Overcap with Method for Making the Same

This application is the divisional of U.S. Non-Provisional application Ser. No. 18/368,684 filed Sep. 15, 2023, which is a continuation of U.S. Non-Provisional application Ser. No. 17/749,522, filed May 20, 2022, now U.S. Pat. No. 11,794,958, entitled “OVERCAP WITH METHOD FOR MAKING THE SAME,” all of which are incorporated by reference in its entirety herein.

The present disclosure relates to container closures, particularly to one-piece, paper-based container closures, and most particularly to overcap closures that provide a reclosable fit over an open end of a container.

Rigid, paper-based, composite container assemblies are often used to package various products, such as snacks and other food items, for example. These container assemblies often comprise a rigid container body (e.g., cylindrical) manufactured with the top and bottom ends open. The composite container bodies may comprise rigid cans made from sheet material (e.g., spirally wound), such as cardboard and/or paperboard. Such container assemblies further include top and bottom end closures. While the bottom end closure (e.g., metal or paper end) is usually permanently affixed (e.g., seamed) to a bottom rim of the container body, the top end closure is often designed to be easily removed by the consumer (e.g., a plastic removable/replaceable overcap and/or a peelable membrane). Typically, the membrane is first sealed to the top rim of the container. The container interior is then filled with products (e.g. food products) through the open bottom end of the container body, and the metal or paper closure is affixed onto the bottom rim of the container body. In a conventional container, the plastic overcap may be applied after sealing of the membrane and/or after affixing the bottom closure onto the container.

One disadvantage to the above-described conventional system is that the plastic removable/replaceable overcap may utilize polymers or polymer blends which are not readily recyclable in a common stream (e.g., curbside). Likewise, if a consumer fails to remove the plastic overcap from the container body prior to placing it in the recycling stream, the combined container/overcap may not be recyclable. Therefore, there is a need for a container assembly and overcap which is more easily recyclable, preferably using paper-based materials.

Existing paper overcaps are often used for drinking cups, ice cream tubs, yogurt containers, oatmeal containers, cheese containers for cheeses such as brie, dry soups, and the like. Paper overcaps are typically formed using a deep draw process which inherently causes the formation of wrinkles on the skirt of the lid. The wrinkles may limit printing and labeling applications and/or provide a product that is less visually appealing to the consumer that may be accustomed to smooth plastic overcaps. Accordingly, reducing the number of, appearance of, and/or feel of the skirt wrinkles is desirable.

Additionally, existing methods of making paper overcaps do not provide an acceptably tight fit or seal with their accompanying containers, do not allow repeated reclosures while maintaining the tight fit, and/or the natural expansion of the paper composition allows the overcap to become loose during repeated use. Still further, other existing paper overcaps are made from multiple paper components which are adhered together (i.e. not made from a single paper-based blank). Disadvantageously, the adhesives used may not be recyclable in the normal stream. Finally, the manufacture of such multi-component overcaps becomes more complicated, requires additional equipment, is time consuming, has a greater possibility for manufacturing defects due to the joining process, and is generally more expensive.

Through ingenuity and hard work, the inventors have developed systems and methods for making paper overcaps which are recyclable in a curbside stream, retain a tight fit or seal around an open end of a container end, even with multiple reseals, are easier and less expensive to manufacture, and provide an aesthetically pleasing skirt with fewer or less noticeable wrinkles.

The present disclosure relates generally to paper-based, one-piece overcaps and methods of making such overcaps. In some embodiments, the present disclosure is directed to a recyclable overcap made from a paper-based material.

As discussed above many paper-based lids do not form a tight seal over the container body when initially applied, and the paper material stretches with every removal and reapplication to the container. The present invention is directed to a paper-based lid defining a circumferential bead circumscribing the base of the lid. The circumferential bead is designed to expand and retract such that the lid may be replaced and removed from a container while maintaining a seal.

Repeated use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present disclosure.

Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the present disclosure, not limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present disclosure without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents.

