METHOD AND DEVICE FOR PRESSURE-PACKAGING A CONTAINER TO BE PROCESSED AND ASSOCIATED PRESSURE-PACKAGING MACHINE

Abstract

Disclosed is a method and a device for pressure-packaging a container to be processed, which is sealed by a stopper arranged above a head space of the container, the method including: engaging sealingly a cap over the stopper, the cap including a piercing unit and sealing unit; piercing a hole through the stopper by lowering the piercing unit; lifting the piercing unit out of the stopper; introducing a fluid into the head space via the hole; sealing the hole by melting the material of the stopper by lowering the sealing unit by melting; lifting the sealing unit by melting; and removing the cap.

Claims

1-17. (canceled)

18. A method for pressure-packaging a container to be processed at least partially filled with contents and stoppered in a tight manner by a stopper arranged above a head space of the container, wherein the method comprises the following steps: engaging sealingly a cap over an outer surface of the stopper, wherein piercing means, fluid injection means and means of sealing by melting being arranged inside the cap; piercing a hole through the stopper by lowering the piercing means toward the stopper; raising the piercing means outside the stopper; introducing a fluid into the head space of the container through the hole, arranged through the stopper, using the fluid injection means, so as to obtain a residual pressure at least equal to the atmospheric pressure in the head space of the container; sealing the hole of the stopper by melting the material of the stopper by lowering the means of sealing by melting toward the stopper; raising the means of sealing by melting; and removing the cap.

19. The method according to claim 18, wherein the step for introducing fluid into the head space comprises introducing fluid in an initial phase at a first pressure value, then introducing fluid in a final phase at a second pressure value below the first pressure value.

20. The method according to claim 18, wherein the method further comprises a step for verification, using one of optical means and inductive means arranged in the cap, of the integrity of the piercing means after the step of raising of the piercing means.

21. The method according to claim 18, wherein the method further comprises a step for verification, using an optical camera arranged inside the cap, of the sealing quality of the hole by the means for sealing by melting.

22. The method according to claim 18, wherein, in the case of hot filling at a temperature above 73 C., the fluid is introduced into the head space after cooling of the contents to a temperature below 45 C.

23. The method according to claim 18, wherein the introduction pressure of the fluid is configured to generate a residual pressure in the container between 1.01 bars and 2.5 bars.

24. The method according to claim 18, wherein the fluid is an inert and sterile gas.

25. The method according to claim 18, wherein the method further comprises a step for circulating sterile fluid between the cap and the stopper.

26. The method according to claim 18, wherein the method further comprises, before the step for engaging the cap over the stopper, a step for sterilization of the outer surface of the stopper by at least one of punctual heating, chemical sterilization, steam, emission of pulsed light.

27. A device for pressure-packaging a container to be processed at least partially filled with contents and stoppered in a tight manner by a stopper arranged above a head space of the container, the device comprising a cap that comprises piercing means, fluid injection means and means of sealing by melting, the device being configured to carry out the pressure-packaging method according to claim 18.

28. The device according to claim 27, wherein the piercing means and the means of sealing by melting are arranged in the cap such that their respective movement axes are secant at a point located in one of the material of the stopper and above the material of the stopper when the cap is engaged over the stopper.

29. The device according to claim 27, wherein the piercing means comprise a needle adapted to move linearly.

30. The device according to claim 29, wherein the needle is solid and has a cone-shaped pointed end.

31. The device according to claim 29, wherein the needle is heated by a heating means.

32. The device according to claim 27, wherein the means of sealing by melting comprise a heating cannula adapted to move linearly.

33. The device according to claim 27, wherein the fluid injection means comprise at least one fluid inlet adapted to receive a pressurized fluid and inject it into the cap engaged sealingly over the stopper.

Description

[0068] In order to better illustrate the subject matter of the present invention, below we will describe, as a non-limiting illustrative example, one preferred embodiment in reference to the appended drawings.

