WO1999005041A1

WO1999005041A1 - Sealing and tamper-proof element for container

Info

Publication number: WO1999005041A1
Application number: PCT/IB1998/001115
Authority: WO
Inventors: Armand Wagner
Original assignee: Lynes Holding S.A.
Priority date: 1997-07-25
Filing date: 1998-07-21
Publication date: 1999-02-04
Also published as: CA2297840A1; DE69806011T2; ATE219011T1; DE69806011D1; LU90111B1; EP0998415A1; ES2178840T3; AU8125498A; EP0998415B1; BR9810797A

Abstract

The invention concerns a combined sealing and tamper-proof element for container (R) whereof the opening (A) is capable of being closed by a lid (C), characterised in that it comprises, in a single piece: a removable inner seal (1) whereof the inner surface is designed to be tightly sealed on the opening (A) rim and the top surface bears a strip (10) forming a prehensile tab; and a joint (2) designed to be maintained in said lid (C) and whereof the bottom surface adheres to the inner seal (1) top surface at least in the zones unoccupied by said strip (10) with a linking force less than the forces maintaining the joint (2) in the lid (C) and the inner seal (1) on the opening (A) rim respectively.

Description

Sealing and tamper-evident element for container

The present invention relates to a combined sealing and inviolability element for containers and more particularly for those whose opening is intended to be closed by a cover as well as a method for manufacturing such an element.

There are already many technical solutions to jointly ensure the tightness and inviolability of a container.

Among these solutions, heat-sealed lids are widely used, in particular in the field of food products.

These lids are sometimes associated with complementary sealing means such as seals arranged inside the cover which is intended to cover the upper part of the container.

These covers can also be provided with gripping means such as tabs generally formed by parts of the cover itself as described in EP 395 660, EP 460 096 and EP 534 949.

However, the presence of these tabs prohibits any possibility of even temporary connection between the upper face of the cover and the seal of the cover.

However, such a connection is necessary to strengthen the inviolability and simplify the manufacturing process insofar as it makes it possible to produce the sealing and inviolability element in one piece.

The present invention aims to solve the above technical problems, on the one hand, by producing the gripping tab in the form of a tape attached to the cover, and on the other hand, by creating a temporary connection around said tongue between said cover and the cover gasket.

This object is achieved, in accordance with the invention, by means of a combined sealing and inviolability element for a container, the opening of which can be closed by a cover, characterized in that it comprises, in one piece: a removable cover, the lower face of which is intended to be sealed or glued in a leaktight manner to the edge of the opening and the upper face of which carries a ribbon forming a gripping tab, and a seal intended to be retained in said cover and the lower face of which adheres to the upper face of the cover at least in the areas left free by said strip with a bonding force less than the forces respectively retaining the seal in the cover and the seal on the edge of the opening.

According to an advantageous characteristic, said strip comprises a longitudinal fold forming an elastic hinge and delimiting, on the one hand, a fixed part integral with the upper face of the cover, and, on the other hand, a movable part folded parallel to said fixed part by pressing the seal.

Preferably, said movable upper part of the ribbon is linked to the seal in a separable manner.

According to a variant, the fixed and mobile parts are of equal widths. According to a particular embodiment, said strip extends diametrically over the upper face of the cover.

According to a variant, said ribbon comprises at least two layers.

In this case, the lower layer of the tape is preferably secured to the upper face of the cover and separably linked to the lower face of the seal.

For example, the lower layer is made of polyethylene and the upper layer of polyethylene terephthalate (PET) or polyester.

According to another embodiment, said cover comprises at least two layers.

According to a variant, said cover comprises a lower sealing layer, a metallic interlayer and an upper layer.

Preferably, said upper layer is formed of at least two sublayers, a lower sublayer compatible with the metal layer and an upper sublayer compatible with the ribbon.

According to yet another embodiment, said seal comprises at least two layers. According to a variant, said seal comprises a lower layer separably linked to the tape and to the cover, a layer expanded intermediate and an upper layer disposed opposite the bottom of the cover.

According to another variant, the lower and upper layers of the joint are each formed of two sub-layers. For example, the lower layer of the joint is made of polyethylene terephthalate or polyamide and the intermediate layer is made of a polyolefin foam.

Preferably, said seal has a symmetrical structure.

According to a specific embodiment, the weak connection between the lower face of the seal and the upper face of the cover is mainly of mechanical origin.

Another object of the invention is a method of manufacturing said element, characterized in that the upper layer of the cover is produced by hot extrusion, then the tape is fixed and the seal is applied to said hot upper layer, trapping said strip, so as to create, after cooling, a weak bond between the seal and the cover.

The invention makes it possible to ensure a reinforced tightness and inviolability of the container because the seal and the cover are assembled to form a single hermetic part.

The constituent layers of the cover and of the seal are, for their part, firmly fixed to one another.

Thus, when the cover is released, the seal and the cover are easily separated without causing delamination of one or the other or any deterioration of their interface or of the tongue.

Once the cover is released, the detachment of the cover is also carried out without delamination or tearing by means of the gripping tab.

Furthermore, the production of a single element for inviolability and sealing makes it possible to simplify the capping and packaging operations.