A one-piece paper lidin accordance with a first embodiment of the invention is shown in. The lidmay be made from any type of paper known in the art for lidding. The paper may be single ply or multi-ply, may be coated, may include a layer of foil or metallization, and/or may include a barrier layer.

In some embodiments, the lid, made from a single piece of paper, comprises a baseand a skirt. The basemay include a central portion, and a peripheral portion. The peripheral portionmay be disposed outwardly of and adjacent to the central portion, such that the central portionis surrounded by the peripheral portion. In some embodiments, the central portionmay be depressed slightly below or raised slightly above the peripheral portion, while in other embodiments the central portionmay be level with the peripheral portion. Such contouring may provide additional strength to the lid and/or may provide useful printing/labeling surfaces for the lidding.

In some embodiments, the skirtmay connect to or transition into the peripheral portionof the lidvia a circumferential bead. The circumferential beadmay be disposed radially outward of the peripheral portionof the lidand may be the connection portion between the peripheral portionand the skirt. In an embodiment, the circumferential bead, in cross-section, may comprise a partial cylinder. For example, the circumferential beadmay be half-cylindrical in cross-section. In other embodiments, the cross-sectional shape of the beadmay comprise a square, triangle, irregular shape, or any shape known in the art. In an embodiment, the peripheral portionof the lidand the skirteach connect directly to the circumferential bead, with no intervening walls disposed therebetween. That is, in this embodiment, there is no upwardly or downwardly disposed transition portion between the peripheral portionof the lidand the circumferential beador between the skirtand the circumferential bead. In an embodiment, the lidis not a drop lid and is not concave.

The circumferential beadmay, in an embodiment, be radially extendable to some degree, laterally, away from the peripheral portion, as will be explained herein. In some embodiments, the lidhas a first inner diameter Dabove the protrusion(see). In some embodiments, the lidmay define a lower diameter Dbelow the protrusion(see).

In, the circumferential beadis biased inwardly. In an embodiment, the lidhas a second inner diameter D(see) when the circumferential beadis flexed outwardly, such as when the lidis being placed atop a container. The degree of outward flex shown inmay be exaggerated for illustration purposes. Further, the outward flex shown inis angular, but the flex could also comprise a curved flexion. The second inner diameter Dmay be greater than the first inner diameter D.

Before the lidis placed over a container opening (), the skirtmay be disposed parallel to the sidewall of the container in an embodiment. Said alternatively, the skirtmay be disposed perpendicular to the baseof the lid. In an embodiment, the first inner diameter Dof the skirtmay be smaller than or equivalent to the outer diameter of the container rim and/or sidewall to which it is designed to be applied. In an embodiment, the skirtscrapes against the rim and/or sidewall of the container as it is applied thereto, while in other embodiments, only the protrusioncontacts the container rim and/or container sidewall.

In an embodiment, the circumferential beadis configured to flex, at least partially, radially outward when the lidis placed over a container rim (see), such that the lid expands from the first diameter Dto the second diameter Dto fit over the rim of the container. In an embodiment, this expansion or flexion occurs primarily or only at and/or above the protrusion. Said alternatively, the upper portion of the skirtmay flex radially outwardly, while the lower portion of the skirtmay not flex outwardly. In an embodiment, the upper portion of the skirtmay flex radially outwardly to a larger degree than the lower portion of the skirt. In an embodiment, minimal or no flexion of the lower portion of the skirtoccurs. In an embodiment, the lower portion of the skirtremains stationary or substantially stationary as the lidis placed over a container rim. As shown in, the flexion appears to be angular or linear, such that the circumferential beadbends, distorts, or deforms to allow the skirtto move angularly outward. However, it is also contemplated that the upper portion of the skirtmay bend, curve, or flex outwardly in and of itself, with or without distortion of the circumferential bead.

