EP3535190A1 - Device and method for pressure-packaging a container to be processed and associated pressure-packaging machine - Google Patents

Abstract

The invention relates to a device and a method for pressure-packaging (1) a container to be processed (2), which is sealed by a stopper (3), said device (1) comprising a cap (4) comprising a needle (15), fluid-injection means (6), and a heating cannula (19), said cap (4) being designed to be applied to the stopper (3) in a tight manner, said needle (15) being able to move so as to pierce a hole (23) through the stopper (3), said cannula (19) being able to move so as to close said hole (23) by the melting of the material of the stopper (3), the needle (15) and the cannula (19) being arranged such that the axes of movement thereof are secant at a point located in the stopper (3), the end (25) of the cannula (19) being convex.

Description

The present invention relates to the field of bottling, and relates in particular to a device and a method for pressure-conditioning a container to be treated. at least partially filled with a content and sealingly sealed by a plug disposed above a headspace of the container, and on an associated pressure conditioning machine.

 The term "content" is understood to mean a liquid or semi-liquid food product intended to be marketed outside the cold chain such as an acidic fruit juice, in a container, a container within the meaning of the present invention being an envelope polymeric material such as a bottle, provided with a plug of known type, for hermetically closing the bottle after filling, usually screw.

 The liquid or semi-liquid food contents are sensitive to microbial growth and the organoleptic qualities are very rapidly modified in the absence of sterilization treatment of the pathogenic organisms and / or the presence of oxygen.

In known manner, the high temperature heat treatment of the order of 90 ° C for a few seconds, also called flash pasteurization, is also applied to liquids or semi-liquid foods with a pH lower than 4.7, such as juices. example. In this known method, the liquid is treated in a specific unit, prior to the filling which must be performed in a sterile manner. It must therefore be ensured that the chain remains sterile. This known filling method consists in cold filling in a sterile environment, the container and its cap being cold sterilized by means of a sterilizing liquid and then rinsing and the contents then being introduced into this container in an aseptic atmosphere. The advantage is to use packaging that requires little material because the necessary mechanical properties are limited. The process does not cause volume variations due to temperature variations. In addition, the necessary mechanical properties being limited, external aesthetic forms are more free. Nevertheless, the oxygen contained in the headspace can be consumed and there is then a depression in the bottle. It is therefore necessary to provide either a bottle resistant to this depression, or a compensation of this depression.

 This "sterile" technique induces complex, expensive, rigorous and expensive maintenance. In addition, the quality control can be achieved only by sampling, so there is no systematic control and therefore no certainty as to the sterilization of liquid or semi-liquid food content and conditioned.

Another known solution is that of sterilization simultaneously with filling by introducing a sterilizing liquid. It is understood that the addition of a sterilizing product, which is a chemical compound, is not necessarily accepted by all the health legislation of countries and that the consumer himself may be reluctant to absorb not only the liquid food product or semi-liquid he has chosen but also the residual sterilant introduced. Such preservatives can induce modifications of organoleptic qualities both during storage and after opening the packaging.

 A last solution among the main solutions known from the prior art is to heat-fill a package, that is to say to introduce the contents brought to a high temperature directly into the container without it having undergone a sterilization treatment. In this case, it is the content itself that ensures the sterilization of the container because it is introduced at a temperature allowing the destruction of pathogenic organisms, so greater than 73 ° C, generally 85 ° C. The package is closed and immediately agitated, generally by turning, to heat treat all internal surfaces of the container, including the inner face of the cap.

 The plug in the case of hot plugging is a known type of plug, monomatiere, obtained by molding, controlled before installation to avoid any installation of a faulty plug. Such caps are extremely inexpensive.

 This solution is interesting because it ensures that each package is necessarily sterilized internally, without there being any lack.

If the plug is inexpensive, the disadvantage of hot filling is to require a package that withstands both the temperature and secondly the collapse phenomenon related to the retraction of the volume of the liquid during cooling, this which depresses the interior of said container. In addition, the oxygen of the air trapped during filling is also "consumed" after cooling by the liquid or semi-liquid food composition, which causes a delayed depression which may also cause additional deformation of the container.

 The packaging must therefore be mechanically resistant and / or deformable, requires a large amount of material and often a specific architecture with panels to resist the deformations of this package and / or to compensate for the depression by appropriate deformations. Thus funds can take two positions, one deformation inwardly under the effect of the depression so as to compensate said depression. The deformation of the bottom being under the bottle, this does not cause stability problem of the bottle when it is placed on said bottom, only the digging of the bottom is more pronounced, which is invisible, except to look from below. It is understood that such a background must be sophisticated, complex to achieve and induces a clear overhead.

 It should be noted that this also goes in the opposite direction of the sustainable development needs which aim to reduce the quantities of polymer material used, which also has an impact on the price of the manufacturing and an impact on the recycling therefore consequently on the final price.

 However, this process is the one that requires the simplest packaging lines both in installation and maintenance, which is simple to control since the main control is on a single parameter: the temperature of the content.

Other compensation solutions have been implemented, one of them for example consists of introducing a drop of liquid nitrogen into the headspace immediately before capping. Liquid nitrogen goes into the gaseous state with a very large increase in volume, This places the volume of the bottle under pressure and makes it possible to compensate as the cooling of the volume of retraction of the liquid. In the final state, at room temperature, the equilibrium is found and the nitrogen can only cause additional inerting. However, this process is relatively complex to control and quite difficult to reproduce.

 Advances in processes and container materials have improved performance. Nevertheless, the purpose which is also that of the present invention is to be able to proceed in particular hot filling using bottles having an overweight of material as low as possible compared to the containers used for filling in sterile environment, cold.

 It is also useful to be able to compensate for depression in cold-filled containers that may also be deformed by depression, or to improve their mechanical strength, especially if the containers themselves have a low mechanical strength, which is also a problem. objective of the present invention.

