US20120043324A1

Movatterモバイル変換

Info

Publication number: US20120043324A1
Application number: US13/211,881
Authority: US
Inventors: Gerald J. Baker; Alvin Widitora
Original assignee: Silgan Containers LLC
Current assignee: Silgan Containers LLC
Priority date: 2010-08-18
Filing date: 2011-08-17
Publication date: 2012-02-23

Abstract

A container assembly includes a can, a can end, and a sheet which hermetically closes an access opening in the can end. The can end includes an opening for accessing the contents of the container. This opening is hermetically sealed closed by a sheet sealed to the end about the periphery of the opening with a closed-loop of adhesive. The sheet preferably includes a tab and a weakened or score line which causes the sheet to tear across the seal at an angle less than 90 degrees to the seal such that the sheet pulls away from the can end along a line generally parallel to the loop where the sheet is being separated from the can end.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims the benefit of U.S. Provisional Patent Application No. 61/374,703, entitled Container with Reduced, Peel-Off-Force Tear Configuration, filed Aug. 18, 2010, which is incorporated herein by reference in its entirety.

BACKGROUND

The present invention relates generally to the field of easy-open containers. More specifically, the present invention relates to cans and can ends for container assemblies which can be opened without the use of an opening tool, such as a can opener.

SUMMARY

One embodiment relates to a container end having a metal rim including an inwardly extending flange with a rolled edge which defines an opening in the end, the metal rim including a thermoplastic layer and an area extending into the opening, and a foil with a thermoplastic layer. The foil covers the opening and includes a weakened formation and a tab formed by at least a portion of the formation. A closed-loop seal is provided which has a central axis. The seal is formed by heating selected portions of the layers to seal the foil to the rim such that the tab is substantially located over the area. The formation is configured to promote tearing of the foil across the seal when a pulling force is initially applied to the tab and separation of the foil from the seal in a direction generally parallel to the central axis of the seal after the foil is torn across the seal. Also provided is a seal extension extending from the closed loop between the area and the tab.

One embodiment relates to a metal container assembly, including a metal can end and a metal can body. The metal can end includes a metal rim, a sheet, and a closed-loop adhesive seal. The metal rim includes an inwardly extending flange with a rolled edge that defines an opening in the end. The sheet covers the opening so that the rolled edge is rolled toward the sheet. The closed-loop adhesive seal hermetically seals the sheet to the flange. The sheet further includes a tab and a weakening line in the vicinity of the tab. The weakening line is configured so that the sheet tears across the seal substantially when the tab is initially pulled by the user at an angle less than 90 degrees. The metal can end is fastened to the open end of the can by overlapping a portion of the can with a portion of the metal rim, and bending the portions into a sealed joint.

Another embodiment relates to a container assembly, including a can, a can end, a metal foil sheet, and an adhesive. The can has an open end and the can end is fastened to the open end. The can end has at least one opening defined by a periphery. The metal foil sheet closes the opening defined by the periphery. The adhesive attaches the metal foil sheet to the periphery of the opening to hermetically close the opening. The adhesive is able to resist at least a force of 20-30 pounds per square inch of the portion of the foil covering the opening. The adhesive includes at least one portion that is resistant to the removal of the foil that is less than the resistance to remove at least another portion of the adhesive. The metal foil portion is configured to be pulled with a force to remove the foil from the opening, the majority of the force is directed to at least one portion.

Still another embodiment relates to a container end, including a generally circular metal flange, a sheet, and an adhesive bead structure. The generally circular metal flange includes an inwardly extending flange that defines an opening in the end. The sheet covers the opening. The adhesive bead structure hermetically seals the sheet to the flange. The bead structure is configured in a generally spiral form to provide concentric areas of adhesive on at least portions of the flange. The sheet is formed to permit independent removal of the sheet from the concentric areas, reducing the force required to separate the sheet from the opening.

Yet another embodiment relates to a container end including, a metal rim, a sheet, and a closed-loop adhesive seal. The metal rim has an inwardly extending flange that defines an opening in the end. The sheet covers the opening. The closed-loop adhesive seal hermetically seals the sheet to the flange. The seal has a seal strength that is reduced at a weakened location along the seal. The sheet includes a tab and a weakening line in the vicinity of the tab that generally crosses the weakened location to cause the foil to tear across the seal at the weakened location.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:

FIG. 1 is a perspective view of a container assembly in a first configuration according to an exemplary embodiment.

