Patent Application
20140166682
The present disclosure relates to container and closure assembly. Preferably, the closure forms a hermetic seal with the container, with the seal being removable and the closure being replaceable on the container.
Closures in the form of a lid or overcap for a container are provided in a number of forms. An example of a container with a flat sealing rim and a plastic overcap is shown in U.S. Pat. No. 7,165,306. Means for hermetically sealing a container in conjunction with the reclosable lid or overcap are also known. One example of a hermetic seal for a container is the provision of a flexible membrane sealed to the rim of the container, with the membrane being removable to provide access to the contents of the container.
U.S. Pat. No. 4,171,084 to Smith shows a closure for a container having an outer ring with a central opening that is closed by a laminate sheet. The ring includes an upper circular portion and vertically positioned skirt portion. The two portions surround the top and outside edge of the rim of the container. The laminate sheet is secured between the bottom surface of the upper ring portion and the upper edge of the container rim. The laminate is sealed to both the ring and container rim by induction heating. Opening the container by removal of the ring causes a separation of the laminate from the rim of the container.
U.S. Pat. No. 4,359,169 to Helms et al shows a closure for a container having a membrane sealed between the underside surface of the outer peripheral edge of the closure and the top surface of the rim of the container. The closure includes a pivotable inner member surrounded by an outer ring member. The pivotable member includes a rim having a downwardly projecting flange that is sealed to the membrane. As the pivotable member is lifted, the membrane tears adjacent the flange and a central portion of the membrane is carried by the member.
U.S. Pat. No. 3,892,351 and U.S. Pat. No. 3,973,719 to Johnson et al show a container with a membrane seal attached to the upper surface of the container rim. An overcap is provided on an underside surface with a pattern of heat deformable ribs that engage the edge of the membrane in the area of the container rim. An RF source is used to heat a conductive portion of the membrane to create a seal with the rim while simultaneously heating the ribs. The heated ribs conform to the surface of the membrane.
U.S. Pat. No. 4,448,345 to Helms shows a composite lid structure for a container. A molded upper ring member is combined with a flexible laminate panel positioned on the underside of the ring member that closes the center area of the ring. An adhesive is provided under the panel and below the ring to temporarily secure the panel during assembly. An RF source is used to heat metal particles in the panel to form a seal with the rim of the container. The lid (ring and panel combination) may be removed from the container, leaving the membrane sealed to the rim.
A container and closure assembly is provided. The container defines an internal volume by one or more walls and an opening therein for access to the product retained within the container. A projecting rim surrounds the opening and includes a rim sealing surface. The closure is provided for covering the container opening. The closure is formed from a support ring, dimensioned to surround the rim of the container, and a sealing membrane. The ring includes a ring sealing surface positioned concentric with the rim sealing surface when the ring is positioned to surround the container rim. The membrane is sealed to the rim sealing surface and further to the ring sealing surface. The seal of the membrane to the rim sealing surface is separable upon removal of the ring from its position surrounding the rim of the container, while the seal of the membrane to the ring remains in place upon ring removal.
In a further aspect of the assembly, the concentric positioned ring and rim sealing surfaces are positioned substantially in the same plane. Further, it is preferred that the membrane is heat sealed to the ring sealing surface and the rim sealing surface.
In a still further aspect of the assembly, a lifting tab may be provided, framing a projection on the periphery of the ring. Preferably, the container rim extends outward, transverse to the opening defined in the container.
In a further aspect of the assembly, the ring may comprise a skirt portion extending substantially transverse to the ring sealing surface. A retaining ridge or similar resilient attachment means may be formed on an inwardly facing surface of the skirt portion. The retaining ridge is preferably formed for engaging the rim of the container and retaining the ring and sealed membrane on the rim.
The container is preferably formed from a thermoplastic material, as is the ring structure. The container and ring are preferably injection molded. The container and ring may be separately formed or may be integrally molded, with a frangible connection there between.
A method of sealing a closure to a container is also contemplated by the present disclosure. The method of sealing the container is defined by providing a container having an interval volume, an opening therein for access to the internal volume, a projecting rim surrounding the opening, and the rim having a sealing surface. A support ring is further provided that is dimensioned to surround the rim of the container, and is preferably concentric with the rim. The ring is provided with a ring sealing surface. The ring sealing surface is positioned to surround the rim sealing surface, with the ring sealing surface preferably positioned in substantially the same plane as the rim sealing surface when the ring surrounds the rim. A membrane is provided having a surface area corresponding to the area defined by the support ring. The membrane is positioned to contact the rim sealing surface and the ring sealing surface and then sealed there to. The seal of the membrane to the rim sealing surface is formed to be separable upon removal of the ring from its position surrounding the rim. The seal of the membrane to the ring remains in place upon ring removal, creating a closure lid that may be repeatedly positioned on and removed from the rim of the container.
