Push-down compressible pouch with one-way valves on sides

Airtight compressible storage containers (e.g., pouches) having one-way valves in the form of respective collapsible channels that run along and adjacent to respective pouch side seals. Each collapsible channel comprises unsealed sections of web material that span the space between a respective side seal and a respective interior seal. Each collapsible channel communicates with a respective air inlet located in the interior volume of the pouch and a respective air outlet located on a periphery of the pouch. When the contents of the pouch are compressed by a user pushing down on pouch, air from the storage chamber containing the compressible contents can be forced into the air inlet, through the open channel and out the air outlet until the desired amount of air has been removed from the pouch.

BACKGROUND OF THE INVENTION

This invention generally relates to reclosable flexible storage containers (e.g., pouches) whose interior volume is hermetically sealed (i.e., airtight) when the container is closed. In particular, the invention relates to, but is not limited to, airtight reclosable storage containers that can be collapsed by removal of air from the interior.

Collapsible reclosable storage containers typically include a flexible, airtight pouch, an opening through which an article is inserted inside the pouch, a zipper for closing the opening and hermetically sealing the pouch, and a one-way valve through which excess air is removed from the pouch. A user places an article into the pouch through the opening, seals the opening, and then removes air from the pouch via the one-way valve. During air removal, a compressible article contained therein may be significantly compressed so that it is easier to transport and requires substantially less storage space.

For one category of compressible reclosable storage pouches, air is removed from the interior volume via one or more one-way valves, each one-way valve being a channel that allows air to escape when the contents of the pouch are compressed, but prevents the return of ambient air into the pouch when the pressure is released. Typically the contents are compressed and air inside the pouch is forced out when the user presses down on the pouch and its contents. However, if a one-way valve channel is disposed adjacent and parallel to a bottom seal, it is possible that a user could accidentally place his hands over the channel. In that situation, when the user presses down on the pouch, the pressure on the channel would make it more difficult to expel air through the now-blocked channel.

There is a need for an improved construction of compressible storage containers that would avoid the user accidentally applying pressure on the one-way valve channel (or channels) when attempting to compress the pouch contents, so that the escape of air via the channel will not be obstructed while the pouch is being pressed.

BRIEF DESCRIPTION OF THE INVENTION

The present invention is directed to airtight compressible storage containers (e.g., pouches) having one-way valves in the form of respective collapsible channels that run along and adjacent to respective pouch side seals. Each collapsible channel comprises unsealed sections of web material that span the space between a respective side seal and a respective interior seal. Each collapsible channel communicates with a respective air inlet located in the interior volume of the pouch and a respective air outlet located on a periphery of the pouch. When the contents of the pouch are compressed by a user pushing down on the pouch, air from the storage chamber containing the compressible contents is forced through the air inlet and into the channel, thereby forcing the collapsed channel open. When the channel has been fully opened, continued pushing down on the pouch causes the air that was forced into the channel to escape via the air outlet. This procedure can be continued until the desired amount of air has been removed from the pouch. When the pressure exerted on the pouch by the user is removed, the channel collapses, thereby blocking the re-entry of ambient air into the pouch. Because the collapsible channels are located at the sides of the pouch, the risk that the user will accidentally obstruct the flow of air through the channel is reduced.

One aspect of the invention is a reclosable pouch comprising: a receptacle having a storage chamber and a mouth in communication with the storage chamber, and an airtight closure for closing the mouth, wherein the receptacle comprises first and second walls made of thermoplastic web material, an air outlet adjacent an edge of the first wall, a first side seal that includes respective first marginal portions of the first and second walls, a second side seal that includes respective second marginal portions of the first and second walls, a seal that includes respective portions of the first and second walls and is parallel to and spaced apart from the first side seal, respective unsealed portions of the first and second walls bridging a first portion of the first side seal and a first portion of the seal to form a collapsible channel, wherein the collapsible channel is in flow communication with the air outlet when the collapsible channel is not collapsed.

Another aspect of the invention is a reclosable pouch comprising: a receptacle having a storage chamber and a mouth in communication with the storage chamber, and an airtight closure for closing the mouth, wherein the receptacle comprises first and second walls made of thermoplastic web material, a first side seal that includes respective first marginal portions of the first and second walls, the first side seal having a gap therein that forms an air outlet, a second side seal that includes respective second marginal portions of the first and second walls, a first seal that includes respective first portions of the first and second walls and is parallel to and spaced apart from the first side seal, respective unsealed portions of the first and second walls bridging a first portion of the first side seal and a first portion of the first seal to form a collapsible channel, and a second seal that includes respective second portions of the first and second walls and extends from the first side seal to a location that is spaced from a first end of the first seal by a second gap that forms an air inlet, the air inlet being in flow communication with the air outlet when the collapsible channel is not collapsed.

