EP3702319A1 - Device and method for guaranteeing a container interior pressure through multiple pressurization of the headspace - Google Patents

Abstract

The invention relates to a device and a method for filling and closing a thin-walled plastic container (11), in particular a PET bottle, a plastic container being produced from a preform by a blow molding process and the plastic container being filled with a flowable medium and in particular a liquid as well as an exchange medium is introduced into the plastic container, whereby an at least partial displacement of the previously contained medium takes place with the formation of an increased internal container pressure and the plastic container is at least partially closed, wherein in at least one section of a wall of the plastic container surrounding a headspace of the plastic container, a wall of the Container closure or between a wall of the plastic container and a wall of the container closure at least one opening is introduced and through this opening in the interior of the customer substance container, a predetermined internal container pressure is set by supplying and / or removing a gaseous medium.

Description

The present invention relates to a device and a method for ensuring an internal pressure in the container by repeatedly applying pressure to the head space of a container.

It is known from the prior art that it can be advantageous to displace the air contained in the headspace of a beverage container, for example by introducing liquid or gaseous nitrogen. In particular, the enormous volume expansion of liquid nitrogen during its transition into the gas phase when it comes into contact with the filling material, which has a temperature well above the boiling point of nitrogen, can be used to displace air (oxygen). As a result, a better shelf life of the product, such as a drink, can be achieved.

Furthermore, from the EP 2 226 179 A1 It is known that the introduction of nitrogen into the headspace of a container can be used to prevent or at least reduce the shrinkage of containers after the hot-filled liquid filling material has cooled down. However, this requires a special control of the container temperature and in particular the setting of a reduced temperature of the container bottom. A particularly stable base geometry is also necessary in order to ensure the required stability. The method is nevertheless limited to essentially cylindrical bottle geometries.

When liquid nitrogen is introduced into the head area, its enormous increase in volume from about 1.24 l / kg to about 0.8 m ³ / kg (at 273.15 K) occurs extremely quickly during the transition to the gas phase. The smallest deviations in the process, such as changed ambient temperature, changed product temperature, volume fluctuations in the headspace volume, volume fluctuations in the liquid nitrogen introduced and the time between the introduction of the liquid nitrogen and the closing of the container, therefore have an enormous influence on the resulting internal pressure in the container. While a slight internal pressure of the container, for example 1.1-2 bar, is usually desired, since it facilitates further handling of the container, for example gripping, labeling and stacking, compared to a pressure that is too low, an excessively high internal pressure can cause the container to burst cause.

The present invention is therefore based on the object of providing a device and a method which overcomes the disadvantages known from the prior art.

In terms of the method, this object is achieved by the method according to patent claim 1. On the device side, the device according to claim 7 solves this problem.

An essential aspect of the invention is therefore a method for filling and closing a thin-walled plastic container, in particular a PET bottle, a plastic container being produced from a preform by a blow molding process, and the plastic container being filled with a flowable medium and in particular a liquid, as well as a Exchange medium is introduced into the plastic container, whereby an at least partial displacement of the previously contained medium takes place with the formation of an increased internal container pressure and the plastic container is at least partially closed.

Furthermore, it is further provided according to the invention that in at least one section of a wall of the plastic container surrounding a head space of the plastic container, a wall of the container closure or between a wall of the plastic container and a wall of the container closure, at least one opening is made and through this or via an opening in the interior of the container Plastic container a predetermined internal container pressure is set by supplying and / or removing a gaseous medium.

In particular, a method is preferred in which the plastic container is first filled with a flowable one and in which an exchange medium is introduced into the plastic container in a further step.

1. a) Herstellen eines Kunststoffbehältnisses durch einen Blasformvorgang aus einem Vorformling;
2. b) Befüllen des Kunststoffbehältnisses mit einem fließfähigen Medium und insbesondere einer Flüssigkeit;
3. c) Austausch bzw. Verdrängen des im Kopfraum des befüllten Kunststoffbehältnisses enthaltenen Mediums durch Einbringen eines Austauschmediums unter Ausbildung eines erhöhten Behältnisinnendrucks und
4. d) anschließendes, wenigstens teilweises Verschließen des Kunststoffbehältnisses.

Weiterhin ist verfahrensseitig vorgesehen, dass in wenigstens einem den Kopfraum des Behältnisses umgebenden Abschnitt einer Wandung des Kunststoffbehältnisses, eine Wandung des Behältnisverschlusses oder zwischen einer Wandung des Kunststoffbehältnisses und einer Wandung des Behältnisverschlusses mindestens eine Öffnung eingebracht wird und durch diese Öffnung im Innenraum des Behältnisses ein vorgegebener Behältnisinnendruck durch Zuführen und/oder Abführen eines gasförmigen Mediums eingestellt wird.A preferred method according to the invention is thus a method for filling and closing a thin-walled plastic container, in particular a PET bottle, with the steps:

1. a) producing a plastic container from a preform by a blow molding process;
2. b) filling the plastic container with a flowable medium and in particular a liquid;
3. c) Exchange or displacement of the medium contained in the head space of the filled plastic container by introducing an exchange medium with the formation of an increased internal pressure in the container and
4. d) subsequent, at least partial closure of the plastic container.

Furthermore, it is provided on the method side that at least one opening is made in at least one section of a wall of the plastic container surrounding the head space of the container, a wall of the container closure or between a wall of the plastic container and a wall of the container closure and a predetermined opening is made through this opening in the interior of the container Container internal pressure is set by supplying and / or removing a gaseous medium.

This method offers the possibility of exchanging the medium contained in the headspace of the container after the container has been filled and thus protecting the contents, for example, from oxygen or contamination with foreign bodies and / or bacteria. Furthermore, by introducing the exchange medium with an overpressure, it can be ensured that after the container is closed, the container withstands external pressures due to the increased internal pressure, such as the pressure from gripping elements or the pressure when the containers are stacked.