 It is therefore necessary to provide a method of compensating for depression in a container, at least, and more generally control of the overpressure, especially in the case of a hot filling. This overpressure, after cooling, compensates for the decrease in volume of the head space which is a few percent cooling. This overpressure also makes it possible to compensate for the pressure decrease related to the oxygen consumption.

These various sources of pressure reduction, when no compensation or no overpressure is provided, cause a distortion of the pressure. bottle and makes it unfit for marketing. These depressed conditions also lead to poor grip by consumers but also to poor mechanical strength of containers during transportation by pallets, even filmed.

 Patents are known which have proposed a method of compensation, such as patent applications FR 2322062 A1 and US 2015/0121807 A1 which propose injecting a gaseous fluid into the headspace through a specific closure member. Such a device consists in introducing a needle through the closure member, injecting a gas through the needle into the head space and removing said needle, the closure member ensuring itself a seal. It turns out that it requires a closure member provided with specific means, which is totally unacceptable compared to the price of the package. In addition to the price and in addition, this leads to complex problems related to the presence of several materials, the complexity of quality control, difficulties in recycling and the lack of certainty of quality capping. In this case, there is provided a membrane which can only be a barrier to the liquid during hot filling for example because the liquid will not pass behind the membrane, then the closure member is perforated which introduces possible organisms understood behind the membrane that will migrate into the container.

Another device also uses an even more specific cap, that described in the patent application WO 2009142510 A1. This plug is manufactured with an opening. After filling, the head space is placed in a pressure vessel, a plug is inserted into the hole provided for this purpose, said plug being immobilized in the hole by means mechanical. Such a process is totally unimaginable industrially, both from the point of view of rates and price and control difficulties and even implementation.

 In addition, the devices known in the prior art do not allow to accurately check the sealing quality of the hole formed in the plug to ensure a perfect seal of the container.

The present invention aims to solve the disadvantages of the prior art, by proposing a device and a method for pressure packaging a container to be treated at least partially filled with a content and sealed with a stopper arranged above a head space of the container, said device comprising a hood with a needle and a heating cannula disposed therein so that their respective axes of movement are intersecting at a point in the material of the cap or above the material of the cap when the cap is approached on the cap, the end of the heating cannula being convex, preferably hemispherical, which allows to proceed in particular to a hot filling using bottles having a overweight material as low as possible compared to the containers used for filling in cold sterile environment, and allowing and also to compensate for depression in cold-filled containers that may experience deformation by depression, especially if the containers themselves have low mechanical strength. In addition, the convex shape of the end of the heating cannula makes it possible to carry out a precise verification of the quality of the shutter by the heating cannula of the hole formed in the stopper by the needle.

 The subject of the present invention is therefore a device for pressure-conditioning a container to be treated at least partially filled with a content and sealed with a stopper placed above a head space of the container, said device comprising a cover which includes inside thereof a piercing needle, fluid injection means and a fused shutter heating cannula, said cap configured to be sealingly abutted against the outer surface of the cap; said needle being adapted to move linearly to drill a hole through the plug, said fluid injection means being configured to introduce a fluid into the head space through said hole, said heating cannula being adapted to linearly moving to close said hole by melting the material of the plug, characterized in that the needle and the heating cannula are arranged in the hood so that their respective axes of movement are intersecting at a point in the material of the cap or above the material of the cap when the hood is approached on the cap, and in that the end of the heating cannula is convex.

 The end of the heating cannula is preferably hemispherical.

Thus, said device for pressure-conditioning a container to be treated makes it possible in particular to perform a hot filling using bottles having an overweight of material as low as possible compared to containers used for filling in cold sterile environment, and allows also to compensate for the depression in cold-filled containers that may suffer deformation by depression, especially if the containers themselves have a low mechanical strength.

 The needle and the heating cannula are inclined with respect to each other so that their respective longitudinal axes of displacement intersect at the same point in the material of the plug or above the material of the plug. Preferably, said point is at the center of the upper surface of the plug.

 The skilled person can easily proceed by trial and measurement to ensure that in the closed position of the heating cannula on the cap, the top of the convex shape of the cannula coincides with the hole formed by the needle: the axes of displacement are thus intersecting on the material of the cap or above it, depending on the convex shape adopted by the end of the heating cannula.

 The needle is movable, in the position of docking the cap on the cap, between a retracted position and a piercing position to pierce the cap. The heating cannula is movable, in the position of docking the cover on the cap, between a rest position and a closed position to seal the hole formed in the stopper by the needle, the plastic material of the plug in contact with the heating cannula.

 The needle is never in contact with the contents during drilling.

The plug used in the context of the invention and therefore in this process is a conventional one-piece cap, without internal membrane and therefore inexpensive and easy to recycle. The invention is however not limited to this respect. By way of nonlimiting example, the following plugs are also within the scope of the present invention, and may be used with the method of the invention:

a plug comprising an annular membrane (or liner or liner) hollowed out in its central part,

 a plug comprising a solid membrane (or inner liner or solid liner) but with a central thickness less than the minimum thickness necessary for self-sealing in the case of a drilling and a subsequent withdrawal of a needle from the plug, this minimum thickness required being below 0.2 mm,

a plug comprising a solid membrane (or inner liner or solid liner) of thickness between 0.2 mm and 0.8 mm, with a polyethylene / ethylene-vinyl acetate (PE / EVA) type material which does not possess no known self-sealing characteristic after removal of a piercing needle with a diameter of between 0.1 mm and 3 mm.

 This device is preferably used for hot content filling, but can also be used for cold content filling.

 The heating cannula reseals, by fusion of the plastic material of the cap, the hole formed in the cap by the needle, which ensures the final seal of the container while compensating for the depression in the container.

The container thus contains a content with a pressure balanced for the least and preferably under a slight pressure so that the pressure difference internal with the external pressure of the container avoids generating any collapse of the container.