FIG. 2 is a side view of the container assembly ofFIG. 1.

FIG. 3 is a bottom view of the container assembly ofFIG. 1.

FIG. 4 is a top view of the sheet shown at the top of the container shown inFIG. 1.

FIG. 5 is a top view of the end of the container ofFIG. 1 without the sheet shown.

FIG. 6 is a top view of the container end ofFIG. 1 including the sheet.

FIG. 7 is a sectional view taken along line7-7 inFIG. 6.

FIG. 8 a sectional view taken along line8-8 inFIG. 6.

FIG. 9 is a view showing the sheet partially torn to expose the opening in the end.

FIG. 10 is a view showing the sheet torn to expose the opening in the end to a greater degree that shown inFIG. 9.

FIG. 11 is a view showing the sheet partially torn to expose the opening in an end having a strainer feature.

FIG. 12 is a view showing the sheet torn to expose the opening in the end with a strainer feature to a greater degree than shown inFIG. 11

FIG. 13 is a top view of an alternate embodiment of a container end including an alternate embodiment of the sheet and seal.

FIG. 14 is a top view of an alternate embodiment of a container end including an alternate embodiment of the sheet and seal.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present invention is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.

Referring toFIG. 1, acontainer assembly100 includes a can102 (e.g., can body) and a can end104 (e.g., top). Thecan102 includes a bottom106 (e.g., second can end) andside wall108 extending vertically from thebottom106. In some embodiments, thesides108 form a cylindrical tube and includeridges110. Thecan102 defines a volume internal thereto, in which contents (e.g., solid items and/or liquid), such as cut fruit suspended in syrup or beans in water, of thecontainer assembly100 may be stored. A label (not shown) may be printed and/or adhered to thesides108 of thecan102, identifying the contents of thecontainer assembly100.

In some embodiments, thecontainer assembly100 is a three-piece assembly, formed from three main parts. The bottom106 andside wall108 are separately stamped and fastened together, such as by forming theside wall108 into a cylindrical tube, and crimping an end ofwall108 to the bottom106. According to an exemplary embodiment, a sealant surface layer or gasket (e.g., rubber coating) may be positioned between the crimped portions, to improve the seal therebetween. With the bottom106 andwall108 fastened together, thecan102 includes an open end, which may be covered by the can end104. According to an exemplary embodiment, bottom106 anend104 may be formed from a single metal sheet using a stamping process, and fastened toside wall108. Edges internal to the openings may be rolled.

In other embodiments a container assembly is a two-piece assembly, where a can body (e.g., having sides and a bottom) is formed by a stamping and/or drawing process, from a single sheet of metal (e.g., aluminum, coated steel, etc.), and a can end is separately formed, stamped from another sheet of metal. In some embodiments, components or features of a container assembly are formed by stretching molding, die cast, blown, or otherwise formed.

Thecontainer assembly100 may be fully assembled, as shown inFIG. 1, partially assembled, or may be an assembly that is configured to be, but not yet fastened together (e.g., assembly of kit components). For example, some embodiments may include a container assembly including a can end and a sheet configured to be coupled thereto. Other embodiments may include a container assembly including a can (e.g., body) and a can end, fastened together, but without a sheet coupled to the can end. Other contemplated embodiments include still other container assemblies, having components that are fastened together and separate components that are unfastened kits.

Referring again toFIG. 1,sides108 of thecan102 extend upward to form an open end of thecan102, to which the can end104 is fastened. According to an exemplary embodiment, the can end104 is fastened to the open end of thecan102 by overlapping a portion of thecan102 with a portion of the can end104, and bending (e.g., crimping and/or rolling) the portions into a sealed joint assembly and a rim of thecontainer assembly100. A sealant or gasket may be positioned between the portions, such as via a coating of sealant material (e.g., elastic material, pliable material, rubber, plastic, polyethylene, etc.) on either or both of the portions. Although the sealed joint ofFIG. 1 shows a particular arrangement of bending and overlapping, other arrangements of bending and overlapping may be used for fastening the can end104 to thesides108 of thecan102. In still other contemplated embodiments, the can end104 is otherwise fastened to the can102 (e.g., glued, welded, pressure fit, etc.) or formed integrally therewith. The can end104 may be fabricated all, or in part, from a metal, and may joined to thesides108 with a rolled joint or soldered joint (i.e., double seam). This rolled joint may be rolled upwardly or downwardly.