In addition, the method offers the possibility of setting the pressure more precisely in step e). If, for example, in step c) the medium previously located in the headspace is expelled by the introduction of liquid nitrogen, the resulting internal container pressure can be influenced by many factors which make it difficult to set a defined internal container pressure. Due to the enormous increase in volume during the transition to the gas phase, even small changes in the volume of liquid nitrogen introduced can have very large effects on the resulting internal pressure in the container. In addition, the temperature of the contents, for example due to the shortened time required for complete evaporation, and the time between the introduction of the exchange medium and the closing, can have an influence on the resulting internal pressure of the container. Thus, the resulting internal pressure in the container could be too low or - for example due to larger amounts of nitrogen that evaporates only after the closure - be so high that there is a risk of the container bursting. It is also conceivable that at increased pressure an oversaturation of liquid filling material occurs in the gaseous exchange medium and this emerges suddenly when the container is opened with foam formation and / or expulsion of the filling material. Setting a predetermined internal pressure in the container in step e) can overcome this problem. The supply and / or discharge of a gaseous medium makes it possible to adapt the previously set internal container pressure to the requirements of the subsequent container treatment steps and thus, for example, to ensure safe transport and / or stackability and to prevent bursting due to excessive internal container pressure.

The flowable medium is advantageously a drink, which is further preferably heated.

In another variant of the method, it would preferably also be conceivable that an exchange medium is first introduced into the plastic container and the plastic container is filled with the flowable medium after the exchange medium has been introduced.

1. a) Herstellen eines Kunststoffbehältnisses durch einen Blasformvorgang aus einem Vorformling;
2. b) Einbringen eines Austauschmediums in das Kunststoffbehältnis;
3. c) Befüllen des Kunststoffbehältnisses mit einem fließfähigen Medium und insbesondere einer Flüssigkeit, wodurch das sich im Kunststoffbehältnis enthaltene Austauschmedium unter Ausbildung eines erhöhten Behältnisinnendrucks verdrängt wird; und
4. d) anschließendes, wenigstens teilweises Verschließen des Kunststoffbehältnisses.

Weiterhin ist verfahrensseitig vorgesehen, dass in wenigstens einem den Kopfraum des Behältnisses umgebenden Abschnitt einer Wandung des Kunststoffbehältnisses, einer Wandung des Behältnis-Verschlusses oder zwischen einer Wandung des Kunststoffbehältnisses und einer Wandung des Behältnisverschlusses mindestens eine Öffnung eingebracht wird und in einem Schritt e) durch diese im Innenraum des Behältnisses ein vorgegebener Behältnisinnendruck durch Zuführen und/oder Abführen eines gasförmigen Mediums eingestellt wird.The method according to the invention is accordingly also directed to a method for filling and closing a thin-walled plastic container, in particular a PET bottle, with the steps:

1. a) producing a plastic container from a preform by a blow molding process;
2. b) introducing an exchange medium into the plastic container;
3. c) filling the plastic container with a flowable medium and in particular a liquid, whereby the exchange medium contained in the plastic container is displaced with the formation of an increased internal pressure in the container; and
4. d) subsequent, at least partial closure of the plastic container.

Furthermore, the method provides that at least one opening is made in at least one section of a wall of the plastic container, a wall of the container closure or between a wall of the plastic container and a wall of the container closure and in a step e) through this In the interior of the container, a predetermined internal container pressure is set by supplying and / or removing a gaseous medium.

The container is preferably rinsed with the exchange medium before it is filled with the flowable medium.

In addition, however, it would also be conceivable that, in a further advantageous variant of the method, an exchange medium is first introduced into the plastic container, then the plastic container is filled with the flowable medium and then a gaseous medium is introduced into or removed from the plastic container to set the internal pressure of the container , wherein the container is closed during and / or after this setting of the container internal pressure.

1. a) Herstellen eines Kunststoffbehältnisses durch einen Blasformvorgang aus einem Vorformling;
2. b) Einbringen eines Austauschmediums in das Kunststoffbehältnis;
3. c) Befüllen des Kunststoffbehältnisses mit einem fließfähigen Medium und insbesondere einer Flüssigkeit, wodurch das sich im Kunststoffbehältnis enthaltenen Austauschmedium unter Ausbildung eines erhöhten Behältnisinnendrucks verdrängt wird;
4. d) Einstellen eines vorgegebenen Behälterinnendrucks durch Einbringen oder Abführen eines gasförmigen Mediums in oder aus dem Kunststoffbehältnis;
5. e) wobei das Kunststoffbehältnis wenigstens zeitweise während des Einstellens des vorgegebenen Behälterinnendrucks wenigstens teilweise verschlossen wird.

The method according to the invention is accordingly also directed to a method for filling and closing a thin-walled plastic container, in particular a PET bottle, with the steps:

1. a) producing a plastic container from a preform by a blow molding process;
2. b) introducing an exchange medium into the plastic container;
3. c) filling the plastic container with a flowable medium and in particular a liquid, whereby the exchange medium contained in the plastic container is displaced with the formation of an increased internal pressure in the container;
4. d) setting a predetermined internal pressure in the container by introducing or discharging a gaseous medium into or out of the plastic container;
5. e) wherein the plastic container is at least partially closed at least temporarily while the predetermined internal container pressure is being set.

The gaseous medium is preferably nitrogen. Particularly preferably, the gaseous medium and in particular the nitrogen are introduced into the plastic container shortly before it is closed. For this purpose, an introduction device, such as for example a nozzle, is preferably arranged to the side of the mouth of the plastic container, which continuously sprays nitrogen in the direction of the mouth. The plastic container is particularly preferably closed at least temporarily during the spraying with the nitrogen.

