EP0690011B1 - Floating metallic insert for a beverage container - Google Patents

Abstract

The insert consists of a chamber (3) with a hole (12) in its base which floats on the surface of the liquid. The insert is made from metal in the shape of a body with a skirt and a base (10) with a hole, fitted to the body with an annular seal. The edge of the body is turned over so that neither it, nor the edge of the base, comes into contact with the drink. The diameter of the rolled edge of the insert is between 1 and 4 mm with a skirt thickness of under 0.35 mm, and resists an inner pressure of over 0.6 MPa. The insert is made from aluminium or an aluminium alloy, and the hole in its base is equipped with a non-return valve in the form of a flexible strip held in place by adhesive. <IMAGE>

Description

FIELD OF THE INVENTION

The invention relates to the field of packaging of carbonated or carbonated drinks in easy-to-open packaging, typically beverage cans.
The pressure in these packages is generally higher than atmospheric pressure, and upon opening, bubbles are released and possible foaming.
The invention relates to an insert to be introduced into the beverage can during packaging of said beverage and intended to promote, by ejection of gas from the insert into said beverage, the formation of foam when opening said beverage can, especially when said drink is beer.

STATE OF THE ART

We already know, for this purpose, floating inserts. Such floating insert is described in Figure 2 of the application for WO 91/07326. It consists of an enclosure, in plastic material, ballasted with a weight orientating said pregnant with respect to the liquid plane of said drink, and comprising a single opening, located below the line flotation, by which, when opening the box, the gas contained in the insert is injected into said drink.

The operation of such an insert is as follows: the opening has closing means sensitive to the difference of pressure between the internal pressure (in the insert) and the external pressure (in the container). This means can be a rupture disc or valve that releases the gaseous content of the insert as soon as, when opening the container, the pressure drops inside of it.

In this type of insert, made of plastic, the deformation of the plastic insert during heat treatments, for example pasteurization, allow internal and external pressures to be balanced.
Furthermore, it is known that the inserts can operate with, as a closure means, an orifice of small dimensions (<0.5 mm in diameter).

Also known from document WO-A-94 04433 is an insert metal to be introduced into a container which must contain a pressurized drink intended to promote the formation of foam. This insert, positioned in said container, is provided an orifice, and can be formed by assembling a body box and cover, a peripheral seal ensuring the tightness of said assembly and positioned so as to prevent contact between said drink and the slices of said box body and said cover. the preambles of the claims 1 and 9 are based on this state of the art.

PROBLEMS POSED

a) d'une part, il est essentiel que l'insert flottant reste toujours correctement orient par rapport à ladite boisson, sinon, il y a un risque que l'insert ne puisse plus jouer totalement son rôle comme propulseur de gaz au sein de ladite boisson lors de l'ouverture de la boíte boisson.

b) d'autre part, il est indispensable que l'insert soit totalement neutre vis à vis de ladite boisson, c'est à dire qu'il n'y ait pas d'altération sensible des propriétés organoleptiques de ladite boisson, ni de migration de produits ou éléments chimiques de l'insert vers ladite boisson ou inversement de ladite boisson vers l'insert (extraction d'arôme).

c) par ailleurs, il importe que l'insert ne complique pas le recyclage dedit récipient (boíte boisson) contenant un insert par rapport à celui de la boíte boisson seule.

d) enfin, il est non moins essentiel que l'insert soit d'un coût de fabrication minime, le développement industriel et commercial des inserts étant en grande partie lié à cette question du prix de revient des inserts.

Floating inserts are much more convenient to use than those which use any assembly intended to precisely position the insert inside said container.
However, the known floating inserts pose problems of several kinds:

a) on the one hand, it is essential that the floating insert always remains correctly oriented with respect to said drink, otherwise, there is a risk that the insert can no longer fully play its role as a gas propellant within said drink when opening the drink box.

b) on the other hand, it is essential that the insert is completely neutral with respect to said drink, that is to say that there is no significant alteration of the organoleptic properties of said drink, nor of migration of products or chemical elements from the insert to said drink or vice versa from said drink to the insert (aroma extraction).

c) moreover, it is important that the insert does not complicate the recycling of said container (drink box) containing an insert compared to that of the drink box alone.

d) finally, it is no less essential that the insert be of minimal manufacturing cost, the industrial and commercial development of the inserts being largely linked to this question of the cost price of the inserts.

The applicant has developed inserts which meet totally to these four objectives, and which present, by compared to the inserts of the prior art, significant progress on all of the plans considered, and in particular on the recyclability plan for the whole "container plus" insert ", and in terms of manufacturing cost.

