EP0481854B1 - Method for the vacuum packaging of liquid or paste products in dispensers, device therefor and dispenser thus obtained - Google Patents

Description

The present invention relates to a process for packaging liquid to pasty products so as to present them in vacuum dispensers. The products concerned are rather cosmetics or medicines which do not tolerate contact with the ambient air due to the risks of oxidation or contamination. As for the distributors, they preferably consist of a variable capacity reservoir (bottle with a deformable envelope, tube closed by a scraper piston, etc.) sealed off by a distribution valve without air intake. The latter finally finds an advantage in being associated with a precompression pump in order to guarantee both cleanliness of distribution and acceptable rate of exhaustion. A device suitable for implementing the present process also forms part of the invention, as do the distributors which result therefrom.

A method of packaging in vacuum packaging is in particular known in the prior art. It is in particular exposed in the American patent US-A-4 845 927 of RAPPARINI having for priority date January 21, 1987. It consists first of all in 'filling a small bag with the product to be packaged by introducing the latter by a open side of the bag. Then the whole is placed in a bucket so that the open side of the bag is on top of the bucket. A bell is then lowered in order to hermetically close this top. The sachet is thus enclosed in an enclosure whose air is evacuated using a vacuum pump system. In the patent specification, provision is then made for jaws to heat seal the open side of the small bag. It is only after this welding operation that the enclosure is brought back to atmospheric pressure and that the sachet is released from the cup by withdrawal of the bell.

The VALOIS company, from June 1988, adapted this process to the case of flexible tubes containing a paste of the toothpaste type. There was however the idea of enclosing the tube in an enclosure in order to create a vacuum, then sealing the bottom of the tube within it before bringing the enclosure to atmospheric pressure. This same company finally used in the French patent application FR-A-2 653 744 filed on October 31, 1989 a comparable method in order to subject a dispensing valve to a bottle. Once the vacuum of air established in the enclosure, the valve was in fact crimped on the bottle, for example, and this inside the enclosure itself with the help of pliers specially arranged in the closing bell.

If the use of a vacuum enclosure to carry out the operations of closing the packaging is particularly effective in the context of vacuum packaging of a liquid to pasty product, it does not however make it possible to completely eliminate the air present in the distributor finally obtained. Indeed, as soon as a certain volume of air is trapped within the product itself, it is not the vacuum which is established in the enclosure, and therefore on the surface of the product contained in the reservoir of the still open distributor, which allows to evacuate it. It is therefore better that such an inclusion of air is not found in the product contained by the distributor. And, for this, it is advisable that the filling of its tank is carried out with sufficient caution.

The problem of trapping air bubbles is particularly acute in the case of a scraper piston tube like the one shown in axial section in FIG. 1 below. This particular type of reservoir R in fact consists of a cylindrical tube 10, the bottom 13 of which is open. A cover 16 retained by a sleeve 12 adapted to forcefully engage around the lower periphery 14 of the tube 10 can however protect this open bottom 13 from untimely pressure from the user or, more simply, from dirt . Behind this cover 16, which has a vent hole 17 for this, a scraper piston 50 is able to circulate along the tube 10. A double peripheral lip 51 then seals the piston-tube contact.

A preferred form of the scraper piston 50 is shown in Figures 1 to 3 in the appendix. On the outside, it comprises a crown 52 which projects sufficiently to come into abutment on the cover 16 when the piston 50 is in the low position (associated with the maximum capacity of the tube 10). On the inside, a crown 53 also extends. Its diameter, greater than that of the previous crown 52, is calculated so that a distribution valve V set on the neck 15 of the tube 10 is able to take place at the within the crown 53 when the piston 50 is in the high position (associated with the minimum capacity of the tube 10). The crown 53 is then in abutment against the base of the neck 15.

The introduction of the product into such a tube 10 can take place in two different ways as soon as the known techniques of filling at atmospheric pressure are implemented. The first (not shown) provides that the piston 50 remains in the low position throughout the operation. An injector is then lowered by the open neck 15 of the tube 10 to the immediate vicinity of the piston 50. It delivers product and is raised relative to the tube 10 as the quantity of product injected increases. Care is then taken to keep the end of the injector above the surface of the product. This in fact limits the risks of air bubbles remaining trapped in the mass already introduced. In practice, however, the inclusion of small volumes of air remains inevitable. And the presence of the crown 53 promotes this undesired phenomenon in this case.