In a preferred variant of the method, the exchange medium is nitrogen, preferably liquid nitrogen. Chemically, nitrogen is largely inert. This means that reactions with the product are largely excluded. In addition, the solubility of nitrogen in aqueous solutions is limited. Therefore - at least if the fill level is known - the required amount of nitrogen to expel the medium (e.g. air) that was previously in the headspace can be determined quite precisely. Nitrogen is gaseous at room temperature, so that high flow velocities can be achieved, which is advantageous for the complete expulsion of the medium previously located in the headspace. The use of liquid nitrogen has proven to be particularly advantageous. The exchange medium and in particular the nitrogen can be fed in continuously or preferably not continuously, for example by a so-called droppler.

In particular, a variant of the method is therefore preferred in which the increased internal pressure in the container is generated by the increase in the volume of nitrogen during the transition from the liquid phase to the gas phase. Almost independently of the usual temperature of the product, there is such a high temperature difference between liquid nitrogen, which has a boiling point of 77.15 K or -196 ° C at normal pressure, and the preferably aqueous product, which usually has temperatures between 268 K (-5 ° C, even aqueous solutions can be flowable at temperatures below 0 ° C due to the dissolved substances, which enables liquid filling below 0 ° C in particular with sensitive substances such as drugs) and 383 K (110 ° C) shows that the nitrogen suddenly changes its physical state and changes into the gas phase. Since the temperature difference between liquid nitrogen and product is always at least 150 ° C, the influence of different product temperatures on the rate of change in the state of the nitrogen is of minor importance for the complete expulsion of the medium previously located in the headspace. The speed of the transition into the gas phase is essentially influenced by a gas cushion that forms between the filling material and the liquid nitrogen and serves as thermal insulation between the liquid nitrogen and the filling material. However, since the gas escapes from the gas cushion, it is a dynamic and volatile insulation that is constantly being re-formed by the nitrogen that changes its physical state, until there is no longer any liquid nitrogen. The delay achieved in the change in the state of aggregation enables the container to be closed before the nitrogen has completely transitioned into the gas phase and thus enables an overpressure to build up inside the container.

In a preferred variant of the method, the flowable medium (in particular at the time of transfer into the plastic container) has a temperature above ambient temperature, preferably in the range of 40-110 ° C., more preferably in the range of 50-100 ° C., particularly preferably in the range of 60 - 90 ° C. In particular in the case of filling goods which are filled at an elevated temperature, an increased internal pressure in the container has proven to be advantageous, since in this way the loss in volume that occurs when the filling substance is cooled can be compensated for. In addition, goods to be filled hot are often sterile and must be protected from contamination with foreign substances. By creating an overpressure in the interior of the container, the present method offers the possibility of preventing foreign substances from flowing into the interior of the container. Thus, in the case of filling goods to be protected in this way, the present method offers not only the provision of the compensating volume for the temperature-dependent change in density (and thus the resulting change in volume) of the filling goods, but also the prevention of contamination, for example by bacteria.

In particular, if the filling material has a temperature above the ambient temperature, it is advantageous if during and / or after a process of preferably active cooling of the filling material, the predetermined internal pressure of the container is set by supplying and / or removing the gaseous medium. In particular for products that must be protected from contamination, it is important that even during the volume decrease occurring due to the cooling, there is never an internal pressure in the container which is below the ambient pressure. This could not only lead to deformation of the container, but could also cause contamination of the contents due to the inflowing medium, for example by the introduction of bacteria. The inflow of air and thus oxygen would also be conceivable, which could react with substances in the filling material and, for example, could inactivate aromas and / or dyes due to their oxidation. In order to be able to ensure the internal pressure of the container, which is higher than that of the surroundings, even after the product has cooled down, it is advantageous that the predetermined internal pressure of the container is set by supplying and / or removing the gaseous medium, at least partially after cooling has ended. In this context, "after the end of the cooling" should not be understood to mean that no further cooling could take place, but the cooling should already be completed to the extent that, even with further cooling, it is ensured that the volume decrease of the product due to this further cooling in such a small framework remains that this can be compensated for by the internal container pressure set in the container while maintaining a lower internal container pressure that is still higher than the environment.

In a further preferred variant of the method, the predetermined internal pressure in the container is set by supplying and / or removing the gaseous medium during and after the cooling of the filling material. In this way, during cooling, the pressure below a minimum internal pressure can be guaranteed and a defined internal pressure can also be set after cooling. The preset internal pressure of the container can be set continuously by supplying and / or removing the gaseous medium or it can be carried out several times. Continuous control and adjustment of the internal pressure of the container to a target pressure by supplying or removing the gaseous medium is particularly useful when the product is cooled rapidly.

However, since the constant control and adjustment of the pressure is expensive in terms of apparatus, the discontinuous control and / or adjustment of the pressure inside the container is advisable in many cases. Any control and / or adjustment of the internal pressure of the container is understood as a discontinuous control and / or adjustment of the internal pressure of the container which at least one control and / or adjustment of the internal pressure of the container takes place offset in time and / or in terms of location to a previous control and / or adjustment of the internal pressure of the container. The accesses to the inside of the container for the respective control and / or adjustment of the internal pressure of the container can be different. For example, it would be conceivable to carry out a first adjustment of the internal pressure of the container via an intermediate space between a mouth and the container closure and a second control and / or adjustment of the internal pressure of the container via a section of a wall of the plastic container or a wall of the container surrounding the headspace of the container Container closure introduced opening.

In order to create an interspace between a mouth and the container closure, it would be possible for the container closure not yet to be completely screwed onto the container, but instead for the gaseous medium to be exchanged via the said gap. The container closure is preferably a screw closure which is screwed in particular onto an external thread of the container.

Preferably, screwing the container closure onto the container not yet completely is understood to mean that, for example, a rotary closure is screwed onto a thread of the container to a certain extent, but is not yet tightly closed. Advantageously, however, the container closure is already screwed tightly and thus sealingly onto the mouth of the container, which thus preferably corresponds to a complete closing of the container with the container closure.

