DEVICE FOR MINIMIZING OXYGEN CONTENT

Abstract

The invention relates to a device for minimizing the oxygen content in containers to be filled, wherein the containers can he provided with a displacement medium by means of a feed unit (20), the displacement medium displacing oxygen from said container before closing the same, wherein the feed device (20) comprises at least one medium feed channel, by means of which the displacement medium can be introduced into the respective container and which is at least partially a component of a filling device (26), by means of which the respective container can be filled. The filling device (26) has a filling mandrel (17) comprising a filling channel (28), from which the respective media feed channel extends in a separated manner, and the filling mandrel (17) has at least one further medium transport channel. The invention is characterized in that the filling channel (28) is guided at the free cross-section thereof in a ring channel region of the filling mandrel (17) having a larger cross-section, and that the filling channel (28) separates the respective medium feed channel from the respective medium transport channel within the ring channel region in a medium-tight manner.

Description

The invention relates to a device for minimizing oxygen content for containers to be filled, such as ampules, which are preferably produced according to a blow, fill and seal process and which can be provided by means of a supply device with a displacement medium which displaces the oxygen out of the container before sealing it, the supply device having at least one medium supply channel by means of which the displacement medium can be supplied to the respective container and which is at least partially a component of a filling device by means of which the respective container can be filled, the filling device having a filling mandrel with a filling channel, separated from which the respective medium supply channel runs, and the filling mandrel still having at least one other medium transport channel.

EP 1 343 693 B1 discloses a device for producing and filling containers such as ampules, with at least one mold which has movable mold walls and into which at least one tube of plasticized plastic material can be extruded, whose mold parts can be closed in order to weld the leading end of the tube to form a container bottom by welding edges which are located on the mold parts, with a device for producing a pressure gradient which acts on the tube and widens it for ejecting the container on the mold walls, with a movable separating element which can be moved to form a fill opening by cutting the tube above the mold between a withdrawn base position and a working position, and with a transfer device for moving the mold into the filling position for filling the container through the fill opening, a sterile barrier being provided in a positional arrangement and with dimensions such that it is located in the working position of the separating element above the path of motion of the mold which leads into the fill position, the sterile barrier being a plate which is heated to a germ-killing temperature and which can be moved together with a blade which is used as a separating element. Furthermore the European patent discloses a production method for these containers using the device.

When highly sensitive products are produced, for example in the form of special pharmaceuticals, in which international standards for aseptic packaging must be satisfied, the mold, when it has been moved into the filling position, is located under a so-called sterile filling chamber (ASR) in which sterile air flows over the open fill opening of the container and forms effective protection against the penetration of germs until after completion of the filling process movable head jaws of the mold are closed in order to form the desired head closure of the container by a combined vacuum welding process. The sterile barrier prevents foreign bodies from being able to fall into the open fill opening after the tube is severed before the mold has reached the sterile filling chamber (ASR) and furthermore the sterile barrier during this segment of the process also prevents objectionable influx of germs into the fill opening.

But it has been shown that oxygen-sensitive products including high quality pharmaceuticals which added to container products such as ampules in this way then come into contact with a residual oxygen content in the respective container which leads to damage processes especially in the form of oxidation on the added product; this is accompanied by a distinct reduction of possible storage life. Accordingly, for sensitive products a remaining portion of oxygen in the head space of the container which is kept free of the added product of less than 0.5%, preferably of less than 0.2%, is currently required. These requirements are not adequately satisfied either by the aforementioned sterile barrier device or other known production methods together with devices as are shown, for example, by U.S. Pat. No. 5,961,039 or JP-A-4147824.

This ultimately also applies to devices which in order to minimize the oxygen content for containers to be filled, such as ampules, use a displacement medium which, supplied by means of a supply device, displaces the oxygen from the container before it is sealed. Thus JP 2004-042961 AA discloses a solution of a device in which by means of a supply device which is moved over the free container opening of a filled container inert gas as a displacement medium is blown out in the direction of the container opening in order in this way to reduce the oxygen content by displacement out of the container opening.

DE 1 566 547 A discloses a process for filling and sealing ampules as containers in which a filling mandrel with a filling channel for supply of the product to be placed in the container is encompassed in a concentric arrangement by a medium supply channel which surrounded to the outside by one wall part of the supply device is used to supply a displacement medium in the form of an inert gas in order in this way to minimize the oxygen content within the container.

