Patent Grant
10882673
The invention relates to a dual-seal liner configured to be bonded between a closure and container to form a non-removable closure assembly that substantially resists rotational movement and is rendered substantially non-removable by the customer.
There are a variety of food, beverage and healthcare products for which a non-removable closure would be advantageous. A non-removable closure system is generally understood to be one in which, following attachment of the closure to the container body, the closure cannot be detached from the container without deliberately applying such large forces that would at least partially damage the container and/or the closure. Such damage would thus prevent continued use of the container body and/or closure.
For example, it is well known to provide an injection molded preform with an upper relatively thick finish portion for forming the mouth of the container, and a lower preform body portion that is subsequently blow molded to form a relatively thin container body. The relatively thick finish portion has an external thread and provides the necessary structural strength for secure application of a closure having a complementary internal thread, while the expanded container body is sufficiently strengthened (e.g., by biaxial orientation) to withstand product filling, handling and expected use. In some applications the closure has a dispensing aperture allowing the product to be dispensed without removal of the closure, often by providing a flip-top that can be repeatedly opened and closed to open and close the dispensing aperture as needed. The container body portion, which is thinner and more flexible than the finish area, can be squeezed by the consumer, while holding the container upside down, to assist in dispensing product through the open dispensing aperture. The preform(s)/container(s) for such applications are typically made from thermoplastic polymers such as polyesters (e.g., polyethylene terephthalate PET) and polyolefins (e.g., polypropylene or polyethylene). The closure is also typically a molded plastic article, formed separately from the container, and may be made of polyolefin or polyester.
Most applications for such thermoplastic containers and closures are single fill applications, wherein the container and closure are essentially discarded after all or most of the product is dispensed. In such applications, it is desirable to minimize the amount of material required, and minimize the complexity of the injection and blow molding equipment, in order to produce a container and closure assembly at a competitive price. These limitations on material usage and equipment/process complexity are also constraints on the design of a non-removable closure/container system where it is desired that a customer be unable to remove the closure and refill (reuse) the container. However, the material and cost constraints make it even more difficult to design a cost-effective closure/container system with sufficient structural integrity to withstand (resist) customer attempts to remove the closure.
The present invention provides a dual-seal liner, positionable between a closure and container, for forming a non-removable closure assembly. The liner includes induction heat seal bonding areas for sealing to a both a top sealing surface TSS surrounding the mouth of a plastic container, and to an inner top wall of a closure cap. The liner is disposed between the closure cap and the TSS of the container and then induction heat seal bonded to both, thus rendering the closure cap non-removable from the container. The liner further includes a conductive heat bonding area that bonds to another portion of the inner cap wall to effectively seal (prevent exposure of) an upper portion of the liner from the product being dispensed from the container.
In accordance with one embodiment, a dual-seal liner is provided for forming a non-removable closure assembly between the liner, a cap and a container, comprising:
the dual-seal liner comprising a disc-shaped body having opposing top and bottom surfaces and a peripheral edge extending in a thickness direction between the top and bottom surfaces;
the dual-seal liner comprising an upper liner component ULC stacked, in the thickness direction, above a lower liner component LLC,
the dual-seal liner configured to form both inductive heat seal and conductive bonding areas to a cap and container as follows:
wherein the respective mating inductive heat seal bonding areas A and A′, B and B′, C and C′ are aligned in the thickness direction with the TSS and are configured to form a non-removable closure assembly by inductive heat seal bonding of the TSS, the liner and the inner top wall of the cap; and further
the LLC top surface having a conductive heat bonding area D, disposed between the LLC dispensing aperture and the area B′, for bonding to a mating conductive bonding area D′ on the inner top wall of the cap, the area D′ being disposed between a cap dispensing aperture in the top wall of the cap and the ULC dispensing aperture thus allowing a product to be dispensed through the dispensing apertures of the liner and cap of the non-removable closure assembly without exposing the dispensing product to the ULC.
In one embodiment, the area A′ is disposed between the cap dispensing aperture and a peripheral sidewall of the cap, to prevent leakage of the product being dispensed through the liner and cap apertures of the non-removable closure assembly.