With reference toFIGS. 1,4, and5, in one embodiment asheet126 is provided. Thesheet126 will be applied to cover and hermetically seal theopening118 in the can end104, as will be further described below. Thesheet126 includes aweakening formation128. The weakeningformation128 includes a radiallyinward cut130 directed substantially towards acenter132 of thesheet126 and ascore134 extending substantially perpendicularly radially outward from theinward cut130. Thecut130 and score134 define atab136 which is configured to rupture theweakening formation128 and allow for removal of thesheet126, as will be discussed further below. Additionally, in other embodiments thecut130 may instead be a score or thescore134 may instead be a cut.

FIG. 5 illustrates a can end104 with thesheet126 removed. In one embodiment, the can end104 includes arim portion116 which defines a generally roundedopening118. In particular, opening118 may be defined by a rolled edge119 (seeFIGS. 7 and 8). Depending upon the content or use of the can, rolled edge119 may not be necessary if exposure of a sheared edge of opening118 is acceptable. Therim portion116 includes a rollededge120 and aflange122 extending inwardly from the rollededge116 and defining theopening118. Theflange122 also includes anarea124 extending farther radially inwardly into theopening118. The can end104 is preferably formed from any suitable metal (e.g., steel, aluminum, etc.) and covered with a thermoplastic layer as necessary. In one embodiment the thermoplastic layer being polypropylene. In other embodiments, the thermoplastic layer may be formed of any suitable material known in the art.

Thesheet126 is in one embodiment preferably a metal foil covered with a thermoplastic layer. In one embodiment, the foil is an aluminum foil and the thermoplastic layer is a polypropylene layer. Thesheet126 is preferably size to completely cover theopening118, as illustrated inFIG. 6.

With reference toFIG. 6,sheet126 is sized to cover theopening118, oriented with the weakeningformation128 overlaying the inwardly extendingarea124, and placed on top of theflange122 of therim portion116. Thesheet126 is hermetically sealed to theflange122 with aclosed loop seal138. Theclosed loop seal138 may be formed by heat fusing or thermowelding thesheet126 to theflange122, by the application of adhesive to one or both of thesheet126 and therim portion116 with or without heat sealing, or by any other suitable means known in the art. Additionally, aseal extension140 extends from the closedloop seal138 underneath a portion of thetab136, holding a portion of thetab136 to the inwardly extendingarea124 of theflange122. It should be understood that an adhesive seal is a seal which adheressheet126 toflange122 and operates withsheet126 to hermetically seal opening118 closed. With reference toFIG. 1, in other embodiments, analternate seal extension141 may be used in place ofseal extension140. Thealternate seal extension141 may be a long extended triangular configuration, as illustrated inFIG. 1, extending down thetab136. Additionally, other alternate seal extensions of various shapes, dimensions, thicknesses, widths, etc., are also envisioned. Any suitable configuration of seal extension may also be used, including a seal extension having a much narrower width than the sealing bead sealing the remainder of the can end104.

In the canning process, upon filling acan102, the can end104 is attached to thecan102 to form thecontainer assembly100. Thecontainer assembly100 and its contents are then typically cooked in a retort process to temperatures of at least 220 to 250 degrees Fahrenheit, creating pressures within thecontainer assembly100 of at least twenty to thirty pounds per square inch. Theclosed loop seal138 preferably is configured to withstand pressures and temperatures within these ranges and maintain the hermetic seal between thesheet126 and theflange122 under these conditions, without overpressure during the cooking process.