U.S. Pat. No. 6,112,780 A discloses a generic device for minimizing the oxygen content for containers to be filled, such as bottle products, with a supply device which has different medium transport channels in a concentric arrangement, the innermost channel in turn forming the filling channel of a filling mandrel. A medium supply channel which encompasses the filling channel for the displacement medium in the form of an inert gas is in turn surrounded by a medium drain channel which is used to remove the displacement medium together with the oxygen from the respective container (3-tube solution). In one especially preferred embodiment of the known device for minimizing the oxygen content, there is still another medium supply channel in a concentric arrangement between the first medium supply channel and the outermost medium drain channel in order in this way to move the displacement medium pulsed into the interior of the container with the added product (4-tube design). In another alternative configuration of the known solution, space permitting, in the respective container, it is also proposed that the indicated medium channels be provided separated from one another and next to one another in a line within the device. The minimization device which is geometrically large in each version of the solution in the area of medium supply also leads to large volumes of oxygen to be displaced so that this known solution is not suitable either for producing the required setpoints of 0.2 to 0.5% residual oxygen content in the free head area of the respective container.

Proceeding from this prior art, the object of the invention is therefore to further improve the known devices such that during the production process they enable minimization of the oxygen content to the required setpoints of 0.2 to 0.5% residual oxygen content in the free head area of the respective container. This object is achieved with a device with the features of claim 1 in its entirety.

In that, as specified in the characterizing part of claim 1, the filling channel with its free cross section is guided in a ring channel region of the filling mandrel, which region is larger in cross section and in that within the ring channel region the filling channel separates medium-tight the respective medium supply channel from the respective medium transport channel, a very small device for minimizing the oxygen content for containers to be filled is devised so that less “dead space” is formed which could fill with air which then can no longer be displaced in order to achieve in this way the low residual oxygen contents of 0.2 to 0.5% of the oxygen which is otherwise present. The displacement medium, preferably consisting of a noble gas such as argon or an inert gas such a nitrogen gas can be flushed by means of the supply device into the respective container such that it almost completely displaces the residual oxygen from the container before it is sealed so that the described oxidation processes which adversely affect the extremely oxygen-sensitive products stored in the container are avoided; this benefits a long storage capacity of the overall product.

In one preferred embodiment of the device according to the invention the medium transport channel is used to remove the displacement medium together with the oxygen from the respective container, or to supply the displacement medium to the respective container. In the former case therefore the displacement medium is supplied by way of the respective medium supply channel and the medium transport channel is made as a medium drain channel in order to remove the displacement medium with the oxygen from the container opening. In the latter case the medium transport channel is used as another medium supply channel so that in spite of the supply situation which is kept small by the installation space a maximum of displacement medium to be supplied is achieved in order in this way to minimize the oxygen content in an extremely efficient manner. In the case in which the displacement medium is supplied both by way of the respective medium supply channel and also by way of the respective medium transport channel, the medium together with the atmospheric oxygen to be displaced can also be displaced outside of the supply device out of the container interior directly into the exterior.

Minimization of the required installation space is gained when the filling channel, the medium supply channel and the medium transport channel which are located medium-tight separately from one another within the ring channel region of the filling mandrel have the same input and/or output directions. The resulting parallel arrangement of the channels also allows streamlined transport of the individual media.

In one especially preferred embodiment of the device according to the invention, it is provided that the ring channel region of the filling mandrel viewed in cross section is made circular and the wall of the filling mandrel bordering the filling channel forms an oval which is reduced in cross section in one transverse direction and which in the longitudinal direction pushes against the inside wall of the circular ring channel region in order to separate from one another the thus formed sickle-shaped free cross sections of the medium supply channel and the medium transport channel. In this way all medium channels are combined centrally in the supply device in an especially space-saving manner.

The indicated displacement results can be still further improved when another medium channel, preferably made as a medium supply channel, is in a concentric arrangement to the wall of the filling mandrel and encompassing it, the other medium channel being chambered to the outside by another wall of the supply device. In addition or alternatively, it can furthermore be preferably provided that the surrounding region of the container to be filled at the time be provided at least partially with a blocking medium by means of another supply device. In this way the oxygen content in the ambient region of the respective container opening can also be reduced; this contributes to improving the result of minimization of oxygen content.