The at least one opening provided in a section of a wall of the plastic container or a wall of the container closure surrounding the head space of the container is advantageously produced by piercing said container wall or a wall of the container closure, for example with a needle-like body. This needle-like body or this needle can preferably have a diameter which is smaller than 4 mm, preferably smaller than 3 mm and particularly preferably smaller than 2 mm. It is also possible that the needle itself is heated in order to pierce the container wall or the closure. In this way, the material of the container can also be melted locally during the piercing.

It is thus possible that a temperature of the needle (at least in that section that contacts the wall of the container) is greater than 60 ° C., preferably greater than 70 ° C., preferably greater than 80 ° C. and particularly preferably greater than 90 ° C.

In a further advantageous variant of this method, the closure is slightly opened after recooling (under defined ambient conditions, e.g. in a chamber) so that a communication link is established between the environment and the interior of the container. This can be done, for example, by slightly unscrewing the closure. An at least partial reduction in the overpressure can thus take place. This opening process can preferably take place in such a way that a tamper-evident band does not tear off and the closure can be turned back normally.

In the case of the discontinuous control and / or adjustment of the internal pressure of the container, it is also advisable to provide one or more further treatments of the container between the controls and / or adjustments of the internal pressure of the container. For example, it is conceivable that the first control and / or adjustment of the internal pressure of the container ensures an internal pressure of the container which enables the container to be labeled (for example, by ensuring sufficient container rigidity). Furthermore, treatments such as setting a predetermined division between containers following one another on the transport path, sealing, grouping, placing in beverage crates or others are conceivable. In the case of the discontinuous control and / or adjustment of the internal pressure of the container, the internal pressure of the container could be different after the respective adjustments and be coordinated with the respective following process steps. For example, after the first control and / or adjustment of the internal container pressure, a higher internal container pressure could be applied, which makes labeling easier and the internal container pressure can only be reduced further after a second control and / or adjustment of the internal container pressure.

A variant of the method is preferred in which the supply and / or discharge of a gaseous medium sets an internal pressure in the container which is in the range of 1.05-5 bar, preferably 1.05-2 bar, more preferably 1.1-1 , 5 bar, particularly preferably 1.1-1.5 bar. These details relate to the absolute pressure. There is preferably a pressure gradient between the interior of the container and the environment in the range of 0.05-4 bar, preferably in the range of 0.1-0.5 bar, particularly preferably in the range Range from 0.1 - 0.5 bar. In these areas, on the one hand, the respective container is sufficiently stable to be able to handle it safely and, for example, to label it. On the other hand, the internal pressure in the container is below a critical value at which the container could burst or deform.

The method preferably offers the possibility of setting the internal pressure of the container so that there are no restrictions with regard to the container geometry. In the process, it is also possible to treat containers with an oval or essentially rectangular cross-section. It is also possible to treat containers or special reinforcements of the container base according to the method described.

In a further advantageous method, after an internal pressure has been set, the opening is closed by supplying and / or removing a gaseous medium. This can be done, for example, by gluing or fusing. An ultrasonic source can also be used for fusing

In a further preferred method, the containers are transported during their manufacture and / or during filling and / or during the supply of the gaseous medium. The containers are advantageously transported at least in sections along an arcuate path.

In a further preferred method, the containers are transported at least in sections through a clean room. This means that the method steps described here, in particular also the step of supplying or introducing or removing the gaseous medium, take place under clean room conditions or under sterile conditions. This clean room is preferably sealed off or separated from a (non-sterile) environment by means of at least one wall. In a further preferred variant, at least one section of the wall is relatively movable with respect to another section of the wall, one of the wall sections following the movement of the container along the transport path at least in sections.

In a further preferred method, the containers are sterilized. It is thus possible for the containers to be sterilized immediately after they have been manufactured. However, it would also be possible for the plastic preforms to be closed before the forming process Plastic bottles are sterilized. This also makes it possible for the actual reshaping process for reshaping plastic preforms into plastic bottles to take place under sterile conditions. This sterilization can take place, for example, by means of a sterilization medium such as hydrogen peroxide or peracetic acid, but also by means of radiation, for example electron beams. However, it should be noted that the sterilization is an optional process step. This applies in particular to those products in which sterility is achieved by heating the liquid to be filled.

In a further preferred method, the container wall is pierced in an upper half of the container and in particular an upper third of the container (or the opening is made at this point). The term “upper half” refers to a longitudinal direction of the container which extends from a bottom of the container to the mouth of the container. The container wall is advantageously pierced in an upper quarter, particularly preferably in an upper fifth, based on the longitudinal direction. It is particularly preferable for the container wall to be pierced in a head or shoulder area of the container or in an area in the immediate vicinity of a support ring of the container, for example below or above said support ring. However, it would also be possible for the wall to be pierced at a different point, for example the circumferential wall, for example when the containers are transported lying down. One advantage of this method is that the circumferential wall can then be pierced, which is generally thinner than the wall in the region of the mouth of the container. A container turner can be used for this purpose. It would be possible here for the container to be rotated and thereby preferably to sterilize the container closure (with the hot product).

It is possible that a second container turner is provided, which turns the container back into the starting position. However, it would also be conceivable that the same container turner is passed through twice.

This embodiment results in a device in which the container comes to rest and can be pierced on the side wall (and in particular an area in which there is no liquid when lying down).

The opening is preferably made in a region of the container in which, when the container is standing, no liquid is present at the time of penetration. In this way, the liquid can be prevented from escaping through the opening.

In a further preferred method, the opening through which the gaseous medium was supplied to the container is closed or sealed again after the gaseous medium has been supplied or removed. This closing or sealing of the opening can take place in different ways. The term sealing is used in the following. This sealing is advantageously carried out by means of a method which is selected from a group of methods which includes melting a section of the container wall, melting a section of a peripheral wall of the container closure, or relative rotation of the container closure with respect to the container.

