EP0340411B1 - Method for packaging substances in a sterile way - Google Patents

Abstract

A device for the sterile packaging of fluid media is described, having a conveyor belt (4) by means of which packages (5) open on one side can be moved through a sterilising chamber (15) onto a second conveyor belt (13) with the aid of an intermediate conveying device (21-23), which belt (13) is mounted in a sterile space (15) closed off by a housing (14), filling means (17) and closing means (18) being arranged in this sterile chamber (15) and an outlet sluice (24) being arranged in a housing wall. <??>In order to simplify and to improve a device of this kind in such a way that a more effective sterilisation is permitted, the invention provides that the sterilising chamber (15) is designed as the inlet sluice (8). <IMAGE>

Description

The invention relates to a device for the sterile packaging of flow agents with an intermediate conveyor, with which packages open on one side can be brought through a sterilization chamber into a sterile room closed by a housing, filling and closing devices being arranged in this sterile room, according to the preamble of the patent claim 1.

It is known in the art to package sterile or aseptic packaging, e.g. So-called durable or UHT milk in packs, the side walls of which are made of plastic-coated paper and the bottom and bottom of which are provided with a lid and lid. With e.g. from GB-A-2 089 191 known processes, the pack is first produced to such an extent that it is sterilized openly on one side by superheated steam, then can be filled and sealed in a sterile room, in order to optionally lead to an overall package in outer packaging in further treatment stations to become and the like.

If one wants to fill, close and finish the package in a sterile room, there is always the difficulty that the package must be sterilized, introduced through an entrance lock into the sterile room, processed there and transported out again through the exit lock without too much energy to lose, for example, by overpressure of aseptic gas in the sterile room, by the sterilization process or by gas curtains as in GB-A-2 089 191.

On the other hand, it is known per se to sterilize packaging webs of paper or the like coated with plastic and optionally also with aluminum by high temperatures, by hydrogen or, in accordance with GB-A-1 525 484, by electron radiation. In the case of electron irradiation in accordance with GB-A-1 525 484, radiation problems arise due to the arrangement of the electron beam device with respect to the sterile room, with regard to the package and the conveyor. In addition, in the known case there is not actually a lock, but only a beam area such as a curtain, so that the introduction of bacteria through the radiation curtain is not reliably avoided.

In addition, market demand has shown that the amount of sterile product, e.g. with sterilized milk, filled packs has risen in such a way that packaging devices for UHT milk or the like should be used with high performance, so that a large number of packs can be filled sterile with this product per unit of time.

It is therefore an object of the present invention to improve a device, for example known from GB-A-2 089 191, for the sterile packaging of flow agents of the type mentioned at the outset in such a way that, without great leakage, more effective sterilization despite large throughput of packs and compact structure of the device is made possible.

This object is achieved in that a first conveyor belt is arranged at a lower level below and in front of the sterilization chamber designed as an entrance sluice and outside the sterile room, of which the packs on a second conveyor belt at a higher level by means of the essentially vertical intermediate conveyor can be brought above the first conveyor belt and within the sterile room that an exit lock is arranged in a housing wall of the sterile room and that a closing device is present at the entrance to the entrance lock. There is a two-way change of direction of the predominantly rectilinear conveying path in such a way that, while reducing the size of the entire device, the sterilization chamber also serves as a lock through which the packs are passed vertically vertically from bottom to top. A two-stage manufacturing process is created, in which the packaging, which is still open and unfilled on one side, is first sterilized on the intermediate conveyor, then placed on the second conveyor belt and filled and closed in the subsequent second stage, in which the packaging is kept sterile. Since a lock with a clean separating function is used to enter the sterile room enclosed by the housing, the sterilization chamber is also designed as a real lock. So if there are entry devices with closing devices between the first conveyor belt and the sterilization chamber, which are designed like a more or less tightly closing door, closable openings or like an intermittently opening door, there is no longer a defective closing of this door or the entry device and also no large leakage losses as in the known devices described above. Instead, the new sterilization device ensures that bacteria or the like that are carried along are largely safely killed off. The combination of the sterilization chamber and the entrance lock considerably alleviates the space and leakage problems and therefore allows the packaging device to be simplified with the additional effect that the sterilization can be made considerably more effective.

