EP1693306A1 - Container comprising two compartments - Google Patents

Abstract

The container has compartments (20, 22) delimited between a base (10B) and a membrane (14) and between an opening (10C) and the membrane, respectively, where the membrane is fixed to a lateral wall (10A). The compartment (20) has a zone with a part reducing a volume of the compartment (20), when the part is deformed by a pressure, for generating an excessive pressure in the compartment (20) in order to subject the membrane to a stress.

Description

The present invention relates to a thermoformed container, comprising a body having a sidewall and a bottom opposed to an opening.

Containers of this type are known, in particular for containing pasty and / or liquid food products. In some cases, it is desired to package in the same container two different products, for example a small product such as a topping (fruit coulis, caramel ...) or granules (brown sugar, praline, chocolate flakes or caramel ...) and a larger product, such as yoghurt. In some cases, the products are mixed in the same container, which is often the case when the product in small quantity is a topping, which is arranged at the bottom of the container, while the product in greater quantity is arranged above. This is not always possible or desirable, especially when it is desired to maintain a crispness to the product in small amounts when it is in the form of granules or flakes. In this case, it is known to use containers having two juxtaposed compartments connected together by their respective upper flanges, by a connecting zone between these flanges which is breakable or foldable so as to allow mixing of the two products. These containers have had some commercial success, but their handling is not always easy and their packaging is subject to certain constraints since, in particular, it is difficult to package together several containers of this type.

The invention proposes a new container capable of containing two different products, substantially free of the aforementioned constraints.

FR 2,781,206 and DE-U-82 07 401 disclose a container of the aforementioned type, comprising a first compartment delimited between the bottom and a membrane, arranged inside the container and fixed to the side wall, and a second compartment, delimited between the membrane and the opening, these compartments each being able to contain a product.

Thanks to the presence of the membrane, the two compartments are initially isolated from each other and can therefore contain two different products, which we do not want to mix initially. This makes it possible to preserve for each product its intrinsic qualities (taste, texture, crunchiness ...) and mix them only when they are consumed. Insofar as the two compartments are formed inside the same body, the container can easily be handled and packaged with several containers of the same type, for example in groups of two, four or eight containers.

To consume the products contained in the container, one can empty the second compartment and pierce or break the membrane to mix with this product, the one that was contained in the first compartment.

Thus, FR 2 781 206 proposes (Figure 7) to equip the bottom of the container with a tip for perforating the membrane when sufficient pressure is exerted on the bottom of the container bottom.

This system is of a delicate implementation because, on the one hand, it is difficult to achieve this tip during thermoforming of the container and, on the other hand, the drilling of the membrane with this tip is uncertain .

DE-U-82 07 401 proposes to tear the membrane using two tongue portions accessible from the top of the container after the opening thereof.

This system is viable only if these tab portions are easily accessible from the top of the container, which requires that the separation of the container into two compartments by means of the membrane is itself located towards the top of the container. In addition, access to the tongue portions requires contact between the fingers of the user and the product contained in the upper compartment which, particularly when the product is pasty or viscous, is unpleasant and unhygienic.

The present invention aims to improve the state of the art by facilitating the breaking of the separation between the two compartments.

This object is achieved thanks to the fact that the body of the container has, in the region of the first compartment, a deformable portion capable of pressure, is deformed, to reduce the volume of this compartment to generate in the latter an overpressure which subjects the membrane to stresses provoking a rupture of this membrane and / or its attachment to the side wall.

The deformable part is in particular made in the region of the bottom of the container. In a manner known per se, it makes it possible to deform the wall of the receptacle in order to promote the demolding of the product contained in the latter. In the present case, a sufficient pressure on this deformable part makes it possible, on the one hand, to pour into a plate or the like the product initially contained in the second compartment and, by the rupture of the membrane or its attachment on the side wall to pour on this product the one contained in the first container.

Thus, the separation between the two compartments can be obtained without complicating the manufacture of the container by thermoforming and without requiring direct manipulation of the separation membrane.

The membrane advantageously has at least one weakening zone, which makes it possible to promote its rupture during the deformation of the container as indicated above.

Alternatively, it is the fixation of the membrane on the side wall that can be locally weakened or, in general, be provided to not withstand stress exerted by the underside of the membrane, due to an overpressure in the first compartment.

Advantageously, the side wall has a recessed surface, for example a shoulder oriented towards the opening, for fixing the membrane, which is advantageously achieved by sealing the membrane on this recess surface.

