GB2037718A

GB2037718A - Sealing means for receptacles having removable caps

Info

Publication number: GB2037718A
Application number: GB7937565A
Authority: GB
Original assignee: Manufacture Generale de Joints SAS
Current assignee: Manufacture Generale de Joints SAS
Priority date: 1978-12-18
Filing date: 1979-10-30
Publication date: 1980-07-16
Also published as: CH631936A5; FR2444863A1; DE7931374U1; FR2444863B1; GB2037718B

Abstract

Sealing means 2 in a cap comprises a plurality of superimposed layers, starting from the base of the cap and moving outwards, a resilient foam layer 4 of synthetic material, e.g., polyethylene, a stiffening layer 5, e.g. of flat card, and a thin sealing layer 6, e.g., a vinyl film or coating, so that even after the first opening the sealing means efficiently seals a cap on a receptacle. A sealing and security cover 14, in the form of a pellicular assembly incorporating aluminium foil may be bonded temporarily by paraffin wax 13 to the sealing layer 6. <IMAGE>

Description

SPECIFICATION Sealing means for receptacles having removable caps The present invention relates to sealing means for receptacles having removable caps, notably for receptacles containing foodstuffs in powder or granular form.

Numerous foodstuffs in powder or granular form are conserved in pots, jars or bottles which are closed by means of a removable cap. A pellicular cover is usually provided which adheres to the rim of the receptacle mouth, preventing leakages and keeping the contents inaccessible. Thus, until the receptacle is first used the sealing problem is overcome by the presence of this cover.

In the base of the cap there is mounted a packing comprising a layer of corrugated card whose outer face is smooth towards the receptacle and coated with paraffin wax.

From the practical viewpoint, the pellicular assembly adheres to the waxed face of the packing, before the receptacle is initially closed.

The rim of the receptacle mouth is coated with a thin film of adhesive. When the cap is put into place, the pellicular assembly adheres to the rim of the receptacle, so that when a user removes the cap the packing remains in the base of the cap whereas the pellicular assembly tears away from the packing and remains bonded to the rim of the receptable. To gain access to the contents, the user destroys the pellicular assembly. Once this pellicular assembly has been destroyed, the problem arises of closing the receptacle in a leakproof manner. The user effects its closure by replacing the cap with a screw or snap action, depending on circumstances. Nevertheless, it is impossible to re-establish satisfactory sealing, since the waxed card is not sufficiently impemeable to moisture and, once it has been torn, the portion fitting over the rim of the receptacle loses some of its resilience.It is possible to combat the second problem in the case of screw-on caps by slightly increasing the closure torque, but this remedy cannot be applied in the case of snap-on caps. Faulty sealing can lead to a deterioration of the contents not used immediately after the receptacle is first opened, particularly when it is stored in humid places, such as the majority of kitchens. For example, the residual contents of jars of soluble coffee frequently become unusable by reason of their agglomeration orcaramelisation if held in stock for a substantial period after first opening.

The present invention relates to sealing means designed to overcome these disadvantages.

According to the present invention the sealing means comprises, a plurality of superimposed layers, starting from the base of the cap and moving outwards, a foam layer of synthetic material, a stiffening layer, and a thin sealing layer.

The layer of synthetic material resting on the base of the cap gives the sealing means a high resilience, so that it always maintains contact with the rim of the receptacle mouth, even after repeatedly opening and closing, the resilience of the material preventing any collapse in the region of the contact zone.

The stiffening layer incorporated in the sealing means ensures that it remains firmly inside the cap, which is provided for this purpose with a rib of spurs behind which the sealing means is engaged.

Moreover, the stiffening layer distributes the force exerted on the foam layer by the rim of the receptacle bounding the closure mouth, thereby preventing local deformations in the foam of sufficient magnitude to remain irreversible.

The sealing layer ensures that the conserved product is properly protected from moisture and that its aroma is properly conserved. The conserved products thus retain all their qualities while in stock, even after the receptacle has been initially opened.

The foam layer is preferably made in polyethylene, the stiffening layer in flat card and the sealing layer consists of a vinyl film or coating.

In cases where the sealing means of the invention must be associated with a pellicular assembly bonded to the rim of the receptacle and adapted to ensure freedom from leakage and inaccessibility prior to the first opening, the sealing barrier is coated with a small amount of paraffin wax, sufficient to bond the assembly in place before the cap is initially added. It should be pointed out that the amount of paraffin wax used need not be large, since it is not intended to take part in the sealing action after the first opening of the receptacle.

While the sealing means of the invention can be adapted to a wide range of applications, it becomes particularly useful in association with a cap held on a receptacle by a snap-on action.

Every aspect of the invention will be readily understandable by referring to the following description of the accompanying diagrammatic drawings which show, by way of nonlimiting example, one embodiment of the sealing means of the invention, and in which drawings: Figure 1 is a diagrammatic cross-section of sealing means of the invention, assembled in the base of a cap mounted on a receptacle; and Figure 2 is a fragmentary exploded cross-section, on a larger scale, showing the various components of the sealing means.

The sealing means 2 shown in the drawings comprises, starting from the base of a cap 3 and moving outwards, a layer 4 of polyethylene foam, a layer 5 of plain card and a layer 6 consisting of a vinyl film or coating. The polyethylene layer gives the sealing means resilience, the card 5 mechanical strength and the layer 6 the sealing action of the closure.

As shown in Figure 1, the sealing means 2 is engaged behind ribs 7 which hold it in the base of the cap 3. Near its outer rim, the cap has a rib 8 projecting radially inwards and adapted to engage in a groove 9 on the neck 10 of a receptacle 12, so as to close the latter by snapping on the cap.

When the receptacle must be fitted with a sealing and security cover, in the form of a pellicular assembly incorporating aluminium foil and adapted to fit over the rim of the neck 10, the sealing layer 6 is coated with a layer 13 of paraffin wax to bond the sealing and security cover 14temporarily in position, until the receptacle is initially closed, during which operation the cover 14 is brought into contact with the previously adhesive-coated rim of the receptacle mouth.

The present invention effects a major improvement to the known art, by providing sealing means which efficiently seals the closures on receptacles even after the first opening, thereby preventing the deterioration of conserved products and offering the further advantage that receptacles can be re-used for the conservation of further products, which in the foodstuffs world can include jams cherries in syrup and so on .... as produced by housewives.

It is self-evident that the invention is not limited to the single embodiment described above by way of example; on the contrary, it covers every alternative embodiment.

It is also noteworthy that the layer of foamed synthetic material could be formed by spotwelding or depositing strips of synthetic material which is subsequently treated to bring about the foaming reaction.

Claims

1. Sealing means for receptacles having removable caps, comprising a plurality of superimposed layers, starting from the base of the cap and moving outwards, a foam layer of synthetic material, a stiffening layer, and a thin sealing layer.

2. Sealing means as in Claim 1, wherein the foam layer is made in polyethylene.

3. Sealing means as in either of Claims 1 and 2, wherein the stiffening layer is made in flat card.

4. Sealing means as in any one of Claims 1 to 3, wherein the sealing layer consists of a vinyl film or coating.

5. Sealing means as in any one of Claims 1 to 4, wherein the outer face of the sealing layer is coated with paraffin wax adapted to secure an assembly having an aluminium foil.

6. A receptacle having a snap-on cap with sea ling means as in any one of the preceding claims.

7. Sealing means for receptacles having remov able caps, the sealing means being substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.

8. A receptacle having a snap-on cap with sea ling means substantially as hereinbefore described with reference to the accompanying drawings.