EP3204307B1

EP3204307B1 - Tamper evident lid and method of making same

Info

Publication number: EP3204307B1
Application number: EP14903692.3A
Authority: EP
Inventors: Stephen Hugh Witt
Original assignee: Stanpac Inc
Current assignee: Stanpac Inc
Priority date: 2014-10-07
Filing date: 2014-12-12
Publication date: 2021-09-22
Anticipated expiration: 2034-12-12
Also published as: WO2016054720A1; AU2017232086A1; EP3204307A4; BR112017006979A2; AU2017232086B2; CL2017000376A1; AU2014408671B2; CA2963825C; PE20170614A1; ES2900854T3; EP3204307A1; AU2014408671A1; BR112017006979B1; CO2017003463A2; CA2963825A1; US20170305615A1; DK3204307T3; CR20170126A; MX2017004377A

Description

FIELD OF THE INVENTION

The invention relates generally to lids for containers and particularly to tamper-resistant, tamper-evident lids for containers for products that present significant concerns for the consumer about unauthorized tampering with the product (e.g. food products and other consumables). The invention relates in particular to a closure according to the preamble of claim 1, to a closure member according to the preamble of claim 10, to a system for forming a tamper resistant push-on closure according to claim 11, to a mould for forming a closure, and to methods of moulding a closure.

BACKGROUND OF THE INVENTION

In the ice cream packaging industry, a variety of closure arrangements are used to hold a paperboard, plastic or composite lid in place on the paperboard container or tub holding the ice cream. Examples include U.S. Patent No. 6,772,901 (Witt ), U.S. Patent No. 7,703,626 (Witt ), and U.S. Patent No. 6,053,353 (Helms ).
Previous solutions involve complex processes for incorporating a paperboard top within a closure. For example, U.S. Patent No. 6,772,901 (to the present inventor Witt) describes that a paper top is peripherally sealed to a downwardly-recessed annular ridge of a plastic rim by induction heating, ultrasonic welding or spin welding. U.S. Patent No. 6,772,901 (to the present inventor Witt) describes that in the alternative, the paper top may be sealed to the annular ridge by applying a coating of adhesive to either side of the face surfaces prior to insertion of the paper lid. U.S. Patent No. 7,703,626 (to the present inventor Witt) describes the pre-assembly heating of the closure components with directed hot air to partially melt the thermoplastic surfaces and allow the parts to be immediately assembled sealingly, and describes a paperboard composite closure in which the plastic rim is of a two-piece snap-fit construction where the paperboard is compressed between first and second annular flanges of the two-piece plastic rim.
It is of great and increasing importance that the consumer, at the point of purchase of a product, be confident that the package that he or she intends to purchase has not been compromised. If there is a problem with the packaging which cannot be spotted until the consumer opens it for use, he or she may well never purchase that product again and consumer confidence is reduced generally.
WO2010053462A1 discloses storage boxes, enabling the preservation of foodstuffs against external environmental conditions, a comprising a main body having a cavity with a closed bottom part and an open top part, a lid which covers the top opening of the said main body and radial surfaces formed on the brim edges of the said main body; characterized in that, it comprises a lid lock-notch which ensures that the lid is locked onto the body every time after the bottom ring is broken during first use and the sealing notch which hold the said main body from the radial surfaces and the internal surface. US20010015341A1 discloses a tamper evident closure.

SUMMARY OF THE INVENTION

There is provided a tamper resistant push-on closure according to claim 1, a tamper resistant push-on closure member according to claim 10, a system for forming a tamper resistant push-on closure according to claim 11, a mould for forming a tamper resistant push-on closure or closure member according to claim 13, a method of moulding a tamper resistant push-on closure according to claim 14, and a method of moulding a tamper resistant push-on closure member according to claim 15.
The container closure (lid) can be used to resist and make readily detectable tampering of the products at the point of sale. Particular examples include dairy products, cosmetics, granular or powdered food products such as tubs for bread crumbs, hardware product tubs for screws, nuts and bolts, and so on.
The tamper-resistant tamper-evident container closure may be provided for ice cream, dairy and other food products that are commercially practical and provides the level of tamper evidence needed for food safety.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will be made, by way of example, to the accompany drawings which show example embodiments of the present application, and in which:

FIG. 1 is a plan view of the top of an example closure; and
FIG. 2 is a cross-sectional view of another example closure, with a plastic top cover panel;
FIG. 3 is a cross-sectional portion view of the example closure of FIG. 2;
FIG. 4A is a perspective view of the example closure of FIG. 1 with a container;
FIG. 4B is a perspective view of the example closure of FIG. 1 attached to a container;
FIG. 5 is a outer side view of the example closure of FIG. 1;
FIG. 6A is a cross-sectional view of a further example closure with a container;
FIG. 6B is a cross-sectional portion view of the example closure of FIG. 6A with a container;
FIG. 7A is a cross-sectional view of the example closure of FIG. 6A attached to a container; and
FIG. 7B is a cross-sectional portion view of the example closure of FIG. 6B attached to a container.

DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 shows an example closure 10 in accordance with the present disclosure. The closure 10 is a snap-on closure such as a lid, and may be suitable for use to close an opening of a food container such as a plastic or paperboard container (e.g., an ice cream container). The closure 10 of FIG. 1 has a top cover panel 20 and may be manufactured using a molding process, as described further below.
As shown in FIG. 2, the closure 10 may include a top cover panel 20, a top cylindrical band portion 30 with upper and lower margins 30a and 30b, respectively, and a bottom cylindrical band portion 40 with upper and lower peripheral margins 40a and 40b, respectively. The top cylindrical band portion 30 and the bottom cylindrical band portion 40 are integrally formed and connected, and these portions 30, 40 as a single unit may be referred to in the application as the cylindrical closure portion (closure member) 15. The top cylindrical band portion 30 and the bottom cylindrical band portion 40 are connected by a line of weakness 50 as described below.
As shown in FIGS. 2 and 3, at the top peripheral margin 30a the top cylindrical band portion 30 has a top cover panel 20 that is recessed from the outer side of the top cylindrical band portion 30 and extends upwardly and inwardly. Beneath the top cover panel 20, the closure 10 provides an annular ledge 18.
As shown in FIG. 1, the top cover panel 20 may consist of a paper disk or the like that may be printed on its upper side for product identification, marketing information, graphics etc. Particularly for use with ice-cream and food products, the cover panel 20 will have a polymer layer attached to the underside for keeping moisture from the product from entering through the paper. In the embodiment illustrated in FIGS. 6A, 6B, 7A and 7B, the top cover panel 20 is continuous with the annular ledge 18.
As shown in FIG. 2, the bottom cylindrical band portion 40 has a plurality of circumferentially spaced tamper evident tooth systems 70 (may also be referred to herein as tamper resistant teeth). Extending upwardly and inwardly from the lower peripheral margin 40b of the bottom cylindrical band 40 at the plurality of tamper evident tooth system 70 are a plurality of circumferentially spaced teeth 60. The plurality of teeth 60 lock under the rim of the container when the closure 10 is first pushed downwardly to seal the container. The plurality of teeth 60 act as a tamper resistant mechanism on the closure 10.
As shown in FIG. 2, the plurality of teeth 60 may include notches 64, 66 located at the right and left sides of a top edge 62 of the teeth 60. The notches 64,66 may further facilitate the locking engagement of the plurality of teeth 60 of the rim of the container.
As shown in FIGS. 3 and 4B, for each tamper evident tooth system 70, between the plurality of teeth 60 and the lower peripheral edge 30b of the top cylindrical band portion 30 is an open space. Each tamper evident tooth system 70 further has a plurality of projections 72 that connect the plurality of teeth 60 to the bottom peripheral area 30b of the top cylindrical band portion 30. The plurality of projections 72 may be seen when viewing the outer side of the closure 10, providing an effective means for determining if the closure 10 has been tampered with. Additionally, the plurality of projections 72 may function to increase the force of engagement of the plurality of teeth 60 against the lip of the container.
As shown in FIGS. 2 and 3, along the inner side of each tamper evident tooth system 70 there are two or more projections 76 that are connected to the bottom of the plurality of teeth 60 and to the lower peripheral margin 40b of the bottom cylindrical band portion 40. The projections 76 may provide additional rigidity to the plurality of teeth 60 and also may assist in increasing the force of engagement of the plurality of teeth 60 against the lip of the container.
As shown in FIG. 2, the upper peripheral margin 40a of the bottom cylindrical band portion 40 is thinned and weakened. In the embodiments shown in FIGS. 2, 3, 4B, and 5, the line of weakness 50 includes one or more of a circumferential notch 52, the plurality of projections 72, and open spaces that are viewable from the outer side of the bottom cylindrical band portion 40. Legitimate opening of the container by a consumer starts by separating the top cylindrical band portion 30 from the bottom cylindrical band portion 40 by tearing away the bottom cylindrical band portion 40 along the line of weakness 50.
For convenience in legitimately opening the container, the bottom cylindrical band portion 40 is provided with a gripping means. In an embodiment, as shown in FIGS. 1, 4A, 4B and 5, the bottom cylindrical band 40 is formed with an accessible edge portion 45 disposed at a location along the outwardly facing surface. The accessible edge portion 45 may include projections or ridges on its outer surface that assist a user's ability to grip and hold the portion 45. By exerting moderate force on the accessible edge portion 45, the bottom cylindrical band portion 40 below the line of weakness 50 can be removed with the plurality of teeth 60 as a tear-away strip. That is, the line of weakness 50 is ruptured and the bottom cylindrical band portion 40 having the plurality of teeth 60 is easily removed from the closure 10 and from the container (not shown).
In some embodiments, as shown in FIGS. 3, 6A, 6B, 7A, and 7B, the closure 10 has a multi-snap closing. The inner surface 32 of the top cylindrical band portion 30 may have a plurality of continuous annular ridges 38 extending inwardly along the circumference of the inner surface 32. As shown in FIGS. 7A and 7B, the plurality of continuous annular ridges 38 provide multiple contact points against a paperboard or cardboard rim 102 of a container 100. As paperboard and cardboard rims are flexibly irregular, the plurality of continuous annular ridges 38 provide multiple places to contact the paperboard rim 102, thereby improving the seal of the closure 10 on the container 100. As well, when the bottom cylindrical band portion 40 has been removed, the plurality of continuous annular ridges 38 provide an improved mechanism for resealing the container 100.
The top cylindrical band 30 and the bottom cylindrical band 40 of the closure 10 may be manufactured by a one-piece molding process, such as injection-molding, using a single mold. This one-step process may help to simplify manufacturing and/or reduce manufacturing costs. The closure 10 may be molded using any suitable polymer, for example any suitable food-grade plastic when used as a closure for a food container (e.g., used as a lid on a yogurt or ice cream container).