The second filling method already disclosed consists in placing the piston 50 in the high position beforehand (cf. fig. 2). An injector 200 is introduced through the neck 15 of the tube 10 as in the first method. However, its end 201 is simply disposed within the crown 53 of the piston 50. It is moreover secured by means of a plug 210 sealing the neck 15 and is thus isolated from the outside. As shown diagrammatically in FIG. 3, product 80 is then injected with sufficient pressure to cause the scraper piston 50 to descend as new quantities of product are introduced. At the end of this filling mode, the volume of air initially understood between the piston 50 and the plug 210, that is to say more or less in the neck 15, remains trapped, however, the pressure d injection causing it to mix with the product in the form of an emulsion 81.

This is how the present invention aims to provide a method of packaging liquid to pasty products in a vacuum dispenser in which filling the dispenser tanks completely avoids trapping air bubbles. It must be particularly effective when the reservoirs are scraper piston tubes like those just described.

This is achieved by assigning a new use to the enclosure already implemented in the prior art in order to vacuum seal the dispensers.

According to the present invention, a method of packaging a liquid to pasty product in a vacuum dispenser according to claim 1 is disclosed. During said filling operation, a quantity of said product equal to said maximum capacity of said tank isolated using a metering cylinder is therefore advantageously pushed back by a piston through said injector, said valve being a hydraulic valve adapted to deliver switching to said quantity of said product as a function of the force developed by said piston. Said metering cylinder is then for example filled with said product prior to said filling operation from a reserve of said product maintained under vacuum, via a valve. Advantageously, said bucket is moved vertically by a jack which brings it into contact with said bell in order to constitute said hermetic enclosure. Likewise, said hermetic enclosure is formed while said bell and said bucket are applied to each other at the level of a joint subject to said bell. Finally, said air vacuum can be created using a vacuum pump system which communicates with said bell through at least one duct.

For example, after said filling operation, said sealed enclosure is brought to atmospheric pressure, then said cup and said bell are separated from each other so that said filled reservoir is released. In this case, following the release of said reservoir, said dispensing member is placed in said opening, a vacuum fixing operation of said member then intervening to complete said process.

Advantageously, said means adapted to vary the capacity of said reservoir consist of a scraper piston, and said dispensing member is a precompression metering pump suitable for dispensing creams.

The present invention also discloses a device according to claim 13 for implementing the above method.

• la figure 1 est une coupe axiale d'un distributeur formé d'un tube à piston racleur obturé par une valve de distribution pour lequel il est avantageux de mettre en oeuvre le présent procédé,
• les figures 2 et 3 sont des coupes axiales du tube à piston racleur de la figure précédente. Ce dernier est représenté respectivement au début et en cours de remplissage avec du produit, et cela selon une méthode de de remplissage de l'art antérieur, et
• la figure 4 est un schéma fonctionnel illustrant la mise en oeuvre de l'opération de remplissage d'un tube à piston racleur selon un mode de réalisation conformément au présent procédé de conditionnement sous vide. S'y retrouvent tous les organes pouvant intervenir dans un dispositif pour mettre en oeuvre le procédé selon la présente invention.

The invention will now be described in the context of a particular embodiment given by way of nonlimiting example. For this, reference will be made to the attached drawings in which:

• FIG. 1 is an axial section of a distributor formed by a scraper piston tube closed by a distribution valve for which it is advantageous to implement the present method,
• Figures 2 and 3 are axial sections of the pig piston tube of the previous figure. The latter is shown respectively at the start and during filling with product, and this according to a filling method of the prior art, and
• Figure 4 is a block diagram illustrating the implementation of the operation of filling a pig piston tube according to one embodiment in accordance with the present vacuum packaging process. There are all the organs that can intervene in a device for implementing the method according to the present invention.

