FR3050439A1 - PROCESS FOR FORMING A PACKAGE FROM A CONTAINER INCLUDING PRESSURIZATION OF THE CONTAINER BY THE VACUUM - Google Patents

Abstract

A method of forming a package (1) from a container (2) including a body (3), an open neck (4) extending from an upper end of the body (3), and a bottom (6) which closes the body (3) from a lower end thereof, this method comprising a filling operation of the container (2) and a closing operation of the container (2) thus filled, this method characterized in that it comprises the steps of: - providing a receptacle (10) defining a cavity (12) terminating in an opening (13) having an edge (14); positioning the container (2) relative to the receptacle (10) so that the opening in the neck (4) of the container (2) opens out of the receptacle (10) and an external area of the container (2), limited by a periphery, comes close the cavity (12) by sealingly applying the periphery of the outer zone against the edge (14) of the opening (13) of the cavity (12); keep open the container (2) thus positioned; - Create a depression in the cavity (12); - fill the container (2) if it is not already; - plug the container (2) thus filled; - restore the pressure in the cavity (12).

Description

A method of forming a package from a container The invention relates to the formation of a package from a container (typically a bottle) of plastics material (such as polyethylene terephthalate or PET) comprising a body. an open neck (or neck) extending from an upper end of the body sometimes separated from the body by a collar, and a bottom which closes the body from a lower end thereof.

Conventionally, the formation of a package comprises the filling of the container after its manufacture (by blowing or stretching blow from a blank), its closure and labeling. Filling is usually done just after manufacture by introducing the contents (liquid or otherwise) through the neck.

Then, the containers are generally grouped to form packs filmed and then palletized for transport. Stacking of the containers causes them to be placed under vertical compression. A container must therefore have a certain mechanical strength to avoid excessive deformation (or collapse) under vertical compression forces, which would endanger the good performance of the pallet.

However, to meet the new environmental standards and to simultaneously save money, manufacturers reduce the amount of material available to manufacture each container. This results in a decrease in the thickness of material, and consequently a decrease in the mechanical strength of the containers, which the manufacturers try to compensate in particular by form tips by providing the containers with mechanical reinforcements (beams, ribs, grooves) .

However, we reach a point of material savings (more than 70% relief in thirty years) where these tricks of form are no longer sufficient to compensate for the loss of mechanical strength.

It has been proposed, in order to overcome the problem of the loss of mechanical strength, to pressurize the containers, including for flat (ie non-gaseous) liquid products, eg still water or Juice).

A first technique, described in European Patent Application EP 2 676 919 (Sidel), consists in injecting, during the filling of the container, a drop of liquid nitrogen into the headspace of the container before proceeding with the capping. The vaporization of the liquid nitrogen thus puts the container under pressure, to the benefit of its rigidity.

This technique is certainly effective (it also allows to fight against the oxidation of certain products). But it requires storing and handling liquid nitrogen, which requires some precautions and a rather impressive installation.

A second technique, described in the European patent EP 2 711 152 (Sidel Participations), consists in forming on the container a bottom provided with a deformable membrane whose inversion, made by mechanical means after the filling and capping of the container have been made, puts its contents under pressure.

This second technique is equally effective; it is, however, reserved for hot-filled containers and supposes that a particular form is given to the bottom. It therefore seems difficult to generalize to all applications (especially to still water).

An objective is therefore to propose an alternative solution for putting the contents of the container under pressure and thus promote the mechanical strength thereof despite a reduced amount of material. For this purpose, there is provided a method of forming a package from a container including a body, an open neck that extends from an upper end of the body, and a bottom that closes the body to from a lower end thereof, which method comprises a filling operation of the container and a plugging operation of the thus filled container, the method comprising the steps of: providing a receptacle defining a cavity which terminates with an opening having an edge; positioning the container relative to the receptacle so that the opening in the neck of the container opens out of the receptacle and an outer zone of the container, limited by a periphery, comes to close the cavity by sealing application of said around the outer zone against the edge of the opening of the cavity; keep the container thus positioned open; create a depression in the cavity; fill the container if it is not already stop the container thus filled; restore the pressure in the cavity. The appearance of the depression in the cavity causes an elastic deformation of the outer zone of the container which closes the cavity, and this zone undergoes suction deformation which causes an increase in the internal volume of the container due to the pressure difference between the inside of the container (at atmospheric pressure) and the inside of the cavity closed by this external zone of the container (at lower pressure).