[0069] In these drawings:

[0070] FIG. 1 is a perspective view of a device for pressure-packaging a container to be processed according to the present invention;

[0071] FIG. 2 is a sectional detail view of the device of FIG. 1 in the non-engaged position;

[0072] FIG. 3 is a sectional view similar to FIG. 2 during the engagement step;

[0073] FIG. 4 is a sectional view similar to FIG. 2 during the piercing step;

[0074] FIG. 5 is a sectional view similar to FIG. 2 during the fluid introduction step;

[0075] FIG. 6 is a sectional view similar to FIG. 2 during the sealing step;

[0076] FIG. 7 is a sectional view of the needle of the device of FIG. 1.

[0077] FIG. 1 shows a device 1 for pressure-packaging a container to be processed 2.

[0078] The container to be processed 2, the shape of which is not limited according to the invention to the shape shown in the figures, is at least partially filled with contents and stoppered in a tight manner by a stopper 3 arranged above a head space of the container 2.

[0079] In the case of the present description, the container 2 undergoes hot filling, and is a bottle, in particular made from PET (polyethylene terephthalate), with a low grammage, with contents, such as fruit juice, brought to a temperature capable of destroying pathogenic organisms, namely a temperature above 73 C. and in the case at hand 85 C.

[0080] Once the container 2 is filled with the hot contents, it is stoppered by the stopper 3 of a known type, in particular an injection- or compression-molded screwcap, monolithic and made from a single material, free of any additional sealing element.

[0081] The tightness is obtained by contact under mechanical pressure of the material of the stopper 3, in the case at hand of its inner face, on the material of the peripheral edge of the neck 2a of the container 2, the screwing making it possible to exert said necessary mechanical pressure.

[0082] During closing, said stopper 3 allows a head space to remain. This space results from the filling without overflow, since the contents must not in any case overflow and find themselves on the lip of the neck 2a before closing, since the contents would then be an entryway below the stopper 3 and the container 2 would be unsuitable for sale.

[0083] The stopper 3 is free of any mechanism or any other accessory for compensating for pressure. The air captured in the head space is hot, but at atmospheric pressure.

[0084] It should be noted that the present invention also applies to certain stoppers commonly used, in particular in the United States, that are of the dual-material type with an inner membrane used to guarantee only the tightness between the surface of the neck of the container 2 and the stopper 3 by compression during screwing, unlike the inner lip for stoppers of the single-material type. However, this inner membrane for such a dual-material stopper does not have the necessary characteristics to guarantee self-sealing of the stopper in the case of piercing using a needle, then a removal of the needle outside the stopper.

[0085] The container 2 is adapted to receive contents at the selected sterilization temperature without damage, but is free of vacuum compensation means.

[0086] The container 2 is set in motion immediately after filling with the contents, in order to place all of the inner surfaces of the container 2 in contact with the contents brought to the sterilizing temperature.

[0087] The container 2 and its contents are next cooled in a cooling tunnel by spraying water, for example to bring the assembly close to ambient temperature.

[0088] When the container 2 reaches a temperature below 75 C., due to its component material, said container 2 collapses on itself because the volume of gas and liquid is reduced to 3 to 5% inside the container 2. This reduction increases over the course of the cooling. The collapse phenomenon is close to its maximum at a temperature of less than or equal to 45 C.

[0089] The pressure-packaging device 1 comprises a cap 4, also called engagement head, that comprises, inside it, piercing means 5, fluid injection means 6 and means of sealing by melting 7.

[0090] The pressure-packaging device 1 further comprises a horizontal lower support 8 on which the container 2 is positioned, a horizontal upper support 9 comprising a notch 9a in which the neck 2a of the container 2 is inserted, and a vertical support 10 to which the lower support 8 and the upper support 9 are connected.

[0091] The cap 4 is vertically movable, by means of a vertical movement motor 11, between an idle position at a distance from the upper support 9 and an engagement position in which the cap 4 is engaged in a tight manner over the stopper 3 of the container to be processed 2. It is of course understood that the invention is not limited in this respect: either the cap is movable, engaged over the container brought below the cap, or the cap is stationary, the container being brought into the cap.