Other advantageous configurations of the device according to the invention are the subject matter of the other dependent claims.

The device according to the invention is detailed below using two exemplary embodiments as shown in the drawings which are schematic and not to scale.

FIG. 1 shows a schematically simplified representation of an open blow mold and an extrusion head located above for formation of tubing of plasticized plastic material;

FIG. 2 shows the partially closed blow mold from FIG. 1 after transfer into the filling position and after forming the container to be filled;

FIG. 3 shows a longitudinal section through the relevant parts of the device according to the invention together with a cross section of part of the molding device as shown in FIGS. 1 and 2;

FIG. 4 shows a section along line IV-IV in FIG. 3;

FIG. 5 shows an embodiment of the device according to the invention which has been simplified relative to the design as shown in FIG. 1, in a longitudinal section.

FIGS. 1 and 2 show parts of a device as is used within the framework of the known bottelpack® system for producing plastic containers in a blow molding process, by means of an extruder device 1 tubing 3 of molten plastic material being extruded between the two mold halves 5 of a mold 6 which is shown in the opened state in FIG. 1. After extruding the tubing 3 into the opened mold 6, the tubing 3 is severed between the nozzle outlet of the extruder device 1 and the top of the mold 6. FIG. 1 shows the cutting line as a broken line designated as 8.

FIG. 2 shows the mold 6 in the partially closed state, the shaping parts for the main part of the container 12 which is to be formed from the tubing 3, specifically the mold halves 5, being moved together such that bottom-side welding edges 7 on the lower end of the tubing 3 execute a welding process to seal the tubing 3 on a bottom-side weld 9.

FIG. 2 furthermore shows the mold 6 in the filling position into which the mold is pushed sideways relative to the position which is shown in FIG. 1 and which is aligned to the extruder device 1. In this filling position the container 12 that has been formed beforehand, in which blowing air has been blown in through the open fill opening 15 by means of a blowing mandrel which is not shown, is filled by way of the fill opening 15 with a filler material, for example in the form of a liquid pharmaceutical. FIG. 2 shows the end of the filling mandrel 17 which has been inserted into the fill opening 15 for this purpose. Instead of the filling mandrel 17 and a previously inserted blowing mandrel, the container can also be formed and filled by means of a combined blow mold-filling mandrel. The container 12 can also be molded instead with compressed air, added by way of the blowing mandrel, also with a vacuum which is applied to the mold. Both methods can also be combined with one another.

In the filling position shown in FIG. 2, the mold is underneath a so-called sterile filling chamber (ASR) which is not shown in FIG. 2 for the sake of simplicity and acts as an aseptic shield of the fill opening 15 which has been formed by the preceding cutting process on the tubing 3 on the cutting line 8 indicated in FIG. 1. After filling the container 12, the filling mandrel 17 is moved away to the top and the still opened movable upper welding jaws 13 of the mold 6 are moved together in order to effect molding on the container neck, and/or to seal it at the same time by welding. With the welding jaws 13 shown in FIGS. 1 and 2 it is also possible to form on the container neck an external thread for a screw cap which can be provided in addition to sealing by welding, for example in the form of a screw cap with a puncture mandrel located therein. Furthermore, several containers can be molded, filled and sealed in successive cavities of a molding tool (not shown).

The molding tools 5, 13 shown in FIGS. 1 and 2, viewed in the direction of looking at FIGS. 3 and 5, analogously are reproduced there. The device according to the invention is now used to minimize the oxygen content for the containers 12 which are to be filled and which as shown preferably are produced completely according to a blow, fill and seal process. The pertinent oxygen contents are located in particular in the cavity 19 as shown in FIG. 2 between the maximum fill level of the added product and the container closure on the top of its head.

In order to displace the thus remaining residual oxygen out of the cavity 19, there is a supply device designated as a whole as 20 which supplies the displacement medium to the cavity 19 which displaces the oxygen out of the container 12 before sealing it. The displacement medium is preferably an inert gas such as nitrogen gas. The supply device 20 has a medium supply channel 22 for the nitrogen gas which in this respect can be supplied to the cavity 19 of the respective container 12. This medium supply channel 22 is shown in FIG. 4 which reproduces a cross section through the supply device 20 along line IV-IV.

