Method for the sterilisation of containers

Abstract

The invention relates to a method for the sterilisation of containers (1), with a circulating transport device having a plurality of container receptacles (3), wherein at a receiving region (4), the containers (1) are received by an allocated container receptacle (3) in each case, are transported by means of the container receptacle (3) along a transport path (5) and are discharged from the allocated container receptacle (3) at a discharge region (6). According to the invention, on a return path (7) between the discharge region (6) and receiving region (4), a sterilisation agent is applied to the unloaded container receptacles (3), wherein the sterilisation agent is at least partially transferred to the containers (1) which are received in the receiving region (4). The invention also relates to a sterilisation system for carrying out the method.

Description

[0001] Method for sterilizing containers

[0002] Description:

[0003] The invention relates to a method for sterilizing containers using a circulating transport device comprising a plurality of container receptacles. Containers are received in a receiving area by an associated container receptacle, transported along a transport path with the container receptacle, and discharged from the associated container receptacle to a discharge area. The invention further relates to a sterilization system for carrying out the method.

[0004] The containers can be sterilized while moving along the transport route.

[0005] The invention relates in particular to the beverage industry, where the containers are then designed as bottles, in particular disposable PET bottles, or as preforms for forming such bottles. During sterilization of the bottle or preform, it is moved by the circulating transport device, which may be, for example, a circulating chain or preferably a star wheel with the container receptacles arranged thereon.

[0006] The container receptacles are usually formed by grippers or fixed pockets, wherein the containers are then received by the container receptacle on at least one contact surface.

[0007] In the known sterilization processes, the sterilizing agent is applied to the surface of the preform or bottle, or is directed or directed onto the surface. Bottles or preforms made of PET (polyethylene terephthalate) often have a so-called neck ring on one

[0008] Bottle neck, by which these containers can be handled. If the container is then held at or near the neck ring, for example, with a gripper, the corresponding area of ​​the surface is covered. There is then a risk that adequate sterilization will not occur there, meaning that germs, spores, viruses, or microorganisms in general will remain or not be killed.

[0009] Against this background, processes and systems are known in practice in which sterilization takes place in two stages, with the containers then being transported using two conveyors and stored or gripped differently during transfer. This ensures that the entire container surface is accessible, but this results in increased effort.

[0010] A generic method is known from EP 2 742 958 B1, wherein the container receptacles are designed as gripping systems. The gripping systems each comprise two pairs of gripping clamps at different heights, whereby during transport of the containers along the transport path, a gripping takes place, thus making all areas of the surface accessible. However, this results in considerable equipment expenditure, whereby the shape of the containers and the gripping force of the gripping clamp must be coordinated in such a way that a gripping at different heights can take place without slipping. In addition, depending on the type of sterilizing agent, certain shutdown effects can occur with gripping clamps positioned directly above one another.

[0011] The invention is based on the object of providing a method for sterilizing containers and a sterilization system for this purpose, which enable reliable sterilization with the least possible effort.

[0012] The subject matter of the invention and the solution to the problem are a method for sterilizing containers according to patent claim 1 and a sterilization system for carrying out the method according to patent claim 9.

[0013] Based on a generic method for sterilizing containers, the invention accordingly provides that the unloaded container receptacles are subjected to a sterilizing agent on a return path between the discharge area and the feed area, wherein the sterilizing agent is at least partially transferred to the containers which are received in the receiving area.

[0014] According to the invention, in normal production operation, which with regard to the containers can also be referred to as transport operation, sterilizing agent is continuously applied to the container receptacles, at least where the containers are subsequently picked up by the container receptacles and carried during transport. The sterilizing agent initially applied to the container receptacles is then transferred to the containers by direct contact. Direct contact with the containers occurs precisely where the containers are picked up and carried by the container receptacle, whereby these areas are otherwise at least partially covered during conventional sterilization. The sterilizing agent can then also effectively act on the areas covered by the container receptacle.

[0015] Within the scope of the invention, it is not usually a question of sterilizing the container holder itself, but of transferring the sterilizing agent to the containers as described.

[0016] Sterilizing agent is then transferred to the containers in a still active and effective state.

[0017] With conventional sterilizing agents, this requirement can also be met because there is usually only a comparatively short distance between the application of the sterilizing agent to the container holder and the subsequent reception of the containers by the container holders.

[0018] This generally applies to different designs of the transport device, which can be implemented, for example, as a chain or with a star wheel. In a design with a star wheel, a rotation angle of less than 90°, preferably less than 45°, can be provided between the application of the sterilizing agent and the pick-up of the containers.

[0019] Also in the interests of efficient process control and space utilization, in a configuration with a star wheel, the transport path between the receiving area and the discharge area preferably extends over an angle of 180° to 330°, particularly preferably 240° to 300°. In relation to a full circle, the return path then remains, where the container receptacles are unloaded and can be filled with the sterilizing agent.