In one embodiment, the ULC is donut shaped with a central through-hole formed by an edge extending in the thickness direction between the top and bottom surfaces of the ULC, the through-hole forming the ULC dispensing aperture and the mating bonding areas D, D′ being disposed radially inwardly of the edge in a direction transverse to the thickness direction.
In one embodiment, the ULC includes an inductive heating layer for heating one or more of the heat seal bonding areas, and the inductive heating layer extends to the edge of the through-hole.
In one embodiment, the ULC comprises upper and lower ULC layers having areas A and B respectively, and an inductive heating layer lying between the upper and lower ULC layers for heating one or more of the mating heat seal bonding areas A and A′, B and B′, and C and C′.
In one embodiment, the inductive heating layer is configured for heating all of the heat seal bonding areas A and A′, B and B′, and C and C′.
In one embodiment, the ULC and LLC are each donut shaped with a central through-hole of each forming the respective ULC and LLC dispensing apertures, and wherein the ULC through-hole has a diameter in a range of 2 to 5 times larger than a diameter of the LLC through-hole.
In one embodiment, the diameter of the ULC through-hole is in a range of +/−20% of a diameter of the cap
In one embodiment, the LLC dispensing aperture is in the form of a slit extending in a thickness direction through the LLC.
In one embodiment, the ULC and LLC dispensing apertures are each in the form of a through-hole extending through the ULC and LLC respectively, and the ULC through-hole has a diameter that is larger than a diameter of the LLC through-hole.
In one embodiment, the liner has a peripheral edge that is substantially equal in diameter to a peripheral edge of the TSS.
In one embodiment, the heat seal bonding areas comprise polymer materials that bond in a temperature range of form 60 to 210 degrees Celsius (140 to 410 degrees Fahrenheit).
In one embodiment, the polymer materials of the heat seal bonding areas comprise one or more of polyolefin, polyester, and nylon materials. In various embodiments: two or more of the heat seal bonding areas are polyolefin materials; two or more of the heat seal bonding areas are polyester materials; the conductive bonding areas D and D′ are both polyolefin materials, such as polypropylene materials; the heat seal bonding areas A and A′ are polyolefin materials, such as polypropylene materials; the heat seal bonding areas B and B′ are polyolefin materials, such as polypropylene materials; the heat seal bonding areas of C and C′ are polyester materials, such as polyethylene terephthalate (PET) materials.
In one embodiment, a non-removable closure assembly is provided comprising the dual-seal liner, attached by the mating heat seal bonding areas and mating conductive heat bonding areas between the cap and container.
In one embodiment, a method of forming a non-removable closure assembly is provided comprising:
providing the dual-seal liner positioned between the inner top wall of the cap and the TSS of the container,
applying a conductive heating source to conductively bond mating areas D and D′ together, and
applying an inductive heating source to inductively heat seal bond mating areas A and A′, B and B′ and C and C′ together respectively.
In one embodiment, a non-removable closure assembly is provided comprising the dual-seal liner and a plastic closure cap:
the area A comprising a closure sealing surface on a lower surface portion of the top wall and disposed radially outwardly of the cap dispensing aperture and radially inwardly of the skirt, and configured to be aligned above the top sealing surface (TSS) surrounding the container mouth,
a closure thread disposed on a radially inwardly facing sidewall of the skirt for engaging a mating container thread surrounding the container mouth, wherein
the dual-seal liner bonds the closure cap and container TSS together to form the non-removable closure assembly.
In one embodiment of the non-removable closure assembly:
the heat seal bonding areas comprise one of more of polyolefin and polyester material layers; and
the inductive heating layer is a metal foil layer.
In one embodiment of the non-removable closure assembly:
the closure sealing surface and the heat seal boding areas of the ULC are polyolefin materials and the inductive heating layer is an aluminum foil layer.
In one embodiment of the non-removable closure assembly:
the top sealing surface TSS of the container and the heat seal bonding area C are polyester materials.
In one embodiment of the non-removable closure assembly:
the heat seal bonding of the closure cap, the dual-seal liner and the TSS of the container renders the assembly non-removable by hand and able to withstand a torque of at least 50 inch-pounds (in-lbs) without loss of the heat seal bonds or distortion of the closure cap or container.