[0092] The pressure-packaging device 1 is configured to carry out a method for pressure-packaging the container to be processed 2 that comprises the following steps: engaging the cap 4 tightly over the outer surface of the stopper 3; piercing a hole through the stopper 3 by lowering piercing means 5 toward the stopper 3; raising the piercing means 5 outside the stopper 3; introducing a fluid into the head space of the container 2 by means of said hole, arranged through the stopper 3, using fluid injection means 6, so as to obtain a residual pressure at least equal to the atmospheric pressure in the head space of the container 2; sealing said hole of the stopper 3 by melting of the material of the stopper 3 by lowering means for sealing by melting 7 toward the stopper 3; raising the means for sealing by melting 7; and removing the cap 4. The different steps of the method will be described in more detail in FIGS. 2 to 6.

[0093] The method according to the invention can be carried out in a production line, with one or several stations upstream or downstream, in which case a conveying device will transport the container to the station of the production line implementing the method according to the invention.

[0094] The pressure-packaging method according to the invention makes it possible in particular to perform hot filling by using bottles with the lowest possible extra weight of material relative to the containers used for cold filling in a sterile atmosphere, and also makes it possible to compensate the vacuum in cold-filled containers that may experience deformations by vacuum, especially if the containers themselves have a low mechanical strength.

[0095] Furthermore, the engagement of the cap 4 over the stopper 3 being done in a tight manner, the piercing means 5 can be raised, before the fluid injection step, while maintaining the pressure between the cap 4 and the stopper 3, the piercing is therefore clean without shavings, or waste by pushing back plastic material from the stopper 3 only, the removal of the piercing means 5 during the fluid injection also making it possible to avoid any splashes of the contents on the piercing means 5 for improved hygiene.

[0096] The stopper 3 used in this method is a traditional single-piece stopper, with no inner membrane, and is therefore inexpensive.

[0097] The container 2 thus contains contents at least with a balanced pressure and preferably under a slight pressure so that the internal pressure difference with respect to the pressure outside the container 2 avoids generating any collapse of the container 2.

[0098] FIG. 2 shows the pressure-packaging device 1 in the non-engaged position of the cap 4.

[0099] The container 2 is partially filled with contents 12 such that a head space 13 without contents remains at the neck 2a of the container 2, the container 2 being stoppered in a tight manner by the stopper 3 arranged above the head space 13 of the container 2.

[0100] The piercing means 5 comprise a piston 14 at the end of which a needle 15 is provided, said piston 14 being adapted to move linearly in a cylinder 16 formed on the cap 4, the travel of the piston 14 being limited by a piston chamber 17 formed in the upper end of the cylinder 16.

[0101] Thus, the needle 15 is configured to pierce the stopper 3 when the cap 4 is engaged over the stopper 3 and the piston 14 is in its deployed position.

[0102] The means for sealing by melting 7 comprise a piston 18 at the end of which a heating cannula 19 is provided, said piston 18 being adapted to move linearly in a cylinder 20 formed on the cap 4, the travel of the piston 18 being limited by a piston chamber 21 formed in the upper end of the cylinder 20.

[0103] The pistons 14 and 18 can be actuated electrically or hydraulically. In order not to overload the figures, the electrical power or hydraulic actuating wires of the pistons 14 and 18 have not been shown in the figures. Likewise, the heating elements making it possible to heat the needle 15 or the heating cannula 19, as well as their respective power sources, have not been shown so as not to overload the figures.

[0104] Thus, the heating cannula 19 is configured to seal, by melting, the hole formed in the stopper 3 by the needle 15 when the cap 4 is engaged over the stopper 3 and the piston 18 is in its deployed position, the plastic material of the stopper 3 melting in contact with the heating cannula 19.

[0105] The needle 15 and the heating cannula 19 are situated in an inner cavity 22 of the cap 4.

[0106] The fluid injection means 6 comprise several fluid inlets adapted to receive a pressurized fluid and inject the latter inside the inner cavity 22 of the cap 4, the cap 4 being adapted to contain up to five fluid inlets 6.

[0107] The pressure-packaging method also comprises, before the step for engagement of the cap 4 over the stopper 2, a step for sterilization of the outer surface of the stopper 3 by punctual heating, chemical sterilization using a sterilizing liquid, steam, pulsed light emission or another similar method, in order to guarantee the destruction of the pathogenic organisms present on the outer surface of the stopper 3.