It is particularly expedient according to the invention if at least one electron beam device is arranged in the sterilization chamber, preferably one electron beam device on each side of the conveying path of the intermediate conveying device. It is known to sterilize surfaces using high temperatures, superheated steam, hydrogen and electron beams. In connection with the problem of the locks, steam or hydrogen has often been used, but the measures according to the invention can now be used to use the more controllable electron beam devices which work with less energy loss and whose electron generators are designed with 250-300 keV energy in a particularly preferred embodiment of the invention are. While it is sufficient to expose a moving chain of packs to an electron beam device, it is particularly expedient if two of these devices are arranged opposite one another on each side of the conveying path of the packs in such a way that the windows which let through the electron beams are arranged, so to speak, opposite one another . In this case, it is expedient to design the arrangement in such a way that, according to the invention, the pack or packs to be irradiated are arranged between the two windows of the electron beam devices facing one another and at those locations where no packs are transported and interrupt or reflect the radiations, Protective walls are arranged, preferably with lead. Of course, it is also expedient to provide the housing of the sterile room with lead walls. Because of the risk of damage, the windows of the electron beam devices should not be directly facing each other, but there should be a protective screen between them.

It is particularly expedient according to the invention if the packs are conveyed through the electron beam field in the direction of their main longitudinal axis. In an advantageous embodiment of the invention, the intermediate conveyor device has a small-sized packing support that can be moved vertically through the sterilization chamber by means of a rod. This packing support can e.g. about the size of the footprint of a pack or a short row of packs and, if necessary, move them over a rod, preferably in the vertical direction, the first conveyor belt then being on a lower level and the second conveyor belt being on a higher level.

According to the invention, it has proven to be particularly advantageous if the sterilization chamber is part of the housing enclosing the sterile room and the entrance lock has a tunnel and at least one movable closure flap. The various types of locks of the prior art have been mentioned above. In particular in the case of the vertical conveying direction of the packing support, which is considered advantageous according to the invention, movable closure flaps can be arranged, which on entry and also afterwards the further movement of the pack into the housing and in it close the movable parts connected to the pack support as best as possible. These flaps preferably open only when the pack enters and then at least partially return to the closed position, during which a rod moves the pack support. It is understood that a flap could already take over this function. However, it is expedient if either a support flap for the pack or, in addition to it, a further closure flap is provided, preferably with lead or entirely of lead, which closes the housing immediately after opening the entrance and entry of the pack. It is thereby achieved that, despite the arrangement of electron beam devices directly next to the lock opening, protective devices ensure that no undesired rays escape when the electron beam devices are switched on. The first closure flap which is opened first then remains in the open position.

The arrangement of a tunnel is preferred, the entry opening of which is closed by a lead plate moved with the support after the open pack has completely entered.

If necessary, this tunnel can also have the closure flap described above as an entry device from the surroundings into the entry lock, which, for example, closes this opening when the pack is removed with a support and thus the lead plate is lifted from the opening. By means of such a closure flap or by other means, the lock can be kept closed with its tunnel even when the package is on the lower first conveyor belt. Then the leakage of the sterile air can be reduced, which tries to escape due to the excess pressure from the sterilization chamber into the environment.

This slight overpressure of sterile air in the chamber is useful to prevent air contaminated with bacteria from entering the sterilization chamber from the environment. The sterile air is obtained, for example, by filtration through a sterile filter. The closure flaps or similar means mentioned then advantageously keep the loss of the continuously escaping sterile air within limits.

It is also expedient according to the invention if the packaging device has devices for rotating the packages by 90 ° about their longitudinal axis, in the case of rectangular packages in a diagonal position. A wide variety of packaging for filling goods, for example for milk, is known. There are tetrahedral, cuboid or partially tubular packs. In some cases there are already packs on the market whose cross-section is square, their Longitudinal section but is rectangular. The tube of such a package thus has essentially flat side walls separated from one another by four edges. If such a package is conveyed in the longitudinal direction past the window of an electron beam device, only that surface becomes irradiated, which is opposite the window of the blasting device. However, it is the wish of the package manufacturer or the filling-processing company to expose all surfaces of a package to the radiation, so that it is flawless and sterilized everywhere when it leaves the sterilization chamber.

