Packaging Article With Visual Display Portion

Abstract

The present invention is directed to a package having “blister” of polymeric material for displaying a product in combination with a backing material, as well as methods for manufacturing the same.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims benefit of U.S. Provisional Patent Application No. 61/144,638, filed Jan. 14, 2009, the disclosure of which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to the field of product packaging, and more particularly to a packaging article having a visual display portion wherein the packaged product is visible when packaged within the packaging article—such as a “blister” of polymeric material in combination with a backing material, as well as methods for manufacturing the same.

BACKGROUND OF THE INVENTION

Product packaging serves a number of different functions, including: protecting the packaged product from accidental damage, attractively displaying the packaged product for potential customers, and preventing theft or tampering of the packaged product. In addition, it is desirable for a packaging article to be as inexpensive and efficient to manufacture as possible, and to provide a minimum amount of waste. One area of particular interest is that of packaging involving a cardboard or paper backing from the front of which a clear or translucent top, sheath or pocket-like member protrudes for displaying the product therein. These types of packaging are commonly referred to as “blister” or “bubble” packages.

There are numerous examples of blister or bubble packages in the art. For example, blister or bubble packages have been described for use in pharmaceutical or drug delivery applications. They have also been used in the packaging of household goods, tools and any other applications in which it may be useful for the consumer to see and/or to evaluate the desirability or suitability of the product before purchasing.

Generally, the packages and methods described in the art comprise a front portion or “blister” that is transparent and formed of pliable thermoplastic material via thermoform and/or vacuum methods. Such methods are generally expensive, as they require custom-made molds and cavities to manufacture the desired blisters and packages, and also require the input of a great deal of energy in the manufacturing processes (i.e., heating up the materials followed by molding them into desired form). Moreover, there are disadvantages to such methods; for example, energy and production costs are high for the above reasons.

In addition, when there is a commercial need to print on the surface of the blisters (for example, printed instructions for use, user warnings, names, graphics and the like), it is difficult to display anything on the surface of the thermoplastic materials, as the melting and heating steps often result in distortion of the printed matter or graphics. As a result, with the blister packages known in the art, it is often necessary to print any required information or graphics onto labels that are then adhered to the packages. This can add significantly to the cost.

Thus, a need remains for a product packaging combination or article that is easy and inexpensive to manufacture, requiring a minimum number of steps, and that provides for a desirable display of the product to be sold without waste of materials.

SUMMARY OF THE INVENTION

In certain embodiments, the present invention provides a packaging article comprising a blister formed of transparent or translucent polymeric material attached to a backing material.

In various embodiments, the polymeric material may be transparent or translucent, and in various embodiments, the backing material comprising plastic or other polymeric material, paper or a paper product such as poster board, cardboard or cardstock.

In other embodiments, the present invention is directed to a method of forming a packaging article, the method comprising the steps of:

(a) cutting a predetermined shape out of a sheet of transparent or translucent polymeric material;

(b) scoring, creasing or folding the material to form a three-dimensional blister having an open end, at least one outer edge and at least one outer rim on the at least one outer edge;

(c) cutting a piece of backing material into a predetermined shape;

(d) folding the piece of backing material to provide a top folded layer and a bottom folded layer;

(e) cutting a hole or opening into the top folded layer; and

(f) attaching the at least one outer rim to the top folded layer or the bottom folded layer.

In other embodiments, the present invention is directed to a method of forming a packaging article, the method comprising the steps of:

(a) cutting a predetermined shape out of a sheet of transparent or translucent polymeric material;

(b) scoring, creasing or folding the material to form a three-dimensional blister having an open end, at least one outer edge and at least one outer rim on the at least one outer edge;

(c) obtaining a first sheet of backing material and a second sheet of backing material;

(d) cutting a hole or opening into the first sheet;

(f) inserting the blister into the hole or opening; and

(g) sandwiching the blister between the first sheet and the second sheet by engaging the at least one outer rim between the first sheet or the second sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a packaging combination according to an embodiment of the present invention, as seen from a side.

FIG. 2 shows another packaging combination according to another embodiment of the present invention.

FIG. 3 is a top view of another embodiment of the present invention, showing an example of a product that can be packaged according to the present invention.

FIG. 4 is a top view of another embodiment of the present invention, minus the product packaged within.