In addition, the convex, preferably hemispherical, shape of the end of the heating cannula makes it possible to carry out a precise verification of the quality of closure by the heating cannula of a hole formed in the stopper by the needle. Indeed, the shape of the obturation formed by the convex heating cannula depends on the shape of the end of the heating cannula, the temperature of the end of the heating cannula, the contact time of the heating cannula with the cap and the depth of penetration of the heating cannula into the cap. Once the convex shape of the end of the known heating cannula, the temperature of the end of the heating cannula determined according to the material constituting the cap, the contact time determined as a function of the desired treatment time, the Those skilled in the art will be able to adapt the depth of penetration into the cap by tests and measurements. A characteristic mark of a certain diameter will be formed on the upper surface of the plug, which, because of the shape, the temperature of the tip of the cannula and the contact time, will ensure that the heating cannula has had sufficient penetration to ensure a tight seal. It is understood that one skilled in the art can, only the convex shape of the end of the heating cannula being imposed, set two parameters among the temperature of the end of the heating cannula, the contact time and the depth of penetration to adapt the third parameter to determine the mark of the heating cannula on the upper surface of the plug which ensures an optimal seal tightness. According to a particular characteristic of the invention, the device further comprises an optical means configured to check the quality of closing the hole in the plug by the heating cannula. The optical means may be a camera or an optical fiber connected to an optical sensor. The optical means may be arranged in the hood or at a station downstream on a production line having the device of the invention.

 Thus, it is possible to optically verify, with the aid of the optical camera, whether the quality of closing the hole by the heating cannula is good or bad, in order to carry out the melt-sealing or throwing step again. the cap / container in case a poor shutter quality is detected.

 According to a particular characteristic of the invention, the device further comprises an optical or inductive means arranged in the cover and configured to check the integrity of the needle after drilling the hole.

 Thus, it is possible to optically verify, with the aid of this optical or inductive means, whether or not the needle is broken after the piercing step, in order to replace the needle and to discard the contents of the container in the case where a breakage of the needle is detected.

A remote optical camera can control the filling level of the container at the end of the pressure conditioning process to detect a possible breakage of the needle. Indeed, during normal processing, the content level must drop to a predetermined level, while in case of non-drilling and therefore no introduction of fluid, the level of content will not drop. A proximity sensor system could also control the presence of the complete and unbroken needle. Such proximity sensor systems could for example be a photoelectric or magnetic cell.

 According to a particular characteristic of the invention, the needle has a pointed end in the form of a cone.

 Thus, said needle is more solid compared to a hypodermic needle with beveled end used in the prior art, which prevents the needle from breaking during the piercing step.

 Said needle ensures a hole by penetration into the plastic material of the plug, by deformation and repoussage of the material, without tearing material. No plastic waste plug thus falls into the contents of the container.

 The diameter of the drilling hole must allow to combine rapid inflation (largest diameter possible) and welding safety (smallest possible diameter). By way of non-limiting example, a 0.7 mm diameter needle seems to be a good compromise. It is understood that the invention is not limited in this respect, the diameter of the needle may be between 0.3 and 0.8 times the thickness of the plug. The thickness of the plug is defined as the maximum thickness of the flat surface of the plug from which extends the skirt of the cap bearing the thread.

According to a first embodiment of the invention, the needle is full, the fluid injection means comprising at least one fluid inlet adapted to receive a fluid under pressure and to inject it into the inside of the hood is sealed against the cap.

 Thus, during the fluid injection, the solid needle is withdrawn from the hole formed in the plug to allow the introduction of the fluid into the head space of the container through said hole. In this first embodiment, a sterilization of the outer surface of the plug before berthing the cap on the cap is mandatory so as not to pollute the contents during the introduction of the fluid into the headspace.

 The removal of the needle during the injection of fluid also avoids any splashing of the content on the needle during the introduction of fluid that creates turbulence of the surface of the contents, for improved hygiene.

 According to a second embodiment of the invention, the pointed end of the needle is solid, and the remainder of the needle comprises a longitudinal central bore and at least two opposite lateral holes connecting said central bore with the outside of the needle. the needle near the sharp end of the needle, the fluid injection means comprising at least one fluid inlet adapted to receive a fluid under pressure and to inject it into the central bore of the needle at the end of the needle opposite the pointed end of the needle.

Thus, the needle is full at its tip but pierced at its center with two lateral openings, which makes it possible to introduce a fluid into the headspace of the container while the needle is still in its piercing position, the fluid being diffused laterally in the head space by the two lateral holes of the needle, thus making it possible to avoid the setting in eventual turbulence of the contents and splashing during the introduction of fluid. This second embodiment avoids the prior sterilization of the outer surface of the plug, which is an important point from an industrial point of view.

 According to a particular characteristic of the invention, the needle is heated by a heating means.

 Thus, the heating of the needle makes it possible both to sterilize the needle and to facilitate the drilling of the plastic material of the stopper. The needle is preferably heated to a temperature above 95 ° C for sterilization and below 130 ° C to prevent possible melting of the plastic material of the plug during drilling and gluing of plastic particles on the needle that could then come off when drilling the cap of another container in a next cycle.

 The temperature of the needle is preferably maintained and continuously monitored by a resistor / probe placed in the needle holder.

The subject of the present invention is also a process for the pressure-packing of a container to be treated at least partially filled with a content and sealed with a stopper placed above a head space of the container, at the same time. using a pressure conditioning device as described above, characterized in that it comprises the following steps: sealing the cover of said device on the outer surface of the plug; drilling a hole through the stopper with the needle of said device; introducing a fluid into the head space of the container via said hole, formed through the cap, using the fluid injection means of said device, so as to obtain a residual pressure at least equal to the atmospheric pressure in the headspace of the container; closing said hole by melting the plug material with the aid of the heating cannula; and removing the hood.

 Thus, said pressure-conditioning method of a container to be treated makes it possible in particular to perform a hot filling using bottles having an overweight of material as low as possible compared to the containers used for filling in cold sterile environment, and also makes it possible to compensate for the depression in cold-filled containers which can undergo deformation by depression, especially if the containers themselves have a low mechanical strength.

