INDUCTION SEAL VENTING CLOSURE AND CONTAINER ASSEMBLY

BACKGROUND

In the art of closures for containers there are several design considerations beyond simply what materials to use, what sizes or dimensions are desired and how will the closure mate or engage with the selected container. Depending on the product to be placed in the container and depending on the target customer, it may be desirable to include a tamper-evident feature or a child-resistant construction. In this context and for this discussion the term “closure” refers to different styles, different materials, different sizes and different manners of engagement.

One design consideration for a container closure and/or for a container-closure combination which may be relevant to the designer is whether the closed combination, when the closure is seated on and fully engaged with the container, with the selected product in the container, needs to be vented. One common venting construction is found as a part of current packaging for carbonated beverages. For this type of product, as the threaded closure is unscrewed from the neck of the container, vent passageways open in order to allow an immediate and gradual release of any internal pressure. The venting passageway for this type of carbonated beverage construction is typically within the threaded interface located between the inner surface of the closure and the outer surface of the container neck.

In this described construction the venting is only intended to occur when the closure is subjected to retrograde removal, i.e. is being unscrewed from the container neck, for opening of the closed container in order to access the contents. There are though other applications where venting of a closed container may be desired on an on-going basis as the closure-container combination is at rest/storage. As one example of such an application, a plastic container may receive a warm fluid as its product contents and the container is sealed closed with the selected closure before the fluid temperature stabilizes. Accordingly, as the fluid cools, the pressure within the container lowers. With flexible plastic containers this can result in shape distortion or partial collapse of the container sidewall. A similar result can occur if there are different atmospheric pressures between the packaging location, such as at a high altitude, and the sale or storage location, such as at sea level. In these situations, it may be desirable to allow “venting” in the form of air entering the container. The introduction of air restores the distorted container to its desired initial and/or static shape.

As another example of when venting may be desirable or important is directed to the nature of the product, i.e. the contents of the container. These contents may have a composition which, over time, results in some level or degree of outgassing. Outgassing could generate an internal pressure and a need or at least a desire to vent the container in order to limit or control any internal pressure buildup within the container.

One closure construction which has been described for venting a closed container is to use one or more radially slotted, annular sealing rings which are formed on the inner surface of the upper panel of the closure. These sealing rings are designed to seal against the exposed upper surface of the land of the neck opening of the container as the closure is fully seated on the container neck, most likely by a secure threaded connection. When these annular sealing rings, one or more, are formed with a radial slot extending therethrough, a vent passageway is opened from the interior of the container to the atmosphere, exterior of the closure. A typical vent path is initially through the slotted pathway across the land which provides clearance between the closure and the container, and then downwardly through the mating and engaged threads.

Another manner of sealing closed a container is to use an induction seal liner. This type of liner is normally constructed with a foil layer and a seal layer which melts due to induction heating thereby bonding the foil layer to the land of the container neck. This style of closure does not lend itself to venting when there is a complete seal of the foil against the entire circumference or periphery of the container neck land. Nevertheless, there are known techniques for venting an induction seal liner, i.e. a foil liner, and these known modification techniques can be improved upon as disclosed herein by the exemplary embodiment of the present invention.

SUMMARY

The following presents a summary of this disclosure to provide a basic understanding of some aspects. This summary is intended to neither identify key or critical elements nor define any limitations of embodiments or claims. Furthermore, this summary may provide a simplified overview of some aspects that may be described in greater detail in other portions of this disclosure.

Described herein is a closure for a container which includes a seal liner, said closure comprising, an upper panel having an inner surface, and side walls extending from the upper panel, wherein said inner surface includes at least one recessed relief positioned proximal the side walls and operatively defining a venting location. The side walls are internally threaded. The closure is a single-piece, molded plastic component. The least one recessed relief has a generally rectangular periphery. The at least one recessed relief has an axial depth of at least 0.010 inches. The at least one recessed relief comprises a first relief and a second relief, and wherein the first relief and the second relief are equally spaced about the upper panel. The closure is a single-piece, molded plastic component. The at least one recessed relief has a substantially rectangular periphery. The at least one recessed relief has an axial depth of at least 0.010 inches. The at least one recessed relief is operatively formed through molding.

A closure assembly may comprise a container having a neck with a land, a closure for engagement with said container, said closure comprising an upper panel, the upper panel comprising at least one recessed relief for venting of said container, and a seal liner position between said upper panel and said land, wherein at least a portion of said seal liner is positioned between said land and said at least one recessed relief. The seal liner is a lamination with a foil layer and a seal layer. An other portion of said seal layer is operatively positioned against said land when said closure is assembled to close said container. The other portion of said liner is operatively positioned between said land and said upper panel in a position that is not adjacent to said at least one relief, and wherein said upper panel and said land apply pressure to said other portion of said liner. The at least a portion of said seal liner defines an airflow passageway with said land. The at least a portion of said seal liner does not contact said upper panel. The at least one other portion of said liner is operatively sealed with the land.