FIG. 5 is a top view of another embodiment of the present invention, wherein the top folded layer and bottom folded layer are made of a single panel of paper, cardboard or cardstock folded in half at its center.

FIG. 6 is a top view of a blister according to one embodiment of the present invention, as it has just been cut from a sheet of polymeric material and before it is forced into a three-dimensional blister configuration.

FIG. 7 is a top view of a blister according to another embodiment of the present invention, as it has just been cut from a sheet of polymeric material and before it is forced into a three-dimensional blister configuration.

DETAILED DESCRIPTION OF THE INVENTION

In certain embodiments, the present invention provides a packaging article comprising a blister formed of polymeric material and a backing material. In various embodiments, the polymeric material is transparent or translucent. As used herein, “transparent” means that light can pass completely through the polymeric material, such that upon viewing the polymeric material, one can see substantially completely with the naked eye what is packaged within it. As used herein, “translucent” means that light can pass only diffusely through the polymeric material, such that one can see less than substantially completely with the naked eye what is packaged within it.

In various embodiments, the backing material is made of a polymeric material such as plastic, or is made of paper or a heavy paper product such as poster board, cardboard or cardstock. In various embodiments, the backing material may comprise, or may be coated at least in part or in the entirety of one side, or in the entirety of both sides with material that is water repellent or adhesive, including material that is selectively adhesive, such as when heat, pressure or moisture-activated.

In various embodiments, the backing material comprises a first sheet and a second sheet, wherein the first sheet contains a hole or opening, over or through which the blister is inserted or attached to provide a space or pocket for the product to be packaged within.

In other embodiments, the entire backing material comprises a single sheet of this backing material, which is then folded to produce a top folded layer and bottom folded layer, the top layer wherein the first sheet is the top folded layer, and wherein the second sheet is the bottom folded layer. In such an embodiment, the top folded layer contains a hole or opening, over or through which the blister is inserted or attached to provide the space or pocket for the product to be packaged within.

In certain embodiments, the backing material is folded substantially in half, or if not in half, at least sufficient to provide portions to form the top folded layer and bottom folded layer. Additionally, in some embodiments the first sheet and the second sheet may be made of different materials; or in the case of a single sheet of backing material, such single sheet may be partially made of one material such as plastic, and partially made of another material, such as paper, cardboard or cardstock. In certain embodiments, the backing material may be folded such that at least a portion of the top folded layer and/or the bottom folded layer comprises plastic or paper or cardboard.

As used throughout the present disclosure, the terms “top folded layer” and “bottom folded layer” or “first sheet” and “second sheet” will be used to refer to the various embodiments wherein the backing material is either in, respectively: (1) two separate sheets that are attached together; or (2) one sheet that is folded in half. The present invention contemplates all embodiments that include any of these configurations.

In various embodiments, the blister is comprised of polymeric material, e.g., plastic such as, for example, polyethylene terephthalate (PET) or polyvinyl chloride (PVC), polystyrene (PS), polyethylene such as high density polyethylene (HDPE), low density polyethylene (LDPE) or any other polymeric material that is capable of being cut from a sheet, scored and folded into shape having at least one corner and an outer rim on at least one edge of the blister. In certain embodiments, the blister is transparent, translucent, or can be characterized in any other similar manner, such that a prospective consumer can easily see the product intended to be sold that is packaged within the space or pocket created by the blister. In certain embodiments, the polymeric material may be colorless or may be colored.

It is important to note that as used throughout the present disclosure, the term “blister” refers generally to any three-dimensional shape comprising a polymeric material that provides a space, hole or pocket for displaying a product within in conjunction with the backing A “blister” may also be referred to, and understood to mean the same as, terms such as a “lid,” a “top,” a “cover,” a “display portion,” or a “protrusion” and may be of any size and any dimensions.