For this reason, the so-called diagonal position is provided. This is such a position that, in the case of the pack having a square cross section, one edge of the side walls faces the window of the electron beam device. In this way, when the pack is guided past the blasting device, both surfaces arranged next to this edge and seen in the projection as seen by the blasting device are irradiated and thus sterilized. In order to achieve this diagonal position, the above-mentioned devices are provided for turning. In the exemplary embodiment described above, the longitudinal axis of the package could be that axis of the package in which the conveyance from the first conveyor belt through the sterilization chamber or lock to the second conveyor belt takes place, preferably in the vertical direction. A tubular elongated pack would therefore stand upright on the pack support so that its longitudinal direction, for example the longitudinal central axis, would be in a vertical position.

These devices for rotating the packs can be provided in front of or on the first conveyor belt, at least before entering the entrance lock, so that the pack in the diagonal position through the entrance lock, i.e. through the sterilization chamber, past the blasting units. The package can then remain in this position in the housing enclosing the sterile room. However, further turning devices can also be provided in order to turn the pack back again and to transport it further in the so-called “straight” position.

In a particularly advantageous manner, the Configure conveyor belts and / or the intermediate conveyor devices as multiple conveyor devices. This means that the pack support receives several packs at the same time and in this way several packs are guided past the electron beam device (s) at the same time. The elongated window of the same in the case of inexpensive electron beam devices could then - in the vertical conveying direction of the intermediate conveyor device - be oriented horizontally, so that there is a broad radiation field through which several packs could be guided simultaneously.

Instead of rotating the packs in order to simultaneously irradiate all of the pack surfaces with the blasting devices, the blasting device can of course also be tilted accordingly. All that matters is that the package is passed through an oblique beam field, from which all surfaces have been irradiated and thus sterilized after passing through the field.

In such a case, it is expedient if at least one electron beam device is arranged radiating at an angle of approximately 45 ° to the conveying direction of the packs. Here you can think of four positions for each blasting device if you lay a plane through the conveying direction of the packs; or if the use of two electron beam devices is planned, one can think of two positions for the respective electron beam device on each side of this plane which is intended by the conveying direction, namely always the position at which the beam direction forms an angle of 45 ° to the conveying direction of the packs or to the surface of the pack.

Fig. 1

schematisch die Gesamtvorrichtung zur Herstellung einer Packung und Füllen derselben unter aseptischen Bedingungen,

Fig. 2

ebenfalls noch schematisch eine etwas modifizierte Ausführungsform mit liegend angeordneten Elektronenstrahlgeräten,

Fig. 3

eine Schnittdarstellung etwa entlang der Linie III-III der Fig. 2,

Fig. 4

schematisch die Anordnung zweier Elektronenstrahlgeräte auf gegenüberliegenden Seiten der wandernden Kette von auf einem Transportband befindlichen Packungen bei Einschluß eines Winkels von 45° zwischen der Strahlung und der Förderrichtung,

Fig. 5

eine ähnliche Ansicht wie Fig. 4, wobei jedoch das zweite Strahlungsgerät um 90° zum ersten gedreht ist, und

Fig. 6

abgebrochen und perspektivisch die Mehrfachförderung und Mehrfachbestrahlung von zu sterilisierenden Packungen.

Further advantages, advantageous configurations and possible uses of the present invention result from the following description of preferred exemplary embodiments in conjunction with the attached drawings. Show it:

Fig. 1

schematically the overall device for producing a pack and filling the same under aseptic conditions,

Fig. 2

likewise also schematically a somewhat modified embodiment with electron beam devices arranged horizontally,

Fig. 3

2 shows a sectional illustration approximately along the line III-III of FIG. 2,

Fig. 4

schematically the arrangement of two electron beam devices on opposite sides of the moving chain of packages located on a conveyor belt with inclusion of an angle of 45 ° between the radiation and the conveying direction,

Fig. 5

a view similar to Fig. 4, but with the second radiation device is rotated 90 ° to the first, and

Fig. 6

canceled and in perspective the multiple conveyance and multiple irradiation of packages to be sterilized.

1 schematically shows the packaging production machine, generally designated 1, in which packs (not shown) are pulled off in the direction of arrow 3 from a turnstile 2 and set up on a first lower conveyor belt 4, as shown for the packaging 5. This is brought with the first conveyor belt 4 in its transport direction 6 into the middle position of the package 5 shown in FIG. 1 under the sterilization chamber 7, which is simultaneously designed as an entrance lock 8, 9. 9 is the passage point of the package 5 into the sterilization chamber 7, and 8 denotes the two electron beam devices, which in the present case are arranged diametrically opposite one another in such a way that their elongated windows 10 produce the radiation field 11 shown in dashed lines , in which the pack 5 is located in the middle and is conveyed in the vertical direction according to arrow 12 upwards onto the second conveyor belt 13.