[0020] The sterilizing agent is typically transferred from the container holder to only a small portion of the container's surface, namely where direct contact occurs. Within the scope of the invention, the transfer of the sterilizing agent to the container in this way is typically intended as a supplement to sterilization of the remaining surface.

[0021] Thus, according to a preferred embodiment of the invention, the containers are exposed to a main sterilizing agent on the inside and / or outside of the container along the transport path. The designation "main sterilizing agent" merely clarifies that sterilization of the typically significantly larger exposed area on the inside and / or outside of the container is thereby provided. In this context, it is clear that, in this sense, the same substance can be provided as the sterilizing agent and the main sterilizing agent.

[0022] Hydrogen peroxide (H2O2) is particularly suitable as a sterilizing agent or primary sterilizing agent. However, other substances such as alcohol, lye, peracetic acid, or similar liquids with a sterilizing effect can also be considered.

[0023] With regard to the sterilizing agent applied to the container holders, it is necessary that this can then be transferred to the containers as a fluid and in particular liquid.

[0024] With regard to the sterilization of the remaining surface on the inside and / or outside of the container, in addition to the use of the main sterilizing agent, irradiation with UV light is also possible for sterilization.

[0025] It should be noted that irradiated UV light has an immediate effect on the surface, with PET being the preferred material for containers, especially in the form of bottles or preforms, being opaque in the corresponding wavelength range. Similar to the application of the main

[0026] Applying the sterilizing agent to the inside and / or outside of the container can cause UV light to shut down the container holder, preventing sterilization using UV light in the hidden areas. According to the invention, the sterilizing agent previously applied to the container holders is then effective there.

[0027] As already explained above, the containers are preferably bottles or preforms made of plastic, especially PET, that have a neck ring. Such containers can then be held by the neck ring in a particularly simple manner.

[0028] For containers in the form of preforms, the described sterilization can be performed, particularly before their conversion into bottles, using compressed air or by filling with the contents (from-fill process). Bottles, for example, can be sterilized before a filling process. For particularly stringent hygiene requirements, multiple sterilization at different points throughout the entire process is also possible. For example, it is conceivable to first sterilize a preform and then a bottle formed from it in several steps.

[0029] For example, container receptacles in the form of simple grippers can grip the container directly above or below the neck ring. Arranging the gripper below the neck ring can be particularly advantageous within the scope of the invention. The neck ring can then rest from above on the gripper, which typically has two gripping jaws, thus ensuring reliable transfer of the sterilizing agent.

[0030] Precisely because the areas of the containers covered by the container holder are, within the scope of the invention, directly transferred with sterilizing agent If the device is to be provided with a protective cover, these contact areas may also be somewhat larger, as sufficient sterilization can be ensured there as well. According to the state-of-the-art designs, however, the person skilled in the art strives to minimize the covered areas that are not to be sterilized as much as possible.

[0031] The sterilizing agent, particularly in the form of H2O2, can be provided as a gas or mist on the return path and then condense or precipitate on the container receptacles passing by. The sterilizing agent can, for example, be vaporized and released with air and / or steam from a discharge device in the form of a nozzle or the like, to then settle on the container receptacle as described. Through the condensation or precipitation of mist, the sterilizing agent is then applied to the container receptacle as a liquid.

[0032] For example, it can be provided that a vapor mixture of water vapor, hydrogen peroxide vapor and air is discharged, preferably continuously, wherein a vapor temperature between 110°C and 150°C, in particular about 120°C, is particularly suitable.

[0033] To ensure that the sterilizing agent can condense or condense on the container receptacles particularly reliably, active cooling of the container receptacles before exposure to the sterilizing agent is also generally considered. For example, a cooling device can be provided that directs a cold fluid, such as cold air, liquid nitrogen, or the like, onto the container receptacles before exposure to the sterilizing agent.

[0034] In principle, however, other methods of wetting are also possible. In addition to direct spraying, application or spreading with a sponge, brush, or similar is also possible. For example, appropriate discharge devices can be arranged along the return path so that the container receptacles are guided past them in direct contact.

[0035] The amount of sterilizing agent that is applied to the container receptacles and subsequently transferred to the containers depends in particular on the contact surface between the containers and the container receptacle, as well as the type of sterilizing agent. Particularly with regard to H2O2, but also other sterilizing agents, according to a preferred embodiment of the invention, the sterilizing agent is applied to the return path with a surface-specific amount of 0.2 pl / cm 2 (microliters per square centimeter) to 3 pl / cm 2 applied to a contact surface of the container holder. A surface-specific amount of 0.3 pl / cm is preferred. 2 up to 2 pl / cm 2 and in particular 0.4 pl / cm 2 up to 1 pl / cm 2 .