In various embodiments of the package, at least one edge of the blister comprises at least one outer edge, which may in turn comprise an outer rim. This outer edge and/or outer rim allow the blister to be attached to the backing material. For example, it may be either: (1) adhered to the top of the hole or opening, by affixing the outer rim to the outer edge of the hole or opening to extend outwardly from the backing material; or (2) pushed through an opening in the backing to protrude outwardly from the backing material, that is, “trapped” or “sandwiched” between the top folded layer and bottom folded layer such that, in some embodiments, a face of the outer rim is affixed to the back side of the top folded layer or first sheet, along the inner edge of the hole or opening. This second embodiment is shown in FIG. 1, where the outer rim 1 of the blister 2 is sandwiched between the top folded layer 3 and the bottom folded layer 4. In an alternative embodiment wherein the backing material comprises two sheets, the top folded layer 3 of FIG. 1 would correspond to the first sheet, and the bottom folded layer 4 of FIG. 1 would correspond to the second sheet. The top folded layer 3 and the bottom folded layer 4 are demonstrated in FIG. 5, which shows the top view of another embodiment of the present invention.

In various embodiments, the blister 2 has a multi-sided shape (i.e., two or more sides or faces) and the outer rim 1 exists on one or more, or all, of the edges of the blister. The outer rim 1 has a top face 8 and a bottom face 9. As shown, for example, in FIG. 2, the outer rim 1 may be present but would not be visible to the naked eye from a side view of the packaging article of the present invention, since it is sandwiched beneath the top folded layer or first sheet. In certain embodiments, the outer rim may have any of the adhesive materials discussed herein on either its top face (adhering it to the top folded layer or first sheet), or its bottom face (adhering it to the bottom folded layer or second sheet), or any combination thereof

In an alternative example, the blister may be attached to the top folded layer or first sheet, by attaching the bottom face of the outer rim to the area immediately adjacent to the hole or opening 10, and therefore the outer rim would be visible to a potential customer.

In various embodiments, the blister may also be of a generally circular or disk-like configuration possessing only one top face and a generally circular pseudo-single side face, and having a plurality of outer rims 1. In various embodiments, the outer rim may exist on a portion of the side of the blister.

In various embodiments, the blister is of a predetermined size and shape and is punched out of a flat sheet of the polymeric material, and then scored or creased either by hand or machine. The blister is then forced in a three dimensional configuration; that is, in various embodiments it is folded along its scored, marked or creased edges either by hand or machine, to provide a blister having an open end forming a space or pocket, which is then ready to be inserted into the backing material via the hole or opening created therein that fits the blister.

In various embodiments, the blister is adhered to the backing material through mechanical or chemical means, for example, by heat sealing, moisture sealing or pressure sealing, or sealing via adhesive materials such as glue, paste, gum, adhesive films, adhesive tape, stitching or the like.

In various embodiments, the blister in its final form in the package may be of any three-dimensional shape that has at least one corner, or of any three-dimensional shape that has at least two faces that define separate planes—that is, they are at an angle to each other of greater than zero. In certain embodiments, the shape comprises at least one corner that is about 90 degrees. In various embodiments, the shape comprises at least one corner of greater than about 90 degrees, or less than about 90 degrees. In various embodiments, the shape comprises at least one corner that is about 85 to about 95 degrees, about 86 degrees to about 94 agrees, about 87 to about 93 degrees, about 88 to about 92 degrees or about 89 to about 91 degrees.

In other embodiments, the blister in its final form may have a substantially curved surface, for example, a half-sphere or half-spheroid, a half-obloid or a half-ovoid, or any portion of a shape that protrudes outward in a substantially curved manner. In such embodiments, the surface of the blister that protrudes from the hole in the top folded layer has no corners at all

The shape of the blister may be either symmetrical or asymmetrical. Various examples of useful blister shapes are five-sided shapes such as three dimensionally cubic or cuboid or rectangular or quadrilateral shapes (as seen in, for example, FIG. 1), for example, three dimensionally trapezoidal shapes (as seen in, for example, in FIG. 2); as well as asymmetrical shapes that are formed to conform with the shape or size of the product to be displayed within, e.g., cosmetics, toys, electronics or associated accessories, or playing cards (as seen, for example, in FIG. 3) or to simulate logos or designs such as animals, flowers or the like, or other regular or irregular three-dimensional shapes that are contemplated within the disclosure of the present invention and that comprise at least two or more flat faces that are at an angle to each other of greater than zero.