DESCRIPTION OF THE INVENTION

The insert according to the invention is defined by the characteristics of claim 1.

The Applicant first had the idea of a floating metal insert (MFI for short) designed so as to reduce its manufacture to an assembly of parts in themselves simple to manufacture, whether it is the body of box or cover intended to form said metallic enclosure.
She was surprised to note that despite the use of a metallic material, it was possible, also using inexpensive means which are easy to implement industrially, to maintain the migration of metallic ions at the - below the admitted threshold.

DESCRIPTION OF THE FIGURES

All the figures relate to the invention.
Figure 1 is a sectional view of a drink box (18) with easy opening, filled with a drink (19) on the surface (25) of which floats said metallic insert IMF (1), formed by assembling a box body (3) and a converge (10), said box body being essentially surrounded by the head space (20), said cover, provided with a lower orifice (12) of small diameter, being immersed in said drink, and generally below the liquid level (25).

Figure 2 shows said cover (10), round, in a sectional view along a plane containing the axis of symmetry of the cover.
This cover (10) has an edge (11) intended for assembly with said box body (3), a re-entrant peripheral part (13) and a central part (14) forming a bowl and carrying said lower orifice (12) of 0.3 mm in diameter, intended for the passage of the gas flow during the opening of said container (18).

Figure 3 shows a box body (3) round according to the invention intended to be assembled in a sealed manner with the cover of Figure 2 (sectional view along a plane containing the axis of symmetry of the box body).
This box body (3) consists of a bottom (4), a side skirt (5) having, a short distance from the end (6) of the skirt, a shoulder (8), surmounted by a portion of skirt (26) of low relative height, and on which said edge (11) of the cover (10) is intended to bear during the assembly of said cover (10) and said box body (3), via a peripheral seal (15).

Figure 4 is an enlarged view, in section similar to that Figures 2 and 3, the assembly of the cover (10) and the box body (3): the edge (11) of the cover is pinched between the rolled edge (9) obtained by rolling the end (6) of the skirt (5), and the shoulder (8) coated with a seal (15), so that the edge edge (21) and the edge (23) of the end of the box body are embedded in the material constituting the seal (15).

FIG. 5 represents a sectional view of an MFI constituted by the metal enclosure (2) formed by assembling the body of box (3) and cover (10), the method of assembly being that shown enlarged in Figure 4. On this figure are indicated different dimensions of the enclosure (2) : the large diameter D, the small diameter d, and the height H.

Figures 6 and 6a, similar to Figure 4, illustrate other means of subtracting the slices (21,23) from contact with said drink, that is, in FIG. 6, in inserting a peripheral seal (15) between the edge of the cover (11) and the rolled edge (9), that is, in FIG. 6a, by masking the edge (23) of the box body by rolling more accentuated from the end (6) of the skirt (5).

Figures 7a and 7b show an alternative assembly by crimping said box body and said cover, by rolling the curved edge (11a) of said cover around the edge dropped (6a) from said box body, curved edge externally and carrying a seal ring (15), so as to ensure, after crimping, the tightness of said assembly, and to drown in minus the edge (21) of the edge of said cover (10), as well as the edge (23) of the end of the box body.

FIG. 8a, similar to FIG. 1, shows in section a MFI according to the invention comprising a lower orifice (12) and an upper orifice (7), each of these orifices, with a diameter of the order of 1 to 3mm, being provided with a non-return valve, referenced (17) for the lower orifice (12), and (16) for the upper orifice (7).
FIG. 8b shows an example of a non-return valve, comprising a flexible strip (27) fixed by an adhesive (28) on the outside of the cover, so as to allow the exit of the gas flow from the insert to said drink. On the other hand, the non-return valve (16) of the upper orifice (7) is fixed to the inner surface of the bottom (4), so as to allow only one flow inlet from the head space towards the inside the insert.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention, said peripheral seal (15) can be positioned in different ways depending on the type of assembly, so as to prevent contact between said drink (19) and the edges (23,21) of said box body and said cover.

According to a first method of assembly, said assembly is formed by pinching the edge (11) of said cover (10) between a shoulder (8) of said side skirt (5) and a rolled edge internally (9) from said end (6) of said skirt (5).

In this case, as shown in Figure 4, said seal peripheral (15) adheres to the inner face of said shoulder (8) and of the skirt portion (26) between said shoulder (8) and said end (6), so that said slices (21,23) of said cover and of said body box are embedded in said seal (15).

As shown in Figure 6, said peripheral seal (15) can also form a tight bead between said edge of the cover (11) and said internally rolled edge (9).
In this case, the sections (21,23) are not embedded in the joint as in the previous case.

