTION

Referring toFIG. 1, a reclosable pouch50has a first sidewall52and a second sidewall54. Illustratively, the first and second sidewalls52,54may be made of one or more thermoplastic materials or resins such as polyolefin, including, for example, polyethylene and polypropylene. The first and second sidewalls52,54are joined at three edges56a-56cby heat sealing or any other sealing method known in the art to define a mouth58leading to an interior60. The edge56bmay also be a fold line separating a single piece of material into the first and second sidewalls52and54. The first sidewall52includes an inner surface72and the second sidewall54includes an inner surface84.

A closure mechanism62extends across the pouch50proximate the mouth58. The closure mechanism62allows the pouch50to be repeatedly opened and closed. When occluded, the closure mechanism62provides an airtight seal such that a vacuum may be maintained in the pouch interior60for a desired period of time, such as days, months, or years, when the closure mechanism is sealed fully across the mouth58. The closure mechanism62comprises first and second closure elements (not shown) that are attached respectively to the inner surfaces72and84of the first and second sidewalls52and54. 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 mechanism62to seal the closure elements across the mouth58. 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 mechanism62. In addition, protuberances, for example ridges (not shown), may be disposed on the inner surfaces72,84of the respective first and second sidewalls52,54proximate the mouth58to provide increased traction in a convenient area for a user to grip, such as a gripping flange, when trying to open the sealed pouch50. 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. Nos. 5,070,584, 5,478,228, and 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, Pawloski U.S. Patent Application Publication No. 2004/0234172, Tilman et al. U.S. Patent Application Publication No. 2006/0048483, and Anzini et al. U.S. Patent Application Publication Nos. 2006/0093242 and 2006/0111226. 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, and U.S. patent application Ser. Nos. 11/818,585, 11/818,593, and 11/818,586, each 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 exterior64of the pouch50is also shown inFIG. 1. An opening66a,66b, or66callows fluid communication between the interior60and the exterior64of the pouch50. The opening66amay extend through or around the closure mechanism62. Alternatively, the opening66bmay extend through either the first or second sidewall52,54. The opening66cmay also extend through a side edge56a-56c, for example, through the bottom edge56b. A valve68may optionally be disposed in or covering the opening66a-66cto allow air to be evacuated from the pouch interior60and maintain a vacuum when the closure mechanism62has been sealed. As shown inFIG. 1, the valve68may be disposed on the second sidewall54spaced from the closure mechanism62. The valve68provides a fluid path with fluid communication between the pouch interior60and the exterior64of 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. Other valves useful in the present invention include those disclosed in, for example, U.S. patent application Ser. Nos. 11/818,592, 11/818,586, and 11/818,591, each filed on Jun. 15, 2007.

Although not shown, in some embodiments an evacuation pump or device may be used to evacuate fluid from the pouch50through, for example, the valve68disposed in one of the sidewalls52,54, or in the closure mechanism62or one of the side edges56a-56cof 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.

In a first embodiment shown inFIGS. 1 and 2, a plurality of flow channel protuberances70are arranged regularly or irregularly on the inner surface72of the first sidewall52. The protuberances70define flow channels74between the first and second sidewalls52,54as depicted, for example, by the lines and arrows inFIGS. 1 and 2, and that extend from the interior60to the opening66a-66cof the pouch50. Illustratively, the flow channel74provides fluid communication between the opening66a-66cand a portion of the interior60that is spaced from the opening66a-66c. For example, an embodiment including the opening66bthat extends through a first sidewall52includes a flow channel74that extends from directly opposite the opening to a portion of the interior60that is spaced from the opening. Alternatively, embodiments including either of the openings66aor66cinclude a flow channel74that extends from directly adjacent the opening to a portion of the interior60that is spaced from the opening. The flow channels74defined by the protuberances70may be straight or curved. The flow channels74defined by the protuberances70may be parallel to one another, or in other embodiments not shown, may extend radially away from the opening66a-66cin, for example, an expanding sunburst configuration, or may have any other configuration such that the flow channels74provide fluid communication between the opening66a-66cand a portion of the pouch interior60spaced from the opening when the pouch50is under vacuum pressure.