[0108] The inner cavity 22 of the cap 4 is still under sterile gas overpressure by a first fluid inlet 6, even before the engagement to maintain the sterility of the stopper 3 done beforehand.

[0109] There are two other sterile gas inlets 6 for the fluid introduction step, also called inflation step.

[0110] The last two fluid inlets 6 could be used for the injection of a sterilizing fluid after the engagement and the piercing and a rapid discharge by aspiration of the sterilizing fluid before the piercing.

[0111] FIG. 3 shows the pressure-packaging device 1 during the engagement step.

[0112] During the engagement step, the pistons 14 and 18 respectively of the needle 15 and the heating cannula 19 are in their retracted positions, also called idle positions.

[0113] The cap 4 is engaged in a tight manner over the outer surface of the stopper 4 such that at least part of the stopper 3 is inserted into at least part of the inner cavity 22 of the cap 4.

[0114] The pistons 14 and 18 are arranged in the cap 4 such that their respective movement axes are secant at a point located in the material of the stopper 3 or slightly above the latter when the cap 4 is engaged over the stopper 3, said point being located preferably at the center of the upper surface of the stopper 3, or slightly above, off-centered, based on the shape of the heating cannula 19.

[0115] The pressure-packaging method may also comprise, after the step for engagement of the cap 4 over the stopper 3, a step for circulating sterile fluid, preferably an inert gas such as nitrogen, in the inner cavity 22 of the cap 4 via certain fluid inlets 6. An overpressure is thus created between the stopper 3 and the cap 4 to maintain a positive pressure greater than or equal to the internal pressure of the container 2 until sealing by melting.

[0116] FIG. 4 shows the pressure-packaging device 1 during the piercing step.

[0117] During the piercing step, the piston 14 of the needle 15 is in its deployed position, such that the needle 15 is lowered to the stopper 3 and pierces a hole 23 through the material of the stopper 3.

[0118] The needle 15 is never in contact with the contents 12 during the piercing.

[0119] The needle 15 makes the hole 23 by penetration in the plastic material of the stopper 3, by deformation and pushing back of the material, without tearing material.

[0120] This piercing step is immediately followed by a step for raising the needle 15 into the idle position of the piston 14.

[0121] The pressure-packaging method may also comprise a step for verification, using an optical or fiber-optic camera connected to an optical sensor (not shown in FIG. 4) arranged in the cap 4, of the integrity of the needle 15 after the step for raising the needle 15, thus making it possible to verify optically whether the needle 15 is or is not broken after the piercing step.

[0122] An optical camera offboard from the cap can inspect the filling level of the container 2 at the end of the pressure-packaging method to detect any break of the needle 15. Indeed, during normal processing, the level of the contents 12 must drop to a predetermined level, whereas in case of non-piercing and therefore non-introduction of fluid, the level of the contents 12 will not decrease.

[0123] A proximity sensor system could also verify the presence of the whole and unbroken needle 15, without deviating from the scope of the present invention.

[0124] FIG. 5 shows the pressure-packaging device 1 during the fluid introduction step.

[0125] During the fluid introduction step, the pistons 14 and 18 respectively of the needle 15 and the heating cannula 19 are in their idle positions.

[0126] A fluid 24 is introduced into the inner cavity 22 of the cap 4, then into the head space 13 of the container 2 via the hole 23, arranged through the stopper 3, using one of the fluid inlets 6, so as to obtain a residual pressure at least equal to the atmospheric pressure in the head space 13 of the container 2.

[0127] The fluid 24 is an inert and sterile gas such as nitrogen, in particular in gaseous form, which makes it possible not to cause subsequent oxidation of the contents 12, after bottling. This avoids over-collapse due to later oxygen consumption, since there is none or very little, the inert gas having in large part replaced the initially confined air.

[0128] In the case of hot filling at a temperature above 73 C., the fluid 24 is introduced into the head space 13 after cooling of the contents 12 to a temperature below 45 C.