In one embodiment of the non-removable closure assembly:
the heat seal bonding is able to withstand a torque of at least 70 in-lbs.
In one embodiment of the non-removable closure assembly:
the closure cap and the container are configured for packaging of a food product, such as a food product that reacts with or corrodes the inductive heating layer, such as an oil based, vinegar based, or acidic food product, such as ketchup, mayonnaise or mustard.
In one embodiment, a sealed package is provided comprising the non-removable closure assembly filled with a food product such as an oil based, vinegar based, or acidic food product, such as ketchup, mayonnaise or mustard.
In one embodiment, a method of making the non-removable closure assembly is provided comprising steps of:
inserting the ULC and LLC of the liner into the closure cap, either separately or together, with the top surface of the ULC adjacent the closure sealing surface,
attaching the closure cap to the container by applying a torque to engage the mating threads of the closure and container, with dual-seal liner positioned in the area between the closure sealing surface and the top sealing surface (TSS),
activating the inductive heating layer to heat seal bond the respective layers of the closure cap, the liner and the TSS of the container.
In one embodiment:
the inserting step comprises inserting the ULC and the LLC as two separate components into the closure cap.
In one embodiment, the method further comprises:
forming the ULC without the ULC dispensing aperture, and then punching through the ULC thickness to form the ULC dispensing aperture and an exposed side edge of the inductive heating layer.
In one embodiment, the method further comprises:
forming the LLC without the LLC dispensing aperture, and then punching through the LLC thickness to form the LLC dispensing aperture.
In one embodiment:
the activating step comprises applying an inductive heating source that applies a top load to the closure cap, liner and TSS while activating the inductive heating layer.
In one embodiment of the non-removable closure assembly, the plastic closure cap comprises a flip top cover joined by a hinge to a lower closure portion, the lower closure portion having the top wall with the cap dispensing aperture and the flip top cover configured to cover the cap dispensing aperture in a closed position.
In one embodiment of the non-removable closure assembly, the cylindrical skirt of the plastic closure cap comprises an inner skirt, the plastic closure also having an outer skirt depending downwardly from the top wall and disposed radially outwardly with respect to the inner skirt.
In one embodiment of the non-removable closure assembly:
In one embodiment, the inner skirt is of a lesser height than the outer skirt with respect to the longitudinal axis.
In one embodiment, the cap has a top wall, a downwardly extending outer peripheral sidewall or skirt, and a downwardly extending inner skirt disposed radially inwardly and of a lesser height than the outer skirt, wherein the height is defined with respect to a central container axis. Providing the bonded areas radially inward of the inner skirt, and more preferably having an inner skirt of lesser height, makes it more difficult to access the heat seal bonded areas if attempts are made to remove the closure. In one embodiment, the finish is relatively more rigid than the closure.
In one embodiment, the closure and/or the finish are each an injection molded article. The finish and closure may be molded from plastic materials such as polyolefins, e.g. polypropylene or polyethylene, or polyesters, e.g. PET. Alternatively, the finish and/or closure may be extrusion or compression molded. The finish may also be blow molded or otherwise expanded after initial molding.
In one embodiment, there are at least two diametrically opposed thread segments on each of the closure and finish. The finish thread segments may have overlapping ends, as well as the closure thread segments; this provides greater rigidity and resistance to removal of the closure. Depending on the finish size, there may be four, six or more sets of diametrically opposed thread segments on each of the closure and finish.
In one embodiment, the container finish and closure form a standing end, e.g. of a top down or inverted container.
The above and further advantages of various embodiments of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which:
One or more embodiments of the present invention will now be described with respect to the liner, container and closure illustrated in
A. Non-Removable Closure Assembly
In one embodiment, the invention is an induction heat seal liner for sealing the finish (open end or mouth) of a plastic container, the liner being disposed between a closure cap and the container finish and being heat seal bonded to both, thus rendering the closure cap non-removable from the container finish. By non-removable it is meant that once heat seal bonded together the closure cap cannot be removed by a customer or consumer (a human) by hand, without substantially distorting the closure cap or container, e.g., it would require the human to use a mechanical tool (e.g., knife or wrench) and in the process of trying to remove the cap with the tool it would substantially deform the closure cap or container and render one or more of them unusable for their intended purpose.