It would also be possible for the needle that pierces the container wall to be warm and then to close the pierced area again. In addition, however, a separate welding head could also be provided which is pressed onto the hole after the needle has been withdrawn in order to close the opening again.

It would also be conceivable that an “external melting point” is applied, which preferably consists of a material that differs from the material of the container wall.

This sealing is possible during or after the container is closed with the container closure.

Preferably, both the production of the opening and the sealing of the opening take place under clean room conditions and / or the formation of the intermediate space existing between an opening and the container closure within a clean room. These processes advantageously take place while the containers are moving and, in particular, while the containers are being transported in their transport direction. In addition to or instead of the clean room, a chamber can also be provided, which in particular surrounds the opening in the container wall and by means of which the gaseous medium enters the container is introduced. This chamber does not necessarily have to be able to accommodate the entire container.

When using such a chamber, on the one hand, the "clean room" (which is formed by this chamber) can be reduced and, on the other hand, it can also be pressurized so that no separate gas supply device is required in the container, but the gas "automatically" after the Penetration or partial opening occurs in the container.

In a further preferred method, closure or sealing of the container (or the opening) is checked by means of an inspection device. For example, a particularly optical inspection can be carried out to determine whether said opening has been closed. This inspection is preferably carried out without contact and particularly preferably optically.

Another essential aspect of the invention is a device for filling and closing a thin-walled plastic container, in particular a PET bottle. Such a device comprises a blow molding device for producing a plastic container from a preform and a filling device for filling the plastic container with a flowable medium and in particular a liquid. Furthermore, a closer is provided for at least partially closing the plastic container with a container closure and at least one transport device for transporting the plastic container along a transport direction on a transport path from one of the above-mentioned treatment devices to a downstream treatment device. It is also essential for this device that an exchange media introduction device is arranged on the transport path along the transport direction downstream and / or upstream of the filling device, through which an exchange medium can be introduced into the plastic container, with the previously contained medium being at least partially displaceable with the formation of an increased internal container pressure .

Furthermore, a device, for example a container internal pressure setting device or an opening generating device, is preferably arranged on the transport path along the transport direction downstream and / or upstream of the closer, by means of which through an opening which is arranged or created in at least one section of a wall of the plastic container or a wall of the container closure surrounding the head space of the container, or via an intermediate space existing between an opening of the plastic container and the container closure, in the interior of the container The internal pressure of the container is adjustable by supplying and / or removing a gaseous medium. This opening can be used to set the pressure inside the container.

Accordingly, it is also proposed on the device side to introduce an exchange medium into the plastic container by means of an exchange medium introduction device, this being done either before or after the plastic container is filled with the flowable medium. In addition, the gaseous medium can be introduced to set the internal pressure of the container, preferably before and / or during and / or after the container is closed.

In a preferred embodiment, in this device the exchange media introduction device is in fluid connection with a nitrogen reservoir, from which nitrogen, preferably liquid nitrogen, can be dispensed into the plastic container in a metered manner. In this embodiment, the device is therefore suitable and intended to be able to handle liquid nitrogen and to be able to deliver it into the interior of the container, preferably in precisely dosed quantities. As a result, a quick exchange of the gas located in the head space of the container can be achieved and - with precise dosing - the internal pressure resulting therefrom can preferably also be set at least within a predetermined range.

If the plastic container is first filled with the flowable medium via the filling device, the nitrogen can preferably be released from the nitrogen reservoir into the head space of the filled plastic container.

In a preferred embodiment of the device it is provided that the container internal pressure setting device has at least one valve which can be at least temporarily brought into fluid connection via the opening with the head space of the filled plastic container and which is preferably adjustable, by means of which an internal pressure of the plastic container is preselectable. By means of such a valve, the flow of the exchange medium can be controlled, preferably in a metered manner.

In a preferred embodiment of the device it is provided that a temperature control device, preferably a cooling device, is arranged on the transport path along the transport direction downstream of the exchange media introduction device and upstream of the container internal pressure setting device, by means of which the plastic container, preferably including the flowable medium it contains, is brought to a target temperature in the range of 4 -70 ° C, preferably 10-50 ° C, particularly preferably 20-30 ° C can be brought. Such a cooling device can accelerate the cooling of hot filled goods and thus accelerate the change in volume of the filled goods which occurs during cooling. After passing through the temperature control device and setting the temperature of the flowable medium to the range specified above, its volume change with further temperature changes is as small as possible that the expected change in volume can be compensated for by the excess pressure of the exchange medium applied in the container.

In a further advantageous embodiment, the temperature control device has nozzles by means of which a cooling medium, for example water, can be applied to the containers.

In a further advantageous embodiment, the device has a penetration device on the transport path along the transport direction downstream of a temperature control device and upstream of the container internal pressure setting device, which is suitable and intended to pierce at least a section of the wall of the container or at least a section of the peripheral wall of the container closure.

In a further advantageous embodiment of the device, a closure device is provided which is designed such that it attaches the closure to the container in two steps, for example only with a few turns initially ensures that the closure is held on the container, but between its mouth and the container closure an intermediate space is formed through which the gaseous medium advances or is deductible. The closing device could then be set up to fix the closure on the container in a sealing manner only at a later point in time.

In a further preferred embodiment of the device, a closure treatment device is provided which, after the closure of the container, again slightly opens the same, for example by rotating the closure with respect to the container in order to form an intermediate space arranged between its mouth and the container closure through which the gaseous Medium is supplied or discharged.

In a further advantageous embodiment, the device has at least one sealing device which is suitable and intended to close or seal the opening through which the gaseous medium can be supplied or removed from the container. As mentioned above, this closing device can be, for example, a fusing device which fuses the section of the container in which the opening was created again. However, it would also be possible for the closing device to be the device which attaches the container closure to the container. For example, the bottle capper could initially only partially screw a cap onto the container or not yet close it completely. This closing process could only be completed in a subsequent step. In general, this process could be carried out in the same closure device that closes the containers with closures or in a separate device.