In an embodiment, as the lidis placed over a container rim, the protrusionexpands or flexes as the protrusionmoves over the rim of the container. In this embodiment, the lower portion of the skirtstill remains stationary or substantially stationary. In an embodiment, the container and/or rim of the container are rigid and do not flex inwardly or do not substantially flex inwardly. After the protrusionmoves over the rim of the container, in an embodiment, the circumferential beadretracts inwardly to form a tight seat above the rim of the container. In this embodiment, the upper portion of the skirtmay flex radially outwardly to accommodate the rim of the container. This flexion may be temporary and may retract after the rim of the container is seated within the lid, or the flexion may be maintained during such time as the lid is seated on the container.

In an embodiment, when the lidis fully seated on the container, the circumferential beadradially retracts towards the biased inward position to form an interference fit between the skirtand/or the protrusionof the lidand the exterior surface and/or rim of the container. In some embodiments, when the lidis removed from a container, the circumferential beadagain flexes radially outward to allow the upper portion of the skirtto flex outwardly and the protrusionto move over the rim of the container and then retracts to the biased inward configuration once removed. In some embodiments, the circumferential beadretracts to its biased position completely.

As described, the purpose of the circumferential beadmay be to allow the upper portion of the skirtand/or the protrusionto flex outwardly when moving over the rim of a container while allowing the lower portion of the skirtto remain laterally (radially) stationary or substantially laterally (radially) stationary. As shown in, the upper portion of the skirtmay allow repetitive lateral movement for multiple lidding and unlidding operations, while the lower portion of the skirtmay remain stationary or substantially stationary during lidding and unlidding operations.

In some embodiments, as illustrated inthe circumferential beadradially extends when the lid is place upon a container, and the extension causes the circumferential beadto radially stretch and, in some embodiments, the curvature of the circumferential beadmay flatten. In some embodiments, as illustrated in, the liddefines a first lid height Hextending from the curlto the top of the circumferential bead. The first lid height Hmay be the height of the lidafter manufacture but before application onto a container. The lidmay also define a skirt height H. The skirt height Hmay extend between the curland the baseof the lid. The skirt height Hmay be constant after manufacture and after application onto a container. In some embodiments, the difference between the first lid height Hand the skirt height Hmay be the height of the circumferential bead. In some embodiments, the difference between the first lid height Hand the skirt height Hmay be between 0.5-5 mm, between 0.6-3 mm, or even between 0.75-2 mm.

In some embodiments, the first lid height Hmay decrease to a second lid height Hwhen the circumferential beadis extended to the outward position. As the position of the baseremains constant, the skirt height Halso remains constant. Thus, the difference in the second lid height Hand the skirt height Hdefines the height of the circumferential bead in the outward position. In some embodiments, the height of the circumferential bead in the outward position may be between 0.25-2 mm, between 0.35-1.5 mm or even 0.45-1 mm. In some embodiments, the height of the circumferential beadmay decrease between 20-60%, between 30-50% or between 35-45% when extended from the inward position to the outward position. In some embodiments, the height of the circumferential beaddecreases by 40% when extended to the outward position.

In some embodiments, as illustrated in, the circumferential beadmay return to the inward position and the lid may return to the first lid height H, while in other embodiments, when returned to the inward position, the circumferential beadmay retain a slight extension, and the lid may define a return lid height HLR wherein the return lid height HLR is slightly smaller than the first lid height H, and larger than the second lid height H.

In some embodiments, the circumferential beadmay have a lifetime number of cycles. In some embodiments, a cycle is a radial extension of the circumferential beadfrom the first lid height Hto the second lid height Hand radial retraction from the second lid height Hto the first lid height H. A first cycle may be putting the lidonto a container, and a second cycle may be removing the lidfrom the container. In some embodiments, the circumferential beadmay be configured to maintain a seal between the protrusionand the container for up to 100 cycles, up to 200 cycles, or even up to 500 cycles. In some embodiments, the circumferential beadmay be configured to retain the seal for at least 50 cycles, at least 100 cycles or even at least 150 cycles.