The recess surface allows easy attachment of the membrane inside the body of the container. As will be seen in the following, it can be fixed by clipping, if it is initially sufficiently rigid. This being so, the fixing by sealing is also advantageous and easy to implement.

The facility for manufacturing containers by thermoforming and filling containers according to the invention, comprises a thermoforming device having at least one thermoforming chamber and a thermoforming piston adapted to push in this chamber of the thermoplastic material to form containers comprising a body having a side wall and a bottom opposite an opening, and a device for filling the containers; the filling device comprises first filling means for disposing a first product at the bottom of the containers, the installation comprises, in addition, a station placing membranes having at least one gripper adapted to introduce a membrane into the body of the containers through the opening of the latter, and means for fixing the membrane to the side wall so as to delimit between the bottom and said membrane, a first compartment containing the first product and the fact that the filling device comprises second filling means for disposing a second product in a second compartment delimited between the membrane and the opening.

Thus, in this installation, the membrane placement station is disposed between the first and the second filling means, which allows to have the two different products in two different compartments, separated by the membrane.

Advantageously, the installation comprises means for cutting membranes in a membrane film and for disposing the membranes cut in the membrane placement station.

The installation advantageously comprises means for decontaminating the membrane. It is preferably first decontamination means capable of decontaminating the face of the diaphragm facing the bottom before the introduction of the membrane and the second decontamination means suitable for decontaminating the face of the membrane facing the opening after the establishment of this membrane.

This decontamination is particularly useful when the container is intended to contain food products. The two-stage decontamination of the membrane by the first and by the second decontamination means is particularly effective.

According to the method of manufacturing containers by thermoforming and filling containers according to the invention, is thermoformed from a thermoplastic material containers comprising a body having a side wall and a bottom opposite an opening; after having thermoformed the body of a container, a first product is placed at the bottom of this container, then a membrane is introduced into the body which is fixed to the lateral wall of the body, to delimit between the and the membrane, a first compartment containing the first product, then a second product is placed in a second compartment delimited between the membrane and the opening.

Advantageously, the process comprises a phase during which the membrane is decontaminated. To do this, it is preferable to decontaminate at least the face of the membrane turned towards the bottom before the introduction of this membrane and decontaminates at least the face of the membrane turned towards the opening after the introduction of this membrane. membrane.

• la figure 1 est une vue en coupe verticale d'un récipient conforme à l'invention ;
• la figure 2 est une vue analogue à la figure 1, pour une variante de réalisation ;
• la figure 3 montre un grossissement de la partie du récipient sur laquelle est fixée la membrane, et permet de comprendre la structure de cette membrane ;
• la figure 4 est une vue analogue aux figures 1 et 2 pour une autre variante ; et
• la figure 5 est une vue schématique montrant une installation conforme à l'invention, permettant de mettre en oeuvre le procédé de l'invention.

The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of an embodiment of the invention shown by way of non-limiting example. The description refers to the accompanying drawings in which:

• Figure 1 is a vertical sectional view of a container according to the invention;
• Figure 2 is a view similar to Figure 1, for an alternative embodiment;
• FIG. 3 shows a magnification of the part of the container to which the membrane is attached, and makes it possible to understand the structure of this membrane;
• Figure 4 is a view similar to Figures 1 and 2 for another variant; and
• Figure 5 is a schematic view showing an installation according to the invention, for carrying out the method of the invention.

The container 1 of Figure 1 comprises a body 10 having a side wall 10A and a bottom 10B opposite an opening 10C which, in this case, is closed by a closure cap 12, fixed on the upper rim 11 of the container.

A membrane 14 is disposed inside the container, being attached to its side wall 10A. As seen better on the partial enlargement, the side wall 10A has a recess surface 16, formed in this case by a shoulder oriented towards the opening 10C. The membrane 14 is fixed on this shoulder, in particular by sealing, a welding zone 18 being identified on the enlargement.

Thus, the container comprises a first compartment 20 which is delimited between the bottom 10B and the lower face of the membrane 14, and a second compartment 22, which is delimited between the upper face of the membrane 14 and the opening 10C.

These compartments may contain two different products. In fact, during the manufacture of the container, the body of the container is first formed, a first product is placed at the bottom of the container, the membrane is placed in place and fixed to the side wall 10A so as to delimit the first compartment 20, then the second product is placed on the membrane 14, that is to say in the second compartment 22, which is finally closed by the introduction of any suitable container closing means, such as the operculum 12 mentioned above.