If the scraper piston tube shown in FIGS. 1 to 3 has already been described above in the part of this thesis devoted to the prior art, it should here be added how a dispenser is advantageously presented at the end of the present vacuum packaging process using this type of reservoir R. The section of Figure 1 illustrates such a dispenser. Partly introduced into the neck 15 of the tube 10 is in fact a distribution valve V. Advantageously, it is associated with a precompression dosing pump adapted to the distribution of creams. It is then the pump body which is housed within the neck 15 while a valve stem 40 protrudes outside, protruding out of a spinner 30. The latter comprises for example an annular wheelbase 32 to rest on the periphery of the neck 15 of the tube 10. A seal 23 is however interposed between this periphery and the wheelbase 32. In this way a crimping flange 20 is able to pinch the corresponding stack in order not only to subject valve V to tube 10, but also to make the attachment particularly watertight.

In FIG. 1, a guiding ferrule 92 is passed around the neck 15 of the tube 10. It guarantees proper actuation of the valve stem 40 by means of a push button 90. The latter determines in this case a lateral distribution of the product which, from the rod 40, is deflected as far as the nozzle 91 within a bent channel of the push button 90. A cap 11 is finally adapted to fit onto the tube 10 over the dispensing members which have just been quickly reviewed. Recall that they are specified here only as an illustration of a dispenser obtainable by the present vacuum packaging process.

A particularly important phase of this process in the context of the present invention is illustrated in the diagram in FIG. 4. It is the operation of filling the reservoir R. The latter is then placed in a bucket 110 having for example the shape of a case with a bottom, but without top. In the case of the preceding pig piston tube, the casing is cylindrical and its internal diameter is adapted to easy engagement as well as to effective maintenance of the reservoir R. The latter is also maintained so as to have its maximum capacity. In other words, its scraper piston 50 is in the low position. The cover 16 and the sleeve 12 are advantageously already assembled to the casing 10. Indeed, the filling operation generally takes place at the product manufacturer and the tanks are delivered by another company which takes care to save this manufacturer any task not related to the actual packaging. The neck 15 of the reservoir R is finally presented on the open top of the bucket 110 so that it is accessible.

Thus, according to the present method, a bell 210 is brought into contact with the bucket 110 in order to close it. According to the diagram in Figure 4, this can be done by means of a jack 100 adapted to raise the bucket as soon as it is plumb with the bell 210. To transfer it to this place (for example from a loading station for the reservoir R), those skilled in the art will not fail to imagine many systems of mobile bases: carousel, treadmill, etc. Similarly, closing the bucket by the bell is likely to have recourse to means of relative displacement of a greater or lesser complexity, the present presentation sticking rather to an operating principle.

The bell 210 is for example provided below with a thick seal 211 in order to ensure the tightness of its contact with the bucket 110. Consequently, the reservoir R is found in a hermetic enclosure. However, it communicates via at least one suitable duct 212 with a vacuum pump system. This is not shown and only an arrow coming from this conduit 212 materializes the evacuation of the air initially contained in the enclosure.

Within the bell 210 there is also an injector 200 adapted for the introduction of the product into the reservoir R. It is for example a cannula subject to a support 202 integral with the bell 210. Its height is in this case calculated so that its end 201 automatically takes place within the neck 15 as soon as the bell and cup are in contact. In other words, no relative movement of this end 201 and of the reservoir R is planned thereafter and, in particular, while the filling of the reservoir is taking place.

The product 80 which is then introduced by the injector 200, is for example withdrawn from a hopper 250. In this case, it is rather maintained under vacuum. This is shown diagrammatically in FIG. 4 by the arrow coming out of the conduit 252. In the constricted part of the hopper, an agitator 261 driven by a motor 260 can advantageously prevent the more or less compact product from preventing the evacuation of the content of the hopper 250 through its lower orifice 251.

This orifice 251 does not communicate directly with the injector 200 due to the air voids maintained in the hopper 250, on the one hand, and in the enclosure, on the other hand, which oppose the transfer of material. A valve 230 first regulates the opening. Figure 4 schematically shows a three-way valve. It is for example a ball valve, its male part comprising three holes. In this way, either the hopper 250 and a metering cylinder 240 shown diagrammatically in FIG. 4 to the right of the valve 230 can be placed in communication, or this metering cylinder 240 and the bell 210.