In one embodiment, the heat seal liner includes an inductive heating layer, e.g., a metal layer, such as an aluminum foil layer, and adjacent plastic polymer layers which collectively form a barrier liner (e.g., preventing exposure to air and/or moisture) to prevent deterioration of the product to be sealed in the container. In one embodiment the product is ketchup, which will discolor when exposed to the atmosphere. In another example the product is mayonnaise, which will spoil when exposed to the atmosphere. The metal foil layer of the liner serves as an inductive heating element for transferring heat to other heat seal layers of the liner, causing the heat seal layers to soften (upon heating) and form a heat seal bond with an adjacent surface of the liner, finish or closure cap.
A heat seal liner for a non-removable closure system has an aperture in the liner to allow the product to be dispensed through the liner and then through a dispensing aperture in the closure. Typically the closure has a flip top cover with a plug that closes the dispensing aperture (when not in use). When the cover is opened, and the container is held upside down with the dispensing aperture facing down, the container can be squeezed to force the product through the dispensing apertures of the liner and closure.
A problem arises when forming a dispensing aperture through a thickness direction of the heat seal liner, namely the act of cutting (e.g., punching) an aperture (hole) through the liner typically exposes a cut side edge of the metal foil layer to the product being dispensed through the liner aperture. This exposure of the metal layer to the product being dispensed, especially with a product that is acidic (e.g., ketchup) or oil-based (e.g., mayonnaise or salad dressing), may compromise the ability of the metal layer to function as an effective heat seal and/or barrier liner due to foil corrosion and subsequent loss of performance, e.g., foil seal layer delamination and/or loss of the liner/finish heat seal bond. The present invention provides a liner that avoids this exposure and thus eliminates this problem.
B. Dual-Seal Liner
In accordance with the present embodiment, a dual-seal liner structure is provided to seal over the exposed inner (cut) side edge of a dispensing aperture in the liner (i.e., surrounding the liner aperture) while also heat seal bonding the liner to both the closure cap and container to provide a non-removable closure assembly. One embodiment of the dual-seal liner 70 (shown in
A disc-shaped, two component liner body 70 is shown in
In accordance with the present embodiment, the two component liner 70 comprises two substantially planar ring-shaped components, each having a central aperture, and stacked vertically one above the other in the liner thickness direction LT (also aligned with a longitudinal container axis CA) as follows: 1) a ring-shaped lower liner component 80 (LLC); and 2) a ring-shaped upper liner component 90 (ULC), both configured to lie in an area A1 between a closure sealing surface 27 and the TSS 38 surrounding the open mouth of the container (see
The inner circular side 93e edge that forms (surrounds) the central aperture 93 in the upper liner component 90, includes an inner edge 94e of the inductive heating layer 94 that may be contacted by (exposed to) the product being dispensed through the lower liner aperture 83 and into the area of the upper liner aperture 93. This can be detrimental to the layer integrity of the upper liner component and/or the inductive heating layer 94 itself (typically Al foil). To solve this problem, a top surface area of the LLC is bonded to the interior (bottom) surface 27 of the top wall TW of the closure cap 21 so as to cover the exposed side edge 94e of the inductive heating layer 94, while allowing the heat seal layers 92, 82 to bond to the closure sealing surface 27 and TSS 38 respectively, thus forming a non-removable closure assembly 5 between the liner 70, closure 20 and container 10. More specifically (see
C. Container and Closure
This particular container is intended for use in commercial establishments, e.g. restaurants, and is designed to provide a substantially non-removable closure assembly. This enables the product manufacturer to deliver a product filled container to the retail establishment (restaurant) and prevents any person (e.g., restaurant employee) from refilling the container with additional product. In this embodiment, the force required to remove the closure assembly is sufficiently high that the closure cannot be manually removed (by hand). Furthermore, if a mechanical element (tool) is used by an employee in an attempt to remove the closure, e.g., a long thin instrument such as a knife, the difficulty in accessing the heat seal bonded areas between the closure and finish and the respective boding strengths of the liner to the container finish and closure are such that the bottle and/or closure will be substantially deformed so as to be rendered unusable (if the employee is successful in removing the closure). Most likely the container will be crushed or buckle and thus rendered unacceptable for further use in a commercial establishment. Similarly, if the employee tries to use a wrench to separate (rotate) the closure with respect to the container finish, the closure and/or container with be crushed, buckled or otherwise deformed (rendered unusable for its intended purpose) in the process of trying to break the inductive heat seal bonds between the liner, closure and container finish.
