GB2278591A - Container sealed with reusable one piece closure - Google Patents

Abstract

A one piece closure is sealed to a lip 12 of a container 2 to ensure that the goods, eg dairy products, held in the container are sealed therein and the closure is further provided with engagement means 21 to allow the same to be reapplied to the container after first use. The closure may be made of plastics material thereby allowing the detection of metal in the contents of the container. The plastics material may be two ply co-extruded PVC or polystyrene and coated with heat resistant varnish. The engagement means 21 may have indents (20, Figure 3) and the seal preferably allows the lid to be peeled off the container lip using a finger tab portion. The closure may be transparent and both the container and closure may be printed. <IMAGE>

Description

Improvements Relating to Container Closures The invention relates to an improvement in the form of closure provided on containers for holding typically, but not exclusively, dairy or perishable, foodstuffs. The closure is required to seal the contents within the container prior to the product being purchased from, for example, a supermarket, and also to provide a means whereby the said closure can be removed from the container to allow access to the contents and then be engagably replaceable to protect any remaining contents within the container to provide further storage of same and to prevent early deterioration in the contents.

Conventional containers for dairy or perishable foodstuffs typically are in the form of containers of plastics material provided with separate closures sealed thereto to enclose the mouth of the container and, where the contents are perishable, the closure comprises two parts namely a metallic foil part which is sealed around the peripheral top edge of the container to enclose the contents therein and a top, normally of plastics material which clips around a lip on the upper edge of the container and acts to enclose the metallic foil. There are several reasons for the provision of this two part closure assembly, one of which is the requirement for the contents to be securely sealed within the container prior to purchase.Thus the metallic foil, which is easily sealed to the upper rim of the container, is used to provide an air tight seal for the contents and to prevent damage or deterioration in the condition thereof. Also the sealed metallic foil is tamper evident in that it clearly indicates any attempt to gain access to the contents and the seal cannot be replaced to conceal any attempt to tamper with the contents. The plastics material top of the closure assembly is provided both to protect the metallic foil from being punctured during storage and prior to the seal being removed and secondly the top can be refitted to the container such that once the container has been opened and the foil removed the lid can still be used to enclose the remaining contents and to maintain the contents in the proper storage condition such that they can be used at a later date.

While this conventional two part closure assembly meets the requirements of the container manufacturers and the suppliers of the product, there are several disadvantages. Namely, use of both a foil lid and a plastics material lid represents overpackaging as, at any one time, only one part of the lid assembly is effective in storing the contents within the container. This overpackaging is expensive and furthermore is wasteful of resources. The use of a two part closure assembly increases material usage and the joining of the container with the closure assembly is more complicated and time consuming than necessary.A further problem is that the use of metal foil to close the container renders metal detection apparatus, which is typically used to detect metal objects within foodstuffs, ineffectual as the presence of the metal foil causes distortions and incorrect readings to be obtained by the metal detectors. Thus there is no effective method available whereby food contents which are placed within containers of this design can be checked for the existence of metal objects therein. This has led to several instances where metal objects have been found in the food and said objects can cause illness to the purchaser and consumer of the food and adverse publicity for the food manufacturer.

This problem has been appreciated in the industry and while several attempts have been made to provide a one piece closure which has the characteristics of the two piece closure assembly of the conventional container, it has not been possible, to date, to obtain a one piece closure which is sufficiently secure to allow widespread use of same in the market place.

One known lid utilises the stamping of perforations on the lid such that, once opened, the area which is sealed to the container remains on the container and a portion of the lid can be torn away around the perforations to effectively form a two part lid to allow the same to be removed and the contents removed. While this portion can be replaced it is inconvenient and requires additional fixing means to be provided in both the torn away portion and on the container thereby leading to the container becoming unnecessarily bulky and the manufacture of the lid requiring relatively complicated forming operations. Furthermore if the perforations are not properly formed the lid is required to be removed by breaking the seal and hence the same can not be reused thereafter.

The aim of the present invention is to provide a one piece container closure which can be used to seal contents within a container wherein said closure is capable of being sealed to the container and also, once removed, is further capable of being reapplied to the container to again enclose the contents remaining within the container. There is no need for a metallic foil to be used and hence the foodstuff within the container can be scanned for metallic objects while the closure of the invention will still be tamper evident.

The present invention provides a one piece closure for a container, said closure provided to close the container and to seal the contents therein; the closure is initially sealed to a lip of the container and the said closure is provided with engagement means for holding the closure on the container and such that, in first use, the seal is required to be broken to gain access to the container and the said closure is reusable to close the container by applying the closure such that the engagement means engage with the walls of the container.