Referring toFIG. 2, the protuberances70may be integral with the first sidewall52. Each of the protuberances70includes a first component76that extends from the first sidewall52. Each protuberance70also includes a second component78that extends laterally away from the first component76proximate a distal end80thereof. The second component78may be round or square or any convenient shape and may extend laterally away from the first component76at any non-zero angle with respect to the first component76around a part or an entire periphery thereof. The second component78provides increased surface area82on a distal end90of each protuberance70.

Further, a solid material that includes fixed or supported portions is displaced at an unsupported portion in response to a force 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 pouch50being evacuated, unsupported portions of each of the first and second sidewalls52,54may sag into the flow channel74by an amount that depends upon spacing between respective ends of the protuberances70, the flex modulus for the material in each of the first and second sidewalls, and/or the level of vacuum drawn on the pouch. Assuming a given composition for the first and second sidewalls52,54, 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 protuberances70. The increased surface area82makes contact over an increased area of the inner surface84of the second sidewall54, thereby leaving less of the second sidewall54disposed over the flow channel74unsupported during evacuation of the pouch50. Inhibiting sag of the first and second sidewalls52,54into the flow channels74allows the flow channels to remain open for a longer period of time while fluid is being evacuated therefrom and from the pouch.

Referring next toFIG. 3, the second component78of each flow channel protuberance70may also extend from an intermediate region86that may be at any position on the first component76between a base end88and the distal end80thereof. The second component78may again be any convenient shape and may extend laterally away from the first component76at any non-zero angle with respect to the first component76around a part or the entire periphery thereof. The second component78extends from the intermediate region86to increase the effective surface area92at the distal end90of the protuberance70. Similar to the above, increased surface area92in contact with the inner surface84of the second sidewall54leaves less of the second sidewall54unsupported during evacuation of the pouch50.

The flow channel protuberances70may also depend from a first side94of a base member96, as illustrated inFIG. 3. A second side98of the base member96is affixed to the inner surface72of the first sidewall52. The base member96may be affixed to the first sidewall52by a thermoplastic weld layer210, a heat seal, an adhesive, or any other method known in the art. In each of the embodiments included herein, the flow channel protuberances70or profiles100(shown inFIGS. 4-9) may either be integral with the first sidewall52as described with respect toFIG. 2, or may depend from the first side94of the base member96as described with respect toFIG. 3. The flow channel protuberances70or profiles100may be extruded integrally with the base member96to form a three dimensional tape structure that may be fastened to the inner surfaces72,84of the respective first and second sidewalls52,54of the pouch50to create the flow channels74.

Referring next toFIGS. 4 and 5, in a further embodiment, flow channel profiles100define flow channels74between the first and second sidewalls52,54as depicted, for example, by the lines and arrows inFIG. 4, and that extend from the interior60to the opening66a-66cof the pouch50. Grooves102are provided on the inner surface84of the second sidewall54. The grooves102align and engage with the flow channel profiles100when the pouch50is brought under vacuum pressure. The engaged profiles and grooves100,102may reduce or limit lateral displacement of the second sidewall54across the profiles100. The engaged profiles and grooves100,102may also reduce or limit bowing of the profiles100in response to vacuum pressure. Therefore, the engaged profiles and grooves100,102may provide increased effective structural rigidity for sections of the second sidewall54between the grooves102. The engaged profiles and grooves100,102therefore may lessen blockage of the flow channels74by limiting collapse of the second sidewall54during evacuation of the pouch50. The flow channel profiles100of this embodiment may also be integral with the first sidewall52as disclosed in detail above with respect toFIG. 2, or may depend from the base member96that is affixed to the inner surface72of the first sidewall52, as disclosed in detail above with respect toFIG. 3.

Referring now toFIG. 6, the flow channel profiles100may also be cut into segments104. The segmented flow channel profiles100define flow channels74between the first and second sidewalls52,54as depicted, for example, by the lines and arrows inFIG. 6, and that extend from a portion of the interior60to the opening66a-66cof the pouch50. The flow channel profiles100and corresponding grooves102may be straight or curved. The profiles100may be parallel to one another, or in other embodiments not shown, may extend radially away from the opening66a-66cin an expanding sunburst configuration, or may have any other configuration such that the continuous flow channels74provide fluid communication between the opening66a-66cand a portion of the pouch interior60spaced from the opening when the pouch50is under vacuum pressure.