 The temperature of the heating cannula and the contact time can be set individually to obtain the desired penetration / weld and are continuously monitored by the pressure conditioning device.

 The temperature at the end of the heating cannula is of the order of 140 ° C - 220 ° C to ensure rapid melting of the plastic material of the cap.

A minimum force, for example using a cylinder controlled at 7 bar, is applied to the heating cannula to ensure a significant compression of the plastic during the melting phase to fill the hole. An insufficient pressure of the heating cannula despite the good temperature and the good contact time compromises the quality / sealing of the weld. Experimentally, the Applicant has found good weld impressions for a contact time of 0.4-0.5 seconds at 7 bars, with a temperature of 180 ° C at the end of the cannula, for plugs in high density polyethylene (HDPE).

 The heating of the cannula is provided by a resistance / temperature probe connected to the device.

 A water cooling circuit placed in the hood preferably ensures the hood is held at a "reasonable" temperature.

 According to the first embodiment of the pressure conditioning device of the invention, the needle is withdrawn from the hole before the fluid introduction step.

 Thus, the berthing of the cap on the cap being made in a sealed manner, the needle can be raised, before the fluid injection step, while maintaining the pressure between the cap and the cap, the piercing is therefore " clean "without chips or waste by pushing the plastic material of the cap only, the removal of the needle during the injection of fluid also to avoid splashing of the contents on the needle when introducing the fluid that creates turbulence of the surface of the contents, for improved hygiene.

 According to the second embodiment of the pressure conditioning device of the invention, the needle is held in the hole during the fluid introduction step, the fluid introduction being through the central bore and the at least two side holes of the needle.

Thus, the fluid is diffused laterally in the head space by the two lateral holes of the needle, thereby avoiding the possible turbulence of the contents and splashing during the introduction of fluid, and also to prevent prior sterilization of the outer surface of the cap.

 According to a particular characteristic of the invention, the method further comprises, after the shutter step, a step of checking the quality of closing the hole in the stopper with the aid of the optical means.

 Leak test systems are currently available to test the quality of the weld. However, for a hole of about one micron (which allows the return of atmospheric pressure of the container in a week), the control time is about thirty seconds, so it would take a number of control covers fifteen times greater than number of treatment covers, which is prohibitive.

 The optical means therefore allows the verification of the shutter quality immediately after the shutter step when the cover is still docked on the stopper, or on a downstream station on a production line in which the device is placed according to 1 invention.

 According to a particular characteristic of the invention, the verification step comprises the following substeps: capturing, by the optical means, an image of the plug at the level of the circular closure formed by the convex heating cannula; measuring the diameter of the captured circular filling; and comparing the measured diameter to a threshold value to determine whether or not the shutter quality is acceptable.

Thus, the optical means allows a visual control of the melt shutter to measure the penetration of the cannula and guarantee the quality of the weld. According to a particular characteristic of the invention, the step of introducing fluid into the headspace comprises introducing a fluid into an initial phase at a first pressure value, and then introducing a fluid into a final phase at a first stage. second pressure value lower than the first pressure value for an acceleration of the process according to the invention.

 Thus, it is possible to greatly increase the pressure in the initial phase of the pressurization immediately after drilling, and to have a lower pressure in the final phase to adjust the final pressure just before the shutter fusion.

 According to a particular characteristic of the invention, in the case of a hot filling at a temperature above 73 ° C., the fluid is introduced into the headspace after cooling the contents to a temperature below 45 ° C. .

 According to a particular characteristic of the invention, the fluid introduction pressure is configured to generate a residual pressure in the container, between 1.01 bars and 2.5 bars, and preferably between 1.01 bars and 1, 4 bars.

 According to a particular characteristic of the invention, the fluid is an inert and sterile gas such as nitrogen, especially in gaseous form.

Thus, the inert and sterile gas makes it possible not to cause subsequent oxidation of the contents after bottling. This avoids over-collapsing due to the subsequent oxygen consumption as there is none or very little, the inert gas having largely replaced the initially confined air. According to a particular characteristic of the invention, the method further comprises, before, during and / or after the bonnet docking step, a step of circulating sterile fluid between the cap and the cap, preferably an inert gas, more preferably nitrogen.

 Thus, this circulation of sterile fluid prevents bacteria from entering the space between the cap and the cap from the outside, to ensure the sterility of the container. An overpressure is created between the cap and the cap to maintain a positive pressure greater than or equal to the internal pressure of the container to the melt shutter.

 According to a particular characteristic of the invention, the method further comprises, before the cap berthing step on the cap, a step of sterilizing the outer surface of the cap by one or more of a punctual heating, a chemical sterilization , a vapor, a pulsed light emission or the like.

 Thus, punctual heating or chemical sterilization using a sterilizing liquid ensures the destruction of pathogenic organisms present on the outer surface of the plug.

The present invention further relates to a pressure conditioning machine comprising at least one pressure conditioning device as described above, said pressure conditioning machine further comprising a means for holding in the container position with respect to which the cover of the at least one pressure conditioning device is movable between a rest position remote from the holding means in the container position and a docking position in which the cover is sealed against the cap of the container to be treated.

 To better illustrate the object of the present invention will be described below, by way of illustration and not limited to two preferred embodiments, with reference to the accompanying drawings.

 In these drawings: FIG. 1 is a perspective view of a pressure conditioning device of a container to be treated according to the present invention;

 Figure 2 is a sectional view of the device of Figure 1 in the non-docked position;

 Figure 3 is a sectional view similar to Figure 2 during the docking step;

 Figure 4 is a sectional view similar to Figure 2 during the piercing step;

 Figure 5 is a sectional view similar to Figure 2 during the fluid introduction step according to a first embodiment of the invention;

 Figure 6 is a sectional view similar to Figure 2 during the sealing step;

 Figure 7 is a sectional view of the heating cannula of the device of Figure 1;

 Figure 8 is a perspective view of the end of the heating cannula of Figure 7;

Figure 9 is a sectional view of the needle of the device of Figure 1 according to a second embodiment of the invention. With reference to FIG. 1, it can be seen that there is shown a device for pressure conditioning 1 of a container to be treated 2.