Typically the closure is formed of plastics material. In one preferred embodiment the closure comprises at least a base of a first plastics material coated with a second plastics material and at least the base plastics material is capable of being sealed to the container. The seal provided between the closure and the plastics container is preferably of a form such that the closure is peelably removable from the container upon force being exerted on the closure.

Typically the closure is formed from a plastics sheet material wherein the plastics sheet is formed by the coextrusion of at least two plastics.

In a preferred embodiment the closure further comprises a layer -of heat resistant varnish applied to at least one surface thereof. Preferably the varnish is applied once the closure has been formed.

Preferably the closure is provided with a finger tab portion which, when the closure is fitted to the container, projects from the side of the container. The application of a lifting force to said tab away from the container by gripping the same creates a peeling movement of the closure to break the seal between the closure and the container.

Typically the closure is provided with engagement means in the form of a flange which provides an engagement fit in contact with the inner wall of the container to close the container. The flange is, in one embodiment, provided with a series of indents on the outer wall thereof to lie adjacent the inner wall of the container when fitted thereto. The provision of said indents improves the engaging fit between the flange and the container inner wall by causing air to be trapped therein and this trapped air creates a holding force to maintain the closure in a closing position in engagement with the container. Preferably the shape of the closure and the downwardly extending flange is of substantially similar shape to the mouth of the container.

Typically the closure is capable of being refitted to the container upon the breaking of the initial seal such that the closure is held in an engaged position relative to the container and requires a further removal force to be exerted thereon to remove the same from the container. The requirement for the closure to be replacable is to ensure that, if the user of the product does not wish to use all of the contents at one time, the contents remaining within the container can still be protected and stored adequately by the replacement of the closure.

As the closure and container of the invention are initially sealed, the closure is tamper evident in that any attempt to remove the closure requires the seal to be broken and this is clearly evident. The use of a plastics material for the closure allows metal detection apparatus to be used to scan the contents of the container and accurate readings to be obtained in relation to any metal objects within the contents. As there is no requirement to use metallic foil to seal the contents in the container there is no opportunity for any metal to be detected other than that which is incorrectly within the product.

The provision of a one piece closure increases the speed of packaging of the containers in that there is only required one application process for the application of the closure onto the container; said closure being sealed in place onto the container top in one operation if required. Typically the closure is sealed to an upwardly facing lip around the periphery of the container and the diameter of the closure is such that it matches the outer edge diameter of the lip.

In a further aspect of the invention the closure is capable of having printed matter applied thereto and in one embodiment the matter printed on the closure is similar to that which is printed around the sides of the container. The closure may also be manufactured from transparent material to allow viewing of the contents in the container through the closure.

In a further aspect of the invention there is provided a method of forming a one piece closure for use in sealing and closing a container comprising co-extruding two plastics material to form a two ply plastics sheet material, stamping out the form of the closure to match the shape of the container to be closed and forming engagement means and a sealing area on said closure to allow sealing and engagement of the closure with the container.

In a preferred embodiment the method further comprises the step of applying a coating of heat resistant varnish to the closure prior to the sealing of the same to the container.

A specific embodiment of the invention will now be described with reference to the accompanying drawings wherein: Figure 1 illustrates a container and closure of the invention; Figure 1A illustrates a cross sectional elevation through the centre of the container and closure of Figure 1; Figure 2 illustrates an elevation of a closure of the invention; and Figure 3 illustrates a bottom plan view of the closure of the invention.

Referring firstly to Figure 1 there is shown a container 2 and closure 4 of the invention. The container is provided with a central cavity (not shown) within which the contents are held; said contents being, for example, dairy products.

The container comprises a body portion 6, a base portion 8 and an upper lip portion 10. The closure 4 is formed of plastics material and is provided with a finger tab section 14.

The closure 4 is shown in greater detail in Figures 2 and 3 wherein the closure can be seen to comprise the finger tab 14, engagement means in the form of a downwardly facing flange 16, an outer rim 18 and a central portion 19. The downwardly facing flange 16 is of a shape to engagedly fit with the inner wall 21 of the container body as shown in Figure 1A at the opening thereon and is provided with a series of indents 20. The engagable fit acts to maintain the closure in position on the container and hence allows the closure to be replaced and to close the container when the seal between the closure and container has been broken.

The seal between the closure and container is formed between the upper face 12 of the lip of the container and the outer rim 18 of the closure. In the initial packaged condition the contents are held within the container by the closure 4 in a sealed closed position on the container 2. To gain access to the contents the exertion of an upward force on the closure by means of finger tab 14 acts to break the seal between the closure and container in such a manner that the closure can be peeled from the container to allow access to the contents.