In some embodiments, the lidmay be formed from a paper material which has clastic properties. In an embodiment, the paper material may stretch up to 20% (e.g., FibreForm®, commercially available from BillerudKorsnäs). In some embodiments, the lid may be formed from a paper material made from post-industrial or post-consumer recycled materials. In some embodiments, the lidmay be made from cupstock.

In some embodiments, the lidmay include up to or at least 95% paper. In other embodiments, the lid may comprise 100% paper. The lidmay be printed, coated (interior or exterior), and/or may include additives. The lidmay comprise a multi-layer structure wherein at least one of the layers comprises a barrier layer. In some embodiments, the paper may have a high tensile strength and a high stretchability, while in other embodiments the paper may have either a high tensile strength or a high stretchability.

Illustrated in, in some embodiments, the skirtof the lidcomprises two or more layers of the same blank curled, rolled, or folded against one another (also referred to as sidewalls), an inner layer and an outer layer. In some embodiments, the skirtcomprises an outer sidewall(facing outwardly from the central axis of the lid) and an inner sidewall(facing inwardly toward the central axis of the lid). The outer sidewallmay extend downward from the circumferential beadand the inner sidewallmay extend upward from the fold or curl, towards the circumferential bead. As noted, in some embodiments, the outer sidewallmay include an inwardly and upwardly extending curl or foldextending between and connecting the outer sidewalland the inner sidewallopposite the circumferential bead. In some embodiments, the inner sidewallmay extend the entire length of the outer side wall. In other embodiments, the inner sidewallmay only extend upwardly a portion of the outer sidewall. In other terms, in some embodiments, the inner sidewallmay extend to abut or be adjacent the peripheral portionof the base, while in other embodiments, the inner sidewall may extend to a position halfway, two thirds of the way, or three quarters of the way between the foldand the peripheral portionof the base.

In some embodiments, the curl or foldmay be compressed such that there is no space between the inner sidewalland the outer sidewall. In other embodiments, the curl may provide a gap between the inner sidewalland the outer sidewall. Likewise, in some embodiments, the inner sidewalland the outer sidewallmay be compressed against one another such that there is no gap therebetween.

In some embodiments, the skirtmay further comprise at least one inner protrusion. In some embodiments, inner protrusionmay be disposed circumferentially about the inner sidewallof the skirt. In some embodiments, the inner protrusionmay be formed in the vertical center of the skirt, while in other embodiments, the inner protrusionmay be closer to the base, or the curl. In some embodiments, the specific vertical location of the inner protrusionon the skirtmay aid in providing a tighter fit of the lid on the container rim.

In some embodiments, the inner protrusionis continuous about the circumference of the inner sidewallof the skirt, while in other embodiments, there may be a plurality of inner protrusionsspaced about the circumference of the inner sidewall. In embodiments having multiple inner protrusionsthe protrusions may be evenly spaced about the circumference.

The inner protrusionmay be configured to have a smaller inner diameter PDthan the inner diameter Dof the inner sidewallof the lid(see). The inner diameter of the inner protrusionmay be greater than the outer diameter of the container sidewall in an embodiment, such that the protrusion never contacts the sidewall of the container. In this embodiment, once the lidis placed over the rim of a container (the rim having a greater outer diameter than the sidewall of the container), the inner protrusionforms an interference fit against the rim of the container and prevents the lid from uncoupling with the container over the rim without application of force.

Alternatively, the inner protrusionmay be configured to interact with a sidewall of a container in an embodiment, such that the inner diameter PDis approximately equivalent to the outer diameter of the sidewall. In this embodiment, once the lidis placed over the rim of a container (the rim having a greater outer diameter than the sidewall of the container), the inner protrusionforms an interference fit with the container sidewall and prevents the lid from uncoupling with the container over the rim without application of force, such that the lidmay not easily slide off the container sidewall.