When the pressure in the cavity is restored after the container has been plugged, the material of the container tends, by elasticity, to regain its original shape. Since the container is closed, it results in a pressure of the contents, and consequently an increase in the rigidity (and therefore the mechanical strength) of the container.

Various additional features may be provided, alone or in combination: the outer zone is constituted by the assembly comprising the body and the bottom of the container, said assembly is housed in the cavity, and the periphery is applied in a sealed manner against the edge of the opening is between the body and the neck. the neck is separated from the body by a flange and the periphery is applied in a sealed manner against the edge of the opening is constituted by said flange; the receptacle is in the form of an enclosure having an open position and a closed position, and the positioning of the container comprises introducing the body into the enclosure in the open position, and closing the enclosure around the container body ; the bottom of the container is limited by an annular seat formed at the periphery of the bottom, the seat constitutes said periphery which is sealingly applied against the edge of the opening and the bottom constitutes said outer zone of the container which closes the cavity when the seat is sealingly applied against the edge of the opening; the depression is created by pumping air present in the cavity outside the container; the filling of the container is performed before its positioning relative to the receptacle; the filling of the container is carried out after the positioning of the container relative to the receptacle, and before the creation of the depression in the cavity. Other objects and advantages of the invention will become apparent in the light of the description of an embodiment, given below with reference to the accompanying drawings, in which: FIG. 1 is a perspective view showing a receptacle in an open position in which a container is being inserted; Figure 2 is a view similar to Figure 1, showing the receptacle in the closed position; Figure 3 is a sectional view along the plane III-III of Figure 2, showing the container solid line before the creation of the depression in the cavity, and dotted after this operation; FIG. 4 is a view similar to FIG. 3, showing the container in solid lines before the restoration of the pressure in the cavity, and in dotted lines after the restoration of the pressure in the cavity; Figure 5 is a view similar to Figure 3 showing another embodiment.

Figures 1 to 4 illustrate a method of forming a package 1 from a container 2 (in this case a bottle) in a plastics material, e.g. polyethylene terephthalate (PET). This container 2 comprises a body 3, a neck 4 which extends from an upper end of the body 3 from which it is separated by a flange 5, and a bottom 6 which closes the body 3 from a lower end of it.

The container 2 is advantageously formed by blowing or stretching from a blank, e.g. a preform or an intermediate container obtained by at least one preliminary blowing or stretch blow molding operation from a preform and intended to undergo one or more additional operations to become a final container. The package 1 comprises, in addition to the container 2: a product 7 (for example a liquid, typically a beverage, it may especially be a flat drink) intended to be introduced into the container 2; a plug 8 intended to be attached to the neck 4 to close, in a sealed manner, the container 2 filled; - a label (not shown) intended to be fixed (eg by gluing) on the body 3.

Before being clogged, the container 2 is subjected to a treatment intended to improve its mechanical strength. This treatment consists of subjecting the outside of the body 3 to a depression which at least locally deforms the material before the container 2 is clogged.

This treatment is carried out by means of a processing unit 9 which, as illustrated in the figures, comprises, in the first place, a receptacle 10 with respect to which the receptacle 2 is intended to be positioned.

This receptacle 10 has a wall 11 defining a cavity 12. The cavity 12 terminates in an opening 13 formed in the wall 11 and has an edge 14 with a closed contour.

The receptacle 10 is advantageously equipped with an attached seal (or overmoulded seal) which extends over the edge 14, for example being housed in a groove 16 made therein.

According to the invention, the container 2 is positioned relative to the receptacle 10 so that the opening in the neck 4 of the container 2 opens out of the receptacle 10 and an outer zone of the container 2, limited by a periphery, comes to close the cavity 12 by sealingly applying the periphery of the outer zone against the edge 14 of the opening 13.

According to a first embodiment illustrated in Figures 1 to 4, the receptacle 10 is in the form of an enclosure whose cavity 12 is dimensioned to accommodate the assembly comprising the body 3 and the bottom 6 of the container 2. Indeed, the cavity 12 is of greater height and width, respectively, at the height and the diameter of the body 3.