In various embodiments, the blister in the package will be a general three dimensionally rectangular shape, such as that seen in FIG. 1, and will have dimensions of about 2 to about 3 inches height, about 3 to about 4 inches width and about 1 to about 2 inches depth (protrusion from the backing material). Of course these dimensions may be varied to up to about 3 inches in either direction within the spirit and scope of the present invention. In other embodiments, a packaging article of the present invention will provide a backing material supporting more than one blister, as the specific commercial need may require. In the final packaging article, the backing material may be generally rectangular, and may have a height greater than its width, as depicted in the Figures, or may have a width greater than its height (as in a “landscape” configuration). The packaging article may further comprise a hook or hole for ease of display such as hanging. In certain embodiments, the package may comprise a separate hang tag for such purposes.

The at least one edge of the blister may, in certain embodiments, comprise at least one outer rim. In various embodiments, the outer rim 1 extends away from the edge in a length of about 0.25 cm to about 2.5 cm, about 0.5 cm to about 2 cm, about 0.75 cm to about 1.75 cm, about 1 cm to about 1.5 cm, about 1 cm, about 1.25 cm, about 1.5 cm or about 1.75 cm. The length of the outer edge's extension past the dimensions of the hole in the top folded layer should be of a length sufficient to attach the edge to the backing material such that the blister will not easily separate from the backing material. In the embodiments wherein the blister is inserted such that it protrudes outward from between the top folded layer (or first sheet) and bottom folded layer (or second sheet), the one or more outer rims serve as a mechanism to trap the blister snugly within its desired configuration, without slipping out and separating from the backing In various embodiments, the top face of the rim (item 8 in FIG. 1) touches the top folded layer or first sheet. In other embodiments, the bottom face of the rim (item 9 in FIG. 1) touches the bottom folded layer or second sheet. In certain embodiments, adhesive may be applied to one or both of the top face of the rim and the bottom face of the rim, and any combination of any of the means for attachment described herein may be present on either face of the rim.

In the embodiments wherein the blister is attached to the top of the top folded layer (or first sheet), the outer rim is not engaged between the top folded layer (or first sheet) and bottom folded layer (or second sheet)—rather, it is adhered to the outer perimeter of the hole or opening. For example, in certain embodiments, the bottom face of the rim may have adhesive on it, be attached to the area on the top folded layer or first sheet that borders the hole or opening, and upon purchase, the customer can merely detach the blister from the backing, leaving the top folded layer (or first sheet) and bottom folded layer (or second sheet) attached to each other.

In certain embodiments, when the top folded layer (or top sheet) and bottom folded layer (or bottom sheet) are adhered together (generally by mechanical or chemical means, for example, by heat sealing, moisture sealing or pressure sealing, or sealing via adhesive materials such as glue, paste, gum, adhesive films, adhesive gels, adhesive tape or the like), in the absence of a product within, a user may see through the transparent or translucent portion of the blister straight through to the bottom folded layer (or second sheet) within (as shown, for example, in FIG. 4). In other embodiments, an additional backing layer may be present along the open portion of the blister, such that when the final package is displayed, a customer will see the additional layer through the translucent portion of the blister. This additional backing layer may be, in certain embodiments, decorative, e.g., exhibiting a pattern or color or the like, in any manner that makes the package attractive to customers or conveys additional information about the product, such as, e.g., with printed information. In various embodiments, there may be no additional backing layer present, but the bottom folded layer itself may exhibit the pattern or color or the like when viewed through the blister. In other embodiments, this additional backing layer may be made of either a reinforcing material, further safeguarding or preserving the product contained within the packaging article (such as any of the materials discussed herein. For example, the additional backing layer may comprise foil, a harder material that preserves the product from easily being ripped out of the packaging article or damaged in transit.

In various embodiments, any portion of the backing material may exhibit printed or embossed information, e.g., information descriptive of the product to be displayed therein or instructions regarding the intended use of the product, identifying the origin of the product and the manufacturer, or product specifications; as well as logos, artwork and the like. In various embodiments, any portion of either the backing material or the blister itself may include either a portion of material that allows the customer to feel the texture of the material, or in certain embodiments, the blister may itself have an opening through which the customer can touch the product packaged within, for example, to feel its texture.

In other embodiments, the present invention is directed to a method of forming a package, the method comprising the steps of:

(a) cutting a predetermined shape out of a sheet of transparent or translucent polymeric material;

(b) scoring, creasing, marking or folding the material to form a three-dimensional blister having an open end, at least one outer edge and at least one outer rim on the at least one outer edge;

(c) cutting a piece of backing material into a predetermined shape;

(d) folding the piece of backing material to provide a top folded layer and a bottom folded layer;

(e) cutting a hole or opening into the top folded layer;

(f) inserting the blister into the hole or opening; and

(g) attaching the at least one outer rim to the top folded layer or bottom folded layer.