As FIG. 3 furthermore shows, the medium supply channel 22 on the top end part of the minimization device is routed to undergo transition into a widened ring channel 24 via which nitrogen gas as the displacement medium can be supplied from the outside by way of suitable transport channels (not shown). As FIGS. 3 and 4 furthermore show, the supply device 20 in this respect is a component of a filling device 26, by means of which the respective container 12 can be filled with the product to be stored. To fill the container 1, the filling device 26 extends back onto the already described filling mandrel 17 which has a filling channel 28 that is located in the middle, the filling mandrel 17 on its free end which is the top end viewed in the direction of looking at FIG. 3 is held in a receiving device 30 which is conventional for this purpose, via whose middle channel 32 the product is supplied to the container 12. Since these receiving and supply devices are conventional, they are no longer detailed here.

Furthermore, the indicated filling mandrel 17 has another medium transport channel 34 as a drain channel which in turn is reproduced only in cross section in FIG. 4 and which is used to remove the displacement medium together with the oxygen from the remaining cavity 19 of the respective container 12. This medium drain channel 34 also ends with its free end which is the top end viewed in the direction of looking at FIG. 3 in another ring channel 36 which is located underneath the first ring channel 24 and which is connected to the drain line (not shown) of the entire device, from which the nitrogen gas as the displacement medium together with the residual oxygen can be removed from the container 12.

By way of a vacuum device which is not shown, this removal can be further supported, and the negative pressure to be set, however, should be chosen such that the product added to the container 12 is not unintentionally exhausted from it. The amounts of displacement medium which are to be supplied, such as nitrogen gas, are also oriented to the free head cross sections of the container 12 together with the free volumes of oxygen within the cavity 19.

Otherwise the filling channel 28 as well as the medium supply channel 22 and the medium drain channel 34 run parallel to one another but separately from one another within the elongated filling mandrel 17. This separation of media is apparent especially from the cross section as shown in FIG. 4 which indicates that the filling channel 28 with its free cross section is routed in a ring channel region 38 which is larger in cross section, as already mentioned, the filling channel 28 separating the respective medium supply channel 22 gastight from the respective medium drain channel 34. For this purpose, the ring channel region 38 viewed in cross section is made circular and the wall 39 which delimits the filling channel 28 forms an oval which is reduced in cross section and which in the longitudinal direction adjoins the inside wall 41 of the circular ring channel region 38 in order in this way to separate the sickle-shaped free cross sections of the channels 22 and 34 from one another. In this way, the desired medium transport is achieved in an extremely narrow installation space within the filling mandrel 17, after emergence of the displacement medium from the medium supply channel 22 in the reverse arrow direction 40 re-entry of the displacement medium taking place with the residual oxygen into the medium drain channel 34. In this way, except for extremely miniscule amounts the residual oxygen content in the cavity 19 can be reduced before actual sealing of the container by way of the upper welding jaws 13.

As FIG. 3 furthermore shows, by way of the supply spaces 42 of another supply device, additionally a blocking medium, preferably in the form of a nitrogen gas, can be supplied to the receiving device 30, which medium viewed in the direction of looking at FIG. 3 emerges downwardly into the exterior on the bottom of the receiving device 30 by way of an annular blocking channel 44 and in this respect forms a blocking curtain formed from the nitrogen gas that helps prevent free entry of ambient oxygen in the direction of the free fill opening 15 of the container 12. Based on this measure the residual oxygen content in the cavity 19 of the container 12 can be further minimized if necessary. The flow direction of the nitrogen gas is indicated with arrows.

The other embodiment as shown in FIG. 5 corresponds in terms of the fundamental structure relating to the supply device 20 and the filling device 26 to the mandrel-like structure as shown in FIG. 3. But in this instance, the displacement medium, preferably in the form of pressurized nitrogen gas, is supplied by way of the two channels 24 and 36 and is blown at the same time into the interior of the container 12 by way of the two opposite medium channels 22 and 34; this can also take place during the filling process by way of the filling channel 28 which is located in the middle. Excess nitrogen gas is then, as the exit arrows shown, blown out into the exterior and in doing so entrains the residual oxygen so that in this respect with this modified embodiment minimization of the oxygen content in the container 12 is possible. By continuous supply of nitrogen in this way the air in the head region of the container 12, as shown, is displaced to the outside. In order to be able to ensure an efficient filing process, it is preferably provided that the free end of the filling mandrel 17 and, accordingly, the filling channel 28 projects in the axial direction relative to the free entry and exit ends of the medium channels 22 and 34. In this embodiment therefore the medium transport channel 34 is also used as an additional medium supply channel.