A further aspect of the invention is a reclosable pouch comprising: a receptacle having a storage chamber and a mouth that is in flow communication with the interior volume, and an airtight closure for closing the mouth, wherein the receptacle comprises first and second walls and a bottom gusset made of thermoplastic web material, a first side seal that includes respective first marginal portions of the first and second walls and the bottom gusset, a second side seal that includes respective second marginal portions of the first and second walls and the bottom gusset, a first bottom seal that includes respective third marginal portions of the first wall and the bottom gusset, a second bottom seal that includes a third marginal portion of the second wall and a fourth marginal portion of the bottom gusset, an interior seal that includes respective first portions of the first and second walls and the bottom gusset and is parallel to and spaced apart from the first side seal, and an air outlet formed by a gap in the first bottom seal, respective unsealed portions of the first and second walls bridging a first portion of the first side seal and a first portion of the interior seal to form a first section of a collapsible channel that is in flow communication with the storage chamber of the receptacle, and respective unsealed portions of the first wall and the bottom gusset bridging a second portion of the first side seal and a second portion of the interior seal to form a second section of the collapsible channel, wherein the first section of the collapsible channel is in flow communication with the air outlet via the second section of the collapsible channel when the first and second sections of the collapsible channel are not collapsed.

Other aspects of the invention are disclosed and claimed below.

Reference will now be made to the drawings in which similar elements in different drawings bear the same reference numerals.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a collapsible reclosable storage pouch2in accordance with one embodiment of the invention. The storage pouch2comprises a receptacle4consisting of a front wall or panel6, a rear wall or panel (not shown) and a bottom gusset (not shown). The upper marginal portions of the front and rear walls form a mouth in which a plastic zipper8is installed. Although not shown inFIG. 1, the receptacle4incorporates side channels that act as one-way valves to allow escape of air from the interior volume when the contents (not shown) of the receptacle are compressed, but prevent the entry of air into the receptacle when the external pressure is released.

During use, one or more discrete compressible articles (not shown) may be placed inside the receptacle4while the zipper8is open, i.e., while the closure profiles of the interlockable zipper strips are disengaged from each other. After the article to be stored has been placed inside the receptacle, the mouth of the receptacle4can be sealed by pressing the zipper strips together to cause their respective closure profiles to interlock. Although the zipper closure profiles may have many different designs, the design must be one that ensures formation of an airtight seal at the receptacle mouth.

Still referring toFIG. 1, the zipper strips can be pressed together using a device10commonly referred to as a “slider” or “clip”, which straddles the zipper. The typical slider has a generally U-shaped profile, with respective legs disposed on opposing sides of the zipper. The gap between the slider legs is small enough that the zipper can pass through the slider gap only if the zipper is in a closed state. Thus when the slider is moved along an open zipper, this has the effect of pressing the incoming sections of the zipper strips together. A suitable slider is disclosed in U.S. patent application Ser. No. 10/940,213. The zipper is opened by pulling apart the zipper upper flanges, as explained in more detail below. The slider can be molded from any suitable plastic.

The front and rear wall panels of the receptacle4are respectively sealed to the zipper by lengthwise conduction heat sealing in conventional manner. Alternatively, the zipper can be attached to the wall panels by adhesive or bonding strips or the zipper can be extruded integrally with the web material. The walls of the receptacle may be formed of various types of gas-impermeable thermoplastic web material. The preferred gas-impermeable thermoplastics are nylon, polyester, polyvinyl dichloride and ethylene vinyl alcohol. The web material may be either transparent or opaque.

To maintain a vacuum inside the storage pouch, the zipper in a closed state must provide a hermetic seal at the mouth (i.e., fourth side) of the pouch. The present invention is not directed to any particular zipper construction. For the sake of illustration, however, a suitable zipper for use with the present invention will now be described with reference toFIG. 2.

FIG. 2shows a conventional zipper8that comprises a pair of mutually interlockable extruded zipper strips34and36. The zipper strip34comprises a pair of projections38and40having ball-shaped closure profiles, an upper flange48, and a lower flange50. The zipper strip36comprises three projections42,44and46(projection44has a ball-shaped closure profile), an upper flange52, and a lower flange54. For each zipper strip, the portions exclusive of the projections will be referred to herein as a “base”. The front wall6and rear wall12of the receptacle may be joined to the respective bases of the zipper strips by conduction heat sealing across their entire height or across only portions thereof. For example, the pouch walls could be joined to the zipper lower flanges and to the upper flanges by means of conduction heat sealing.