It is noted in Figure 1 that the bottom 10B has a particular conformation. Indeed, the central portion of this bottom has a notch 24 projecting towards the inside of the container, and oriented along a diameter of the bottom 10B extending preferably over the entire diameter. This notch 24, which has a section substantially open V downward, gives the bottom portion of the container an ability to deform under the effect of a pressure exerted simultaneously on both sides of the notch 24, on the lower portion of the side wall 10A, that is to say on the sides of the compartment 20, symmetrically with respect to the notch 24 as indicated by the arrows P of Figure 1. This pressure has the effect to tilt the two points of support on which this pressure is exerted relative to the tip 24A of the notch 24, thus reducing the volume of the compartment 20 and consequently generating, in this compartment, an overpressure which causes the rupture (For example by bursting) of the membrane 14 when the latter is determined not to withstand such overpressure.

The container of Figure 2 is similar to that of Figure 1, and is distinguished only by the particular conformation of its bottom. Indeed, in Figure 2, the notch 24 of Figure 1 is replaced by a recess 25 with a domed central portion 26, the concavity is turned towards the interior of the container. The one of this central part is thus substantially on the plane of rest Pr of the bottom of the container. The entire container advantageously has a symmetry of revolution with respect to the axis A of the container, the curved portion 26 having the shape of a spherical cap centered on this axis, while the recess 25 provides an annular groove around this cap. In this case, it is by a pressure P 'exerted upwards (that is to say towards the opening 10C), on the convex portion 26, that it can cause a deformation of the container in the region of its first compartment 20, to reduce its volume and put it under pressure so as to cause the rupture of the membrane or the rupture of its attachment to the side wall.

According to a first possibility, it is possible to provide the sealing weld 18 of the membrane on the container body in such a way that the weld resists, during the filling of the second compartment 22 and the storage of the container, the stresses exerted on the membrane. by the product contained in the second compartment 22, but it yields at least partially when the compartment 20 is put under pressure to be emptied.

However, it will be preferred to choose the attachment of the membrane on the wall so as to avoid the rupture of this attachment, to prevent the membrane is detached from the container during emptying and does not mix with the product to be consumed.

Consequently, according to a second preferred possibility, the membrane is chosen to break (tear or burst) when it is desired to empty the first compartment.

Advantageously, the membrane may be provided with zones of weakening favoring its rupture, as will be seen in the following.

The constraints necessary for the rupture of the membrane or its attachment can not normally be exercised when the two compartments are full and the container is closed by the seal 12 because the deformability of the bottom is then less.

Figure 3 shows the conformation of the membrane and its attachment to the shoulder 16. There is shown by a shaded portion sealing 18 of the membrane on the shoulder.

Advantageously, the membrane is sealed by an autogenous weld. This means that the materials of the side wall of the container body and the membrane in contact in the weld area are the same. This is in particular polystyrene (PS), a thermoplastic material in which the body of the container. The membrane can in turn have a lower layer 14A PS, allowing the aforementioned autogenous welding, and a top layer 14B polyethylene terephthalate (PET) facilitating its handling and holding during sealing. To prevent this upper layer from conferring on the membrane an excessively high resistance to the previously mentioned breaking stresses, said upper layer advantageously has incisions 15, which extend only on the upper layer 14B without affecting the lower layer 14A, and which form zones of weakening for the membrane allowing the rupture thereof to the traction constraints previously mentioned.

These incisions may be arranged to form one or more lines of incisions, in particular curved lines having a shape similar to that of the Greek letter Ω.

Of course, other conformations than that shown in Figure 3 are also possible. In particular, rather than autogenous welding, it may be desired to use a membrane which, at least in the sealing zone 18, is coated with a material such as a lacquer having a melting temperature lower than that of the body material. of the container. The use of such lacquers is known, for example to achieve the sealing of a cap 12 on the rim of the container. For example, it will be possible to make the body of the PS container, and to use a PET monolayer membrane, the lower face of which is coated, entirely or only in the zone corresponding to the weld 18, with a lacquer having a lower melting temperature than PET. Such a membrane may also be provided with zones of weakening of the type of the incisions 15, in which case these will advantageously extend over approximately half at most of its thickness.

In general, the container body wall and the membrane may be monolayer or multi-layered.

We now describe the 4 which, in a variant, shows a container 1 whose membrane 14 'is fixed to the side wall 10A of the body by clipping. Indeed, the recessed surface 16 'that this side wall has is formed in the form of an annular groove open towards the inside of the container. The membrane 14 'is then relatively rigid and its outer peripheral edge is introduced by clipping or snapping into the groove 16'.