In the latter case, however, the communication is further regulated by a hydraulic valve 220. The diagram in FIG. 4 is limited to recalling that such a valve comprises a needle 221 adapted to collaborate with a valve seat. In this case, this seat is advantageously provided by the end 201 of the injector 200, the latter being for this purpose narrowed relative to the internal channel of the injector 200 in which the needle 221 takes place. The hydraulic valve 220 also includes a piston head retained protected from the product on the side opposite the needle 221 by a spring (not shown) while the product under pressure can infiltrate under the head on the side where the needle 221 takes root.

These various members arranged between the orifice 251 of the hopper and the end 201 of the injector make it possible to pass a dose of product corresponding to the maximum capacity of the tank R from the hopper to this tank. This is done by a round trip of the piston 241 of the metering cylinder 240 which must consequently be driven by an appropriate energy source (not shown). The cylinder 240, in addition to withdrawing the desired dose, in fact guarantees that the injection pressure is sufficient to keep the hydraulic valve 220 open. As for this last valve, it prevents the vacuum of air created in the enclosure from causing an uncontrolled aspiration of the product located upstream of the injector. The assembly formed by these members therefore constitutes an advantageous device for implementing the filling operation according to the present invention.

The filling operation, the principle of which has just been reported, ensures that at no time during its transfer, the dose of product to be introduced into the reservoir R is not in contact with the air. It cannot therefore contain the slightest bubble. The packaging process can then be completed by a vacuum sealing operation of the reservoir R according to a known embodiment. In the case of the pig piston tube which is more particularly concerned here, its valve V is advantageously crimped empty according to the teaching of the application FR-A-2 653 744 cited above. Note that it is then more practical to restore atmospheric pressure in the enclosure of FIG. 4 in order to separate the cup 110 from the bell 210 and to be able to arrange the valve V in the neck 15 of the tank. Contact of the free surface of the product with the ambient air thus called into question does not, however, risk losing the benefit of the filling operation as described above. Also the vacuum dispensers containing such doses devoid of totally air are also part of the present invention.

Claims (21)

1. Method of vacuum packaging a paste or liquid product (80) in a dispenser in the form of a reservoir (R) comprising an opening and means for varying its volume and a dispensing member (V) adapted to prevent ingress of air and to close off in a sealed way said reservoir (R), said method consisting in:

   - disposing said reservoir (R) in its maximum content configuration in a bucket (110) having an open top so that its opening is above said top;

   - closing said bucket (110) by means of a bell (210) to constitute an hermetically sealed enclosure, said bell (210) comprising filling means comprising an injector tube (200) having an end (201), said injector (200) being coupled to said bell (210) so that, when said hermetically sealed enclosure is formed, said end (201) of said injector tube is engaged in said opening of said reservoir (R);

   - creating a vacuum in said hermetically sealed enclosure;

   characterized in that is following a filling operation consisting in:

   - feeding said product (80) in vacuum into said reservoir (R) through said injector tube (200) via a valve (220) at a sufficient pressure to hold open said valve (220), said valve being further adapted to close said injector tube (200) at all times except during said filling operation so that said vacuum created in said hermetically sealed enclosure does not cause said product (80) to be aspirated into said enclosure via said injector tube (200).
2. Vacuum packaging method according to claim 1, characterized in that during said filling operation, a quantity of said product (80) equal to said maximum content of said reservoir (R) is isolated by means of a metering cylinder (240) and is expelled by a piston (241) through said injector tube (200), said valve (220) being an hydraulic valve adapted to allow said quantity of said product (80) to pass by virtue of the force exerted by said piston (241) .
3. Vacuum packaging method according to claim 2, characterized in that said metering cylinder (240) is filled with said product (80) prior to said filling operation via a valve (230) and from a store (250) of said product in which a vacuum is maintained.
4. Vacuum packaging method according to claim 3, characterized in that said store (250) of said product (80) is a hopper having a lower orifice (251) at the level of which said valve (230) is disposed, a motor (260) driving a stirrer (261) in said product (80) near said orifice (251) so that said product (80) is evacuated via said orifice (251) under good conditions.
5. Vacuum packaging method according to claim 3 or 4, characterized in that said valve (230) is a three-way valve for establishing communication either between said store (250) and said metering cylinder (240) or between said metering cylinder (240) and said injector tube (200).
6. Vacuum packaging method according to claim 5, characterized in that said valve (230) is a plug valve, its male part having three holes.
7. Vacuum packaging method according to any one of claims 1 to 6, characterized in that said bucket (110) is displaced vertically by an actuator (100) which brings it into contact with said bell (210) to constitute said hermetically sealed enclosure.
8. Vacuum packaging method according to any one of claims 1 to 7, characterized in that said hermetically sealed enclosure is constituted while said bell (210) and said bucket (110) are brought into contact with each other via a gasket (211) attached to said bell (210) .
9. Vacuum packaging method according to any one of claims 1 to 8, characterized in that said vacuum is created by a system of vacuum pumps which communicate with said bell (210) via at least one pipe (212) .
10. Vacuum packaging method according to any one of claims 1 to 9, characterized in that after said filling operation said hermetically sealed enclosure is returned to atmospheric pressure and said bucket (110) and said bell (210) are separated from each other to release said filled reservoir (R) .
11. Vacuum packaging method according to claim 10, characterized in that following release of said reservoir (R) said dispensing member (V) is fitted into said opening, a fixing operation in a vacuum of said dispensing member (V) being then realised to terminate said method.
12. Vacuum packaging method according to any one of claims 1 to 11, characterized in that said means for varying the volume of said reservoir (R) consist in a scraper piston (50), and in that said dispensing member (V) is a precompression metering pump adapted to dispense a creme product.
13. Device for vacuum packaging a paste or liquid product (80) in a dispenser formed by a reservoir (R) comprising an opening and means for varying its volume and a dispensing member (V) allowing no ingress of air adapted to close said reservoir (R) in a sealed way, said device being comprised of at least:

    - a bucket (110) having an open top adapted to receive said reservoir (R) so that said opening is above said top;

    - a bell (210) adapted to close said bucket (110) to constitute and hermetically sealed enclosure, said bell (210) containing filling means which comprise an injector tube (200) having an end (201), said injector tube (200) being attached to said bell (210) so that when said hermetically sealed enclosure is formed, said end (201) of said injector tube is inserted in said opening of said reservoir (R);

    - means for creating a vacuum in said hermetically sealed enclosure;

    characterized in that a valve (220) is adapted to open said injector tube (200) during the filling and to close said injector tube (200) except during said filling operation so that said vacuum created in said hermetically sealed enclosure does not cause said product (80) to be aspirated into said enclosure through said injector tube (200) .
14. Device according to claim 13, characterized in that said valve (220) is an hydraulic valve adapted to allow the passage for a quantity of said product (80) equal to said maximum content of said reservoir (R) which is isolated in a metering cylinder (240) and expelled by a piston (241) through said injector tube (200) .
15. Device according to claim 14, characterized in that said metering cylinder (240) communicates via a valve (230) with a store (250) of said product (80) held in a vacuum.
16. Device according to claim 15, characterized in that said store (250) of said product (80) is a hopper having a bottom orifice (251) at which level is disposed said valve (230), a motor (260) driving a stirrer (261) in said product (80) near said orifice (251) so that said product (80) is evacuated under good conditions by said orifice (251).
17. Device according to claim 15 or claim 16, characterized in that said valve (230) is a three-way valve to establish communication either between said store (250) and said metering cylinder (240) or between said metering cylinder (240) and said injector tube (200) .
18. Device according to claim 17, characterized in that said valve (230) is a plug valve its male part having three holes.
19. Device according to any one of claims 13 to 18, characterized in that said bucket (110) is mounted on an actuator (100) adapted to move said bucket (110) vertically to bring it into contact with said bell (210) to constitute said hermetically sealed enclosure.
20. Device according to any one of claims 13 to 19, characterized in that said bell ( 210) is provided with a gasket (211) arranged to constitute said hermetically sealed enclosure when applied to said bucket (110) .
21. Device according to any one of claims 13 to 20, characterized in that said means for creating a vacuum in said hermetically sealed enclosure consist in a system of vacuum pumps communicating with said bell (210) via at least one pipe (212).

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