In an embodiment, the rim and the protrusionresist movement beyond each other when the lidis positioned fully on a container. The inner protrusionmay be configured to have a first diameter PD(in the biased position) which is less than the outer diameter of the container rim. The inner protrusionmay be configured to have a second diameter PDwhen the lidis in an expanded position (see). The second protrusion diameter PDmay be greater than the first protrusion diameter PD. The expansion of the lidmay be sufficient such that the second protrusion diameter PDis equivalent to or substantially equivalent to the outer diameter of the container rim when the lidis in the expanded position. In this embodiment, the inner protrusionmay move over the rim of the container via application of human force and when the lidretracts to its inwardly biased position, the inner protrusion may again have a diameter which is less than the outer diameter of the container rim, thereby retaining the lidon the container.

In an embodiment, the protrusionmay comprise any shape known in the art. In an embodiment, (see), a cross-sectional view of the protrusioncomprises a partial cylindrical shape, such as a half-cylinder. In other embodiments, the cross-sectional view of the protrusionmay comprise a square, rectangle, triangle or irregular shape. Any shape known in the art to retain the lidon a container rim is encompassed herein.

In some embodiments, the skirtmay flex in an outward direction, such that the skirt exhibits a degree of flex α. Returning tothe lidmay define an upper outer diameter Dand a lower outer diameter D. Each of the upper outer diameter and the lower outer diameter may be the diameter of the lidextending between the outer surface of the skirt. In some embodiments, in the inward position the upper outer diameter Dei and the lower outer diameter Dmay be equivalent. In some embodiments, illustrated inin the extended state the circumferential beadis extended, and the skirtmay be flexed outward, such that a second upper outer diameter Dis less than a second lower outer diameter D. The degree of flex α may be determined based on the difference X in the upper outer diameter Duz and the lower outer diameter D, in addition to a length of the skirt L. In some embodiments, a small degree of flex α is desired. In some embodiments, the degree of flex α may be less than 5%, less than 3% or even less than 1%.

In some embodiments, the upper outer diameter Duz is measured at a point below the baseor the circumferential bead. Thus, to accurately determine the degree of flex α a length of measure Lmust be subtracted from the skirt length L.

In some embodiments, the paper to make lidmay be preprinted with a design, pattern, logo, color, or other source identifying marks, while in other embodiments, the color, design, pattern, logo, or source identifiers may be printed or added to the lidafter manufacture. In some embodiments, a lacquer may be applied to the exterior and/or interior of the lid.

In some embodiments, the bottom closure may be recessed into the bottom end of the container and may form a seal with an interior surface of a cylindrical container body. The container body and bottom closure may comprise a plurality of layers, including one or more paper-based layers. The one or more paper-based layers of the cylindrical container body and bottom closure may comprise at least about 95% by mass of the container assembly. This percentage of paper content may advantageously qualify the container assemblies as mono material, allowing them to be accepted in the recycling streams of most countries globally.

A container assemblyis shown in. The container systemmay include a lidand a container. The containermay have a sidewalldefining an upper end, wherein the upper end includes a top rimcircumscribing a top end of the sidewall, and a bottom peripheral edgecircumscribing a bottom end of the sidewall. The bottom end may comprise a bottom closure, optionally recessed into the container body. The top rimmay be a rolled rim and may have an outer diameter Dthat is larger than the outer diameter Dof the container sidewall. Alternatively, the top rimmay comprise a metal (or other material) end having bead, wherein the end is seamed onto the container. For example, the metal end may have a peelable aluminum membrane, easy-open (“EZO”) function, or ring-pull, and the bead may also have an outer diameter that is larger than the outer diameter of the container sidewall.

