This invention is directed to a lid for a plastic container, and more particularly, to a lid providing a detachable container within the lid.
It is a common expedient to provide food, drugs, chemicals and other perishable or ingestible items in plastic containers for sale. The containers are covered with lids which either snap on the top of the container to close the container, or are fused to the container and are removed by breaking the seal by a tear away tab or the like.
What is known in the prior art is that consumers require that the contents of the container be protected against tampering and spoilage. It is known that oxygen and humidity are the primary spoilers of foods and other products contained within the container. For example, in dairy products oxygen destroys the good bacteria in dairy resulting in accelerated degradation of the food's properties. The container lids, either when originally in place or when reapplied, do not provide a sufficient oxygen barrier to prevent rapid spoilage. As a result, preservatives are required as a food ingredient. Furthermore, because the plastic lids are thick and often have design on them, it is not readily apparent whether or not the lid has been tampered with.
The current solution to providing a tamper evidence structure and a spoilage barrier is to place a seal across the container top prior to the lid being placed thereon as is known from yogurt containers by way of example. The seals are placed on containers by mass production devices. The use of plastic seals is desirable for their oxygen barrier characteristics. However, plastic seals have the shortcoming that the plastic seal stretches as it is applied in mass production. As a result, printing or decorations on the seal become distorted, making them unusable. Therefore, as is known in the art, to allow printing on the seal, a metal foil, commonly made from aluminum, is placed across the top of the plastic container and a plastic cap is placed over the container with the foil disposed therebetween.
This two-step process has been satisfactory, but it suffers from the shortcomings that it in fact requires two steps to produce: (1) the placing of the foil onto the container and (2) the placing of the cap over the foil. This results in a significant increase in the time required to seal containers for shipment. Furthermore, the packager must warehouse two products, the rolls of plastic film or foil barriers and the lids. This requires an excessive amount of space for warehousing and provides a bottleneck at the packaging line.
In an attempt to overcome the shortcomings of the traditional method, it is also known in the art to merely provide a precut or printed film across the top of the container without the additional plastic cap. However, without the plastic cap, there is no structural integrity to the top layer of the container. The container top is merely an exposed film, which is either glued or lightly melted to the top of the container. Because there is no structural integrity, the containers cannot be stacked one upon the other. Therefore, although space and time efficiencies are accomplished at the packaging plant, as a result of the inability to stack, this container requires more space to transport the goods, to store the goods and requires more and special packaging to hold the containers in facing relationship as is known from individual Jell-O dessert or pudding containers. Additionally, the film only containers are susceptible to breakage and leakage when stacked.
It has been known in the art, to provide separating layers within either a bottle cap, as is known by way of example from U.S. Pat. No. 4,588,099, or to provide a composite lid, in which a portion of the cover separates and remains with a non-bottle type container as is known from U.S. Pat. No. 4,448,345. However, these devices either (1) separate through shearing forces, and therefore are only applicable for twist caps, (2) are made of a conglomerate of materials, such as metal, plastics, and paper, and therefore, are not recyclable and are wasteful, or (3) do not provide a sufficient surface to allow the integrity for stacking one container upon another.
Accordingly, a container lid, which is more efficient in application and maintains the structural integrity of the container is desired.
A lid is shaped to be received on and enclose a container in a fitting relationship. A membrane made of one or more layers is affixed to the interior of the lid. The uppermost surface of the membrane comes in contact with the lid and is detachably affixed to the lid. The bottommost surface of the membrane becomes attached to the container when the lid is placed on the container to close the container. The force affixing the bottommost surface to the container is greater than the force affixing the uppermost surface to the lid. Therefore, when the lid is removed for use, at least one layer of the membrane detaches from the lid and remains affixed to the container until broken or removed by the user.
In one embodiment of the invention, the layer is a film, which can be either an oxygen barrier, an oxygen scavenger, a tamper evidence structure, a label, or a support for an object such as a spoon, a collectable, a flavor packet or a radio frequency identification device (RFID tag) disposed thereon. In another embodiment, the at least one layer can be more than one layer in which any one of the layers may have one or more of the functionalities described above. Furthermore, in the multilayer embodiment, the bond between any of the intervening layers may be less than the bond of either the uppermost layer to the lid or the bottommost layer to the container such that the desired functionality may be selectively deposited by separating the layers between desired functionalities.