For the purpose of illustrating the invention, there is shown in the drawings one or more forms that are presently preferred; it being understood that the invention is not limited to the precise arrangements and instrumentalities shown,
Referring now to the drawings, where like numerals identify like elements, there is shown in
In
In the partial cross section of
The present form of the rim 18 and container 12 are provided for illustration purposes. Other forms of containers and rims are known and may be used along with the closure contemplated herein. As a non-limiting example, the container may have a shape other than a round body and opening, as illustrated. The container shape may be oval, square, rectangular, oblong, etc. In addition, the shapes of the opening and container may differ. Further, the rim of the container may included various flat, pointed, undulating, or rounded (concave, convex or both) surfaces. Generally, the rim is contemplated to be defined by a substantially continuous surface that surrounds the container opening. Preferably, the rim is formed on a projection from the container body. The top surface of the rim is sometimes referred to as a chime and generally faces outwardly, transverse to the area of the container opening. The top surface may further be formed as a radial inwardly projected flange or surface.
In
In
The strength of each of the two seals 48, 50 is preferably different so as to create a peelable or separable seal between the rim 18 and membrane 22 and a more permanent seal between the membrane 22 and ring 20. Generally, upon sealing the membrane 22 to the rim, the container 12 is hermetically sealed, protecting the product retained within the interior volume. In addition, the sealing of the membrane 22 to the ring 20 creates a closure 14 for the container 12.
In
In
The seal 50 between the ring 20 and the membrane 22 remains in place in the creation of the closure 14. The seal (48) between the membrane 22 and rim 18 has previously been removed. Hence, the replacement of the closure 14 on the rim is no longer a hermetic seal, but provides a (temporary) freshness closure for the container contents. Further, the closure 14 may be removed (
The assembly 10 and its method of formation may create a number of advantages. The creation of a composite closure, formed from a ring and membrane, is contemplated to create a relatively light weight structure that has a reduced production cost, as compared to a molded overcap with a central body also part of the molded element. Further, the structure may be formed with a hermetic seal using the membrane that also forms the closure lid.
In forming a seal for the container, it is preferred that the sealing surfaces be aligned adjacent one another, with both facing upwardly from the top surfaces (32, 40) of the rim (18) and ring (20). The similarly facing sealing surfaces provide for forming the two seals in a single step, using a single sealing tool structure. The two surfaces may be positioned in a single plane. Variations in the form of the tool or the sealing process may permit formation at differing surface levels. For example, small variations in the position of the two sealing surfaces may result in an advantageous difference in sealing force applied. Hence, a relatively greater heat and/or pressure on the ring seal may result in a stronger seal as compared to the seal formed with the container rim. Such variation are intended in the creation of the rim seal, which is contemplated to be peelable or otherwise breakable while the ring seal is contemplated to be permanent so as to form the reusable closure lid. In the figures, the rim seal (48) is shown as being wider than the ring seal (50). However, such is not a fixed requirement for the formation and use of the assembly. Other variations in the size of the seal, the amount of heat and pressure applied, and the materials involved in creating a seal are contemplated.
The materials used to form the rim of the container, the container body, the ring and the membrane may vary without departing from the advantages contemplated by the structure specifically described herein. As shown, the rim is integrally formed with the container body and is preferably formed by an injection molding process. The rim may be separately attached to the container and may have forms different from those shown. The rim and ring may also be integrally formed with a frangible connection provided between the two parts. A coating or other adhesive may be used to create or assist in creating the various seals between the rim, ring and membrane.
The membrane may have a variety of forms. For example, the membrane may be composed of a laminate material or a single layer of a flexible plastic. A foil material may also be utilized, with a desired coating applied on the inside surface for forming the heat seal with the rim and ring structures. Alternatively, the membrane may be formed of polyethylene or other flexible plastic. The container may be injection molded from a polypropylene material. The ring may also be molded using polypropylene or another moldable plastic. The container may be formed from a composite material, incorporating one or more layers of paper. The container may include a rolled rim or a separately attached rim structure, formed of metal, plastic or a composite structure. A coating may be applied to the exposed top surface of the rim and/or the ring to assist in the formation of the membrane seal.
In the drawings and specification, there has been set forth one or more embodiments of the invention and, although specific terms are employed, these terms are used in a generic and descriptive sense only and not for purposes of limitation. The scope of the invention is set forth in the following claims.