As well, in another embodiment, the cover panel 20 may be made of the same plastic material as the top cylindrical band portion 30 and the bottom cylindrical band portion 40. Accordingly, in this embodiment, the cover panel 20, the top cylindrical portion 30 and the bottom cylindrical portion 40 may be manufactured by a one-piece molding process, such as injection-molding, using a single mold.
The closure 10 of the present application has specific elements that facilitate the molding process. As shown in FIGS. 1 and 2, the closure 10 has one or more openings or gates 80 located on the upper peripheral portion 30a of the top cylindrical band portion 30. The gates 80 act as an opening for the plastic resin to enter a mold and fill the mold cavity.
As shown in FIGS. 3, 4B and 5, the upper peripheral portion 40a of the bottom cylindrical band portion 40 has multiple tooth channels that allow the plastic to flow into the tamper evident tooth system 70. The tamper evident tooth system 70 includes the plurality of teeth 60 that is formed on the bottom cylindrical band 40 and the plurality of projections 72. The plurality of projections 72 define and/or delineate the tooth channels in the corresponding mold. The tooth channels improve the process of filling the mold cavity and also increases the speed by which the tamper evident tooth system 70 that includes the plurality of teeth 60 and the projections 72 are formed. As well, the tooth channels reduce the amount of defects in the tamper evident tooth system 70. Also, the tooth channels further facilitate the creation of larger and thicker tamper resistant bands than conventional solutions, thereby increasing the rigidity of the plurality of teeth 60.
As shown in FIG. 2, the tamper evident tooth system 70 has edges 64, 66 that slope inwardly. In the embodiment shown in FIG. 1, 4, and 5, during the injection molding process, the cover panel 20 is inserted into the mold. The mold is filled with resin by injection. The resin covers the edge of the paper cover panel 20, creating the lid. The mold then collapses at the edges of the tamper evident tooth system 70 to facilitate the ejection of the part from the mold.
FIG. 4A illustrates the closure 10 with a container 100 and FIG. 4B illustrates the closure 10 attached to the container 100. In an embodiment as shown in FIGS. 4A and 4B, the cover panel 20 (e.g. a disc) is inserted into the mold and then plastic resin is molded around the top and bottom to hold it in place. In other embodiments, a coating of suitable adhesive may be applied to either of the outer edge of the facing surfaces prior to insertion of cover panel 20 onto the annular ledge 18 located on the bottom of the projection 34. Alternatively, heating, ultrasonic welding, or spin welding may be used. In another embodiment, the cover panel 20 is secured to the top cylindrical band 30, by the interference fit in recess 19. The cover panel 20 is secured to the cylindrical closure portion 15 prior to attaching the closure 10 to the container 100 (FIG. 4B). The closure 10 is attached to the container 100 by applying a downward force to the top to the closure 10 onto the top of the container 100. As previously discussed, the plurality of teeth 60 of the closure 10 lock under the rim of the container when the closure 10 is pushed downwardly to seal the container.
FIGS. 6A and 6B illustrate a further embodiment for incorporating the cover panel 20 into the cylindrical closure portion 15. As shown in FIGS. 6A and 6B, during assembly the cover panel 20 may be positioned above the container 100. For example, the cover panel 20 may be placed to sit and rest on the circumferential paperboard rim 102 of the container 100. As well, the cylindrical closure portion 15 is positioned above the cover panel 20. At this stage of assembly, the closure (i.e. cover panel 20 and cylindrical closure portion 15) has not yet been assembled, and the container 100 would contain a material or food product to be sealed.
To seal the container 100 with the cylindrical closure portion 15 and the cover panel 20, downward force is applied to attach the cylindrical closure portion 15 onto the cover panel 20 and the top of the container 100. As shown in FIGS. 7A and 7B, the cylindrical closure portion 15 snaps onto the paperboard rim 102 and in this process, the cover panel 20 is secured to the cylindrical closure portion 15, creating an assembled closure. For example, the cover panel 20 is pushed into position in the upper cylindrical band portion 30 and is secured within an annular recess 19 located along the inner circumference of the upper peripheral margin 30a of the top cylindrical band portion 30. In some embodiments, the cover panel 20 may also have an adhesive applied to its top circumference to further secure the cover panel 20 to annular ledge 18 of the top cylindrical band portion 30.
As shown in FIGS. 7A and 7B, the plurality of teeth 60 lock under the rim of the container when the closure 10 pushed downwardly to seal the container. As well, as shown in FIGS. 7A and 7B once the closure 10 is attached to the container 10, the plurality of continuous annular ridges 38 provide multiple contact points against the paperboard rim 102 of a container 100, providing an improved interference fit. This improves the seal of the closure 10 on the container 100. As well, when the bottom cylindrical band portion 40 has been removed, the plurality of continuous annular ridges 38 provide an improved mechanism for resealing the container 100.
In the embodiments shown in the figures, the lid is circular. In other embodiments, it is rectangular, oval, square, or other shapes.
Although particular embodiments of the invention have been illustrated and described herein, one of ordinary skill in the art will appreciate that changes or additions may be made to the design of the closure without departing from the scope of the invention, which is defined in the claims attached hereto. For example, a solid resilient band might be used on the tear-away strip portion of the closure instead of individual tamper-evident teeth. In lieu of paperboard, different flexible sheet materials might be used, according to the final intended application. The inside wall of the top cylindrical band could be formed with threads to adapt the closure for use on a threaded container.