A method of forming a vent in a closure assembly may comprise providing closure for engagement with a container, said closure comprising an upper panel, the upper panel comprising at least one recessed relief for venting of said container, positioning a seal liner between the closure and the container, applying a closing force to the closure and the container to operatively apply pressure to the seal liner, wherein a portion of the seal liner disposed between the at least one recessed relief and the container (e.g., such as at position 104) does not receive the closing force, and inductively heating said seal liner. Other portions of the seal liner that are disposed between the land 30 and the upper surface 50 experience the closing force and are sealed with the land. The method may also include forming the at least one recessed relief via at least one of machining or molding.

The following description and the drawings disclose various illustrative aspects. Some improvements and novel aspects may be expressly identified, while others may be apparent from the description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a representative closure and container assembly which includes a foil liner and the closure modification according to the present invention.

FIG. 2 is a perspective view of the FIG. 1 container.

FIG. 3 is a perspective view of the FIG. 1 closure.

FIG. 4 is a perspective view of the FIG. 1 liner.

FIG. 5 is an exploded, side elevational view of the FIG. 4 liner showing the individual liner layers.

FIG. 6 is a bottom plan view of the FIG. 3 closure.

FIG. 7 is a partial, front elevational view, in full section, of the FIG. 1 assembly.

FIG. 8 is an enlarged detail of one portion of the FIG. 7 full section view.

DESCRIPTION OF THE SELECTED EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized, and structural and functional changes may be made without departing from the respective scope of the invention. Moreover, features of the various embodiments may be combined or altered without departing from the scope of the invention. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the invention.

As used herein, the words “example” and “exemplary” mean an instance, or illustration. The words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment. The word “or” is intended to be inclusive rather an exclusive, unless context suggests otherwise. As an example, the phrase “A employs B or C,” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles “a” and “an” are generally intended to mean “one or more” unless context suggests otherwise.

Described embodiments may refer to a container and closure assembly, or simply an assembly, primarily comprising a closure and a container. The closure may comprise various materials and shapes. For instance, the container may comprise plastics, metals, glass, or other materials. Moreover, the container may be cylindrical, ovoid, irregular in shape, or otherwise shaped. The term “closure” generally refers to a cap, lid, or other closure that operatively closes an aperture or opening of the container. Closures may be attachable to the container via threads, press-fit arrangements, bayonet-type locking, adhesives, or the like. Moreover, closures may comprise flip top lids, spouts, ribs, or other aspects. Unless state or context warrants otherwise, a particular distinction, a variety of container assemblies having different shapes and arrangements may be utilized according to the present disclosure.

In some traditional containers with an induction seal liner, the liner is completely and physically attached to a peripheral end or land of an opening of a container. When one wishes to vent the container, the traditional methods either mechanically generate holes through the liner, add a “venting” layer in the liner or otherwise use a liner with a glued or added permeable membrane. The containers and liners require specialized membranes or additional physical actions to create vents. When producing such containers, each additional step or specialized membrane can greatly increase costs, increase production time, and reduce efficiency.

Described embodiments of this disclosure provide for venting modification to the closure through one or more reliefs formed within a panel of a closure or cap. The relief is operatively positioned at a location in the top surface of the panel that abuts a land of a container neck. Thus, when the liner and closure are operatively attached to the container, a portion of the liner that is disposed between the land and the relief is not physically forced downward or compressed between the closure and the container. When the liner is inductively heated, the compressed portions of the liner are sealed with the land, while any un-compressed portion of the liner forms an air or venting passageway with the land.

As such, described embodiments provide for venting without specialized membranes, venting layers, or additional mechanical piercing of a liner. In an example, the induction seal liner itself may be the same for described venting closures and for traditional non-venting closures. As such, the liner need not be modified or redesigned with respect to traditional liners. This allows for the same style of liner to be utilized for vented and non-vented containers and closures. Moreover, the liner need not include specialized venting layers, physically added venting devices, or apertures formed through the liner.

This disclosed provides for a venting container assembly that may provide benefits in the form of a recessed relief area formed, molded, machined, or otherwise positioned into the inner surface of the upper panel of the closure. This recessed relief area extends axially in what would be an upward direction from the inner surface of the upper panel of the closure. The radial extent of this recessed relief area must be sufficient to create a radial vent path.