Lastly, in the multilayer design, an object such as a prize, an RFID chip, a spoon or the like may be held between layers which is then released as the weakest bond amongst the bonds between layers, container and lid is at the layer in which the article is embedded.
Reference is now made to
Container 20 is made of a material sufficiently rigid to maintain contents therein, whether liquid or solid, without substantially deforming the shape of container 20. In a preferred embodiment, sidewall 24 and the bottom of container 20 are formed of an oxygen barrier material for preventing passage of oxygen therethrough such as thermo formed plastics (PET), metal or glass.
In a preferred embodiment, lid 10 encloses a top opening 26 of container 20. As is known in the art, a catch 16 may be formed on sidewall 14 to catch a lip 22 extending from a sidewall 24 of container 20. Catch 16 is disposed along sidewall 14 so that when lid 10 is disposed on container 20, catch 16 cams over lip 22 so that lip 22 is in facing relationship with catch 16 to prevent lid 10 from inadvertently being removed from container 20.
Container 20 includes sidewall 24, a bottom (not shown) and an opening 26 at its top to provide a cuplike container. As known in the art, a lip 22 is formed on sidewall 24. Container 20 may be made of any shape and may be relatively shallow, to be more bowl like, or taller than wide to be more like a can.
Lid 10 may be made of any material, but is preferably an injection molded plastic. In a preferred embodiment, lid 10 is shaped to conform to the shape of the sidewall 24 of container 20. The distance across the interior in any one direction of lid 10 is substantially equal to the corresponding distance between sidewall 24.
Membrane 18 is detachably affixed to cover surface 12 of lid 10 at the interior of lid 10. Membrane 18 is affixed to cover surface 12 by means known in the art such as adhesive, weak weld, a laser-function weld, compression weld, static charge, friction or, in the case of plastic, by melting the film to cover surface 12 of lid 10. Membrane 18 is dimensioned so as to be at least substantially coextensive with sidewall 24 of container 20. In this way, at least a portion of membrane 18 overlaps wall 24 (see
Reference is now made to
Membrane 18 is attached with sufficient strength to remain in place, but to become separated from either one of container 20 or lid 10, dependent upon the relative strength of the bonds, as desired, upon removal of lid 10 from container 20. Because the container is a slip over type of container, which is pressed onto and retains sidewall 24 at container 20, there is no need to shear membrane 18 by twisting. The mere action of removal, i.e., lifting the lid 10 away from container 20, exerts sufficient force to separate membrane 18 at its weakest bonding point. As discussed above, this can be either at lid 10, or at sidewall 24, depending on the desired functionality of membrane 18. As will be discussed below, in a preferred embodiment of a multi-layer membrane 180, this point of shearing may additionally be at some mid-layer point.
Membrane 18 may serve a multitude of functions. First, it may act as an oxygen barrier. Membrane 18 may be formed of any plastic film, or Ethylene Vinyl Alcohol Copolymer (EVOH) film or other material capable of being recycled with the remainder of lid 10 or container, by way of non-limiting example. An object such as a utensil, collectable, food packet or RFID circuit is disposed on membrane 18. Membrane 18 may be a plastic film infused with an aroma if such a presentation is desired for the contents of the container. Membrane 18 may merely be a label-carrying layer to provide an indicia-bearing surface presenting the trademark, ads, instructions on use or other information to the user. Membrane 18 may be an oxygen scavenger such as OS® manufactured by Chevron, which when activated by ultraviolet light eliminates oxygen within the container increasing shelf life. Membrane 18 may also serve as a tamper evidence structure exposing any tampering through the container top as a puncture hole or tear, evidencing the tampering. Lastly, as is known from foil coffee pouches, a gas release valve may be formed in membrane 18 where it is desirable to release gas and/or the odors carried by the gas.
It is also contemplated, that a portion of the membrane may be made of a metal foil. However, that portion of the metal foil, in a preferred embodiment, is that portion of the membrane, which remains with the container to maintain the recyclable nature of the lid. In this way, the metal foil may be removed from the container and recycled individually upon ultimate opening of container 20. By way of example, a layer of membrane 18 may be formed of an aluminum, mylar® film or other type of metal foil.