FIG. 6a represents a variant of FIG. 4, where only the edge (21) of the cover is embedded in the joint, while the edge (23) of the rolled edge (9) is not, taking into account the rolling more important in this case.
The rolled edge (9) must have a diameter between 1 mm and 4 mm, for a skirt end of thickness less than 0.35, so as to withstand a relative internal pressure greater than 0.6 MPa.
In fact, when the container is opened, there suddenly develops a large pressure difference on either side of the metal enclosure (2) forming the MFI, which can cause the rolled edge to "unwind" ( 9), and consequently the ineffectiveness of said insert.

According to a second method of assembly shown in Figures 7a and 7b, said assembly is formed by crimping the edge (11a) of the cover with the end of said skirt forming an edge fallen (6a), said peripheral seal (15) adhering to the outer surface of said fallen edge (6a), so that, at least said edge (21) of said cover is embedded in said joint.

To strengthen the certainty of always having an MFI (1) with adequate orientation, it is preferable to have an MFI (1) in which the section of said insert is, at its largest diameter D or D '(see Figures 5, 6, 6a, 7b), at least 15% greater than the section of said insert at said bottom.
Another complementary means contributing to making the orientation of the MFI (1) more reliable, consists in choosing the weight of the cover (10) at least equal to 0.5 times that of the box body (3).
For that, it is enough to start from a thicker metal strip to make the cover than to make the box body.
This reinforces the "tilting" effect of the MFI, in the sense that the MFI always tends to regain its optimum orientation, whatever the efforts exerted tending to tilt it sideways.

The Applicant has studied the impact of the shape of the cover on the stability of the MFI, in particular during the opening of said container.
The Applicant has observed that the shape of the cover could also make a contribution to the solution of the problem posed.
Following his observations, it is preferable that said cover comprises a re-entrant peripheral part (13) intended to facilitate centering of said cover (10) relative to said side skirt (5).
For unclear reasons, a cover as described above has led to more stable and better oriented MFIs - that is to say MFIs always repositioning themselves in the desired way ("tumble effect") - than those obtained, for example, with a cover comprising a flat central part.
It is possible that the reentrant peripheral part (13) plays a stabilizing role by the liquid ring formed trapped under said reentrant peripheral part (13).
The Applicant has observed that this preferred configuration of cover very greatly reduces the tendency of prior art MFIs to "take off" when the container (18) is opened by the propellant effect of the gas jet leaving the MFI. . According to a hypothesis put forward by the applicant, the re-entrant peripheral part (13) would lead to a "suction cup" effect tending to "join" - perhaps by wetting effect and surface tension - the base of the MFI and its element surrounding liquid.
In addition, the re-entrant peripheral part (13) of the cover also appears advantageous to facilitate the assembly of the cover (10) with the box body (3) and the centering of one relative to the other, centering which contributes to guarantee a good orientation of the MFI.
In addition, in the case of the configuration shown in Figures 4 and 6a, this re-entrant peripheral part (13) allows, by pressing against the shoulder (8) during assembly of the cover and the box body, to make obligatorily creep the seal (15) upwards, and thus to drown in the seal (15) at least the edge (21) of the cover, if not the edge (23) of the rolled edge (9).

The MFI according to the invention can also have two orifices, a lower orifice (12) on the cover (10), and an upper orifice (7) on the bottom (4) of the box body (3). In this case, as shown in Figures 8a and 8b, these orifices are provided with non-return valves. FIG. 8b represents a typical non-return valve, made of inert elastomeric material.
These valves are mounted so as to close said orifices only in one direction, with respect to said metal enclosure: in the "outside ->inside" direction for the upper non-return valve (16), in the "inside -> outside direction. "for the lower non-return valve (17).

Such a device permanently ensures the balance of internal and external pressures (= head space pressure (20)) of the MFI, avoids filling the MFI with said drink, while allowing the MFI to play its full role when opening said container.
The upper (16) and lower (17) valves can be either identical or different, each of them being adapted to its own environment (head space or drink).
Other non-return valve configurations are possible according to the invention insofar as they allow the aims of the invention to be achieved.

According to the invention, said metal enclosure (2) is in aluminum or aluminum alloy, or steel, and is coated a protective layer, usually a layer of varnish or sometimes a layer of plastic film, forming a barrier for said drink.

Generally, the same metal is chosen for the MFI (1) and for the container (18), which can therefore be made of aluminum or an alloy aluminum, or steel.

According to the invention, said metal enclosure is, preferably aluminum or aluminum alloy.