Referring next toFIGS. 7 and 8, the flow channel profiles100a-100eeach have a first component106that extends from the inner surface72of the first sidewall52or from the first side94of the base member96that is affixed to the inner surface72of the first sidewall52, as disclosed in detail above with respect toFIG. 3. Each profile100a-100ealso includes a second component108that extends laterally from the first component106proximate a distal end110thereof. The second component108may have a straight or curved cross section and may extend laterally away from one side of the first component106, as illustrated in left-most profile100ainFIG. 8, or may extend laterally away from both sides of the first component106as illustrated in right-most profile100einFIG. 8.

Illustratively, the second component108may extend laterally away from the first component106perpendicular to the first component106, as shown in profiles100aand100einFIG. 8. In another embodiment, the second component108may extend laterally away from the first component106at an obtuse angle as illustrated in profiles100band100cinFIG. 8. Further, in a further embodiment, the second component108may extend laterally away from the first component106at an acute angle as illustrated in profile100dinFIG. 8. The second component108provides increased surface area112on a distal end114of each profile100a-100e, and as discussed above, provides additional support area for the second sidewall54to assist in preventing collapse thereof into the channel74when the pouch50is being evacuated.

Referring next toFIG. 9, in still other embodiments, the second component108of each of the flow channel profiles200a-200cmay also extend from an intermediate region116of the first component106between a base end118and the distal end110thereof. In one embodiment, the second component108may have a straight or curved cross section and may extend laterally away from both sides of the first component106as illustrated in left-most profile200ainFIG. 8, or in other embodiments, may extend laterally away from one side of the first component106, as illustrated in profiles200band200cinFIG. 9. The second component108may extend laterally away from the first component106at any non-zero angle with respect to the first component106, for example, an acute angle, an obtuse angle, or a 90 degree angle. The second component108may extend from both sides of the first component106and away from the base member96as illustrated by left-most flow channel profile200ainFIG. 9, because such a configuration may provide an increased effective surface area112across the distal end114of the profile200a.

The flow channel profiles100a-100eand200a-200cmay be straight or curved. The profiles100a-100eand200a-200cmay be parallel to one another, or in other embodiments not shown, may extend radially away from the opening66a-66cin an expanding sunburst configuration, or may have any other configuration such that the continuous flow channels74provide fluid communication between the opening66a-66cand a portion of the pouch interior60spaced from the opening when the pouch50is under vacuum pressure.

Although not shown, one or both sidewalls, such as the second sidewall54, may also be embossed or otherwise textured with a pattern, such as a diamond pattern, on one or both surfaces spaced between the bottom edge56band the closure mechanism62, or a separate textured and embossed patterned wall may be used to provide additional flow channels (not shown) within the pouch interior64. Illustrative flow channels useful in the present invention include those disclosed in Zimmerman et al. U.S. Patent Application Publication No. 2005/0286808 and Tilman et al. U.S. Patent Application Publication No 2006/0048483.

In one embodiment, the first and second sidewalls52,54and/or the closure mechanism62are formed from thermoplastic resins by known extrusion methods. For example, the sidewalls52,54may be independently extruded of thermoplastic material as a single continuous or multi-ply web, and the closure mechanism62may 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 surfaces152,154of the respective sidewalls52,54or 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 sidewalls52,54proximate and parallel to the closure mechanism60to provide an additional cohesive seal between the sidewalls when the pouch50is evacuated of fluid. One or more of the sidewalls52,54in other embodiments may also be formed of 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 sidewalls52,54. 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 mechanism62may be extruded primarily of molten PE with various amounts of slip component, colorant, and talc additives in a separate process. The fully formed closure mechanism62may 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.

The protuberances70, and flow channel profiles100,100a-100e, and200a-200cas disclosed herein may be composed of any thermoplastic material such as would be used for the first and second sidewalls52and54of the pouch50as disclosed herein. Illustratively, the protuberances70, and flow channel profiles100,100a-100e, and200a-200cmay, for example, be composed of a polyolefin plastomer such as an AFFINITY™ resin manufactured by Dow Plastics.

The resealable pouch50described 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 use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which 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.