The invention will be better understood on reading which follows, accompanied by the drawings in which:

- Figure 1 shows a sectional view of the element of the invention; - Figure 2 shows a perspective view of the element of the invention after release of the cover.

The element E shown in Figure 1 is intended to jointly seal and inviolability of a container R (apparent in Figure 2) whose opening A is closable by a cover or a plug C.

Element E comprises the combination of a cover 1 and a seal 2, in one piece.

The underside of the cover 1 is intended to be glued or sealed in a leaktight manner on the rim of the opening A of the container R and its upper face carries a strip 10 forming a gripping tab.

The cover 1 is, for example, heat sealed in a known manner by high frequency induction.

The seal 2 is intended, for its part, to be housed in the cover C provided for this purpose. The retention of the seal is ensured, for example, by means of a peripheral ring produced on the internal wall of the cover and behind which the seal is blocked at least in part. According to the invention, the lower face of the seal 2 adheres easily separable to the upper face of the cover 1 at least in the areas left free by the tape 10.

The bonding force between the underside of the seal 2 and the upper face of the cover 1 is determined so that it is less, on the one hand, than the forces ensuring the retention of the seal 2 in its housing, and on the other hand, the resistance to tearing of the seal 1 on the rim of the opening A of the container R. Preferably, this bonding force is such that any movement of the cover C, and in particular of the seal 2 relative to the container R, causes the immediate separation of the seal and the cover 1. Such a weak bond is preferably obtained by extruding or coextruding at high temperature (melting temperature of the materials) the upper layer of the cover 1 then by fixing the tape 10 and then quickly applying the seal 2 to the upper layer of the cover thus formed, trapping the tape 10.

When applying the seal 2, the upper layer extruded from the cover is still hot enough to at least partially maintain a state favorable to adhesion. The lack of chemical compatibility which is more or less pronounced between the constituent materials respectively of the lower layer of the seal 2 and of the upper layer of the seal 1, then ensures, after cooling, a weak bond, mainly of mechanical origin ( by vacuum or suction effect). Thus, the higher the degree of compatibility between the materials in contact, the greater the bonding force between the seal and the lid because the chemical bonds, which are the strongest, are more numerous.

The ribbon 10 comprises a longitudinal fold 100 forming an elastic hinge and delimiting, on the one hand, a fixed part 10a secured to the upper face of the cover 1, and, on the other hand, a mobile part 10b, folded parallel to the lower part 10a by pressing the seal 2. The fixed 10a and mobile 10b parts are preferably of equal widths as shown in FIG. 1, and extend diametrically on the upper face of the cover 1 here of circular outline.

The movable part 10b of the tape 10 which is folded flat on the fixed part 10a is optionally linked to the underside of the seal 2 by an adhesion phenomenon similar to that which relates to the areas of the upper face of the seal 1 adjacent to the fixed part 10a of the ribbon.

In this case, the release of the cover, at the first opening of the container, contributes to the lifting of the movable part, which facilitates its subsequent gripping.

However, the internal faces facing the fixed 10a and movable 10b parts of the strip 10 which are in contact in the folded state, are never linked to each other to allow the hinge 100 to act by action elastic deployment of the movable part 10b upwards after separation of the seal 2.

When the ribbon 10 comprises at least two layers 101, 102; the lower layer 101 is firmly fixed to the upper face of the cover 1 and the layer 101 is free or separably bonded to the lower face of the seal 2. By the adhesion phenomenon described above, on the 'folded state of the ribbon 10, the upper layer 102 is disposed inside the fold, between the fixed parts 10a and mobile 10b. The lower layer 101 is made, for example, of polyethylene while the upper layer 102 is made of polyethylene terephthalate (PET) so as to avoid any phenomenon of adhesion between the fixed parts 10a and mobile 10b.

The cover 1 comprises at least two layers and, preferably, three layers according to the embodiment of FIG. 1. These three layers consist, from bottom to top, of a lower sealing layer 11 on the edge of the opening A, an intermediate metal layer 12, for example aluminum and an upper layer 13.

The upper layer 13 is formed of at least two sublayers 131,132.

The lower sublayer 131 is compatible with the metal of layer 12 and the upper sublayer 132 is compatible with the lower layer 101 of the tape 10.

The layers 11, 12, 131, 132 and 101 are joined together in a firm and definitive manner, for example, by extrusion or coextrusion of surface coatings taken by heat sealing so as to obtain a sufficiently strong bond to avoid delamination during the separation of the cover 1 by pulling on the movable part 10b of the ribbon 10 forming a gripping tab. Where appropriate, the bonding forces between, on the one hand, the lower layer 11 and the edge of the opening A, and on the other hand, the lower layer 11 and the intermediate layer 12 will be determined one with respect to to the other to produce a partial delamination of the lower layer 11 when the cover 1 is torn off. This partial delamination is intended to leave, at the first opening, a peripheral portion of the lower layer 11 on the edge of the opening, after tearing off the cover 1, as a seal and tamper-proof indicator.

The joint 2 comprises one or more layers and, preferably at least two layers as in the embodiment of Figure 1, with three layers 21, 22, 23 defining a symmetrical structure.

