Container with Reduced, Peel-Off-Force Tear Configuration
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.
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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.
BACKGROUNDThe 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.
SUMMARYOne 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.
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:
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 to
In some embodiments, the container assembly 100 is a three-piece assembly, formed from three main parts. The bottom 106 and side wall 108 are separately stamped and fastened together, such as by forming the side wall 108 into a cylindrical tube, and crimping an end of wall 108 to the bottom 106. 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 bottom 106 and wall 108 fastened together, the can 102 includes an open end, which may be covered by the can end 104. According to an exemplary embodiment, bottom 106 an end 104 may be formed from a single metal sheet using a stamping process, and fastened to side wall 108. 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.
The container assembly 100 may be fully assembled, as shown in
Referring again to
With reference to
The sheet 126 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. The sheet 126 is preferably size to completely cover the opening 118, as illustrated in
With reference to
In the canning process, upon filling a can 102, the can end 104 is attached to the can 102 to form the container assembly 100. The container assembly 100 and its contents are then typically cooked in a retort process to temperatures of at least 220 to 250 degrees Fahrenheit, creating pressures within the container assembly 100 of at least twenty to thirty pounds per square inch. The closed loop seal 138 preferably is configured to withstand pressures and temperatures within these ranges and maintain the hermetic seal between the sheet 126 and the flange 122 under these conditions, without overpressure during the cooking process.
Depending upon the use and application of assembly 110, the material used to adhere the sheet 126 to can end 104 may not be uniform in adherence strength and/or material type. By selective placement of adhesive types, the peeling and pressure handling characteristics of the sheet 126 can be controlled. Additionally, in other embodiment the thermoplastic layer on the sheet 126 and/or the can end 104 may be omitted, and the sheet 126 may instead be adhered to the can end 104 by placing adhesive on the sheet 126 and/or the can end 104 and applying the sheet 126 to the can end 104. Other suitable mechanisms known in the art for adhering the sheet 126 to the can end 104 are also contemplated. Similarly, the portion of the tab 136 adhered by the seal extension 140 to the area 124 of the flange 122 may be formed in the same way as the closed loop seal 138 or in various other ways known in the art differently from the closed loop seal 138.
With reference to
In another embodiment, the tab 136 formed in the weakening formation 128 may further include a pull ring coupled to the tab 136 to allow for gripping and pulling the tab 136 by a user. Additionally, in other embodiments, other known removal devices are also contemplated.
In another embodiment, with reference to
As is illustrated in
In another embodiment of the seal, as illustrated in
In another embodiment, as illustrated in
The weakening portion 428 is preferably configured such that when a user pulls the tab 436, the sheet 426 tends to break across the second continuous seal 472 exposing the second openings 452. As the user continues to pull the tab 436 around the periphery of the can end 404, in one embodiment the sheet 426 will tend to separate from the can end 404 along both the radially inner and radially outer portion of the second continuous seal 472 concurrently exposing the second openings 452. Once the second openings 452 are totally or partially exposed and the tab 436 has reached the second openings 452 distal from the original location of the tab 436, in some embodiments the removed portion of the sheet 426 may encounter a second weakening portion 474. This second weakening portion 474 may comprise scoring or any other suitable weakening of the sheet 426 at any suitable angle, proximate the corner of the semi-circular first opening 418 that is farthest from the initial location of the tab 436.
This second weakening portion 474 is configured to allow for breaking across a portion of the first continuous seal 470. The second weakening portion 474 may be configured to allow the sheet 426 to break at various different angles across the first continuous seal 470. Once the first continuous seal 470 has been broken, the sheet 426 may continue to be removed from the first opening 418 by a user continuing to pull the tab 436 and/or the sheet 426 around the periphery of the can end 404 until the sheet 426 is completely removed from the can end 404. As the user continues to pull, the sheet 426 will be freed from the can end 404 as in previous embodiments. The sheet 426 may tear across the first opening 418 or may tend to follow the first continuous seal 470 depending on the application and configuration of the sheet 426.
As previously discussed, container assembly 100 is formed from metal, such as tin-coated steel, or aluminum. In some embodiments, the can 102 is formed from aluminum and the can end 104 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 the container assembly 100. In some embodiments, the sheet 126 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, the sheet 126 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 the can 102 is illustrated as a round cylinder, other can shapes are contemplated, along with other can end 104 shapes to suitably couple to the can 102.
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
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 of claim 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 of claim 1, wherein the foil is an aluminum foil and the thermoplastic layer is polypropylene.
4. The container end of claim 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 of claim 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 of claim 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 of claim 7, wherein the sheet is a metal foil having a thermoplastic layer.
9. The metal container of claim 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 of claim 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 of claim 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 of claim 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 of claim 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 of claim 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 of claim 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 of claim 16, wherein the at least one portion has a reduced amount of adhesive.
18. The container assembly of claim 16, wherein the can is fabricated from metal.
19. The container assembly of claim 16, wherein the can is fabricated from a non-metallic material.
20. The container assembly of claim 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 of claim 19, wherein the sheet is integrally formed from a flexible material, and peelable from the can end.
22. The container assembly of claim 20, wherein the flexible material is a polypropylene aluminum.
23. The container of claim 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 of claim 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 of claim 25, wherein the adhesive is a thermoplastic.
27. The container end of claim 26, wherein the sheet is generally circular and is sealed to the can end around the perimeter of the sheet.
28. The container end of claim 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 of claim 29, wherein the seal is formed from first and second adhesive layers located on the sheet and rim, respectively.
31. The container end of claim 30, wherein the adhesive is a thermoplastic material.
32. The container end of claim 31, wherein the adhesive seal is formed to have a projection extending from the closed-loop toward the tab.
33. The container end of claim 32, wherein the weakening line crosses the adhesive loop at an angle less than 90 degrees.
34. The container end of claim 32, wherein the flange includes a rolled edge which defines the boundary of the opening.
35. The container end of claim 34, wherein the sheet is formed from a metal foil.
36. The container end of claim 32, wherein the flange includes a widened location generally located below the tab and the weakened location.
Type: Application
Filed: Aug 17, 2011
Publication Date: Feb 23, 2012
Applicant:
Inventors: Gerald J. Baker (Wauwatosa, WI), Alvin Widitora (Los Angeles, CA)
Application Number: 13/211,881
International Classification: B65D 17/353 (20060101); B65D 17/40 (20060101);