 The container to be treated 2 is at least partially filled with a content and sealed with a plug 3 disposed above a head space of the container 2.

 In the case of the present description, the container 2 undergoes a hot filling, and is a bottle, in particular of PET (polyethylene terephthalate), of low basis weight, with a content, such as a fruit juice, brought to a temperature capable of destroying pathogenic organisms, namely a temperature greater than 73 ° C., in this case 85 ° C.

 Once the container 2 is filled with the hot content, it is plugged by the plug 3 of known type, namely a monolithic and monomatized injection-molded or compression-molded screw plug without any additional sealing element.

 The seal is obtained by contact under mechanical pressure of the material of the plug 3, in this case its inner face on the material of the peripheral edge of the neck 2a of the container 2, the screwing to exert said mechanical pressure required.

 When closing, said cap 3 leaves a head space. This space results from filling without overflow because the content should in no way overflow and end up on the lip of the neck 2a before closing because the content would then be an entry door under the cap 3 and the container 2 would be unfit for sale .

The plug 3 is free from any mechanism or other pressure compensation accessory. The air trapped in the head space is hot but at atmospheric pressure.

 It should be noted that the present invention also applies to certain plugs commonly used, particularly in the United States, which are bi-material type with an inner membrane used to ensure only the seal between the surface of the neck of the container 2 and the cap 3 by compression during screwing, unlike the inner lip for the monomatiere-type plugs. However, this inner membrane for such a bi-material cap does not have the necessary characteristics to ensure a self-sealing of the plug in the case of a piercing with a needle and then a withdrawal of the needle out of the cap.

 The container 2 is able to receive a content at the sterilization temperature retained without degradation but is free of depression compensation means.

 The container 2 is set in motion immediately after filling with the contents, in order to put all the internal surfaces of the container 2 in contact with the contents brought to the sterilizing temperature.

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

When the container 2 reaches a temperature below 75 ° C, because of the material that constitutes it, said container 2 collapses because the volume of gas and liquid is reduced to 3 to 5% inside the container 2 This reduction increases as and when cooling. The collapse phenomenon is close to its maximum at a temperature below or equal to 45 ° C.

 The pressure conditioning device 1 comprises a cover 4, also called docking head, which comprises inside the latter piercing means 5, fluid injection means 6 and closure means by merger 7.

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

 The cover 4 is vertically movable, by means of a vertical displacement motor 11, between a rest position remote from the upper support 9 and a docking position in which the cover 4 is sealed against the stopper 3 of the container to be treated 2. It is understood that the invention is not limited in this respect: either the hood is movable, docked on the container brought under the hood, or the hood is fixed, the container being brought into the hood.

The pressure conditioning device 1 is configured to implement a pressure-conditioning process of the container to be treated 2 which comprises the following steps: sealing the bonnet 4 on the outer surface of the plug 3; drilling a hole through the stopper 3 by lowering the piercing means 5 towards the stopper 3; introducing a fluid into the head space of the container 2 through said hole, formed through the cap 3, using the fluid injection means 6, so as to to obtain a residual pressure at least equal to the atmospheric pressure in the head space of the container 2; closing said plug hole 3 by melting the plug material 3 by lowering the muffling closure means 7 towards the plug 3; and removing the cover 4. The various process steps will be described in more detail in Figures 2 to 6.

 The docking of the cover 4 on the cap 3 being made in a sealed manner, in the first embodiment of the invention, the piercing means 5 can be reassembled, before the fluid injection step, while maintaining the pressure between the cover 4 and the plug 3, the bore is "clean" without chips or waste by pushing the plastic of the cap 3 only, the removal of the piercing means 5 during the injection of fluid also allowing d avoid any splashing of the contents on the piercing means 5 for improved hygiene.

 The plug 3 used in this process is a conventional one-piece plug, without internal membrane and therefore inexpensive.

 The container 2 thus contains a content with a pressure balanced for the least and preferably under a slight pressure so that the internal pressure difference with the external pressure of the container 2 avoids generating any collapse of the container 2.

 Referring to Figure 2, it can be seen that there is shown the pressure conditioning device 1 in the non-approached position of the cover 4.

The container 2 is partially filled with a content 12 so that a head space 13 without content remains at the neck 2a of the container 2, the container 2 being sealed by the cap 3 disposed above the head space 13 of the container 2.

 The piercing means 5 comprise a piston 14 at the end of which is fixed a needle 15, said piston 14 being able to move linearly in a cylinder 16 formed on the cover 4, the stroke of the piston 14 being limited by a chamber of piston 17 formed in the upper end of the cylinder 16.

 Thus, the needle 15 is configured to pierce the cap 3 when the cap 4 is docked on the cap 3 and the piston 14 is in its extended position.

 The melt sealing means 7 comprise a piston 18 at the end of which is fixed a heating cannula 19, said piston 18 being able to move linearly in a cylinder 20 formed on the cover 4, the piston 18 being limited stroke by a piston chamber 21 formed in the upper end of the cylinder 20.

 Thus, the heating cannula 19 is configured to melt seal the hole formed in the cap 3 by the needle 15 when the cap 4 is docked on the cap 3 and the piston 18 is in its extended position, the plastic material of the cap 3 melting in contact with the heating cannula 19.

 The needle 15 and the heating cannula 19 are located in an internal cavity 22 of the cover 4.

The pistons 14 and 18 can be actuated electrically or hydraulically. In order not to overload the figures, the power supply or hydraulic actuation son of the pistons 14 and 18 have not been shown in the figures. Similarly, the heating elements for heating the needle 15 or the heating cannula 19, as well as their power supplies respective electric wires, have not been shown to avoid overloading the figures.