Reference is now made to
A Membrane 180 includes a bottommost layer 18A. A second layer 18B is disposed upon layer 18A. Layer 18B is affixed to layer 18A as is known in the art by either an adhesive, a weld, a melt, laser, static charge or compression affixing processes or the like to form a bond therebetween. It is also contemplated within the scope of the invention that a layer may be “affixed” to an adjacent layer merely by being disposed thereon so that the weight of the lid keeps the adjacent layers in facing relationship. A layer 18C is affixed to layer 18B and may be affixed by the methods discussed above to form a bond therebetween. A layer 18D is affixed atop layer 18C in a manner as discussed above and a topmost layer 18E is affixed to cover surface 12 and layer 18D to form a bond therebetween.
A bottommost surface of layer 18A comes in contact with container 20 as discussed above when lid 10 is placed to cover container 20. The bond between container 20 and layer 18A of membrane 180 is stronger than any bond between any remaining layer of membrane 180 and either an adjacent layer or lid 12. Furthermore, the functionality of each layer may be different from the functionality of an adjacent layer or any other layer merely by utilizing materials to provide different functionalities as discussed above. Additionally, by controlling the strength of the attachment between adjacent layers, so that the strength of the attachment between adjacent layers is less than the strength of the attachment between the uppermost layer and the lid and the bottommost layer and the container, membrane 180 may be selectively divided between any of the adjacent layers. Part of membrane 180 remains with lid 100 and part of membrane 180 remains affixed to container 20. In this way, desired functionality may remain both with container 20 and with lid 10.
Furthermore, by controlling the relative strengths of the bond between layers, a resealable container may be provided. Once the layer on container 20 is removed, a remaining layer within lid 10 can be engineered to affix to container 20 once lid 12 is reattached. It can then be retained on container 12 while lid 10 is removed by setting an intermediate bond with less strength then the bond to lid 10 or the bond to container 20.
By way of non-limiting example, bottom layer 18A and layer 18B may both provide oxygen barriers. By making the bond between layers 18A and 18B weaker than the bond between any other layers, the membrane separates between layer 18B and layer 18A, if the user removes oxygen barrier 18A during use, the oxygen barrier may be replaced merely by refitting the lid with the newly exposed layer 18B.
Lid 10 is preferably formed in one of two ways, however any process for attaching a film to a lid for enclosing a container may be used. In a first manufacturing method, the desired layers 18A-E of membrane 180 are attached to each other with desired respective bonding strength and then placed in an injection mold. The cover surface 12 and sidewalls 14 of lid 100 are then injection molded about membrane 180. A top surface of membrane 180 attaches to the inner cover surface of the molded cover. This results in a weak attachment force between lid 100 and the uppermost surface of membrane 180.
In a second embodiment, a plastic lid 10 is made separately from membrane 180. The membrane 180 is then affixed to the interior area of cover surface 12 by heating an adhesive, applying it to one of the membrane and cover surface, and contacting the membrane 180 to cover surface 12. Membrane 180 (or 18) may also be affixed to cover surface 12 by one of laser-function weld, compression-weld, friction adhesion, melting, static charge or other like attachment devices or methods to form a bond with the cover. Both of these methods work equally well with a single layer membrane 18 or a preconstructed membrane 180.
By providing a membrane made up of one or more layers, in which the membrane is affixed either at intermediate layers of the membrane or at the top most surface and bottom most surface of the membrane, in such a way that the bond formed by the affixing, has a strength which is unequal amongst its parts, the membrane will separate at its weakest bond. In this way, the membrane may be selectively separated from either the container, the lid, or an intermediate position (when a plurality of layers are used as the membrane) as desired.
This will occur so long as the bond strengths at the point where separation is desired is substantially different than the bond strength at the point in the structure where separation is not desired.
While there have been shown, described, and pointed out novel features of the present invention as applied to the preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form of details of the disclosed invention may be made by those skilled in the art without departing from the spirit and scope of the invention. It is the intention therefore to be limited only as indicated by the scope of the claims appended hereto. There also is to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which is a matter of language might be said to fall there between. In particular, this invention should not be construed to being limited to the use of the specific structures, materials, or methods as disclosed herein.
This Application is a utility application and claims the benefit of U.S. Provisional application 60/575,582 filed on May 28, 2004.
Number | Date | Country | |
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60575582 | May 2004 | US |