In the example illustrated in Figures 1 to 4, the enclosure constituting the receptacle 10 comprises two half-enclosures 10A, 10B each having an inner face 17 and in each of which is formed a half-cavity 12A, 12B. These two half-enclosures 10A, 10B are movable relative to each other (in translation or, as in the example shown, in rotation about a common hinge 18), so that the enclosure constituting the receptacle 10 can adopt: an open position (Figure 1) in which the half-enclosures 10A, 10B are spaced from each other to allow the introduction of the container 2 for its treatment, and the evacuation of the container 2 treated, and a closed position (Figures 2, 3) wherein the two half-speakers 10A, 10B are applied against each other to jointly form the enclosure constituting the receptacle 10 and close the cavity 12 around the body 3 of the container 2.

In the closed position of the enclosure constituting the receptacle 10, the inner faces 17 of the half-enclosures 10A, 10B are in mutual contact to form a joint plane 19. In order to guarantee the sealing of the cavity 12 in the closed position, at least one of the half-chambers 10A, 10B is preferably provided with a peripheral seal 20, attached or overmoulded on the internal face 17, for example being housed in a groove 21 formed therein.

In this first embodiment, the container 2 is intended to be suspended by its flange 5, which is sealingly applied against the edge 14 of the opening 13. In the example shown, the opening 13 (formed half in each half-enclosure 10A, 10B), is circular in outline and of greater diameter than the diameter under the neck of the container 2, while being of smaller diameter than the external diameter of the collar 5.

Thus, according to this embodiment, the outer zone is constituted by the body 3 and the bottom 6 of the container 2 and the periphery of this zone, which is sealingly applied against the edge 14 of the opening 13 is constituted by the collar 5.

However, it should be noted that the sealing instead of being performed by the collar could be achieved for example by tightening the neck 4 in the seal 15 or by enclosing the junction zone between the body 3 and the neck 4.

In the illustrated example, the seal 15 is formed by assembling two half-seals 15A, 15B each included in a half-chamber 10A, 10B so as to come, in the closed position of the chamber constituting the receptacle. 10, in sealing contact against each other in the plane 19 of joint.

As illustrated in FIGS. 1 and 2, the enclosure 10 is equipped with a locking system 22 in the closed position. This locking system 22 comprises for example a latch 23 carried by a half-enclosure 10A and a bolt 24 carried by the other half-enclosure 10B. The bolt 24 is movable between an unlocked position (Figure 1) in which it is released from the striker 23 to allow the opening and closing of the enclosure constituting the receptacle 10, and a locked position in which, in the closed position of the enclosure, it is engaged in the striker 23 to maintain it in its closed position. As seen in Figures 1 and 2, the striker 23 as the bolt 24 may include several points of attachment on the height of each half-chamber 10A, 10B, so as to distribute the holding forces.

According to a second embodiment, the receptacle 10 is substantially in the form of a bowl. In this embodiment, the receptacle 10 is advantageously monobloc. The seal 15, fixed on the edge 14, can therefore also be monobloc and have a closed contour. The edge 14 (and therefore the seal 15 which follows the profile) forms a counterprint of the portion of the container 2 (body 3 and / or bottom 6) against which it is intended to be applied (or reciprocally). In the example shown, the edge 14 is of annular shape, and allows the sealing application of an annular seat 25 formed at the periphery of the bottom 6 of the container 2. In this case, it is the bottom 6 which forms the outer zone and the seat 25 which forms the periphery which applies sealingly against the seal 15.

According to another embodiment, not shown, the receptacle 10 is substantially in the form of a bowl, the edge 14 and the seal 15 are profiled so as to conform to the shape of a side wall portion of the container, other words a portion of the body 3. According to this mode, it is the wall portion which forms the outer zone and the periphery of this wall portion which is applied in a sealed manner against the seal. When the vacuum is effected, it is the wall portion thus positioned which is deformed. The treatment unit 9 comprises, secondly, a pneumatic distribution system 26 designed to create the depression (and conversely restore the pressure) in the cavity 12.

This system 26, simply shown diagrammatically in FIGS. 3, 4 and 5, comprises a vacuum pump 27, a circuit 28 connecting the pump 27 to the cavity 12, a distributor 29 (eg a three-way valve) mounted on the connection circuit 28 being interposed between the pump 27 and the cavity 12, as well as a control unit 30 (eg computerized) capable of controlling the distributor 29. The connection of the connection circuit 28 to the receptacle 10 is for example realized by means of a connection 31 (particularly rapid type) mounted in the wall 11 of the receptacle 10 and communicating with the cavity 12 through a bore 32 formed therein.