FIG. 7 is a cross-sectional view taken along line7-7 inFIG. 6 and illustrates thesheet126 hermetically sealed to theflange122 by the closed-loop seal138.FIG. 8 is a cross-sectional view taken along line8-8 inFIG. 6 and similarly illustrates theclosed loop seal138. With reference toFIGS. 7 and 8, the closed-loop seal138 extends substantially around theopening118. As discussed above,sheet126 may be fastened to theflange122 with an adhesive (e.g., adhesive layer, fused coatings, coating, glue, etc.) attached to thesheet126 and/or to the can end104. In some embodiments, the adhesive138 may include a thermoplastic layer or coating on thesheet126—such as on a side of thesheet126 that is to be fastened to the can end104. Heating of the adhesive138, such as by a heated press, temporarily melts the adhesive138, which subsequently solidifies, bonding thesheet126 to the can end104. The can end104 may also have a thermoplastic adhesive layer on the side to be attached to thesheet126, and, with the use of a heated press or other heating means, may similarly be bonded to thesheet126. By selectively heating the thermoplastic layers onsheet126 andflange122, the configuration ofseal138 can be selected or modified depending upon the can end shape (e.g., round, square, rectangular, oval, etc.), the sheet, can and/or can end materials, and/or particular retort process parameters. In some embodiments, thesheet126 seals the can end104 such that thecontainer assembly100 is hermetically sealed, helping to preserve perishable contents of thecontainer assembly100.

Depending upon the use and application ofassembly110, the material used to adhere thesheet126 to can end104 may not be uniform in adherence strength and/or material type. By selective placement of adhesive types, the peeling and pressure handling characteristics of thesheet126 can be controlled. Additionally, in other embodiment the thermoplastic layer on thesheet126 and/or the can end104 may be omitted, and thesheet126 may instead be adhered to the can end104 by placing adhesive on thesheet126 and/or the can end104 and applying thesheet126 to the can end104. Other suitable mechanisms known in the art for adhering thesheet126 to the can end104 are also contemplated. Similarly, the portion of thetab136 adhered by theseal extension140 to thearea124 of theflange122 may be formed in the same way as theclosed loop seal138 or in various other ways known in the art differently from the closedloop seal138.

With reference toFIG. 9, the removal of thesheet126 to expose theopening118 in the can end114 is illustrated. Theclosed loop seal138 defines acentral axis142 extending longitudinally along theclosed loop seal138. To remove thesheet126, a user will grasp thetab136 and urge thetab136 upwardly. Thesheet126 will tend to break theclosed loop seal138 at a break point146 proximate thescore134 in thesheet126. When a pulling force is initially applied totab136, weakeningformation128 promotes tearing of thesheet126 acrossseal138. Depending on the configuration offormation128,sheet126 material and/or theseal138 configuration, thesheet126 will tear acrossseal138 at an angle of less than or equal to 90 degrees tocentral axis142. After tearing acrossseal138,sheet126 will be removed by breakingseal138 in a direction along thecentral axis142 of the closed loop seal138 (as indicated by arrow144). Other directions are also contemplated. The outer portion of thetab136 will tend to follow thecentral axis142. As thesheet126 is removed, the leading edge of separation148 (e.g., fold-over of sheet126) is formed generally perpendicular to thecentral axis142, will tend to move in a direction generally parallel to thecentral axis142 of the closed loop seal138 (though other directions are also contemplated) around the perimeter of the can end104 as a user continues to urge thetab136 in the direction indicated byarrow150 inFIG. 10. The user may continue to urge thetab136 around the entire perimeter of the can end114, separating thesheet126 entirely from therim portion116, at which point theopening118 is completely exposed and thesheet126 may be disposed of.

In another embodiment, thetab136 formed in theweakening formation128 may further include a pull ring coupled to thetab136 to allow for gripping and pulling thetab136 by a user. Additionally, in other embodiments, other known removal devices are also contemplated.

In another embodiment, with reference toFIGS. 11 and 12, a can end204 is shown attached tocan202 as illustrated. The can end204 defines a first opening218 (e.g., large opening, hole, aperture, etc.) and one or more second openings252 (e.g., a plurality of small openings, i.e., strainer opening) defined by aflange area projection254 projecting radially inwardly from theflange222. Thefirst opening218 is wide enough to pour solid contents of thecontainer assembly200 therethrough. In some embodiments, thefirst opening218 has an area that is slightly less than half the area of the can end204, and is formed in a crescent shape, a half-circle, or otherwise shaped, the size of thefirst opening218 being defined by thearea224 projecting from theflange222 upon which thetab236 is seated in the closed configuration, and theprojection254 projecting radially inwardly. While thearea224 and theprojection254 are illustrated as separate, it is contemplated that these could be formed into an integral combined unit. Additionally, theprojection254 may be located at any circumferential location around the can end204. Eachsecond opening252, in one embodiment, is sized for straining, such that the solid contents of thecontainer assembly200 are generally too large to fit therethrough. In some embodiments, eachsecond opening252 is less than one fifth the size of thefirst opening218, such as less than one tenth the size of thefirst opening218. However, in other embodiments the first218 and second252 openings are the same size.