[0129] The introduction pressure of the fluid 24 is configured to generate a residual pressure in the container 2, between 1.01 bars and 2.5 bars, and preferably between 1.01 bars and 1.4 bars.

[0130] The step for introducing the fluid 24 into the head space 13 preferably comprises introducing fluid 24 in an initial phase at a first pressure value, then introducing fluid 24 in a final phase at a second pressure value below the first pressure value. It is thus possible to greatly increase the pressure in the initial pressurization phase immediately after the piercing, and to have a lower pressure in the final phase in order to adjust the final pressure just before the sealing by melting.

[0131] FIG. 6 shows the pressure-packaging device 1 during the sealing step.

[0132] During the sealing step, the piston 18 of the heating cannula 19 is in its deployed position, such that the heating cannula 19 is lowered to the hole 23 formed in the stopper 3 by the needle 15.

[0133] The heating cannula 19 makes it possible to re-stopper, by melting of the plastic material of the stopper 3, the hole 23 formed in the stopper 3, which makes it possible to guarantee the final tightness of the container 3 while compensating the vacuum in the container 2.

[0134] The sealing step is carried out in a period of between 0 and 5 seconds.

[0135] The pressure-packaging method can also comprise a step for verification, using an optical camera (not shown in FIG. 6) arranged in the inner cavity 22 of the cap 4, of the sealing quality of the hole 23 by the heating cannula 19, which thus makes it possible to verify optically whether the sealing quality of the hole 23 by the heating cannula 19 is good or bad.

[0136] The sealing step is followed by a step for raising the heating cannula 19 into the idle position of the piston 18, then a step for removing the cap 4 from the stopper 3.

[0137] The method according to the present invention allows the hot filling in containers 2, for example made from PET, with reduced grammages of about 15% relative to the hot filling method with deformation of the container, which is a considerable material reduction in light of the multiplier coefficient of the number of containers 2 produced.

[0138] No particular architecture must be studied for the wall; any technical panel and/or complex petalod bottom becomes unnecessary.

[0139] The shapes of containers 2 are in fact much freer and plainer, and recycling is less expensive, since less material is used.

[0140] Placing the container 2 under atmospheric pressure or slight pressure allows better stacking and palletizing.

[0141] The method according to the present invention applies to all filling modes, and even to pressurizing of containers 2 cold filled under sterile atmosphere for which one wishes not only to compensate a potential decrease in the volume of the head space 13 by consumption of the oxygen, but also to create a slight overpressure to reinforce the mechanical strength, or even to inject a neutral gas to replace air confined in the head space 13 in order to preserve all of the organoleptic properties of the products that oxidation may alter.

[0142] FIG. 7 shows the needle 15 of the pressure-packaging device 1.

[0143] The needle 15 is forcibly fitted into a substantially cylindrical needle holder 25, said needle holder 25 comprising an end 25a, opposite the needle 15, configured to fit forcibly in the end of the piston 14.

[0144] The needle 15 is cylindrical and solid and has a cone-shaped pointed end. Thus, the needle 15 is more solid compared to the hollow hypodermic needle with a beveled tip of the prior art, which makes it possible to prevent the needle 15 from breaking during the piercing step.

[0145] The needle 15 is preferably heated by a heating means (not shown in FIG. 7), the heating of the needle 15 making it possible both to sterilize the needle 15 and facilitate the piercing of the plastic material of the stopper 3. The needle 15 is preferably heated to a temperature above 95 C. for sterilization thereof and below 130 C. to avoid possible melting of the plastic of the stopper 3 during piercing and adhesion of plastic particles on the needle 15, which could then detach during piercing of the stopper 3 of another container 2.

[0146] The temperature of the needle 15 is preferably maintained and monitored at all times by a resistance/probe placed in the needle holder 25.

[0147] The diameter of the piercing hole must make it possible to combine rapid inflation (the largest possible diameter) and welding safety (the smallest possible diameter). As a non-limiting example, a needle with a diameter of 0.7 mm appears to be a good compromise. It is of course understood that the invention is not limited in this respect, the diameter of the needle being adapted to be between 0.3 and 0.8 times the thickness of the stopper.