Still referring toFIG. 2, the projections38and40interlock with projections42,44and46by fitting inside the respective spaces therebetween. The upper flanges48and52can be gripped by the user and pulled apart to open the closed zipper. The opened zipper can be reclosed by pressing the zipper strips together (e.g., using a slider) along the entire length of the zipper with sufficient force to cause the projections38and40to enter the respective spaces between the projections42,44and46. Typically, such a slider takes the form of a U-shaped clip that fits over the zipper with clearance for the upper flanges, while the legs of the clip cam the zipper profiles of the incoming zipper section into engagement when the slider is moved along the zipper in either direction. Typically, the ends of the zipper strips34and36are joined together at the sides of the pouch. The ends of the zipper strips may be fused together at the same time that the container side seals are formed. The side seals are typically formed by applying heat and pressure in amounts sufficient to fuse and flatten the closure profiles at the ends of the zipper, which process is often called “thermal crushing”.

In accordance with the embodiments disclosed hereinafter, an airtight compressible storage pouch is provided with one-way valves in the form of respective collapsible channels that run along and adjacent to respective pouch side seals. Each collapsible channel communicates with a respective air inlet located in the interior volume of the pouch and a respective air outlet located on a periphery of the pouch. When the contents of the pouch are compressed by a user pushing down on the pouch, air from the storage chamber containing the compressible contents is forced through the air inlet and into the channel, thereby forcing the collapsed channel open. When the channel has been fully opened, continued pushing down on the pouch causes the air that was forced into the channel to escape via the air outlet. This procedure can be continued until the desired amount of air has been removed from the pouch. When the pressure exerted on the pouch by the user is removed, the channel collapses, thereby blocking the re-entry of ambient air into the pouch. Because the collapsible channels are located at the sides of the pouch, the risk that the user will accidentally obstruct the flow of air through the channel is reduced.

A collapsible reclosable storage pouch having one-way valves on respective sides thereof in accordance with one embodiment is shown inFIG. 3, in which heat-sealed regions are indicated by hatching. For ease of description, the empty pouch is shown in a planar state. The reclosable pouch comprises a receptacle having a storage chamber56and a mouth in communication with the storage chamber, and an airtight zipper8for closing said mouth. Other types of airtight closures can be used instead of a zipper, e.g., opposing strip-shaped layers of low-tack adhesive or cohesive material. The receptacle comprises a front wall6and a rear wall (not shown inFIG. 3), both walls being rectangular panels made of thermoplastic web material. A first side seal16includes respective first marginal portions of the front and rear walls, while a second side seal18includes respective second marginal portions of the front and rear walls. The first side seal16has a gap64therein that forms an air outlet, while the second side seal16has a gap66therein that forms another air outlet.

Still referring toFIG. 3, the receptacle further comprises a bottom gusset68that is formed by folding rectangular section of thermoplastic web material and placing the folded web material between the lower portions of the front and rear walls before the side seals are formed by heat sealing, thereby capturing a first folded marginal portion of the gusset bottom in the first side seal16and capturing a second folded marginal portion of the gusset bottom in second side seal18. The dashed line inFIG. 3indicates the apex of the folded gusset bottom. The portions of side seals16and18disposed at elevations above the dashed line inFIG. 3consist of respective marginal portions of the front and rear walls that have been joined together by heat sealing, while the portions of side seals16and18disposed at elevations below the dashed line inFIG. 3consist of respective folded marginal portions of the gusset bottom sandwiched between respective marginal portions of the front and rear walls, each folded marginal portion of the gusset bottom being joined by heat sealing to itself and to the respective marginal portions of the front and rear walls on opposite sides thereof.

The relationship of the folded gusset bottom68to the front wall6and rear wall12is shown inFIG. 4. One marginal portion of the gusset bottom is joined to a marginal portion of front wall6by a first bottom seal20(see alsoFIG. 3), while another marginal portion of the gusset bottom is joined to a marginal portion of rear wall12by a second bottom seal21, both bottom seals being formed by conventional heat sealing (i.e., by the application of pressure and heat sufficient to meld the aforementioned marginal portions).

For the embodiment depicted inFIG. 3, the first bottom seal20does not extend the full width of the receptacle. Instead a first end of the first bottom seal20is separated from an end of the first side seal16by a gap60that forms a third air outlet, while a second end of the first bottom seal20is separated from an end of the second side seal18by a gap62that forms a fourth air outlet. The bottom seal21may optionally have similar gaps.