The distributor 29 is designed to adopt, on control of the control unit 30, at least two positions: a depression position, illustrated in Figures 3 and 5, wherein the cavity 12 is placed in communication with the pump 27, and a pressurization position, illustrated in Figure 4, wherein the cavity 12 is in communication with the atmosphere. To form package 1 from container 2, the procedure is as follows.

The container 2 is first positioned relative to the receptacle 10 so that the opening in the neck 4 of the container 2 opens out of the receptacle 10 and an outer zone of the container 2, bounded by a periphery, to close the cavity 12 by sealingly applying the periphery of the outer zone against the edge 14 of the opening 13.

In the first embodiment, the body 3 of the container 2 is introduced, in the open position of the enclosure constituting the receptacle 10, into the cavity 12. The enclosure constituting the receptacle 10 is closed around the body 3 and locked, the 2 container being suspended from the edge 14 by its flange 5, with its body 3 housed in the cavity 12 and closed. Thus, the opening of the neck 4 remains outside the cavity 12. The closure of the enclosure 10 with the crushing of the peripheral seal 20, on the one hand, and the application of the flange 5 against the seal 15, on the other hand, seal (air) the cavity 12.

In the second embodiment, the periphery of the bottom 6 of the container 2 is applied against the edge 14, and more precisely against the seal 15. In the example of FIG. 5, the seat 25 is applied against the annular seal and the bottom faces the cavity 12.

In the other mode mentioned, but not shown, a portion of the wall 3 is opposite the cavity 12, and it is the periphery of this part which is applied against the edge 14, and more precisely against the seal 15 sealing.

The container 2 may have been filled prior to its positioning relative to the receptacle 10. Alternatively, the container 2 may be filled after being positioned relative to the receptacle 10.

Once the positioning of the container 2 has been completed, a depression is created in the cavity 12. This operation is carried out by placing the cavity 12 with the pump 27 in communication with the control unit 30 and via the distributor 29. empty. At least a partial vacuum (for example a few hundred millibars, counted negatively from atmospheric pressure, typically from 400 to 800 mbar) is thus achieved in the cavity 12 by pumping air present in the cavity 12 to the outside of the container 2. The value of the vacuum depends on the shape of the container and the mechanical characteristics of the material, in particular its elastic limit, as well as the wall surface 3 contained or facing the cavity 12. can consider that the largest value of vacuum is preferred, as the container does not deform plastically (that is to say, not reversible).

This partial vacuum causes, by pressure difference between the inside of the container 2 (maintained at atmospheric pressure, possibly doubled by the hydrostatic pressure of the contents) and the outside of the container 2 (maintained at an at least partial vacuum), the deformation of it, which undergoes inflation, and therefore an increase in its internal volume.

In the first embodiment (FIG. 3), the depression in the cavity 12 (outside the container 2) causes inflation of the entire body 3 and the bottom 6 of the container 2, as illustrated by the black arrows. , the container 2 adopting an inflated form (in dashed lines) in which its interior volume is greater than its initial internal volume (which corresponds to its normal internal volume in the absence of external stress).

In the second embodiment (FIG. 5), the depression in the cavity 12 (outside the container 2) causes a localized deformation of the bottom 6 of the container 2, which tends to be sucked into the cavity 12 As illustrated in FIG. 5 by the black arrow, the bottom 6, initially concave, adopts a more flattened shape (in dotted lines) which induces an increase in the interior volume of the container 2.

In the third mode mentioned, it is a wall portion 3 which would be deformed.

It will be observed that the appearance of the depression in the cavity 12 causes a tightening of the contact between the container 2 and the seal 15 (and, in the first embodiment, a tightening of the contact between the two half-enclosures 10A, 10B, at the level of the peripheral seal 20), for the benefit of sealing the cavity 12.

The container 2 is then filled, unless it has been filled before being positioned relative to the receptacle 10, or after having been positioned therein, but before the pressure is restored in the cavity 12.

If the cavity 12 is subjected to a depression after the filling of the container 2, the increase in the internal volume of the container 2 causes a drop in the level of the product 7, as shown by the horizontal dotted line at the top of FIG.

Anyway, the filling of the container 2 is made so as to leave, above the product 7, a volume 33 in the neck, that is to say a volume of air trapped between the surface of the product 7 and the plug 8).