 The fluid injection means 6 comprise a plurality of fluid inlets adapted to receive a pressurized fluid and to inject it into the internal cavity 22 of the cover 4, the cover 4 being able to contain up to five inputs of fluid 6.

 In the first embodiment of the invention, the pressure-conditioning method also comprises, before the step of docking the cap 4 on the cap 3, a step of sterilizing the outer surface of the cap 3 by point heating, by chemical sterilization using a sterilizing liquid, by steam, by pulsed light emission or by another similar process, in order to ensure the destruction of the pathogenic organisms present on the outer surface of the stopper 3.

 The internal cavity 22 of the cover 4 is always overpressured with sterile gas by a first fluid inlet 6, even before docking to maintain the sterility of the plug 3 previously made.

 There are two other sterile gas inlets 6 for the fluid introduction step, also known as the inflation step.

 The last two fluid inlets 6 could be used for the injection of a sterilizing fluid after the docking and drilling and a rapid suction evacuation of the sterilizing fluid before drilling.

The device 1 further comprises an optical camera C disposed in the internal cavity 22 of the cover 4 and configured to check the quality of closing the hole in the plug 3 by the heating cannula 19. This step Verification of shutter quality will be described in more detail with reference to Figure 6.

 Referring to Figure 3, it can be seen that there is shown the pressure conditioning device 1 during the docking step.

 During the docking step, the pistons 14 and 18 respectively of the needle 15 and the heating cannula 19 are in their retracted positions, also called rest positions.

 The cover 4 is sealed against the outer surface of the stopper 3 so that at least a portion of the stopper 3 is inserted into at least a portion of the internal cavity 22 of the cover 4.

 The pistons 14 and 18 are arranged in the cap 4 so that their respective axes of displacement are intersecting at a point in the material of the cap

3 or slightly above it when the cover 4 is docked on the plug 3, said point being preferably at the center of the upper surface of the plug 3 or slightly above, eccentrically, depending on the shape of the heating cannula 19.

 The pressure conditioning process may also comprise, after the step of docking the cover 4 on the plug 3, a step of circulating sterile fluid, preferably an inert gas such as nitrogen, into the internal cavity 22 of the cover 4 via some of the fluid inlets 6. An overpressure is thus created between the cap 3 and the hood

4 to maintain a positive pressure greater than or equal to the internal pressure of the container 2 to the melt shutter. Referring to Figure 4, it can be seen that there is shown the pressure conditioning device 1 during the piercing step.

 During the piercing step, the piston 14 of the needle 15 is in its extended position, so that the needle 15 is lowered to the cap 3 and pierces a hole 23 through the material of the cap 3.

 The needle 15 is never in contact with the contents 12 during drilling.

 The needle 15 makes the hole 23 by penetration into the plastic material of the plug 3, by deformation and embossing of the material, without tearing material.

 In the first embodiment of the invention, this drilling step is immediately followed by a step of raising the needle 15 in the rest position of the piston 14.

 The pressure conditioning method can also comprise a verification step, using an optical camera or optical fiber connected to an additional sensor (not shown in FIG. 4) disposed in the cover 4, of the integrity of the the needle 15 after the step of raising the needle 15, thus making it possible to optically verify whether the needle 15 is or not broken after the piercing step.

An additional optical camera remote hood can control the filling level of the container 2 at the end of the pressure conditioning process to detect a possible breakage of the needle 15. Indeed, during normal processing, the level of content 12 must drop to a predetermined level, while in case of no drilling and therefore no introduction of fluid, the level of the content 12 will not drop. A proximity sensor system could also control the presence of the complete and unbroken needle without departing from the scope of the present invention.

 Referring to FIG. 5, it can be seen that there is shown the pressure conditioning device 1 during the fluid introduction step according to the first embodiment of the invention.

 In the first embodiment of the invention, the needle 15 is cylindrical and solid and has a pointed end in the form of a cone.

 The needle 15 is preferably heated by a heating means (not shown in FIG. 5), the heating of the needle 15 making it possible both to sterilize the needle 15 and to facilitate the drilling of the plastics material. The needle 15 is preferably heated to a temperature above 95 ° C for sterilization and below 130 ° C to prevent possible melting of the plastic material of the plug 3 during drilling and gluing. plastic particles on the needle 15 which could then become detached during the drilling of the cap 3 of another container 2.

 The temperature of the needle 15 is preferably maintained and continuously controlled by a resistor / probe placed in the piston 14.

In the first embodiment of the invention, during the fluid introduction stage, the pistons 14 and 18 respectively of the needle 15 and of the heating cannula 19 are in their rest positions, the needle 15 the solid is thus removed from the hole 23 formed in the plug 3. In this first embodiment, the sterilization of the outer surface of the plug 3 before the berthing of the cover 4 on the plug 3 is mandatory in order not to pollute the contents 12 during the introduction of fluid into the head space 13.

 A fluid 24 is introduced into the internal cavity 22 of the cover 4 and then into the head space 13 of the container 2 via the hole 23, formed through the stopper 3, using one of the inputs of FIG. fluid 6, so as to obtain a residual pressure at least equal to the atmospheric pressure in the head space 13 of the container 2.

 The fluid 24 is an inert and sterile gas such as nitrogen, especially in gaseous form, which makes it possible not to cause subsequent oxidation of the contents 12, subsequent to bottling. This avoids over-collapsing due to the subsequent oxygen consumption as there is none or very little, the inert gas having largely replaced the initially confined air.

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

 The fluid introduction pressure 24 is configured to generate a residual pressure in the container 2, between 1.01 bar and 2.5 bar, and preferably between 1.01 bar and 1.4 bar.

The step of introducing the fluid 24 into the head space 13 preferably comprises a fluid introduction 24 in an initial phase at a first pressure value, then a fluid introduction 24 in a final phase at a second pressure value lower than the first pressure value. It is thus possible to increase the pressure in the initial phase of the pressurization immediately after drilling, and to have a lower pressure in the final phase. to adjust the final pressure just before the melt shutter.