In other embodiments, the present invention is directed to a method of forming a packaging article, the method comprising the steps of:

(a) cutting a predetermined shape out of a sheet of transparent or translucent polymeric material;

(b) scoring, creasing or folding the material to form a three-dimensional blister having an open end, at least one outer edge and at least one outer rim on the at least one outer edge;

(c) obtaining a first sheet of backing material and a second sheet of backing material;

(d) cutting or punching a hole or opening into the first sheet;

(f) inserting the blister into the hole or opening; and

(g) sandwiching the blister between the first sheet and the second sheet by engaging the at least one outer rim between the first sheet or the second sheet.

As used herein, “sandwiching” refers to trapping, as between layers. In any of the embodiments shown herein, the outer rim may be attached to either the first sheet or the second sheet (or the top folded layer or bottom folded layer, as the case may be). If attached to the first sheet, the outer rim may be attached to the first sheet on its face that faces the second sheet, or on top of the first sheet (such that a user may easily remove it off the top of the first sheet after purchasing. If attached to the second sheet, the outer rim will be sandwiched between the first sheet and the second sheet.

In its simplest embodiments, the blisters of the present invention will be attached to the backing material directly, with no additional materials between the blister and the backing material. For example, in an embodiment wherein the outer rim of the blister is sandwiched between the first sheet and second sheet (or top folded layer and bottom folded layer), there may be no need for adhesive between the two layers. In other embodiments, adhesive, glue, or any other means discussed herein may be used to enhance any portions of the attachment.

In various embodiments, the flat sheet of polymeric material may comprise any plastic material such as PET, PVC, PS, HDPE or LDPE as described previously in this disclosure. The predetermined shape of step (a) may be cut out of, for example, a flat sheet of plastic, and the predetermined shape may be such as those shown in FIG. 6 and FIG. 7. In particular, FIG. 6 and FIG. 7 demonstrate that in those embodiments, the predetermined shape comprises creases or scores 6 that may be cut or formed either by hand or by machine (for example, a custom tool or a steel rule die) and then folded either by hand or by machine (for example, a custom tool or a steel rule die) into the desired three-dimensional shape before insertion into the backing material.

When the die is folded or otherwise formed into the desired three-dimensional shape, the folding may generally follow the creases, marks or scores 6 previously provided. The flaps 5 may be folded inward to “force” the blister into the desired three-dimensional shape. In certain embodiments, the flaps 5 may be covered with adhesive material such as glue, tape, gum or the other adhesives described previously in the present disclosure, at any point during the methods described herein, to aid in the formation of the three-dimensional shape of the blister. The flaps 5 may be adhered to the inside or outside of the side faces 7 of the blister. In certain embodiments, the polymeric material is material that is coated or otherwise treated such that it will adhere upon the application of pressure, heat or water.

In various embodiments, step (f) comprises trapping and/or sandwiching the blister into the hole or opening; that is, the outer rim of the blister is sandwiched between the top folded layer and the bottom folded layer. In other embodiments, step (f) comprises adhering the outer rim 1 of the blister to the top surface of the top folded layer—that is, the side of the top folded layer that faces the customer when the package is in its state for commercial use (containing a product in the space or pocket of the blister), such that the outer rim may or may not be seen when a customer sees the displayed package.

In various embodiments, the backing material is cut into a predetermined symmetrical shape in step (c) above. In various embodiments, step (d) above comprises folding the piece of backing material in half to provide the top folded layer and the bottom folded layer. In some embodiments, each of the top folding layer and bottom folding layer is one half the area of the predetermined shape of backing material. In various embodiments, the backing material comprises a plastic or other polymeric material, e.g., polyethylene terephthalate (PET) or polyvinyl chloride (PVC), polystyrene (PS), polyethylene such as high density polyethylene (HDPE), low density polyethylene (LDPE) or any other polymeric material that is capable of being cut from a sheet and used as a backing In various embodiments, the backing material comprises paper or a heavy paper product such as poster board, cardboard or cardstock.