As is illustrated inFIGS. 11 and 12, the removal of thesheet226 from thecontainer end204 may be done by a user in substantially the same way as in the previous embodiment, with a user grasping thetab236 and urge thetab236 upwardly and along the central axis of theclosed loop seal238 as indicated byarrow244, with thesheet226 tending to break theclosed loop seal238 at abreak point246 proximate the score234 in thesheet226, the outer portion of thetab236 tending to follow theclosed loop seal238 and the leading edge ofseparation248 tending to move parallel to theclosed loop seal238 around the perimeter of the can end204 as a user continues to urge thetab236 in the direction indicated byarrow250 inFIG. 12. The weakening formation228 may also be configured in various ways to allow for thebreak point246 to be directed at various different angles, allowing for tearing of thesheet226 in various different ways for various different effects and applications.

In another embodiment of the seal, as illustrated inFIG. 13, the closed loop seals138,238 of previous embodiments are replaced with a spiral closedloop seal337. The spiral closedloop seal337 seals thesheet326 to thecontainer end304 in a concentric circular spiral pattern of seals progressing radially inwardly. The circular pattern may meet in a hermetically sealing complete seal at aseal junction339 which may be disposed anywhere around the perimeter of the can end. Thus, in this embodiment, the seal at thebreak point346 may be of decreased width as compared to previous embodiments, thus allowing for a user to more easily break the seal using thetab336 at this point. When a user pulls on thetab336, thesheet326 will tend to pull away from the spiral closedloop seal337 in a series of strips following the perimeter of the container end and the concentric portions of the spiral closedloop seal337. Once thetab336 has followed all of these concentric portions, thesheet326 will be generally free of thecontainer end304 and may be discarded.

In another embodiment, as illustrated inFIG. 14, asheet426 may be used in conjunction with an alternate embodiment of a can end404. The can end404 includes aflange area portion454 that defines, along with the periphery of the can end404, a semi-circular first opening418 (e.g., large opening, hole, aperture, etc.). In its interior, theflange area portion454 also defines one or more second openings452 (e.g., a plurality of small openings, i.e., strainer opening). Asheet426 is preferably positioned over the can end404 with atab436 located adjacent thesecond openings452 over a portion of theflange area portion454. Thetab436 may be defined by a weakeningportion428, similar to that of previous embodiments. Thesheet426 is preferably sealed with two continuous seals. A firstcontinuous seal470 surrounds and hermetically seals thefirst opening418. The second continuous seal is located around thesecond openings452, hermetically sealing thesecond openings452. These

continuous seals

470,472 may be of any suitable type known in the art.

The weakeningportion428 is preferably configured such that when a user pulls thetab436, thesheet426 tends to break across the secondcontinuous seal472 exposing thesecond openings452. As the user continues to pull thetab436 around the periphery of the can end404, in one embodiment thesheet426 will tend to separate from the can end404 along both the radially inner and radially outer portion of the secondcontinuous seal472 concurrently exposing thesecond openings452. Once thesecond openings452 are totally or partially exposed and thetab436 has reached thesecond openings452 distal from the original location of thetab436, in some embodiments the removed portion of thesheet426 may encounter asecond weakening portion474. Thissecond weakening portion474 may comprise scoring or any other suitable weakening of thesheet426 at any suitable angle, proximate the corner of the semi-circularfirst opening418 that is farthest from the initial location of thetab436.

Thissecond weakening portion474 is configured to allow for breaking across a portion of the firstcontinuous seal470. Thesecond weakening portion474 may be configured to allow thesheet426 to break at various different angles across the firstcontinuous seal470. Once the firstcontinuous seal470 has been broken, thesheet426 may continue to be removed from thefirst opening418 by a user continuing to pull thetab436 and/or thesheet426 around the periphery of the can end404 until thesheet426 is completely removed from the can end404. As the user continues to pull, thesheet426 will be freed from the can end404 as in previous embodiments. Thesheet426 may tear across thefirst opening418 or may tend to follow the firstcontinuous seal470 depending on the application and configuration of thesheet426.