Referring to FIGS. 1-4 there is illustrated an assembly 20 comprising a container 22, a closure 24, and an induction seal liner 26 according to an exemplary embodiment of the present invention. The positioning of the liner 26 relative to the container 22 and closure 24 is illustrated in FIGS. 7 and 8. In an exemplary embodiment, the assembly 20 may include a threaded engagement for application and securement of the closure 24 onto the neck 28 of container 22. The liner 26 is positioned so as to lay over the land 30 of the neck 28 for sealing of the liner 26 to the upper surface 32 of the land 30. The neck 28 may be externally threaded with either male or female threads. The land 30 may be annular and the upper surface 32 of the land may be circular and generally planar. For instance, the supper surface may comprise an annular ring form. Complete sealing of the liner 26 to the upper surface 32 would include circumferential sealing of the liner to the upper surface 32. However, as disclosed herein, there may be one or more locations where the liner 26 is not sealed to the upper surface 32 such that a passage or flow path operatively vents the container 22 as described herein.

In embodiments, the container 22 may comprise a single-piece construction or may comprise different pieces operatively attached together. As an example, the container 22 may comprise a monolithic molded plastic construction. The container 22 may include a body 22a (which may comprise a generally annular body), a tapering portion 22b or section leading to the neck 28. The neck 28 may be generally cylindrical and may comprise is externally threaded. The size, shape and materials for container 22 may vary and the external finish on the neck 28 is selected to be compatible with the internal finish on the outer wall of the closure 24. Some of the material options for container 22 include high density polyethylene (HDPE), polyethylene terephthalate (PET) and glass.

In one or more embodiments, closure 24 is a single-piece, molded plastic construction with a side walls 24a that may form a generally annular body whose internal or inner surface is internally threaded with a thread design and construction compatible with the external threads on the container neck 28. The thread fit between closure 24 and neck 28 is selected so as to maintain an air or gas vent path from the inside of the container to the outside atmosphere by passing through the clearance between the engaged threads. This air or gas vent path exists even when the closure is fully engaged onto neck 28 with a secure fit. Some of the material options for closure 24 include polypropylene (PP) and high density polyethylene (HDPE).

According to examples, the seal liner 26 is a lamination of three layers (see FIG. 5), including in order from the axially outer or upper position to an axially inner position, a backing layer 38, a foil layer 40 and a seal layer 42. Once liner 26 is applied to the land 30 of the container neck 28, backing layer 38 is facing the inside surface of the upper panel of closure 24. As would be understood, once the closure is removed from the container 22 (e.g., such as by retrograde rotation), the backing layer 38 is exposed and visible. The seal layer 42 is melted by induction heating of the foil layer 40 resulting in sealingly bonding the seal layer 42. In an example, the foil layer 40 may be bonded to the upper surface 32 of the land 30, though with at least one vent relief location as described herein.

In some traditional systems, the foil layer 40 is directly sealed completely around the circumference of the land 30 over the entirety of the exposed annular ring upper surface 32. To defeat or break the seal, a user would have to puncture or remove the liner 26. Moreover, the seal would not allow for venting of contents within the container 22. Embodiments described herein allow for venting of an induction sealed liner 26 without requiring breaking, removing, or otherwise physically altering the liner 26.

As shown in FIGS. 7 and 8, liner 26 may include an outwardly extending edge 44. While one might see edge 44 as a way or means to peel off liner 26, the strength of the seal layer bond is such that puncturing of liner 26 is preferred. Prior to induction heating, the edge 44 or overhang retains the liner 26 in the closure 24 and may prevent the liner 26 from falling out or coming misplaced with respect to the closure 24. As such, the liner 26 is generally larger in diameter than the diameter of an inner surface 50 of the closure 24 such that the liner 26 and the closure 24 have an interference fit with each other. When operatively assembled with the container 22, the edge 44 overhangs the land 30.

As noted herein, liner 26 may comprise other or different layers. For instance, liner 26 may comprise w layers, where w is a number. Accordingly, the three layers 38, 40 and 42 of liner 26 illustrate examples of possible liner constructions for disclosed embodiments. As noted herein, various styles of sealed liners may be compatible with the vented closure 24.

In embodiments, the liner 26 is placed within the closure 24. The closure 24 and liner 26 are then assembled with the container 22. An induction sealing procedure may then be applied to operatively bond liner 26 to at least a portion of the land 30 as described here and elsewhere in this disclosure. It is noted that the container 22 may be filled with contents prior to the operative attachment of the closure 24 (with the liner 26 preassembled) with the neck 28.