Once the user has removed sufficient contents to meet their requirements it is possible to replace the closure onto the container and the said downwardly facing flange 16 acts to maintain the closure in a closed and engaged position relative to the container to protect and store the remaining contents securely.

The closure and container of the invention therefore provides a more attractive and easier to use closure means than the conventional metal foil and plastic two piece closure assemblies. The closure of the invention allows the container to be reusable and also for liquid contents to be sealed therein. The closure is tamper proof and allows the detection of any metal deposits in the contents of the container to be undertaken. The closure is further capable of being reused once the seal between the closure and container has been broken as the closure can be replaced in an engagement fit to reseal the contents within the container. However any attempt to illegitimately gain access to the contents before purchase of the product requires the seal between the closure and container to be broken and hence any tampering with the contents will be evident. The use of this closure allows an increased range of printing to be placed on top of the closure, such printing could be for the information of customers for storage and such like or quite simply further advertising of the product.

The closure can be made from plastics material of a type to allow the closure to be transparent so that the contents of the container can be viewed prior to purchase and a decision made as to whether or not to purchase the same based on the actual appearance of the contents.

When the closure is manufactured from two co extruded plastics materials to form a two ply sheet material from which the closures are stamped and subsequently formed by conventional moulding techniques. PVC and Polystyrene based materials are particularly suited to this use but any material which allow a seal to be formed between the closure and the container could be used and it is further beneficial to coat the closure with a heat resistant varnish such that, at least during the sealing of the closure to the container, the closure is prevented from sticking to the heat sealed die.

Claims (19)

1. A one piece closure for a container, said closure provided to close the container and to seal the contents therein; the closure is initially sealed to a lip of the container and the said closure is provided with engagement means for holding the closure on the container and such that, in first use, the seal is required to be broken to gain access to the container and the said closure is reusable to close the container by applying the closure such that the engagement means engage with the walls of the container.

2. A one piece closure according to Claim 1 wherein the closure is formed of plastics material.

3. A one piece closure according to Claim 2 wherein the closure comprises at least a base of a first plastics material coated with a second plastics material.

4. A one piece closure according to Claim 2 wherein the closure is formed of at least two plastics materials and the plastics are co-extruded to form a plastics sheet material from which the closure is formed.

5. A one piece closure according to claims 3 or 4 wherein the closure further includes a coating of heat resistant varnish.

6. A one piece closure according to any of Claims 3, 4 or 5 wherein at least the base layer of plastics material of the closure is capable of being sealed to the container.

7. A one piece closure according to any preceding claim wherein the seal between the closure and the container is such that the closure is peelably removable from the container upon the application of a lifting force thereon.

8. A one piece closure according to Claim 1 wherein the closure includes a finger tab portion which, when the closure is in engagement with the container, protrudes from the side of the container.

9. A one piece closure according to Claim 1 wherein the engagement means is in the form of a flange which engagingly fits in contact with the inner wall of the container.

10. A one piece closure according to Claim 9 wherein the flange extends downwardly from the closure and is provided with a series of indents around its outer wall, said indents lying adjacent to the inner wall of the container when fitted thereto.

11. A one piece closure according to any preceding claim wherein the closure is initially sealed to a lip of the container and is tamper evident in that to gain access to the contents of the container the seal is required to be broken.

12. A one piece closure according to any preceding claim wherein the closure is produced from a transparent plastics material to allow the contents of the container to be viewed therethrough.

13. A one piece closure according to any preceding claims wherein the closure has applied, to at least one surface thereof, printed matter.

14. A closure according to Claim 13 wherein the printed matter is similar to that printed around the sides of the container.

15. A method of using a one piece closure for a container according to any preceding claim wherein the closure is first provided in a sealed closing position on the container; peelably removing the closure, removing at least a quantity of the contents, replacing the closure to close the container by contacting the engagement means with the walls of the container.

16. A method of forming a one piece closure for use in sealing and closing a container comprising co-extruding two plastics materials to form a two ply plastics sheet material, stamping out the form of the closure to match the shape of the container to be closed and forming engagement means and a sealing area on said closure to allow sealing and engagement with the container.

17. A method of forming a one piece closure according to claim 16 wherein there is applied to the closure a layer of heat resistant varnish prior to sealing the same to the container.

18. A closure as in hereinbefore described with reference to the accompanying drawings.

19. A method of forming and using a closure for a container as hereinbefore described.