According to this variant, to promote the holding of the membrane, it is advantageous to add at least one other zone of attachment of the membrane to the side wall of the container. For this, the bottom portion of the container has a central recess 28 whose apex extends above the membrane 14 'and thus delimits in part the bottom of the second compartment 22. Thus, on the sides of this central recess 28 a groove 16 "open towards the inside of the container is formed, in the same plane as the aforementioned groove 16. In this case, the membrane 14 'may have an annular shape, whose inner and outer peripheral edges are respectively engaged in the gorges 16 'and 16 ".

The membrane 14 'may for example be made of PS, with a suitable thickness to give it the desired rigidity.

To consume the products contained in the container, it can be turned against a plate or the like after opening the lid 12 and pinch the lower end of the side wall between two fingers to exert the pressure P shown in Figure 4, this which will have the effect of demolding the product contained in the second container 22 and, if the pressure is sufficient, to clear the edges of the membrane of at least one of the grooves 16 'and 16 ", to empty the contents of the first compartment 20. Advantageously, the clipping in the groove 16 "is less tight than in the groove 16 'so that the membrane is detached only from the groove 16", thus allowing the emptying of the first compartment 20 by its center, keeping the membrane integral with the body of the container.

An example is now described for the installation of the invention, with reference to FIG.

The illustrated installation is used to thermoform containers according to the invention, from a sheet of thermoplastic material 50 advanced step by step. Of course, one could achieve the same type of containers from individual parts such as tokens or the like, as for example described in the patent FR 2,766,123.

The installation of FIG. 5 thus comprises means for advancing step by step the band 50 and, successively arranged in the forward direction F of this band, a heating station 52 intended to locally carry the thermoplastic material at a temperature of 50.degree. thermoforming temperature, a thermoforming station having at least one thermoforming device 54, first filling means 56 for disposing a first product at the bottom of the containers, a station 58 for placing membranes, means 60 for fixing a membrane placed in a container at the side wall of this container, second filling means 62 for disposing a second product on the membrane, means 64 for closing containers and means 66 for cutting closed containers.

In this case, the thermoforming station shown comprises a single row of thermoforming devices. Of course, in a manner known per se, this station may comprise several rows of thermoforming devices. Each device comprises a mold having at least one thermoforming chamber 70 and a counter-mold having at least one thermoforming piston 72 to push back into the chamber of the thermoplastic material.

In a manner known per se, the thermoforming station may be associated with wrapping means 74, able to arrange in the chambers 70 streamers, for example passed through an annular slot 71 of the chamber, so that the body of each container be surrounded by such a streamer.

It can be seen that the side wall 70A of the chamber 70 has a recess 70B, which is able to form a recess on the side wall of the containers. This recess of the containers is advantageously formed by a shoulder 16, in which case the recess of the side wall of the chamber 70 is a shoulder.

The filling station of the first filling means comprises a nozzle 56 which, as indicated by a broken line, can advantageously be moved inside the body of a container to dispose the first product against the bottom of this container practically without projecting it. first product on the rest of the container wall.

Downstream of the nozzle 56, the containers containing the first product p1 then pass into a membrane placement station which comprises at least one gripper 74 adapted to introduce a membrane 14 into the body of the containers through the opening 10C of these last. In this case, the station 58 comprises a carousel 76 having a plurality of arms or rows of arms 74 oriented radially. Free ends arms are provided with gripping means 78 such as suction cups allowing them to maintain the membranes 14 at their ends.

In the present case, these membranes 14 are cut in a membrane film 80 which is driven above the membrane placement station 58. The membranes are cut concomitantly on at least one row, using, for each membrane, a punch 82 and a die 84. During cutting, the arm 74 which is under the punch 82 enters the matrix 84, to collect the membrane which is cut. This arm then retracts to occupy the position shown in solid line, and, during the rotation of the carousel, it carries with it the membrane 14 that carries its suction cup 78.

As indicated above, the installation advantageously comprises means for decontaminating the membrane. These are, for example, ultraviolet ray lamps 86 disposed in the path of the membranes carried by the arms 74. FIG. 5 shows a lamp 86 exposing the underside of a membrane 14 to its ultra-violet rays. -violet just before the introduction of this membrane in the body of a container. The underside of the membrane is the bottom face when the membrane is in place. This lamp 86 is a first means of decontamination. As will be seen in the following, other means of decontamination, for example in the form of one or more other ultraviolet lamps 88, are also provided. All types of suitable decontamination means can be provided. The membranes can be decontaminated (sterilized) in advance and then placed in the containers in a part of the facility forming a sterile tunnel.