During manufacture of the embodiment depicted inFIG. 3, a first interior seal22is formed that extends parallel to and spaced apart from the first side seal16, and a second interior seal24is formed that extends parallel to and spaced apart from the second side seal18. One end of the interior seal22is contiguous with the bottom seal20(as well as bottom seal21seen inFIG. 4). Likewise one end of the interior seal24is contiguous with the bottom seal20(as well as bottom seal21). The interior seals22and24are both formed by conductive heat sealing in a well-known manner using a heated sealing bar. The storage chamber56, in which the compressible contents are placed before air removal, is bounded by the first and second interior seals22and24.

The first interior seal22includes a first section wherein respective portions of the front and rear walls are heat sealed together. The first interior seal22also includes a second section wherein respective portions of the front and rear walls and the bottom gusset are heat sealed together. The boundary between the first and second sections of the first interior seal22is located where the horizontal dashed line inFIG. 3intersects the first interior seal22. As a result of the formation of the first interior seal22, respective unsealed portions of the front and rear walls span the space between a first portion of the first side seal16and a first portion of the first interior seal22to form a first collapsible channel26, the lower limit of which is generally indicated by the horizontal dashed line inFIG. 3. Furthermore, respective unsealed portions of the front wall6and bottom gusset68span the space between a second portion of the first side seal16and a second portion of the first interior seal22to form a second collapsible channel27, the upper limit of which is generally indicated by the horizontal dashed line inFIG. 3. The first and second collapsible channels26and27are in fluid communication when those channels are not collapsed.

Similarly, the second interior seal24includes a first section wherein respective portions of the front and rear walls are heat sealed together, and a second section wherein respective portions of the front and rear walls and the bottom gusset are heat sealed together. The boundary between the first and second sections of the second interior seal24is located where the horizontal dashed line inFIG. 3intersects the second interior seal24. As a result of the formation of the second interior seal24, respective unsealed portions of the front and rear walls span the space between a first portion of the second side seal18and a first portion of the second interior seal24to form a third collapsible channel28, the lower limit of which is generally indicated by the horizontal dashed line inFIG. 3. Furthermore, respective unsealed portions of the front wall6and bottom gusset68span the space between a second portion of the second side seal18and a second portion of the first interior seal22to form a fourth collapsible channel29, the upper limit of which is generally indicated by the horizontal dashed line inFIG. 3. When not collapsed, the third and fourth collapsible channels28and29are in fluid communication with each other.

Although not shown inFIG. 3because they are located directly behind the collapsible channels27and29, additional collapsible channels are formed by the bottom gusset and rear wall. More specifically, respective unsealed portions of the rear wall and the bottom gusset68span the space between the aforementioned second portion of the first side seal16and the aforementioned second portion of the first interior seal22to form a fifth collapsible channel directly behind the collapsible channel27, which fifth collapsible channel is also in fluid communication with the collapsible channel26when those channels are not collapsed. Similarly, respective unsealed portions of the rear wall and the bottom gusset68span the space between the aforementioned second portion of the second side seal18and the aforementioned second portion of the second interior seal24to form a sixth collapsible channel directly behind the collapsible channel29, which sixth collapsible channel is also in fluid communication with the collapsible channel28when those channels are not collapsed.

In the disclosed embodiment, each collapsible channel has a constant width and extends parallel to the side seals16,18and perpendicular to the zipper8and the bottom seals20,21.

As seen inFIG. 3, the receptacle further includes a first angled seal30that includes respective portions of the front and rear walls that have been joined by heat sealing. The first angled seal30includes a leg that extends from the first side seal16to a location that is spaced from a distal end of the first interior seal22by a gap that forms a first air inlet59. The first air inlet59will be in flow communication with the first air outlet64when the first collapsible channel26is not collapsed, and will be in flow communication with the third air outlet60when the first and second collapsible channels26and27are not collapsed. On the other side, the receptacle further includes a second angled seal32that includes respective portions of the front and rear walls that have been joined by heat sealing. The second angled seal32includes a leg that extends from the second side seal18to a location that is spaced from a distal end of the second interior seal24by a gap that forms a second air inlet61. The second air inlet61will be in flow communication with the third air outlet66when the third collapsible channel28is not collapsed, and will be in flow communication with the fourth air outlet62when the third and fourth collapsible channels28and29are not collapsed.