In some embodiments, the container bodymay comprise a rigid cylinder. In such cylindrical embodiments, the container bodymay have an inner diameter of about 3-16 cm (about 1-8 in.). For example, the container bodymay have an inner diameter of about 7.315 cm (about 2.880 in.). In some cylindrical embodiments, the container bodymay have an outer diameter De within a range of about 3-20 cm (about 1-8 in.). For example, the container bodymay have an inner diameter of about 7.630 cm (about 3.004 in.). The bottom closureof the containermay be circumscribed by a bottom peripheral edgeformed by the terminating edge of the sidewallthat forms the body of the container body. The sidewallmay include an interior surfacefacing the container interior and an exterior surfacefacing the outside of the container body. The interior surfacemay be the product-facing side of the sidewallof the container body. In some embodiments, the product(s) may be food products, and the interior surfacemay include a food safe layer, lacquer, film, liner, and/or coating to help protect the integrity of the food product(s) to be contained within the container body. The exterior surfacemay include printing or other applied graphics for labeling and/or advertising the product(s) to be contained within the container body. In an embodiment, the outer surface of the lidmay be coated with polyethylene or any lacquer known in the art.

In some embodiments, the sidewallof the container bodymay have a thickness (e.g., as measured from the interior surfaceto the exterior surfaceof the container sidewall) of about 0.05-0.2 cm (about 0.02-0.787 in.). For example, the sidewallof the container bodymay have a thickness of about 0.157 cm (0.062 in.).

As discussed with reference the lid, the first inner diameter Dis smaller than the outer diameter of the rim, also referred to as the rim diameter Dof the container. Thus, before application of the lidonto the containerthe skirtmay rest on the rim of the container. In some embodiments, to overcome the difference in diameters the lidmay be applied onto the containerusing an application of force. A minimal force allows the upper portion of the skirt to flex, via the circumferential bead. The flex within the circumferential beadallows the first inner diameter Dand the first protrusion diameter PDto expand to the second inner diameter Dand the second protrusion diameter PD. The second protrusion diameter PDis slightly larger than the rim diameter D, thus allowing the protrusion to shift about the rim an create a seal about the container.

In some embodiments, the upper portionof the skirt is about the height of the rim, such that the protrusionrests slightly under the widest part of the rim of the container, thus protrusioncreates a seal with a portion of the rim.

In other embodiments, the first inner diameter Dof the lid, is approximately equivalent to the rim diameter D, thus in the inward state, (e.g., after the protrusionis over the rim) the inner portion of the skirt may be in contact with the rim, thereby forming an interference fit.

While the container may be cylindrical, is should not be so limited. In some embodiments, the container may have a square, hexagonal, pentagonal, rectangular, triangular, or irregular cross-section. The lidmay have a shape and configuration which correlates to the cross-section of the container. Thus, for a cylindrical container, the lidmay be disc shaped. However, a container with a square cross section may be fitted with a square lid, for example.

In some embodiments, the rigid sidewallof the container bodymay include multiple layers, such as a paper-based layer, a barrier layer, an ionomer layer, and/or a tie layer, for example. Each component layer (paper-based layer, a barrier layer, ionomer layer) may comprise a single layer or may comprise a plurality of layers.

In an embodiment, the lidis strong enough to withstand transportation of the container on its lid, from the production line to the customer. Likewise, the lidis strong enough to withstand the filling and finishing of the container by the customer, transportation to retail stores, and ultimately transportation to the home of the consumer and use/reuse by the consumer. In an embodiment, the lidis able to withstand temperature and humidity changes that may occur during transportation. In an embodiment, the lidprotects the goods contained within the container, is optically/aesthetically acceptable, is recyclable (preferably in the same stream as the container body), and meets other customer requirements.

In some embodiments, the paper lidmay be used in connection with a membrane seal. In this embodiment, the membrane seal may be sealed onto the container rim prior to application of the paper lidthereto. In other embodiments, the paper liditself may be sealed onto a container rim and may, therefore, avoid the need for a membrane seal. That is, the lidmay form a hermetic seal with the rim of the container in an embodiment.

To illustrate the change of the circumferential bead height and the skirt height throughout the use of the lid, measurements of the lid were taken during each phase with a measuring clock. The measuring clock uses relative measurements for both the lid height Hand the skirt height H, however the circumferential bead height Δ is an absolute measurement as the difference between the lid height Hand the skirt height H. The measurements were taken at three points about the lid, each spaced about 120 degrees apart. Table 1 illustrates measurements for a lid before application, during application, and after removal from a container.