This second conveyor belt 13 is located in a sterile space 15 enclosed by a housing 14 with lead walls. After placing the pack 5 on the second conveyor belt 13, it is conveyed in the direction of the arrow 16 shown to the right into the middle position under the filling station 17, where the package 5, which is open on one side, is filled with filling material. Thereafter, the further conveying takes place in the direction of arrow 16 into the position shown on the right in FIG. 1 under the closing station 18. From there, the pack 5 is conveyed vertically out of the sterile space 15 in the direction of arrow 19 onto the first conveyor belt 4, whereby the one-sided open and non-sterile package conveyed on the left of this belt is now sterilized, filled and sealed at the right end under the arrow 19.

It can be seen how the sterilization chamber 7 is designed as an entrance lock 8, 9, because even with slight leaks in the passage point 9 from the non-sterile exterior into the sterilization chamber 7, bacteria are eliminated by the electron beam field 11 of the two radiation devices 8. This provides the full lock function, and the packs, which are placed upward on the higher, second conveyor belt 13 according to arrow 12, are open on one side and completely sterilized.

The sterile room 15 is preferably kept sterile in that a slight excess pressure of, for example, sterile-filtered air is maintained as a sterile environment.

A somewhat modified and particularly preferred embodiment of the packaging device is shown in FIGS. 2 and 3. While here the mandrel wheel 2 of the non-sterile packaging machine 1 shown in FIG. 1 is omitted, the first conveyor belt 4 arranged on the lower level can be seen with the tubular packaging 5 standing upright on it, the longitudinal central axis 20 of which is vertical. From the position shown in dashed lines at the bottom left in FIG. 2, the package 5 is drawn into the position shown in dashed lines on the right Position promoted in the direction 6 and placed on a packing support 23 which is attached to a lifting rod 22. This rod 22 is slidably provided with friction by a closure flap 21, which is made of lead and, when the pack 5 is being lifted up from the position shown in broken lines in FIG. 2 to the position shown in solid lines above, with the rod 22 in the vertical direction moved upwards according to arrow 12 until it comes into contact with the lower wall of the housing 14. This closure flap 21 closes the opening formed in the housing 14 below.

This opening, which can be closed in the lower wall of the housing 14 by the closure flap 21, is the lower free end of a tunnel 24, on which one or two rotatably arranged further closure flaps, not shown, are optionally arranged near the wall 14 in order to also close the space 15 close when the flap 21 is pulled down and the electron beam devices are switched off.

If the lead closure flap 21 has come into contact with solid lines on the lower wall of the housing 14 as shown in FIG. 2, the pack 5 shown in dashed lines in this position, with its support 23 and the lifting rod 22, can move further up onto the second conveyor 13 move. This upper position is shown in Figure 2 with solid lines.

Practically at the moment when the upper edge of the package 5, which is shown in dashed lines in FIG. 2 in the lower region of the housing 14, has passed over the windows 10 of the electron beam devices 8, these devices are switched on, so that the entire package is started up further 5 is sterilized. The electron beams are therefore only emitted if there are one or more packs between the windows 10 of the electron beam devices 8 which face one another. The blasting units are then switched off so that they do not damage one another.

After sterilization, the package 5 is now open on one side on the upper conveyor belt 13 in the position shown above with the solid lines, as shown in FIG. 2. Here, as in the case of FIG. 1, the package is moved to the right under the arrow 16 Filling station 17 and from there further under the locking station 18 to then leave the sterile room 15 after this filling and closing through the exit lock 24.

From the illustration in FIG. 3 it can be seen in connection with FIG. 2 that the two diametrically opposed electron beam devices 8 with their elongated radiation windows 10 are arranged horizontally. 3, in this embodiment only one pack 5 after the other is passed vertically through the radiation field for sterilization. Since the two blasting devices 8 should not irradiate one another, a lead screen 25 is arranged next to the space for the packaging 5.