 Referring to Figure 6, it can be seen that there is shown the pressure conditioning device 1 during the sealing step.

 During the closing step, the piston 18 of the heating cannula 19 is in its extended position, so that the heating cannula 19 is lowered to the hole 23 formed in the stopper 3 by the needle 15.

 The heating cannula 19 can, by melting the plastic material of the plug 3, seal up the hole 23 formed in the plug 3, which makes it possible to guarantee the final seal of the container 2 while compensating for the depression in the container 2.

 The shutter step is performed within a period of between 0 and 5 seconds.

 The pressure conditioning method may also comprise a step of verifying, by means of the optical camera C disposed in the internal cavity 22 of the cover 4, the quality of closing the hole 23 by the heating cannula 19, which Thus, it is possible to optically verify whether the quality of closure of the hole 23 by the heating cannula 19 is good or bad. The closure leaves on the upper surface of the stopper a characteristic mark of the quality of closure by the heating cannula 19.

Said verification step comprises the following sub-steps: the capture, by the optical camera C, of an image of the plug 3 at the circular closure formed by the hemispherical heating cannula 19; measuring the diameter of the captured circular filling; and comparing the measured diameter to a threshold value to determine whether or not the shutter quality is acceptable.

 The optical camera C thus allows a visual control of the shutter to measure the penetration of the heating cannula 19 and guarantee the quality of the weld.

 The shutter step is followed by a step of raising the heating cannula 19 in the rest position of the piston 18, then a step of removing the cover 4 from the stopper 3.

 The method according to the present invention allows the hot filling in containers 2, for example PET, with reduced grammages of the order of 15% compared to the hot filling process with deformation of the container, which is a reduction considerable material in view of the coefficient multiplier of the number of containers 2 products.

 No particular architecture needs to be studied for the wall, any technical panel and / or complex petaloid background becomes useless.

 The forms of containers 2 are in fact much more free and sober, and recycling is less expensive since the amount of material used is less.

 Having the container 2 under atmospheric pressure or slight pressure allows better stacking and palletizing.

The method according to the present invention applies to all the filling modes and even for a pressurization of cold-filled containers 2 in a sterile environment, of which it would be desirable not only to compensate for a possible decrease in the volume of the head space 13 by a consumption of oxygen but also put in slight overpressure to reinforce the mechanical strength, or even inject a neutral gas to replace the confined air in the head space 13 in order to retain all the organoleptic qualities of the products that the oxidation can alter.

 Referring to Figure 7, it can be seen that there is shown the heating cannula 19 of the pressure conditioning device 1.

 The heating cannula 19 comprises a cannula end 25 (which will be described in more detail in FIG. 8) and a hollow and cylindrical cannula holder 26 in which a portion of the cannula end 25 is force-fitted, part of the cannula holder 26 being force-fitted into the lower part of the piston 18 which is hollow.

 A heating resistor / temperature probe 27 is disposed within the hollow cannula holder 26, the lower portion of the heating resistor / temperature probe 27 being in contact with the cannula end 25, and the upper portion of the heating resistor / temperature probe 27 being connected to two electrical wires 28 configured to bring a power supply to the heating resistor / temperature probe 27.

 The temperature of the cannula end 25 and the contact time can be set individually to obtain the desired penetration / weld and are continuously monitored by the pressure conditioning device 1.

The temperature of the cannula end 25 is of the order of 140 ° C - 220 ° C, preferably of the order of 180 ° C - 200 ° C, depending on the material constituting the plug 3, to ensure rapid melting of the plastic material of the cap 3. A minimum force, for example using a cylinder controlled at 7 bar, is applied to the heating cannula 19 to ensure a significant compression of the plastic during the melting phase to fill the hole 23. An insufficient pressure of the heating cannula 19, despite the good temperature and the good contact time, would compromise the quality / sealing of the weld.

 A water cooling circuit (not shown in Figure 7) placed in the cover 4 preferably ensures the maintenance of the hood 4 at a "reasonable" temperature.

 Referring to Figure 8, it can be seen that there is shown the cannula end 25.

 The cannula end 25 comprises a plate 25a, one of whose faces comprises a projection 25b configured to be force-fitted into the cannula holder 26, and the other opposite face comprises a hemispherical stud 25c. It should be noted that the hemispherical shape shown is not limiting, and that any convex shape of the end of the heating cannula is within the scope of the present invention.

 The hemispherical shape of the stud 25c makes it possible to carry out a precise verification of the quality of closure by the heating cannula 19 of the hole 23 formed in the stopper 3 by the needle 15. In fact, the filling formed by the shaped nipple hemispherical 25c is circular, which allows to measure, with the aid of the optical camera C, the diameter of the circular shutter made to determine whether the shutter quality is acceptable or not.

Referring to FIG. 9, it can be seen that there is shown a needle 29 of the pressure conditioning 1 according to the second embodiment of the invention.

 In this second embodiment of the invention, the pointed end 29a of the needle 29 is full, and the remainder of the needle comprises a longitudinal central bore 30 and two opposite lateral holes 31 connecting said central bore 30 with the outside the needle 29 near the pointed end 29a of the needle 29.

 It should be noted that the needle 29 could also comprise at least three lateral holes 31, without departing from the scope of the present invention.

 In this second embodiment, the fluid injection means 6 comprise at least one fluid inlet adapted to receive the fluid 24 and to inject it into the central bore 30 of the needle 29 at the end. the needle 29 opposite the pointed end 29a. The needle 29 is held in the hole 23 during the fluid introducing step, the introduction of fluid being through the central bore 30 and then the two lateral holes 31.

 An introduction of the fluid 24 into the head space 13 of the container 2 is thus performed while the needle 29 is still in its piercing position, the fluid 24 being diffused laterally in the head space 13 by the two lateral holes 31, thus avoiding the possible turbulence of the content 12 and splashing during the introduction of fluid. This second embodiment also makes it possible to avoid prior sterilization of the outer surface of the stopper 3.