The upper layer 21 is arranged opposite the bottom of the cover C, possibly being fixed by gluing or any other means.

The intermediate layer 22 is expanded and has a thickness much greater than the other two layers 21, 23. This layer is made, for example, with a cellular material such as a polyolefin foam.

The lower layer 23 is separably linked, on the one hand to the movable part 10b of the ribbon 10, and, on the other hand, to the upper face of the sublayer 132 of the cover 1. The upper layer 21 and the lower layer 23 of the joint 2 are each formed from two sublayers 211, 212 and 231, 232.

The lower layer 23 and, if appropriate, the upper layer 21 are made of polyethylene terephthalate or polyamide. According to a variant, the extreme layers have very small thicknesses and are, for example, made of films

Thus, the ribbon 10 is temporarily closed in the folded state between the cover 1 and the seal 2.

When using the container for the first time, the consumer removes the cover C as shown in FIG. 2.

This action has the effect of separating the seal 2 from the cover 1 by releasing the movable part 10b of the tape 10 which can then pivot upwards to come into a position substantially perpendicular to the common plane of the fixed part 10a and the 'operculum 1. Then by pulling on the part 10b, the consumer separates the operculum 1 from the rim of the container 1 to release the opening A.

Various embodiments are given below by way of nonlimiting examples with the following list and nomenclature:

PET = polyethylene terephthalate or polyester

PA = polyamide

PVC = polyvinyl chloride

PVDC = polyvinylidene chloride

PE = polyethylene PP = polypropylene

PO = Polyolefin

* The upper layer (13 or 132) is produced by extruding a material or coextruding several materials taken, for example, from the above list, alone or in alloys. Example 1

Example 2

Example 3

Example 4

Example 5

Claims

1. Combined sealing and inviolability element for container (R), the opening (A) of which can be closed by a cover (C), characterized in that it comprises, in one piece:

- a removable cover (1), the lower face of which is intended to be sealed in a sealed manner on the edge of the opening (A) and the upper face of which carries a strip (10) forming a gripping tab, and - a seal ( 2) intended to be retained in said cover (C) and the lower face of which adheres to the upper face of the cover (1) at least in the areas left free by said strip (10) with a bonding force less than the forces retaining respectively the seal (2) in the cover (C) and the cover (1) on the edge of the opening (A).

2. Element according to claim 1, characterized in that said strip (10) comprises a longitudinal fold (100) forming an elastic hinge and delimiting, on the one hand, a fixed part (10a) integral with the upper face of the cover (1), and, on the other hand, a movable part (10b) folded parallel to said fixed part (10a) by pressing the seal (2).

3. Element according to claim 2, characterized in that said movable upper part (10b) of the tape (10) is linked to the seal (2) in a separable manner.

4. Element according to claim 2 or 3, characterized in that the fixed (10a) and mobile (10b) parts are of equal widths.

5. Element according to one of the preceding claims, characterized in that said strip (10) extends diametrically on the upper face of the cover (1).

6. Element according to one of the preceding claims, characterized in that said strip (10) comprises at least two layers (101,102).

7. Element according to claim 6, characterized in that the lower layer (101) of the tape (10) is integral with the upper face of the cover (1) and separably linked to the lower face of the seal (2) .

8. Element according to claim 6 or 7, characterized in that the lower layer (101) is made of polyethylene and the upper layer of polyethylene terephthalate (PET).

9. Element according to one of the preceding claims, characterized in that said cover (1) comprises at least two layers (11, 12, 13).

10. Element according to claim 9, characterized in that said cover comprises a lower sealing layer (11), a metallic interlayer (12) and an upper layer (13).

11. Element according to claim 10, characterized in that said upper layer (13) is formed of at least two sublayers (131,132), a lower sublayer (131) compatible with the metallic layer (12) and a sub - upper layer (132) compatible with the ribbon (10).

12. Element according to one of the preceding claims, characterized in that said seal (2) comprises at least two layers (21, 22, 23).

13. Element according to claim 13, characterized in that said seal (2) comprises a lower layer (23) separably linked to the tape (10) and to the cover (1), an intermediate layer (22) expanded and a upper layer (21) disposed opposite the bottom of the cover (C).

14. Element according to claim 13, characterized in that the lower (23) and upper (24) layers of the seal (2) are each formed of two sub-layers (231,232) and (211,212).

15. Element according to claim 13 or 14, characterized in that the lower layer (23) of the seal is made of polyethylene terephthalate or polyamide.

16. Element according to claim 13 or 15, characterized in that the intermediate layer (22) is made with a polyolefin foam.

17. Element according to one of the preceding claims, characterized in that said seal (2) has a symmetrical structure.

18. Element according to one of the preceding claims, characterized in that the weak connection between the underside of the seal (2) and the upper face of the cover (1) is mainly of mechanical origin.

19. Method for manufacturing an element according to one of claims 1 to 18, characterized in that the upper layer of the cover (1) is produced by hot extrusion and then the seal (1) is applied to said hot upper layer, by trapping said previously fixed ribbon, so as to create, after cooling, a weak bond between the seal (2) and the cover (1).