As previously discussed,container assembly100 is formed from metal, such as tin-coated steel, or aluminum. In some embodiments, thecan102 is formed from aluminum and the can end104 is formed from tin-coated steel. In other embodiments, other metals or materials (e.g., high-temperature plastic, ceramic, etc.) may be used to form some or all of thecontainer assembly100. In some embodiments, thesheet126 is a metal foil (e.g., aluminum foil, steel foil, etc.), having a thickness substantially between 1/1000 to 1/100-inch. The metal foil may include an outer (top, outside, etc.) layer (e.g., coating) of polyethylene terephthalate (PET), a middle layer (e.g., substrate) of foil, and a bottom layer (e.g., 70 microns thick) of polypropylene, where the outer layers are applied via a coextrusion process. The polypropylene is configured to be heated and used as an adhesive. In other embodiments, the metal foil includes additional layers of different materials, and/or layers of similar materials in different arrangements (e.g., order). In still other embodiments, thesheet126 is plastic or composite (e.g., plastic foil with one or more coatings thereon).

Additionally, other container proportions are contemplated. For example, contemplated embodiments include ⅞ size, 1-“picnic” size, size 303, size 10, and other size cans, such as those standard sizes and shapes that are commercially available in the United States and abroad. Such cans may be configured to hold 4 ounces, 10.5 ounces, and even over 100 ounces of liquid. Some embodiments are cylindrical, while other embodiments are rounded-rectangular (e.g., box container), and still other embodiments include other container assembly geometries. Although thecan102 is illustrated as a round cylinder, other can shapes are contemplated, along with other can end104 shapes to suitably couple to thecan102.

The construction and arrangements of the container assembly, as shown in the various exemplary embodiments, are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention.

Claims

What is claimed is:

1. A container end, comprising:

a metal rim including an inwardly extending flange with a rolled edge which defines an opening in the end, the metal rim including a thermoplastic layer and an area extending into the opening;

a foil with a thermoplastic layer, the foil covering the opening, the foil including a weakening formation and a tab formed by at least a portion of the formation;

a closed-loop seal having a central axis and formed from the layers to seal the foil to the rim such that the tab is substantially located over the area, wherein the formation is configured to promote tearing of the foil across the seal when a pulling force is initially applied to the tab and separation of the foil from the seal in a direction generally parallel to the central axis of the seal after the foil is torn across the seal; and

a seal extension extending from the closed loop between the area and the tab.

2. The container end ofclaim 1, wherein the seal includes a weakened area adjacent to the weakened formation to further promote tearing of the seal across the seal.

3. The container end ofclaim 1, wherein the foil is an aluminum foil and the thermoplastic layer is polypropylene.

4. The container end ofclaim 2, wherein the seal is configured to prevent breach of the hermetic seal when a force of at least 20-30 pounds per square inch is applied to the portion of the foil covering the opening.

5. The container end ofclaim 4, wherein the seal is further configured to prevent breach of the hermetic seal when the end is exposed to at least 220 to 250 degrees Fahrenheit.

6. A metal container assembly comprising:

a metal can end including:

a metal rim including an inwardly extending flange which includes a rolled edge with defines an opening in the end,

a sheet which covers the opening such that the rolled edge is rolled toward the sheet, and

a closed-loop adhesive seal which hermetically seals the sheet to the flange, wherein the sheet includes a tab, and a weakening line in the vicinity of tab configured to promote tearing of the sheet across the adhesive seal; and

a metal can body having an open end, wherein the can end is fastened to the open end of the can by overlapping a portion of the can with a portion of the metal rim and bending the portions into a sealed joint.

7. The metal container ofclaim 6, wherein the tab is oriented to be pulled in a direction generally parallel to the central axis of the adhesive seal.

8. The metal container ofclaim 7, wherein the sheet is a metal foil having a thermoplastic layer.

9. The metal container ofclaim 8, wherein the flange includes a thermoplastic layer and the adhesive seal is formed from a portion of the thermoplastic layers by selectively heating the overlapping layers.

10. The metal container ofclaim 9, wherein the seal has a seal strength which is reduced, relative to the majority of the seal, at a weakened location along the seal, and the weakening line is located substantially at the weakened location to cause the foil to tear across the seal substantially at the weakened location.