In a further advantageous embodiment, the device has a clean room, within which the containers are transported at least temporarily. This clean room can at least enclose the area within which the exchange medium and / or the gaseous medium can be supplied to or removed from the interior of the container. It is possible that the clean room is formed by a standing housing, but it would also be possible that the clean room only surrounds the transport path of the containers in a channel-like manner, at least one wall of the clean room preferably being relatively movable with respect to at least one other wall of the clean room and at least section-wise follows the transport movement of the containers. It would also be possible for the reshaping device to reshape the plastic preforms into plastic bottles within a clean room. It would also be possible that at least one Chamber is provided, within which the exchange medium and / or the gaseous medium can be fed to the containers. This chamber could, for example, be designed as a hollow cylinder in which the containers are located.

In a further advantageous embodiment, the penetration device and / or the exchange media introduction device and / or the container internal pressure setting device is integrated into an area of the closing device which provides the containers with closures. For example, this penetration device could be integrated into a gripping or holding device which holds the containers during the filling process. This gripping device could preferably have a holding element which prevents rotation of the plastic bottle with respect to its longitudinal direction. This element could, for example, be designed as a so-called spike plate, which absorbs the closer torque.

In a further advantageous embodiment, the container internal pressure setting device has a pressure control device and / or a pressure regulating device which is suitable and intended to control and / or regulate the pressure by means of which the gaseous medium is brought into or out of the containers. For example, a sensor device could be provided which is suitable and intended to determine the respective pressure of the gas within the container and / or the pressure with which the gas is supplied to the container. A control and / or regulating device is therefore preferably provided on the device side, which controls and / or regulates the pressure by means of which the gas is supplied to the container and / or under which the gas is subsequently located in the container.

It is pointed out that this pressure control device can be used in all of the methods and devices described here, that is to say also in variants in which there is no penetration of the containers in the closing device or which is penetration-free.

It is preferably provided on the device side that the transport path runs along a circular segment at least in the area of the exchange media introduction device. A closer which at least partially closes the container is preferably also arranged in this circular segment. The segment of a circle on which during the When the container is transported, the closure is greater than in the case of systems known from the prior art. This enables both the closing of the containers with the container closures and the feeding of the exchange medium into the container can be carried out on the same segment of a circle. It is further preferred that these two processes can be carried out essentially at the same time. Overall, this results in a more compact design option for the device, since in this way it is possible to dispense with two separate system parts, namely the exchange media introduction device and the closer.

It is pointed out, however, that the configuration described here with the exchange media introduction device in the area of the closer is not absolutely necessary. It is also possible for the exchange media introduction device to be arranged downstream of the sealer and for the exchange medium to be carried out in a later treatment step, for example in a separate unit, for example after (partial) opening of the container closure or a piercing of a wall of the container or its closure. For example, the exchange media introduction device could be arranged along a transport path that lies between the closer and another device, such as a temperature control device.

In a preferred embodiment of the device, the internal pressure setting device in the container comprises a chamber which at least partially encloses the container. It is further preferably provided that a predetermined pressure is applied within this chamber and this pressure is transmitted into the interior of the container through the opening in the wall of the plastic container or the container closure or via an interspace between the mouth of the plastic container and the container closure. It is advantageous if the opening or the intermediate space are produced in the said chamber. It has proven to be particularly advantageous if penetration means are arranged in the region of the chamber. Optical penetration means, such as lasers, have proven to be particularly suitable. For example, a hole can be welded into the container wall within the chamber by means of a laser, which offers the advantage that mechanical elements such as the needles mentioned above can be dispensed with. The opening could also be sealed using a laser. It is thus possible that the opening is welded into this chamber by means of a laser and the correct pressure is then established.

This procedure also has the advantage of high hygiene, since no mechanical components attack the container.

In a further preferred embodiment of the device it is provided that the opening is made in a wall of the container in the side wall or in the base. For this purpose, the device preferably has a tilting device which tilts the container that has already been filled.

It is preferred that the container is tilted by about 90 ° and, for example, brought into a horizontal position so that the puncture can be made in the side wall. In the event of a stitch in the side wall, penetration in the area of the later labeling area is particularly advantageous, since any visual impairments can already be covered by a label.

A penetration in the bottom area of the container is also conceivable, for example in the injection point. In this area, the container is essentially unstretched and therefore amorphous. This applies in particular to a manufacturing process for stretch-blown containers, such as PET containers. In addition, a relatively large amount of material is available in the area of the injection point, in order to subsequently melt the opening again.

Further advantages and embodiments emerge from the accompanying drawings.

Fig. 1

eine schematische Darstellung des Verfahrens zur Gewährleistung eines Behältnisinnendrucks durch mehrfache Druckbeaufschlagung des Kopfraums;

Fig. 2

eine schematische Darstellung einer beispielhaften Ausgestaltung einer Vorrichtung zur Gewährleistung eines Behältnisinnendrucks durch mehrfache Druckbeaufschlagung des Kopfraums.

Show in it:

Fig. 1

a schematic representation of the method for ensuring a container internal pressure by multiple pressurization of the headspace;

Fig. 2

a schematic representation of an exemplary embodiment of a device for ensuring an internal pressure of the container by multiple pressurization of the head space.

Figure 1 shows a schematic representation of the method for ensuring an internal pressure of the container by multiple pressurization of the head space. For this purpose, it is provided that, in a first method step 1, a plastic container is blow molded is made from a preform. This is then filled in a second method step 2 with a flowable medium and in particular a liquid. It is then provided that in a further method step 3, the medium contained in the head space of the filled plastic container is exchanged by introducing an exchange medium with the formation of an increased internal pressure in the container. This could be done, for example, by introducing liquid nitrogen, which evaporates on contact with the filling material and thus displaces the medium previously contained in the head space of the filled plastic container as a gas. The use of liquid nitrogen also has the advantage that the transition to the gas phase takes place at the contact surface with the filling material and a nitrogen flow is formed from there in the direction of the mouth, which also displaces the medium previously contained in the head space in this direction .