The device, the method and the machine according to the invention can be implemented in a line of production, with one or more stations upstream or downstream, in which case a conveying device will transport the container to the position of the production line embodying the invention.

Claims

1 - Device for pressure conditioning (1) of a container to be treated (2) at least partially filled with a content (12) and sealed with a plug (3) arranged above a head space (13) of the container (2), said device (1) comprising a cover (4) which comprises inside thereof a piercing needle (15; 29), fluid injection means (6) and a melt shutter heating cannula (19), said hood (4) being configured to be sealingly abutted against the outer surface of the plug (3), said needle (15; 29) being adapted to move linearly for piercing a hole (23) through the plug (3), said fluid injection means (6) being configured to introduce a fluid (24) into the head space (13) through said hole (23); ), said heating cannula (19) being able to move linearly to close said hole (23) by melting the plug material (3), characterized in that the needle (15; 29) and the heating cannula (19) are arranged in the cover (4) so that their respective axes of displacement are intersecting at a point in the material of the plug (3) or above the plug (3). when the cover (4) is approached on the plug (3), and in that the end (25) of the heating cannula (19) is convex.  2 - Device (1) according to claim 1, characterized in that it further comprises an optical means (C) configured to check the quality of closing the hole (23) in the plug (3) by the heating cannula (19). 3 - Device (1) according to one of claims 1 and 2, characterized in that it further comprises a optical or inductive means disposed in the cover (4) and configured to check the integrity of the needle (15; 29) after drilling the hole (23).  4 - Device (1) according to one of claims 1 to 3, characterized in that the needle (15; 29) has a pointed end (29a) in the form of a cone.  5 - Device (1) according to claim 4, characterized in that the needle (15) is solid, the fluid injection means (6) comprising at least one fluid inlet adapted to receive a fluid under pressure and injecting it inside the cover (4) sealed against the plug (3).  6 - Device (1) according to claim 4, characterized in that the pointed end (29a) of the needle (29) is full, and the remainder of the needle (29) comprises a longitudinal central bore (30). ) and at least two opposite lateral holes (31) connecting said central bore (30) with the outside of the needle (29) near the pointed end (29a) of the needle (29), the means fluid injection (6) comprising at least one fluid inlet adapted to receive a fluid under pressure and to inject it into the central bore (30) of the needle (29) at the end of the fluid needle (29) opposite the pointed end (29a) of the needle (29).  7 - Device (1) according to one of claims 1 to 6, characterized in that the needle (15; 29) is heated by a heating means. 8 - Process for pressure-conditioning of a container (2) at least partially filled with a substance (12) and sealed with a stopper (3) arranged above a head space (13) of the container (2), using a packaging device pressure (1) according to one of claims 1 to 7, characterized in that it comprises the following steps:  sealing the hood (4) of said device (1) on the outer surface of the plug (3);  - drilling a hole (23) through the plug (3) with the needle (15; 29) of said device (1); - The introduction of a fluid (24) in the head space (13) of the container (2) via said hole (23), formed through the plug (3), using the means fluid injection (6) of said device (1), so as to obtain a residual pressure at least equal to the atmospheric pressure in the headspace (13) of the container (2);  - Closing said hole (23) by melting the material of the plug (3) with the aid of the heating cannula (19); and  - removing the cover (4).  9 - Process according to claim 8 taken in dependence on claim 5, characterized in that the needle (15) is removed from the hole (23) before the fluid introduction step.  10 - Process according to claim 8 taken in dependence on claim 6, characterized in that the needle (29) is held in the hole (23) during the fluid introduction step, the introduction of fluid is making through the central bore (30) and the at least two lateral holes (31) of the needle (29). 11 - Method according to one of claims 8 to 10 taken in accordance with claim 2, characterized in that it further comprises, after the shutter step, a quality verification step closing the hole (23) in the plug (3) by means of the optical means (C).  12 - Process according to claim 11, characterized in that the verification step comprises the following substeps:  - capturing, by the optical means (C), an image of the plug (3) at the circular closure formed by the heating tube (19) convex;  measuring the diameter of the captured circular filling; and  - Comparing the measured diameter to a threshold value to determine whether the shutter quality is acceptable or not.  13 - Method according to one of claims 8 to 12, characterized in that the fluid introduction step (24) in the head space (13) comprises a fluid introduction (24) in an initial phase at a first pressure value, then a fluid introduction (24) in a final phase at a second pressure value lower than the first pressure value.  14 - Method according to one of claims 8 to Characterized in that, in the case of hot filling at a temperature above 73 ° C, the fluid (24) is introduced into the head space (13) after cooling the contents (12). at a temperature below 45 ° C.  15 - Method according to one of claims 8 to Characterized in that the fluid introduction pressure (24) is configured to generate a residual pressure in the container (2) between 1.01 bar and 2.5 bar, and preferably between 1.01 bar. bars and 1.4 bars.  16 - Method according to one of claims 8 to 15, characterized in that the fluid (24) is a gas inert and sterile, such as nitrogen, especially in gaseous form.  17 - Method according to one of claims 8 to 16, characterized in that it further comprises, before, during and / or after the step of docking the cover (4) on the plug (3), a sterile fluid circulation step between the cap (4) and the plug (3), preferably an inert gas, more preferably nitrogen.  18 - Method according to one of claims 8 to 17, characterized in that it further comprises, before the docking step of the cover (4) on the plug (3), a step of sterilization of the surface outer plug (3) by one or more of a punctual heating, chemical sterilization, steam or pulsed light emission.  19 - Pressure packaging machine comprising at least one pressure conditioning device (1) according to one of claims 1 to 7, said pressure conditioning machine further comprising a container holding means (9) by a ratio at which the hood (4) of the at least one pressure conditioning device (1) is movable between a rest position remote from the container holding means (9) and a docking position in which the hood (4) is sealed against the stopper (3) of the container to be treated (2).