A further medium channel 45 according to the embodiment as shown in FIG. 5 on the peripheral side encloses the wall 47 of the filling mandrel 17 and is chambered to the outside by another wall 49 of the supply device 20. Furthermore, the medium channel 45 is supplied with the displacement medium by way of the channel 36. As furthermore follows from FIG. 5, the free end of the medium channel 45 is set back in turn relative to the free end of the filling mandrel 17 in order to achieve an effective blocking curtain by means of a blocking medium such as inert gas for the container opening. Advantageously, the blocking gas is blown into the still open mold tubing for the container 12 when the filling mandrel 17 is already engaged in lifting. Inert gas flows permanently through the external medium channel 45 until the head jaw 13 of the molding tool is closed and in this respect the container opening. The medium channel 45 which encompasses the filling mandrel 17 as shown in FIG. 5 is combined with the described device as shown in FIG. 3 such that the medium channel 45 encompasses the filling mandrel 17 with the other medium channels 22, 28, 34 in order to equally form a blocking gas curtain relative to the ambient air; this is especially advantageous when the indicated filling mandrel 17 is engaged in lifting.

With the device according to the invention, the residual oxygen in the container products can be pressurized to less than 0.5% and lower into the range of 0.2% and less.

Claims

1. A device for minimizing the oxygen content in containers (12) to be filled, such as ampules, which are preferably produced according to a blow, fill and seal process and which can be provided by means of a supply device (20) with a displacement medium which displaces the oxygen out of the container before sealing it, the supply device (20) having at least one medium supply channel (22) by means of which the displacement medium can be supplied to the respective container (12) and which is at least partially a component of a filling device (26) by means of which the respective container (12) can be filled, the filling device (26) having a filling mandrel (17) with a filling channel (28), separated from which the respective medium supply channel (22) runs, and the filling mandrel (17) also having at least one other medium transport channel (34), characterized in that the filling channel (28) with its free cross section is guided in a ring channel region (38) of the filling mandrel (17), which region is larger in cross section and that within the ring channel region (38) the filling channel (28) separates medium-tight the respective medium supply channel (22) from the respective medium transport channel (34).

2. The device according to claim 1, characterized in that the medium transport channel (34) is used to remove the displacement medium together with the oxygen from the respective container (12) or to supply the displacement medium to the respective container (12).

3. The device according to claim 1, characterized in that the filling channel (28), the medium supply channel (22) and the medium transport channel (34) which are separated medium-tight from one another within the ring channel region (38) of the filling mandrel (17) have the same input and/or output directions.

4. The device according to claim 1, characterized in that the ring channel region (38) of the filling mandrel (17) viewed in cross section is made circular and the wall (39) of the filling mandrel (17) bordering the filling channel (28) forms an oval which is reduced in cross section in one transverse direction and which in the longitudinal direction adjoins the inside wall (41) of the circular ring channel region (38) in order to separate from one another the respectively formed sickle-shaped free cross sections of the medium supply channel (22) and the medium transport channel (34).

5. The device according to claim 1, characterized in that the filling channel (28) projects over the medium supply channel (22) and the medium transport channel (34) in the filling mandrel (17).

6. The device according to claim 1, characterized in that another medium channel (45) is in a concentric arrangement to the wall (41) of the filling mandrel (17) and encompassing it and is chambered to the outside by another wall (49) of the supply device (20).

7. The device according to claim 1, characterized in that the displacement medium consists of a noble gas such as argon or an inert gas such a nitrogen gas.

8. The device according to claim 1, characterized in that the surrounding region of the container (12) to be filled at the time can be provided at least partially with a blocking medium by means of another supply device (42).

9. The device according to claim 8, characterized in that the blocking medium is a noble gas such as argon or an inert gas such a nitrogen gas.