Alternatively, however, it would also be conceivable that an exchange medium is introduced into the plastic container in a method step 2 and the plastic container is filled with a flowable medium and in particular a liquid in a method step 3, whereby the exchange medium contained in the plastic container is displaced with the formation of an increased internal pressure in the container .

After the exchange medium and the flowable medium have been introduced, the plastic container is at least partially closed in a subsequent step 4.

In the subsequent step 5, a variant of the method provides that at least one opening is made in at least one section of a wall of the plastic container or a wall of the container closure surrounding the head space of the container. This step 5 is not absolutely necessary, provided that other measures ensure that there is an opening through which a gaseous medium can be supplied and / or removed in the subsequent step 6 to set the predetermined internal pressure in the container. This could be done, for example, by only partially closing the container in step 4, whereby a channel remains between the container and the closure through which a gas exchange is possible.

In step 6 it is provided that through the opening introduced in step 5 or the space existing between a mouth and the container closure (which is also to be understood as an opening in the context of this invention) in the interior of the container, a predetermined internal container pressure by supplying and / or Removal of a gaseous medium is set. This could for example be implemented in such a way that the container is arranged at least in sections, this section enclosing the opening, in a chamber in which the desired internal pressure of the container is applied. By exchanging gas through the opening, the desired internal pressure in the container can also be set inside the container. Alternatively, the active supply or removal of the gaseous medium could also be provided, for example via a hollow needle used in step 5 to create the opening.

As a further alternative, it would also be conceivable that, after method steps 1 - 3, in a fourth method step 4 for setting a predetermined internal container pressure, a gaseous medium is introduced into the plastic container and, in a fifth method step 5, the container is closed at least temporarily while the gaseous medium is being introduced becomes. With this procedure, step 6 is omitted. However, a renewed, preferably partial opening of the closure could possibly be provided in order - for example after setting a target temperature of the filling material - to be able to set a desired pressure inside the container, preferably permanently.

Figure 2 shows a schematic representation of an exemplary embodiment of a device 10 for ensuring an internal pressure in the container by multiple pressurization of the head space. In the Figure 2 the method variant is shown as an example in which the plastic container is first filled, then an exchange medium is introduced into the plastic container and the container is then closed.

The device 10 comprises a blow molding device (not shown) which produces plastic containers 11 from preforms. These are fed to a filling device 14, where they are filled with a flowable medium and in particular a liquid. The filling material can in particular be a drink. It is preferably a hot-filled product. Hot filling is particularly advantageous in the case of perishable or sterile filling goods, since in this way contamination with heat-sensitive germs can at least largely be avoided and at least a certain degree of sterility is guaranteed can be. It is therefore possible and in many cases also advantageous if at least some of the treatment devices 14, 18, 19, 22 of the device are arranged within a clean room (not shown).

The filling device 14 is preferably a rotating filling device which has a plurality of treatment devices 12, here filling elements, along the circumference of a carrying wheel 13, through which the filling material can be filled into one of the containers 11.

The filled containers 11 are then transferred, preferably by means of a transfer device 15, to an exchange media introducing device 18, which delivers an exchange medium into the head space of the filled plastic container. The transfer device 15 is preferably designed as a transfer star and preferably has holding devices 16 which can preferably each receive a container 11. The transfer device 15 also represents a transport device for transporting plastic containers 11 along a transport direction on a transport path. The transfer device 15 can be designed so that it changes the division of the containers, i.e. changes the distance between two containers following one another along the transport path .

In the embodiment shown, the containers 11 are also transported to the respective treatment devices 14, 18, 19, 22 during the individual treatment steps, so that the treatment devices 14, 18, 19, 22 are themselves transport directions.

In the exchange media introduction device 18 shown on the transport path along the transport direction downstream of the transfer device 15, the medium contained in the head space of the filled plastic container is at least partially exchanged by introducing an exchange medium with the formation of an increased internal container pressure. For this purpose, at least one, preferably a plurality, exchange media introduction units 17 is arranged on the exchange media introduction device 18. In the example shown, the exchange media introduction device 18 is also designed as a closer 18, so that the plastic container is also at least partially closed with a container closure on the same carrying wheel. Closing takes place in a sector of the Carrying wheel formed circular segment-shaped transport path, which follows the sector in which the exchange medium is introduced into the filled plastic container.

In the present case, the introduction of liquid nitrogen is provided. This evaporates when it comes into contact with the filling material and, due to its increased volume, drives the medium previously contained in the head space out of the container 11. Since the transition to the gas phase takes place primarily on the contact surface with the filling material, a gas cushion forms on the underside of the liquid nitrogen, which acts as an insulating layer and delays the evaporation of the nitrogen. This ensures that liquid nitrogen is available inside the container for some time. As long as liquid nitrogen is still present in the interior of the container, due to its progressive evaporation there is a continuous gas flow in the direction of the mouth, through which the medium previously contained in the headspace is expelled and contamination of the contents and the interior of the container from the outside is avoided. The closure is preferably applied to the container by the closure device 18 during this phase.

The nitrogen which then evaporates can no longer flow out unhindered through the mouth, so that an overpressure is built up inside the container. If the container is only partially closed, the pressure can be slowly reduced through the remaining opening, but remains above the ambient pressure for a longer period of time, so that contamination from the inflow of foreign substances from the outside can still be avoided.

The overpressure remaining in the container 11 is necessary in order to avoid the ingress of germs during the temperature control in the temperature control device 19 that follows the exchange of the head space medium. Since the volume of the product usually decreases during the cooling process, the excess pressure in the head space can (over) compensate for this decrease in volume, so that the internal pressure of the container remains above the ambient pressure overall.