The exit lock 24 could indeed be a turnstile lock known per se (as at the entrance to larger buildings), but the diagonal position of the packs 5 is preferably a cuboidal space which is itself closed by the packs traveling through it. A turnstile always takes non-sterile air from the outside to the inside during rotation, which can cause sterilization problems. In the present case, there is only a small slot between the packing and the wall of the exit lock 24, but it is so small that the resulting leakage losses are small.

3 shows the diagonal position of the packages open on one side, so that each of the two electron beam devices 8 arranged opposite one another can fully irradiate two of the four side walls.

This full irradiation of two tube sides of the pack by an electron beam device 8 is clearly shown in FIGS. 4 and 5 shown. The chain of packages 5 and their transport direction 12 can be seen in both figures. If an imaginary plane is laid through the conveying direction 12 on the one hand and the longitudinal direction or longitudinal central axis 20 of the package 5, the radiation 11 of each electron beam device 8 closes an angle of 45 ° this level. Of course, this angle can also be between 40 and 50 °, and even with an angle of incidence of the radiation 11 in the range from 25 to 70 ° there is still good sterilization. The packs can then be conveyed "straight".
5 is the same, except that here one of the electron beam devices 8 is on the same side of the package to be irradiated with respect to the plane defined by lines 12 and 20. 5, the front surface of the package 5 "straight" conveyed in the direction of the arrow 12 is being irradiated; a little later the right device will irradiate the right side wall and the left device simultaneously the left side wall.

6 finally shows, in perspective and schematically, the multiple irradiation of packages 5 by the electron beam device 8 through the radiation window 10 lying horizontally in the direction of arrow 6. Three or more packages 5 are thus conveyed in the direction of arrow 6 into a lower position, then by one here, the packing support 23, which is designed as a partial conveyor belt, is pushed in the direction of arrow 12 in front of the radiation window 10 and from there is moved further in the manner described above. It goes without saying that pushing the packs 5 closer together is advantageous, but is not shown here for clarification.

The movement of the lifting rod 22 can also be non-linear, in order to convey a different radiation dose to different parts of the packaging. For example, the bottom area, which is almost parallel to the electron beams, can be exposed to the radiation longer than the remaining part of the container. A corresponding control for the non-linear movement of the lifting rod 22 is available on the market for the person skilled in the art if required.

Claims (7)

1. An apparatus for the sterile packaging of flowable substances, with an intermediate conveyor means (21-23) with which packages (5) open at one end can be conveyed through a sterilising chamber (9) into a sterile chamber (15) which is closed off by a housing (14), filling means (17) and sealing means (18) being disposed in this sterile chamber (15), characterised in that beneath and in front of the sterilising chamber (7) which is constructed as an inlet sluice (8, 9) and outside the sterile chamber (15) there is a first conveyor belt (4) at a lower level by which, by means of the substantially vertically acting intermediate conveyor means (21-23) the packages (5) can be moved onto a second conveyor belt (13) at a higher level above the first conveyor belt (4) and within the sterile chamber (15) and in that an outlet sluice (24) is disposed in a housing wall of the sterile chamber (15) and in that a sealing means is provided at the entrance to the inlet sluice (8, 9).
2. An apparatus according to Claim 1, characterised in that there is in the sterilising chamber (7) at least one electron beam unit (8), preferably an electron beam unit (8) on each side of the conveying path of the intermediate conveyor means (21-23).
3. An apparatus according to Claim 1 or 2, characterised in that the intermediate conveyor means (21-23) comprises a small package support (23) adapted for movement vertically through the sterilising chamber (7) by means of a rod (22).
4. An apparatus according to one of Claims 1 to 3, characterised in that the sterilising chamber (7) is a part of the housing (14) enclosing the sterile chamber (15) and in that the inlet sluice (8, 9) comprises a tunnel (24) and a movable closure flap (21).
5. An apparatus according to one of Claims 1 to 4, characterised in that the packaging apparatus comprises means of rotating the packages (5) through 90° about their longitudinal axis (20).
6. An apparatus according to one of Claims 1 to 5, characterised in that the conveyor belts (4, 13) and/or the intermediate conveyor means (21-23) are constructed as multiple conveyor means.
7. An apparatus according to one of Claims 1 to 6, characterised in that at least one electron beam unit (8) is disposed to irradiate at an angle of about 45° to the direction (12) of conveyance of the packages (5).

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