In various embodiments, any steps of the methods of the present invention, including any one or more steps (a) through (f), are undertaken either by a machine (e.g., by a custom tool, e.g., steel rule die) or by a person (i.e., by hand). For example, the methods of the present invention may comprise any of steps (a) through (f) performed by a machine such as a custom tool, e.g., a steel rule die or the like.

In certain embodiments, a method of the present invention comprises one or more custom tools in any of the steps previously described. For example, in one embodiment, a first custom tool cuts a piece of backing material into a predetermined shape, a second custom tool cuts a piece of polymeric material into a predetermined shape, a third tool cuts a hole or opening into a portion of the backing material, a fourth tool folds the backing material, and a fifth tool folds the piece of polymeric material to provide the three dimensional blister, and a sixth tool inserts the blister into the hole or opening within the backing material.

In other embodiments, any combination of the above actions may be combined into a single custom tool, or more than one custom tool. For example, the same tool may cut the piece of backing material into a predetermined shape and cut the hole or opening into the backing material; or the same tool may first fold the backing material and then cut the hole or opening into the top folded layer.

As another example, the same tool may fold the polymeric material into a three dimensional blister and insert the blister into the hole or opening in the backing material, followed by folding the backing material into a top folded layer and bottom folded layer. Additionally, the steps above may be performed in any order. Order of the steps is immaterial as long as a skilled artisan is motivated to add efficiency to the processes and methods described herein.

In still other embodiments, one or more (or all) of the steps may be done manually; or any combination of manual and machine-driven methods for performing the required steps may be employed, without departing from the scope and spirit of the present invention.

The materials and methods described herein exhibit many advantages over those currently available. For example, words, logos or artwork may be printed directly on the blister according to the manufacturer's commercial needs, as there is no fear of distortion of the polymeric material, since in various embodiments the shape of the blister is formed by cutting polymeric material and folding it, rather than producing it via thermal methods or vacuum. This will save many steps and much expense in the manufacturing methods of the present invention, and may provide a commercial advantage over methods known in the art. Moreover, the methods of the present invention can be undertaken without expending energy to heat up thermoplastic materials or preparing molds. All of these advantages, as well as others that may become apparent upon use, will lead to significant reduction of costs and waste.

Claims

1. A packaging article comprising a blister formed of transparent or translucent polymeric material attached to a backing material.

2. The packaging article of claim 1, wherein the backing material comprises plastic, paper, cardboard or cardstock.

3. The packaging article of claim 1, wherein the backing material comprises a first sheet and a second sheet, wherein the blister is sandwiched between the first sheet and the second sheet.

4. The packaging article of claim 3, wherein the first sheet and the second sheet are each a portion of a single sheet of backing material that is folded such that the first sheet is a top folded layer, and the second sheet is a bottom folded layer.

5. The packaging article of claim 1, wherein the blister comprises at least one edge.

6. The packaging article of claim 5, wherein the at least one edge comprises at least one rim.

7. The packaging article of claim 6, wherein the at least one rim is sandwiched between the first sheet and the second sheet.

8. A method of forming a packaging article, the method comprising the steps of:

(a) cutting a predetermined shape out of a sheet of transparent or translucent polymeric material;

(b) scoring, creasing or folding the material to form a three-dimensional blister having an open end, at least one outer edge and at least one outer rim on the at least one outer edge;

(c) cutting a piece of backing material into a predetermined shape;

(d) folding the piece of backing material to provide a top folded layer and a bottom folded layer;

(e) cutting a hole or opening into the top folded layer;

(f) inserting the blister into the hole or opening; and

(g) attaching the at least one outer rim to the top folded layer or bottom folded layer.

9. A method of forming a packaging article, the method comprising the steps of:

(a) cutting a predetermined shape out of a sheet of transparent or translucent polymeric material;

(b) scoring, creasing or folding the material to form a three-dimensional blister having an open end, at least one outer edge and at least one outer rim on the at least one outer edge;

(c) obtaining a first sheet of backing material and a second sheet of backing material;

(d) cutting or punching a hole or opening into the first sheet;

(f) inserting the blister into the hole or opening; and

(g) sandwiching the blister between the first sheet and the second sheet by engaging the at least one outer rim between the first sheet and the second sheet.

10. The method of claim 9, wherein the at least one outer rim is attached to the first sheet.

11. The method of claim 9, wherein the at least one outer rim is attached to the second sheet.