Claims

A tamper resistant push-on closure (10) for a container (100) having an opening with a peripheral outwardly extending lip formation (102), the closure (10) comprising:
a top cover panel (20);

a top cylindrical band portion (30) having an upper peripheral margin (30a) extending from the top cover panel (20), and a lower peripheral margin (30b);

a bottom cylindrical band portion (40) having an upper peripheral margin (40a) and a lower peripheral margin (40b);

a rupturable line of weakness (50) between the lower peripheral margin (30b) of the top cylindrical band portion (30) and the upper peripheral margin (40a) of the bottom cylindrical band portion (40);

a plurality of rigid teeth (60) extending from the lower peripheral margin (40b) of the bottom cylindrical band portion (40) in an upward and inward direction for locking engagement against the lip (102) of the container when the closure member (10) is secured on the container (100); and
characterized in that the plurality of rigid teeth (60) are connected directly to the lower peripheral margin (30b) of the top cylindrical band portion (30) by a plurality of projections (72) for providing a visual tamper evident indication, for increasing the force of engagement of the plurality of teeth against the lip of the container, and for facilitating the flow of plastic resin through a plurality of tooth channels of a complementary mould during the production of the plurality of rigid teeth.
The closure according to claim 1, wherein the top cylindrical band portion (30) has a plurality of continuous annular ridges (38) extending inwardly along the circumference of an inner surface each of said ridges for contacting a side surface of the container (100) in an interference fit.
The closure according to claim 1 or claim 2, wherein a bottom of the plurality of teeth (60) are connected to the lower peripheral margin (40b) of the bottom cylindrical band portion (40) by a plurality of inwardly extending projections (76) for increasing the rigidity of the plurality of teeth and for increasing the force of engagement of the plurality of teeth against the lip of the container.
The closure according to any one of claims 1 to 3, wherein the top cylindrical band portion (30), the bottom cylindrical band portion (40), the rupturable line of weakness (50), the plurality of rigid teeth (60), and the plurality of projections (72) of the closure (10) are formed of plastic material in a single injection molding step.
The closure according to any one of claims 1 to 4, wherein the rupturable line of weakness (50) is an apex of a circumferential groove along an outer wall of the bottom cylindrical band portion (40).
The closure according to any one of claims 1 to 5, wherein an accessible edge portion (45) is formed in the bottom cylindrical band portion (40) to permit ready gripping and tearing a part of the bottom band below the line of weakness.
The closure according to any preceding claim, wherein the top cover panel comprises a pre-formed top cover panel (20), and wherein the top cylindrical band portion (30) comprises a recess (19), and the pre-formed top cover panel (20) is secured to the top cylindrical band portion (30) by an interference fit in the recess (19).
The closure according to any one of claims 1 to 6, wherein the top cover panel comprises a pre-formed top cover panel (20) that is held in place in the top cylindrical band portion (30) by plastic resin moulded around the edge of the pre-formed top cover panel (20) or moulded around the top and bottom of the pre-formed top cover panel (20).
The closure according to any one of claims 1 to 6, wherein the top cover panel comprises a moulded top cover panel (20), the top cylindrical band portion (30) and the bottom cylindrical band portion (40) are made of the same plastic resin by a one-piece moulding process.
A tamper resistant push-on closure member for forming a tamper resistant push-on closure (10) for a container (100) having an opening with a peripheral outwardly extending lip formation (102), the closure member (10) comprising:
a top cylindrical band portion (30) having an upper peripheral margin (30a) for receiving a pre-formed top cover panel (20), and a lower peripheral margin (30b);