During use of the pouch depicted inFIG. 3, the zipper8is opened and then the storage chamber56is loaded with compressible contents. The zipper8is then closed, thereby hermetically sealing the mouth of the receptacle. If the user then places the loaded pouch on a support surface and pushes down on the loaded pouch, thereby compressing the compressible contents, air will be forced out of the pouch via the flow paths indicated by arrows70,72,74on one side and via the flow paths indicated by arrows76,78,80on the other side. More specifically, arrow70indicates the flow of air through the first air inlet59and into the first collapsible channel26; arrow72indicates the flow of air through the first collapsible channel26and then out the first air outlet64; arrow74indicates the flow of air through the second collapsible channel27and then out the third air outlet60; arrow76indicates the flow of air through the second air inlet61and into the third collapsible channel28; arrow78indicates the flow of air through the third collapsible channel28and then out the second air outlet66; and arrow80indicates the flow of air through the fourth collapsible channel29and then out the fourth air outlet62(the flows through the fifth and sixth collapsible channels are not shown inFIG. 3).

When the user pushes down on the loaded pouch, the air pressure causes the collapsible channels to open. When the external pressure is released, the collapsible channels collapse (i.e., close), thereby preventing the entry of ambient air into the receptacle.

FIG. 5is a drawing showing a plan view of a stage in the automated manufacture of pouches of the type shown inFIGS. 3 and 4. Pouches are produced by paying out first and second webs of thermoplastic material, having the same width, which are placed in overlying relationship. A zipper tape is also paid out, arranged between marginal portions on one side of the first and second webs, and then joined to both webs by conductive heat sealing. Also a third intervening web of thermoplastic material, narrower in width, is paid out, and folded. The intervening folded web (which is the precursor for bottom gussets68) is arranged between marginal portions on the other side of the first and second webs and then heat sealed thereto. The three webs are heat sealed to form channels using a heated sealing bar that has formed thereon the pattern depicted by hatching inFIG. 5. After heat sealing, a separate pouch is made by severing along the cut lines100and102, indicated inFIG. 5by vertical dashed lines.

In accordance with a further embodiment, two intervening layers of valve film material, each having a smoothness greater than the smoothness of the thermoplastic web material of the pouch walls and bottom gusset, are incorporated in one or more collapsible channels. In forming the valve film layers, various materials may be employed. Such materials include, but are not limited to, low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE).FIG. 6shows a portion of an airtight compressible reclosable storage pouch having a bottom gusset68and further having a double-layered one-way valve90installed as part of a collapsible channel28′ disposed on one side of the pouch. [A similar double-layered one-way valve is installed as part of a collapsible channel disposed on the other side of the pouch (not shown).] The two horizontal dashed lines inFIG. 6that extend between seals18and24indicate the extent of the double-layered one-way valve90, while the hatching indicates the pattern of heat seals as previously described.

FIG. 7is a cross-sectional view of the double-layered one-way valve depicted inFIG. 6, in a collapsed state, the section being taken along the line7-7indicated inFIG. 6. The double-layered one-way valve comprises a portion of a front wall6, a first layer92of valve film, a second layer of valve film94and a portion of a rear wall12. The layers of valve film92and94may be rectangular pieces of valve film disposed between the front and rear walls6and12. Marginal portions of the front and rear walls and the first and second layers of valve film are joined at the side heat seal18; while portions of the front and rear walls and other marginal portions of the first and second layers of valve film are joined at the interior heat seal24. The ends of the valve film layers92,94located closest to the air inlet61should be respectively sealed to the front and rear walls6,12to avoid air entry between the pouch walls and the valve film.

FIG. 8is a drawing showing a cross-sectional view, similar toFIG. 7, but showing the opened (i.e., not collapsed) state of the double-layered one-way valve while air is being removed from the pouch by application of external pressure on the loaded storage chamber, as indicated by arrows104,106. As a result, the air being removed from the pouch travels between the two valve film layers92,94. Since the valve film layers are smooth, regardless of any texture imparted to the pouch walls, a reliable seal of the valve is obtained. When no external pressure is physically exerted on the pouch walls6,12, ambient atmospheric pressure is sufficient to press the valve film layers92,94toward one another, effectively closing the channel (as seen inFIG. 7), thereby impeding unwanted air from entering the channel28′ and the storage chamber.

A person of ordinary skill in the art will appreciate that instead of two valve film layers (as seen inFIGS. 7 and 8), one valve film layer could be used (not shown in the drawings).

As used in the claims, the verb “joined” means fused, welded, bonded, sealed, adhered, etc., whether by application of heat and/or pressure, application of ultrasonic energy, application of a layer of adhesive material or bonding agent, interposition of an adhesive or bonding strip, co-extrusion (e.g., of zipper and bag), etc. Also, as used in the claims, the phrase “gap in a bottom seal” should be construed to include, but is not limited to, a gap between an end of a bottom seal and an end of a side seal”.