The depression is performed at a pressure level and / or for a period such that the deformation of the container 2 remains elastic, that is to say that the container 2 tends to return to its original shape when the depression is stopped and the cavity 12 is returned to atmospheric pressure.

The depression in the cavity 12 being maintained, the filled container 2 is then sealed by means of a plug 8 attached (Figure 4), mounted (for example screwed) on the neck 4.

Once the closure of the filled container 2 has been completed, the pressure in the cavity 12 is restored. This operation is carried out by placing the control unit 30 in command on the control unit and via the dispenser 29. cavity 12 with the atmosphere.

Under the inherent elasticity of the material, and as illustrated by the black arrows in Figure 4 (in the first embodiment), the container 2 tends, from its inflated form (solid line in Figure 4) to return to its original shape (dashed in Figure 4) - and thus its initial volume.

This results in a pressurization of the internal volume of the container 2. The product 7 (eg a liquid) being incompressible, it is the volume 33 under the neck which is compressed by the rise of the level of the product 7, as illustrated by FIG. the dashed horizontal line in Figure 4.

This pressurization of the container 2 increases the rigidity, and therefore the mechanical strength, especially in axial compression. This results in a better resistance of the container 2 during its handling, especially when stacked within a pallet. The packaging 1 thus formed can then be dissociated from the receptacle 10 to undergo, outside thereof, finishing operations (labeling, packaging and palletizing). The treatment unit 9 can be mounted on a carousel equipped with a series of receptacles 10 all identical, each able to accommodate a container 2 to be treated. In this case, the pump 27 may be common to all the processing units 9, the distributor 29 then being connected thereto via a collector which is also common.

Claims (9)

A method of forming a package (1) from a container (2) including a body (3), an open neck (4) extending from an upper end of the body (3) , and a bottom (6) which closes the body (3) from a lower end thereof, this method comprising a filling operation of the container (2) and a closing operation of the container (2) thus filled , said method being characterized in that it comprises the steps of: providing a receptacle (10) defining a cavity (12) terminating in an opening (13) having an edge (14); positioning the container (2) relative to the receptacle (10) so that the opening in the neck (4) of the container (2) opens out of the receptacle (10) and an external area of the container ( 2), limited by a periphery, comes to close the cavity (12) by sealingly applying said periphery of the outer zone against the edge (14) of the opening (13) of the cavity (12); keep open the container (2) thus positioned; creating a depression in the cavity (12); fill the container (2) if it is not already filled; plug the container (2) thus filled; restore the pressure in the cavity (12). 2. Method according to claim 1, characterized in that the outer zone is constituted by the assembly comprising the body (3) and the bottom (6) of the container (2), in that said assembly is housed in the cavity ( 12), and the periphery sealingly applied against the edge (14) of the opening (13) is between the body (3) and the opening of the neck (4). 3. Method according to claim 2, characterized in that the neck (4) is separated from the body (3) by a flange (5) and the periphery sealingly applied against the edge (14) of the opening (13) is constituted by said flange (5). 4. Method according to one of claims 2 or 3, characterized in that, the receptacle (10) being in the form of a chamber having an open position and a closed position, the positioning of the container (2) comprises the introducing the body (3) into the enclosure in the open position, and closing the enclosure around the body (3) of the container (2). 5. Method according to claim 1, characterized in that the bottom (6) of the container is limited by an annular seat (25) formed at the periphery of the bottom (6), the seat (25) constitutes said periphery which is applied sealingly against the edge (14) of the opening (13) and the bottom (6) constitutes said external zone of the container (2) which closes the cavity (12) when the seat is applied in a sealed manner against the edge (14) of the opening (13). 6. A method according to claim 1, characterized in that a portion of the wall (3) of the container (2) constitutes the outer zone which closes the cavity (12) by sealingly applying the periphery of the wall portion. (3) against the edge (14) of the opening (13) of the cavity (12) 7. Method according to one of claims 1 to 6, characterized in that the creation of the depression is effected by pumping air present in the cavity (12) outside the container (2). 8. Method according to one of claims 1 to 7, characterized in that the filling of the container (2) is performed before its positioning relative to the receptacle (10). 9. Method according to one of claims 1 to 7, characterized in that the filling of the container (2) is performed after positioning the container (2) relative to the receptacle (10), and before the creation of the depression in the cavity (12).