The interior volume of said metal enclosure (2) is related to the capacity of said container (18), and is preferably between 0.005 and 0.02 times the interior volume of said container.
Thus, by way of example, said insert has an interior volume of 7 cm ³ (volume between 6.8 and 7.2 cm ³ ) for an interior volume of said container of 500 cm ³ .

Preferably, said box body (3) and said cover (10) adapted to said box body, therefore said final MFI, are round in shape, for reasons of ease of manufacture and of MFI orientation stability, and said MFI presents a height H / outside diameter D ratio measured at level of said rolled edge, or of the largest diameter, between 0.4 and 1. See Figure 5.

Another object of the invention is a method for manufacturing the MFIs according to the invention.
This method comprises the steps as defined in claim 9.

To assemble said cover (10) and said body (3), it is advantageously possible to roll said edge internally while pressing against said cover, so that, in particular thanks to the elasticity of said seal, the edge of the box body does not damage, during the rolling phase, said protective layer covering said cover.
In addition, in order to facilitate said support, a die can support said shoulder during the interior rolling of said edge.

EXAMPLE OF IMPLEMENTATION

1) On a fabriqué des corps de boíte (3), comme représenté à la figure 2, avec les dimensions portées sur la figure 3, par emboutissage de bande métallique en alliage d'aluminium de 0,21 mm d'épaisseur.
On a adapté un dispositif, utilisé pour le dépôt de joint à la périphérie des couvercles, pour déposer, sur l'épaulement (8) du corps de boíte, un joint (15), analogue au joint standard des couvercles de boíte boisson, et selon un profil de joint comme représenté sur la figure 2.

2) On a fabriqué des couvercles (10), comme représenté à la figure 2, avec les dimensions portées sur la figure 1, par emboutissage de bande métallique en alliage d'aluminium de 0,50 mm d'épaisseur. On a percé un orificé (12) de 0,3 mm de diamètre.

3) On a obtenu les IMF finals en assemblant les corps de boíte et les couvercles, à l'aide d'une sertisseuse modifiée de manière à former un bord roulé (9) comme représenté à la figure 5.

Figures 1 to 8b show non-limiting examples according to the invention.
The example of MFI shown in Figures 1 to 5 is carried out as follows:

1) We made box bodies (3), as shown in Figure 2, with the dimensions shown in Figure 3, by stamping metal strip of aluminum alloy 0.21 mm thick.
A device has been adapted, used for depositing a seal at the periphery of the lids, for depositing, on the shoulder (8) of the can body, a seal (15), analogous to the standard seal for beverage can lids, and according to a joint profile as shown in Figure 2.

2) Lids (10) were made, as shown in FIG. 2, with the dimensions shown in FIG. 1, by stamping of metal strip of aluminum alloy 0.50 mm thick. A hole (12) 0.3 mm in diameter was drilled.

3) The final MFIs were obtained by assembling the box bodies and the covers, using a modified crimper so as to form a rolled edge (9) as shown in Figure 5.

Results obtained:

The MFIs obtained were tested using two methods.

On the one hand, they were tested in drink cans (easy-open cans) of 500 cm ³ capacity. For this, they were first introduced into beverage cans during the packaging of beer, then subjected to the standard pasteurization treatment.
The effect of MFIs was then evaluated, by a person skilled in the art of brewing, when opening drink cans, by the quality of the foam obtained (finesse, persistence ...). This effect was deemed completely satisfactory by this skilled person.
On the other hand, to visualize the behavior of MFIs with regard to the problem of the stability of their orientation, MFIs were tested and observed using a device comprising a transparent container, similar to a container (18 ), and containing an IMF (1), this container can be oriented in all directions and can simulate the various situations (shock, pasteurization, opening of the can, etc.) to which the beverage canisters are subjected.
It was observed that the MFIs according to the invention had a remarkable "tumble" effect, great orientation stability, including, which is important, when opening the box.
It is thanks to this type of device that the configuration and the dimensions of the MFIs according to the invention have been selected, numerous tests having been carried out before arriving at the general and particular means of the invention.

Furthermore, analyzes of the aluminum content in the beer have shown that the protection of the slices (21,23) of the edge of the cover and box body allowed to decrease considerably the metal ion content in said drink. It is possible to further reduce this content, either by protecting, in a manner known per se, and typically by a varnish, the edge of said orifice (12), either in using valves (17) which protect the edges from holes, as shown in Figure 8b.

ADVANTAGES OF THE INVENTION

The invention makes it possible to solve all of the problems posed, whether it is the technical efficiency of the MFI, its chemical inertia during a prolonged stay in said drink, or its manufacturing cost greatly reduced by compared to the inserts of the prior art.