The container 10 has an open mouth or finish portion 11 (shown generally in phantom lines in
The container finish 11 (shown in
D. Container, Closure and Liner Assembly
A non-removable closure assembly can be constructed, from the liner, closure and container previously described, in accordance with one embodiment of the invention as follows.
As described above, inductive heat seal bonding areas are provided on the liner in an area A1 between a container TSS and an inner top wall 27 of the closure cap to form the non-removable closure assembly (
As best shown in
the dual-seal liner comprising a disc-shaped body 70 having opposing top 73 and bottom 74 surfaces and a peripheral edge 72 extending in a liner thickness direction LT between the top and bottom surfaces;
the dual-seal liner comprising an upper liner component ULC 90 stacked, in the thickness direction, above a lower liner component LLC 80,
the dual-seal liner configured to form both heat seal A1 and conductive A2 bonding areas to a cap 20 and container 10 as follows:
wherein the respective mating heat inductive seal bonding areas A and A′, B and B′, C and C′ are aligned in the thickness direction with the TSS and are configured to form a non-removable closure assembly by inductive heat seal bonding of the TSS 38, the liner 70 and the inner top wall 27 of the cap; and further
the LLC top surface 81 having a conductive heat bonding area D, disposed between the LLC dispensing aperture 83 and the area B′, for bonding to a mating conductive bonding area D′ on the inner top wall 27 of the cap, the area D′ being disposed between a cap dispensing aperture 25 in the top wall of the cap and the ULC dispensing aperture 93 thus allowing a product to be dispensed through the liner and cap dispensing apertures 83, 93 and 25 of the non-removable closure assembly without exposing the dispensing product to the ULC.
The area A′ is disposed between the cap dispensing aperture 25 and a sidewall 28 of the cap, to prevent leakage of the product being dispensed through the liner and cap apertures 83, 93, 25 of the non-removable closure assembly.
The ULC 90 is ring (donut) shaped with a central through-hole 93 formed by an edge 93e extending in the thickness direction LT between top 92 and bottom 91 surfaces of the ULC, the through-hole 93 forming the ULC dispensing aperture and the mating bonding areas D, D′ being disposed radially inwardly of the edge 93e in a direction transverse to the liner thickness direction LT.
The ULC 90 includes an inductive heating layer 94 for heating one or more of the heat seal bonding areas, and the inductive heating layer extends to the edge 93e of the through-hole 93.
The ULC comprises upper 92 and lower 91 ULC layers having areas A and B respectively, with the inductive heating layer 94 lying between the upper and lower ULC layers for heating one or more of the mating heat seal bonding areas A and A′, B and B′, and C and C′.
The inductive heating layer 94 may be configured for heating all of the heat seal bonding areas A and A′, B and B′, and C and C′.
The ULC and LLC are each ring (donut) shaped with a central through-hole of each forming the respective LLC and LLC dispensing apertures, and wherein and the ULC through-hole 93 has a diameter ULD that is larger than a diameter LLD of the LLC through-hole. In one embodiment the ULC through-hole 93 has a diameter in a range of 2 to 5 times larger than a diameter LLD of the LLC through-hole 83. The diameter of the ULC through-hole may be in a range of +/−20% of a diameter of the cap dispensing aperture 25.
In another embodiment, the LLC dispensing aperture 83S is in the form of a slit extending in a thickness direction through the LLC.
The liner may have a peripheral edge 72 that is substantially equal in diameter to a peripheral edge TSSD of the TSS (see
The heat seal bonding areas may comprise polymer materials that bond in a temperature range of from 60 to 210 degrees Celsius (140 to 410 degrees Fahrenheit).
The polymer materials of the heat seal bonding areas may comprise one or more of polyolefin, polyester, and nylon materials.
The heat seal bonding areas B and B′ may be polyolefin materials, such as polypropylene materials.