The band 50 being advanced in step by step, the carousel 76 rotates in synchronism to gradually bring the membranes that carry his arms to the bottom of the containers. The arm 74 which is pointing downwards in FIG. 5 may, as indicated in broken lines, be expanded to bring the membrane 14 which it carries against the shoulder 16 of the body 10 of the container in which this arm penetrates. At this time, the suction cup can relax its effect, and the arm returns to its position indicated in solid line, while the membrane remains on the shoulder as indicated for the container immediately downstream of the station 58.

The arms 74 can be replaced by non-telescopic arms, by moving the carousel 76 between a high position for cutting the membranes and the advancement of the band and a low position for the placement of the membranes.

After its installation, the membrane can be fixed to the side wall of the container by means 60. In the example shown, these fixing means are formed by a welding station, the welding arm 90 can be moved in a withdrawal position indicated in solid lines, and an extended position in which it penetrates inside the body of a container so that its annular welding head (electrode) 92 cooperates with the upper face of the membrane to weld the latter on the shoulder 16, cooperating with an annular counter-tool (counter-electrode) 93.

This welding done, the arm returns to its retracted position and the counter-tool is moved down to allow the advancement of the band.

According to one variant, the means for fixing the membrane may comprise ultrasonic welding means, in particular of the type using an annular sonotrode.

The fixing means can be integrated in the station 58, in particular when it comes to ultrasonic welding means, using an annular sonotrode 91 working upwards under the shoulders of the pots, while the gripping means 78, which have just put in place a membrane, support sealing efforts. For the sake of convenience, FIG. 5 shows a sonotrode 91 in the station 58 and the welding station 60 although normally only one of these two means is provided.

The membrane which has just been welded is then subjected to the decontamination action of the means 88, which decontaminate the upper face of the membrane, facing the opening 10C of the body of the container.

Downstream of these decontamination means 88, the installation comprises the second filling means, the filling station 62 of which has a second product p2 in the second compartment delimited above the membrane 14.

Downstream of this filling station 62, the containers are closed and cut from the strip. Thus, the installation shown in FIG. 5 comprises, on the one hand, means (not shown) for bringing a lidding strip 94 over the containers and a sealing station 64 including the sealing tool (electrode). 96 seals a lid on the rim of each container by cooperating with a counter-tool (counter-electrode) 97. Downstream of this sealing station, the installation comprises a cutting station 66 whose cutting tool 98 cuts the containers and their covers strips 50 and 94, either by group of containers or individually.

Of course, the cover strip 94 may be replaced by a system for depositing individual lids across the opening of each container, for example using a carousel system of the type shown in FIG. place membranes in the containers.

Claims (8)

A thermoformed container comprising a body (10) having a side wall (10A) and a bottom (10B) opposite an opening (10C), comprising a first compartment (20) defined between the bottom (10B) and a membrane (14). , 14 '), arranged inside the container and fixed to the side wall (10A), and a second compartment (22) delimited between the membrane (14, 14') and the opening (10C), these compartments each being able to contain a product,
characterized in that the body (10) of the container (1) has, in the region of the first compartment (20), a pressure deformable portion (P, P ') adapted, when deformed, to reduce the volume of this compartment to generate in the latter an overpressure which subjects the membrane (14, 14 ') to stresses (T) causing rupture of the membrane and / or its attachment to the side wall. Container according to claim 1, characterized in that the side wall has a recess surface (16, 16 ') for fixing the membrane (14, 14'). Container according to claim 2, characterized in that the side wall (10A) has a shoulder (16) facing the opening (10C). Container according to claim 2 or 3, characterized in that the membrane (14) is sealed to the recess surface (16). Container according to any one of claims 1 to 4, characterized in that the membrane (14) is sealed by an autogenous weld (18). Container according to any one of claims 1 to 4, characterized in that , at least in the sealing zone (18), the membrane (14) is coated with a material having a lower melting temperature than the material of the body (10) of the container. Container according to any one of claims 1 to 6, characterized in that the membrane (14) has at least one weakening zone (15). Container according to claim 7, characterized in that the membrane (14) comprises an upper layer (14B) having incisions (15) and a lower layer (14A) unaffected by these incisions.

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