The temperature control device 19 preferably has at least one delivery device 20 for a temperature control medium. A plurality of these delivery devices 20 are preferably provided, which are arranged in the temperature control device 19 along the transport path and the containers during the transport of the containers through the temperature control device 19 apply the temperature control medium. In a preferred embodiment, the temperature control device 19 is a cooling device, which particularly preferably applies cooling water to the containers to be cooled. If the containers are to be heated (for example in order to bring them back to a target temperature after cooling), radiation such as IR and / or microwave radiation could be used as the temperature control medium.

A container internal pressure adjustment device 22 is arranged on the transport path along the transport direction downstream of the closer 18 and in the present example also downstream of the temperature control device 19. After the at least partial closure and tempering, the containers are fed to this by means of a transfer device 21. Treatment devices 23 are provided in this container internal pressure setting device 22, which can grip and transport the container and also set a predetermined internal container pressure during transport through an opening by supplying and / or removing a gaseous medium. For this purpose, a reservoir of the gaseous medium (not shown) can be provided, from which the missing gas or into which excess gas from the head space of the container can be drawn off or supplied. For this purpose, the headspace of the container and the reservoir are at least temporarily in fluid connection.

The at least one opening is arranged at least in a section of a wall of the plastic container 11 or a wall of the container closure surrounding the head space of the container or is formed by an intermediate space existing between an opening of the plastic container 11 and the container closure. It can be introduced, for example, by means of a penetration device (not shown). This could be part of the treatment device 23 and thus of the container internal pressure setting device 22.

The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they are new to the state of the art, individually or in combination.

List of reference symbols

1-6

Process step

10

contraption

11

container

12

Treatment facility

13

Carrying wheel

14th

Filling device

15th

Transfer device

16

Holding device

17th

Exchange media insertion unit

18th

Exchange media feeding device, closer

19th

Temperature control

20th

Dispensing device

21st

Transfer device

22nd

Internal container pressure setting device

23

Treatment facility

Claims (12)

A method for filling and closing a thin-walled plastic container (11), in particular a PET bottle, a plastic container (11) being produced from a preform by a blow molding process, and the plastic container (11) being filled with a flowable medium and in particular a liquid, and an exchange medium is introduced into the plastic container, whereby an at least partial displacement of the previously contained medium takes place with the formation of an increased internal container pressure and the plastic container is at least partially closed,
characterized in that
at least one opening is made in at least one section of a wall of the plastic container (11) or a wall of the container closure surrounding a head space of the plastic container and a predetermined internal container pressure is set through this opening in the interior of the plastic container (11) by supplying and / or removing a gaseous medium becomes. Method according to claim 1,
characterized in that
the exchange medium is nitrogen, preferably liquid nitrogen. Method according to claim 2,
characterized in that
the increased internal pressure in the container is created by the increase in the volume of nitrogen during the transition from the liquid phase to the gas phase. Method according to one of the preceding claims,
characterized in that
the flowable medium has a temperature above the ambient temperature, preferably in the range from 40-110.degree. C., more preferably in the range from 50-100.degree. C., particularly preferably in the range from 60-90.degree. Method according to claim 4,
characterized in that
During and / or after a process of preferably active cooling of the filling material, the predetermined internal pressure of the container is set by supplying and / or removing the gaseous medium. Method according to one of the preceding claims,
characterized in that
an internal container pressure is set which is in the range of 1.05-7 bar, preferably 1.1-5 bar, more preferably 1.2-3 bar, particularly preferably 1.25-2 bar above the ambient pressure. Method according to one of the preceding claims,
characterized in that
after setting an internal pressure in the container, the opening is closed by supplying and / or removing a gaseous medium. Device (10) for filling and closing a thin-walled plastic container (11), in particular a PET bottle, comprising a blow molding device for producing a plastic container from a preform, a filling device (14) for filling the plastic container (11) with a flowable medium and in particular a liquid; a closer (18) for at least partially closing the plastic container with a container closure, and at least one transport device (15, 21) for transporting the plastic container along a transport direction on a transport path from one of the above-mentioned treatment devices (14, 18) to a downstream treatment device ,
characterized in that
an exchange media introduction device (18) is arranged on the transport path along the transport direction downstream and / or upstream of the filling device (14), through which an exchange medium is introduced into the plastic container can be introduced, the previously contained medium being at least partially displaceable with the formation of an increased internal container pressure, and a device is arranged on the transport path along the transport direction downstream of the closer (18) by means of which an opening in at least one of the head space of the plastic container (11) surrounding portion of a wall of the plastic container (11) or a wall of the container closure (2) can be introduced and a predetermined internal container pressure can be set via this opening by supplying and / or removing a gaseous medium. Device according to claim 8,
characterized in that
the exchange media introduction device (18) is in fluid connection with a nitrogen reservoir, from which nitrogen, preferably liquid nitrogen, can be dispensed into the plastic container (11) in a metered manner. Device according to one of claims 7-9,
characterized in that
the container internal pressure setting device (22) has at least one valve which can be at least temporarily brought into fluid connection via the opening with the head space of the filled plastic container (11) and which is preferably adjustable, by means of which an internal pressure of the plastic container (11) can be preselected. Device according to one of claims 7-10,
characterized in that
a temperature control device (19), preferably a cooling device, is arranged on the transport path along the transport direction downstream and / or upstream of the exchange media introduction device (18) and upstream of the container internal pressure setting device (22), by means of which the plastic container (11), preferably including the flowable medium contained, is arranged can be brought to a target temperature in the range of 4-70 ° C, preferably 10-50 ° C. Device according to at least one of the preceding claims 7-11,
characterized in that
the device has a closing device which is suitable for closing the opening produced, in particular after the pressure inside the container has been set by supplying and / or removing a gaseous medium.

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