Furthermore, the production of MFIs only requires manufacturers' standard technology, requiring only stamping tools adapted to the shape of the box body and the cover of the metal enclosure, this which is another advantage of the invention.

An additional advantage of the invention lies in the choice metallic material constituting the main part of MFIs. In effect, the drink boxes being generally recycled, especially when made of aluminum alloy, the use of MFIs in the same metal or alloy as that of the beverage can allows on the one hand to exclude practically any risk of corrosion by electrochemical cell effect between the two materials, and above all facilitates the recycling of metal from the set "drink box + insert".

Claims (11)

1. Metallic insert (1) to be inserted in a receptacle (18) that will contain a pressurized drink (19) on top of which there is a head space (20) which, when the said receptacle is opened, will encourage the formation of foam on the surface of the said drink, comprising a chamber (2) in which there is at least one lower orifice (12) designed to remain below the surface of the liquid (25) in the said drink, enabling gas to be transferred from the said chamber (2) to the said drink (19), the said chamber (2) being metallic and formed by assembly of a can body (3) and composed of a bottom (4) and a side skirt (5), the end (6) of which forms the opening of the said can body, and a cover (10) so as to close the opening of the said can body with the said cover, characterized in that,

   a) the said cover (10) is fitted with the said lower orifice (12), the weight of the cover (10) being chosen to be at least equal to 0.5 times the weight of the body of the can (3), so that the insert, which is designed to float, is correctly oriented with the head at the bottom,

   b) a peripheral seal (15) sealing the said assembly, is positioned so as to prevent contact between the said drink (19) and the edges (23, 21) of the said body of the can and the said cover, the said assembly being formed either by the edge (11) of the said cover being trapped between a shoulder (8) of the said side skirt and an edge rolled on the inside (9) of the said end (6) of the said skirt, either by crimping the edge of the cover (11a) with the end of the said skirt forming a dropped edge (6a), the said seal (15) adhering to the outside surface of the said dropped edge (6a), so that at least the said edge of the said cover (21) is embedded in the said seal.
2. Insert according to claim 1, in which the said peripheral seal (15) adheres to the inner surface of the said shoulder (8) and the portion of the skirt (26) between the said shoulder and the said end, so that the said edges (21, 23) of the said cover and the said body of the can are embedded in the said seal (15).
3. Insert according to claim 1, in which the said seal (15) forms a tight strip between the said edge (11) of the cover and the said edge rolled on the inside (9).
4. Insert according to any one of claims 1 to 3, in which the diameter of the said rolled edge (9) is between 1 mm and 4 mm for a skirt end with a thickness of less than 0.35 mm, in order to resist an internal relative pressure of more than 0.6 MPa.
5. Insert according to any one of claims 1 to 4 in which the section of the said insert (1), at its largest diameter D or D', is at least 15% larger than the cross-section of the said insert at the said bottom.
6. Insert according to any one of claims 1 to 5, in which the said cover (10) comprises a re-entrant peripheral part (13) designed to facilitate centering of the said cover (10) with respect to the said side skirt (5).
7. Insert according to any one of claims 1 to 6, in which the weight of the cover (10) is chosen to be at least 0.5 times the weight of the can body (3) using a metal strip thicker than the metal strip used to make the can body, to make the said cover.
8. Insert according to any one of claims 1 to 7, in which the said metallic chamber (2) is made of aluminum or an aluminum alloy.
9. Process for manufacturing an insert according to any one of claims 1 to 8 comprising the following steps:

   a) a can body (3) is formed by stamping from strip metal coated with a protective layer, the can body presenting a side skirt and a shoulder (8) between two portions of the skirt, and a cover (10) equipped with an orifice (12) and an edge (11) adapted to the said body of the can (3), the thickness of the said metal strip to be used to form the said cover (10) being greater than the thickness of the said metal strip used to form the said can body (3),

   b) the said cover (10) and the said body are assembled, by trapping the edge of the said cover between the shoulder of the said side skirt and an edge rolled on the inside of the end of the skirt, so that the edges (21, 23) of the said cover and the said can body are protected by the said seal and cannot come into contact with the drink, through a seal placed on the shoulder of the can body or on the cover edge.
10. Process according to claim 9 in which, in step b) of the said process, the said edge is rolled on the inside while applying pressure against the said cover (10) such that, due particularly to the elasticity of the said seal (15), the said protective layer covering the sid cover (10) is not domaged by the the edge (23) of the can body during the rolling phase.
11. Process according to claim 11 in which a matrix supports the said shoulder during internal rolling of the said edge, to facilitate the said support.

Images