In an embodiment of the present invention this assembly and secure engagement of the closure 24 onto the neck 28 is by threaded engagement. Once the closure is fully engaged with the neck 28 and completely seated in terms of its axial advance, there is a down force exerted by the closure 24 on the liner 26 pushing the liner 26 down against the upper surface 32 of land 30. The assembly of the closure 24 on to the container 22 is typically an automated process. Once assembled, the inner surface 50 of upper panel 52 pushes against backing layer 38 such that the seal layer 42 is pushed tightly against the entirety of upper surface 32. In an aspect, the closure may include at least one relief area 54 formed into the upper panel 52 of the closure 24. At the location of each relief area 54 the upper panel 52 does not make the requisite contact so as to push the seal layer 42 which is directly beneath that relief area 54 tightly against upper surface 32. However, in all remaining areas of the seal layer 42 there is a down force applied by the closure 24 and this down force is what facilitates and results in a sealed interface between the foil layer 40 and the upper surface 32 of land 30. This down force as applied by the closure as it is axially advanced downwardly onto the neck 28 of the container 22 is known in the container closure industry as “closure torque.”

As shown in FIGS. 6 and 7, when the closure 24 is operatively assembled with the container 22, the land 30 is disposed at position 100 as indicated by the dashed lines. The liner 26 is disposed between the land 30 and the closure 24. In an aspect, a first portion of the liner 24 is disposed at position 102 generally defined as between the land 30 and closure 24, and extending between the relief area(s) 54. This first portion of the liner 24 may be compressed or may otherwise be subject to force between the neck 28 and closure 24 as described herein. The second portion of the liner 24 may be disposed at position 104, as shown in greater detail in FIG. 8. The second portion is generally between the land 30 and relief 54. It is noted that various other portions of the liner 24 may be disposed between one or more other reliefs 54 and the land 30.

The next step in this closing and sealing process is to inductively heat the foil layer 40 which raises the temperature of the foil layer 40 and melts the seal layer 42. When melted, the sealing material flows onto the land 30 and when the sealing material sets, the liner 26 is bonded to the land 30. Again, this is only occurring in those locations where there is a sufficient down force exerted by the upper panel 52 of the closure on the liner 26. Assuming that the correct amount of energy is induced into the foil layer 40, preferably an aluminum foil layer, then the necessary temperature will be induced. The direct contact between the foil layer 40 and the seal layer 38 due to the down force exerted by the upper panel 52 of the closure 24, and with the necessary temperature established, the seal layer 38 will melt and bond the liner 26 to land 30. As described, one of the important aspects of getting a secure bond of the liner 26 around the entire circumference of the upper surface 32 of land 30 is to have a sufficient down force from closure contact against the backing layer of the liner 26. This down force is axially aligned with land 30 and extends around the entire circumference of the land, with the exception of any relief areas 54, as described herein.

Turning back to FIGS. 6 through 8, the closure 24 includes at least one recessed relief 54. Relief 54 comprises an area of the upper panel 52 which is axially recessed into the upper surface 50. There are two reliefs 54 illustrated in FIG. 6 and while this number represents an exemplary embodiment of this disclosure, venting can be accomplished with one relief 54 or with more than two reliefs 54 (e.g., 3, 4, 5, etc.). Substantially equal circumferential spacing of the two reliefs 54 provides venting balance and may provide faster venting as compared to having only one relief 54.

The reliefs 54 may comprise various shapes, such as generally rectangular, generally an n-sided polygon (where n is a number), irregular in shape, or the like. In one aspect, the reliefs 54 may comprise groves or notches. It is further noted that the size and position of the reliefs 54 may depend on a desired airflow pattern or amount. As such, embodiments may include different or other reliefs 54 formed through within the panel 52.

In an embodiment, two liner 26 locations are aligned with (i.e. positioned axially directly beneath) the two reliefs 54 (e.g., such as at position 104) are locations where the liner 26 does sufficient contact with land 30 for bonding. Threading the closure 24 onto neck 28 results in the axial stack of land 30, liner 26 and relief 54 of the upper panel 52 at position 104. This stack does not place sufficient down force between the upper panel 52 and liner 26 to inductively seal the liner 26 with the land 30 at position 104. It is noted that there may not be any contact between the liner 26 and upper panel 52 at these locations adjacent to the reliefs 54. Even in embodiments where there may be contact, the contact there is not a sufficient down force at the relief 54 locations to result in bonding of the liner 26 to the upper surface 32 at locations axially aligned with the relief 54 locations. The liner 26 and land 30 are, however, forced together at other locations (e.g., position 102) and direct contact between adjacent portions due to the down force or closure torque which is applied as the closure 24 is threaded onto the neck 28 of the container 22.