a bottom cylindrical band portion (40) having an upper peripheral margin (40a) and a lower peripheral margin (40b);

a rupturable line of weakness (50) between the lower peripheral margin (30b) of the top cylindrical band portion (30) and the upper peripheral margin (40a) of the bottom cylindrical band portion (40);

a plurality of rigid teeth (60) extending from the lower peripheral margin (40b) of the bottom cylindrical band portion (40) in an upward and inward direction for locking engagement against the lip (102) of the container when the closure member (10) is secured on the container (100); and

wherein top cylindrical band portion (30) comprises a recess (19), and the top cylindrical band portion (30) is configured for the pre-formed top cover panel (20) to be pushed into the recess (19) during assembly of the top cylindrical band portion (30) onto the rim (102) of a container (100),

characterized in that the plurality of rigid teeth (60) are connected directly to the lower peripheral margin (30b) of the top cylindrical band portion (30) by a plurality of projections (72) for providing a visual tamper evident indication, for increasing the force of engagement of the plurality of teeth against the lip of the container, and for facilitating the flow of plastic resin through a plurality of tooth channels of a complementary mould during the production of the plurality of rigid teeth.
A system for forming a tamper resistant push-on closure (10) for a container (100) having an opening with a peripheral outwardly extending lip formation (102), comprising:
the closure member according to claim 10; and

a pre-formed top cover panel (20) configured to be received into the recess (19) of the closure member.
The closure of any one of claims 1 to 7 or the system of claim 11, wherein the top cover panel comprises a pre-formed top cover panel (20), and wherein adhesive is provided on a face of the pre-formed top cover panel (20) to secure the pre-formed top cover panel (20) to an annular ledge (18) of the top cylindrical band portion (30).
A mould for forming a tamper resistant push-on closure (10) for a container (100) according to any one of claims 1 to 9 and 11, or for forming a tamper resistant push-on closure member according to claim 10 or claim 12, the mould comprising:
a plurality of tooth channels positioned between the portions of the mould for forming the lower peripheral margin of the top cylindrical band portion and the upper peripheral margin of the bottom cylindrical band portion for facilitating the flow of plastic resin during the production of the plurality of rigid teeth to form a plurality of projections (72).
A method of moulding the tamper resistant push-on closure (10) for a container (100) according to any one of claims 1 to 6 and 8 to 9, the method comprising:
filling the mould with a resin to form the top cylindrical band portion (30), the bottom cylindrical band portion (40), the rupturable line of weakness (50), and the plurality of rigid teeth (60); and either
i. wherein the top cover panel comprises a pre-formed top cover panel (20), placing the pre-formed top cover panel (20) in the mould before filling the mould with resin; or

ii. wherein the top cover panel comprises a moulded top cover panel (20), filling the mould with resin additionally forms the moulded top cover panel (20) in a one-piece moulding process with the top cylindrical band portion (30), the bottom cylindrical band portion (40), the rupturable line of weakness (50), and the plurality of rigid teeth (60).
A method of moulding a tamper resistant push-on closure member according to claim 10, the method comprising:
filling the mould with a resin to form the top cylindrical band portion (30), the bottom cylindrical band portion (40), the rupturable line of weakness (50), and the plurality of rigid teeth (60).