11. The container ofclaim 10, wherein the seal is formed from first and second adhesives wherein the second adhesive is weaker than the first adhesive and the second adhesive forms a portion of the seal at the weakened location.

12. The container ofclaim 10, wherein the adhesive seal is formed with at least first and second cross-sections wherein the second cross-section in smaller than the first cross-section and the adhesive located at the weakened location has the second cross-section.

13. The container ofclaim 9, wherein the flange has an increased area, all or a portion of the weakening line is located above the increased area, and the metal foil includes a tab at least partially defined by the weakening line.

14. The container ofclaim 13, wherein the seal includes a projection located between the tab and increased area of the flange.

15. A container assembly, comprising:

a can having an open end;

a can end attached to the open end, having at least one opening defined by a periphery,

a metal foil sheet configured to close the opening; and

an adhesive which attaches the foil to the periphery of the opening to hermetically close the opening, the adhesive being configured to resist at least a force of 20-30 pounds per square inch of the portion of the foil covering the opening;

the metal foil including a weakened formation configured to promote tearing of the foil across the adhesive the foil is pulled to remove the foil from the can end.

16. The container assembly ofclaim 15, the adhesive includes at least one portion which has resistance to removal of the foil which is less than the resistance to removal of at least another portion of the adhesive.

17. The container assembly ofclaim 16, wherein the at least one portion has a reduced amount of adhesive.

18. The container assembly ofclaim 16, wherein the can is fabricated from metal.

19. The container assembly ofclaim 16, wherein the can is fabricated from a non-metallic material.

20. The container assembly ofclaim 15, wherein the can end is fastened to the open end of the can by overlapping a portion of the can with a portion of the can end and bending the portions into a sealed joint.

21. The container assembly ofclaim 19, wherein the sheet is integrally formed from a flexible material, and peelable from the can end.

22. The container assembly ofclaim 20, wherein the flexible material is a polypropylene aluminum.

23. The container ofclaim 15, wherein the foil sheet and the periphery include a thermoplastic layer, the periphery includes an increased area, and the adhesive is the combination of portions of the thermoplastic layers which are formed by selectively heating overlapping layers into a closed-loop of adhesive with a projection located at the increased area.

24. A container end, comprising:

a generally circular metal flange including an inwardly extending flange which defines an opening in the end;

a sheet which covers the opening;

an adhesive bead structure which hermetically seals the sheet to the flange, the bead structure being configured in a generally spiral form to provide concentric areas of adhesive on at least portions of the flange, the sheet being formed to permit independent removal of the sheet from the concentric areas thereby reducing the force required to separate the sheet from the opening.

25. The container end ofclaim 24, wherein the sheet is a metal foil sheet which includes at least one weakening line which facilitates tearing of the foil to permit independent removal of the sheet from the concentric areas.

26. The container end ofclaim 25, wherein the adhesive is a thermoplastic.

27. The container end ofclaim 26, wherein the sheet is generally circular and is sealed to the can end around the perimeter of the sheet.

28. The container end ofclaim 27, wherein the sheet includes a tab extending therefrom, configured to facilitate peeling of the sheet from the can end.

29. A container end, comprising:

a metal rim including an inwardly extending flange which defines an opening in the end;

a sheet which covers the opening; and

a closed-loop adhesive seal which hermetically seals the sheet to the flange, the seal, wherein the sheet includes a tab, and a weakening line in the vicinity of tab to cause the foil to tear across the seal substantially at the weakened location.

30. The container end ofclaim 29, wherein the seal is formed from first and second adhesive layers located on the sheet and rim, respectively.

31. The container end ofclaim 30, wherein the adhesive is a thermoplastic material.

32. The container end ofclaim 31, wherein the adhesive seal is formed to have a projection extending from the closed-loop toward the tab.

33. The container end ofclaim 32, wherein the weakening line crosses the adhesive loop at an angle less than 90 degrees.

34. The container end ofclaim 32, wherein the flange includes a rolled edge which defines the boundary of the opening.

35. The container end ofclaim 34, wherein the sheet is formed from a metal foil.

36. The container end ofclaim 32, wherein the flange includes a widened location generally located below the tab and the weakened location.