Without bonding of the liner 26 to the upper surface 32 at those relief 54 locations, the liner 26 and the upper surface 32 do not form an airtight seal at those locations. This allows the container 22 to vent. For example, when there is not a sufficient down force exerted by the upper panel 52 on the liner 26, the melted sealing material of seal layer 42, melted as a result of induction heating of the foil layer 40, will not bond the foil layer 40 to the land 30 over an area and at locations which match reliefs 54. While the number of reliefs 54 may vary, noting that two reliefs 54 may be preferred for some embodiments, the size and shape of each relief may also change as described herein. In at least one exemplary embodiment each relief 54 has a generally rectangular form, though with a curved outer edge. The straight length is approximately 0.25 inches and the straight width is approximately 0.225 inches. The depth into the inner surface 50 of upper panel 52 is approximately 0.02 inches. Design variations would be related to container neck size and the anticipated venting needs, including volume and rate and these may depend in part on the particular product placed in the container as well as the volume of that product. The axial depth of each relief into the upper panel 52 needs to be selected in cooperation with the container and closure sizes, but importantly also in cooperation with the level of closing torque. In an embodiment, an axial depth generally prevents or reduces the possibility that the relief 54 locations the foil layer 40 will not be bonded to the upper surface 32 of land 30. The shape of each relief 54 may vary, but the rectangular form (with one curved side) represents a form which is easy to produce. The radial dimension must be sufficient for a vent path 56 to be established across the land 30 and liner 26.

As a result of sealing portions of the liner 26 with the land 30, and preventing other portions of the liner from sealing with the land 30, the vent path 56, as shown in FIGS. 7-8, is formed. An increase (with respect to external pressure) in interior pressure within the container 22 may result in the container 22 being vented, the internal pressure buildup releases pressure through the venting passageway 56. This venting passageway 56 may be defined by a portion of the liner 26 and a portion of the land 30. It is noted that the venting passageway 56 allows for fluid communication from within the interior of container 22, upwardly and then radially outwardly beneath liner 26 and then axially downwardly through the thread clearance 58 of the mated closure and container threads, 60 and 62, respectively. The “beneath liner 26” location(s) correspond to the relief 54 location(s) or positions 104 and is a path or passageway between the liner 26 and land 30.

As explained, it is the reduction of down force in the (recessed) relief 54 locations which keeps the induction seal from forming a bond at each relief 54 location. As noted, there are generally at least three steps for creating a bonded seal:

heat applied through induction of energy;

sufficient down force; and

time for the glue or adhesive of the seal layer to bond to the land 30.

The venting structure of the exemplary embodiment of the present invention provides a cost-effective, simple form of venting for closure and container assemblies which have a foil liner which is bonded to at least a portion of the land of a container neck.

In at least one embodiment, the closure 24 may not contain a relief 54. Instead, the container 22 may include one or more reliefs formed through the upper surface 32 of the land 30. It is noted that reliefs of the upper surface 32 may comprise similar aspects as reliefs 54. For example, reliefs in the upper surface 32 may reduce downward force experienced at portions of the liner 26 that abut the reliefs as described herein.

As described herein, a method of forming a vent in a closure assembly may comprise providing closure for engagement with a container, said closure comprising an upper panel, the upper panel comprising at least one recessed relief for venting of said container, positioning a seal liner between the closure and the container, applying a closing force to the closure and the container to operatively apply pressure to the seal liner, wherein a portion of the seal liner disposed between the at least one recessed relief and the container (e.g., such as at position 104) does not receive the closing force, and inductively heating said seal liner. Other portions of the seal liner that are disposed between the land 30 and the upper surface 50 experience the closing force and are sealed with the land. The method may also include forming the at least one recessed relief via at least one of machining or molding.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes, equivalents, and modifications that come within the spirit of the inventions defined by following claims are desired to be protected. All publications, patents, and patent applications cited in this specification are herein incorporated by reference as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference and set forth in its entirety herein.

Although the embodiments of this disclosure have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present disclosure is not to be limited to just the described embodiments, but that the embodiments described herein are capable of numerous rearrangements, modifications and substitutions without departing from the scope of the claims hereafter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present specification, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present specification are possible. Each of the components described above may be combined or added together in any permutation to define a closure. Accordingly, the present specification is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.

INDUCTION SEAL VENTING CLOSURE AND CONTAINER ASSEMBLY

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

International Classifications

Abstract

Description

Claims

CROSS-REFERENCE TO RELATED APPLICATION

Provisional Applications (1)