The heat seal bonding areas C and C′ may be polyester materials, such as polyethylene terephthalate (PET) materials.
A method of forming a non-removable closure assembly is shown in
There has thus been described an embodiment of the present invention comprising a inductive heat seal bonding mechanism for preventing reverse (loosening) rotation of the closure by application of manual force. The amount of force required to overcome the bonding is sufficiently high that the closure cannot be manually removed. In one embodiment, the bonding of the closure, the two component liner and the TSS of the container renders the assembly non-removable by hand, optionally able to withstand a torque of at least 50 inch-pounds (in-lbs) (e.g., for a 33 millimeter (mm) diameter container finish), optionally able to withstand a torque of at least 70 in-lbs (e.g., for a 38 mm diameter container finish), without loss of the heat seal bonds or distortion of the closure or container finish.
In one embodiment, if a user attempts to deform the container or closure either manually or with a tool in order to gain access to the bonding areas, such efforts are substantially thwarted by providing the inductive bonding areas A and A′, B and B′, C and C′ radially inwardly of the inner skirt 28 of the closure 20. Because this inner skirt 28 is radially (laterally) inwardly disposed with respect to the outer skirt 21, and also of a lesser height, simple insertion of a knife beneath the lower edge of the outer skirt will not be sufficient to engage or disrupt the bonding areas. Generally, the structural integrity of each of the closure and container will be such that any successful effort to reach the bonding areas and overcome the bonding force will substantially deform either the closure or container (or both) such that they will be rendered unusable.
In alternative embodiments, the placement of the bonding areas and the structural configuration of the various components and the materials thereof can be varied to suit a particular application. Also, the number of thread segments can be varied. Preferably there are at least two thread segments which are preferably diametrically opposed, so that the forces between the closure and finish are evenly distributed around the circumference of the closure and finish. Preferably, the thread segments have overlapping ends for greater engagement of the closure and finish thread segments.
The material used for the closure and finish will depend upon the particular application. In the present embodiment, the closure is made of polypropylene, and the container is made from bottle grade polyethylene terephthalate (PET) resin. The container is made from an injection molded preform, the body portion of which is blow molded to form the container body. The finish has an outer diameter of 33 mm, a wall thickness (upper portion 32) of 0.088 inch, and a thread diameter (T dimension) of 1.255 inch; the sidewall thickness of the container is about 0.63 mm. The closure in the present embodiment is injection molded. The closure has an inside wall diameter of about 33 mm, a wall thickness of 0.045 inch, a thread diameter on the inside wall (E dimension) of 1.224 inch, and a thread diameter (TD dimension) of 1.280 inch. For greater rigidity, both the finish and closure can be injection molded from PET. Preferred ranges for the finish and closure are:
a) for the finish:
b) for the closure:
The container body (sidewall or weakest area) would typically have a wall thickness of 0.015-0.080 inch.
In alternative embodiments, the container and/or finish may be extrusion molded or compression molded. The finish may also be blow molded or otherwise expanded after the initial molding step.
There are various advantages to providing a substantially non-removable and substantially non-rotatable closure and finish assembly. One benefit is to provide security to the customer that the product has not been tampered with. A second benefit is an improvement of the mechanical seal between the top sealing surface and the closure, which prevents leakage. One or more of these advantages may be useful in a particular application.
These and other modifications would be readily apparent to the skilled person as included within the scope of the described invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6378715 | Finkelstein et al. | Apr 2002 | B1 |
| 7648764 | Yousif | Jan 2010 | B2 |
| 7900789 | Johnston | Mar 2011 | B2 |
| 8080118 | Yousif | Dec 2011 | B2 |
| 8863991 | Cleary | Oct 2014 | B2 |
| 20120132609 | Cleary | May 2012 | A1 |
| Number | Date | Country |
|---|---|---|
| 20667955 | Nov 2017 | CN |
| 2018200662 | Nov 2018 | WO |
| Entry |
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| International Search Report and Written Opinion in corresponding international application PCT/US2019/062539 dated Apr. 3, 2020. |
| Number | Date | Country | |
|---|---|---|---|
| 20200165044 A1 | May 2020 | US |