[0036] The specified area-specific defects refer to each cycle, whereby - as already explained - sterilizing agent is usually transferred to the container holders and from there to the containers during each cycle.

[0037] The invention also relates to a sterilization system for carrying out the method described above. The sterilization system comprises a transport device comprising a plurality of container receptacles, which has a receiving area and a removal area and is designed to place containers at the receiving area, each with a assigned container receptacle, transported with the container receptacle along a transport path, and delivered to the delivery area. A return path for the container receptacles is provided between the delivery area and the receiving area. A sterilization device for the containers is arranged on the transport path, with a first discharge device being provided on the return path for applying a sterilizing agent to the container receptacles.

[0038] The first discharge device is intended to enable the sterilization of covered areas prior to sterilization by the sterilization device. The sterilization device can comprise at least one second discharge device and / or a UV light source.

[0039] As already explained above, the container holders can be designed as grippers, whereby the grippers can then each have flat contact surfaces for the flat support of a neck ring.

[0040] Regardless of the specific design of the container receptacles, it is advantageous if the container either rests directly against them, allowing transfer of the sterilizing agent, or if the remaining areas are largely exposed. Against this background, it is particularly useful if the preferably flat contact surfaces end at edges or steps, providing a larger free space there, allowing easy access to the inside and / or outside of the container for separate sterilization.

[0041] The invention is explained below with reference to a drawing.

[0042] The only figure shows a sterilization system for sterilizing containers.

[0043] The single figure shows a schematic view of a sterilization system into which containers 1 in the form of preforms are fed. The sterilization system has a star wheel 2, which carries a plurality of container holders 3 in the form of grippers.

[0044] As can be seen from the figure, the containers 1 are picked up in a continuous operation at a receiving area 4 by an associated container receptacle 3, transported with the container receptacle 3 along a transport path 5 and delivered to a delivery area 6 by the associated container receptacle 3.

[0045] The transport path 5 extends over approximately 3 / 4 of the circumference of the star wheel 2, whereby a return path 7 remains opposite the transport path 5 between the discharge area 6 and the receiving area 5, where the container receptacles 3 are unloaded.

[0046] A first discharge device 8 is arranged on the return path 7, with which a sterilizing agent is applied to the container receptacles 3. For example, H2O2 can be vaporized as the sterilizing agent and conveyed in gaseous form with air and / or steam, to then condense on the surface of the container receptacles 3 and form a liquid film there.

[0047] When the containers 1 are subsequently picked up by the container receptacles 3 provided with the sterilizing agent during the rotation of the star wheel 3, the sterilizing agent is transferred to the containers 1 in some areas by direct contact, namely where the containers 1 are held by the container receptacle 3.

[0048] In the illustrated embodiment, the containers 1 each have a neck ring 9 by which the containers 1 are worn. The sterilizing agent is thus transferred in particular to the neck ring 9.

[0049] Further, a sterilization device with a second discharge device 10 is provided along the transport path 5. A main sterilizing agent is applied to the inside and outside of the container. The distinction between the terms "sterilizing agent" and "main sterilizing agent" refers in particular to the fact that different areas of the container 1 are sterilized, whereby the same substance, such as H2O2, can be provided.

[0050] In principle, however, the sterilization device provided on transport path 5 can also work with another substance or UV light.

[0051] With regard to the first discharge device 8, a nozzle design is particularly expedient. However, a liquid sterilizing agent can also be applied by direct contact with a sponge, a brush, or in a similar manner.

[0052] Within the scope of the invention, a particularly efficient sterilization of the entire container 1 is possible because the transfer of the sterilizing agent also allows reliable sterilization in the areas covered by the container receptacles 3.

[0053] List of reference symbols:

[0054] 1 container

[0055] 2 star wheel 3 container holders

[0056] 4 Recording area

[0057] 5 Transport route

[0058] 6 Drop-off area

[0059] 7 Return path 8 First discharge device

[0060] 9 Neckring

[0061] 10 second discharge device

Claims

Patent claims:

1. Method for sterilizing containers (1) with a circulating transport device having a plurality of container receptacles (3), wherein the containers (1) are received in a receiving area (4) by an associated container receptacle (3), transported with the container receptacle (3) along a transport path (5) and delivered to a delivery area (6) by the associated container receptacle (3), characterized in that the unloaded container receptacles (3) are subjected to a sterilizing agent on a return path (7) between the delivery area (6) and the feed area (4), the sterilizing agent being at least partially transferred to the containers (1) which are received in the receiving area (4).

2. Method according to claim 1, characterized in that the containers (1) along the transport path (5) are subjected to a main sterilizing agent on an inside and / or an outside of the container.

3. Method according to claim 2, characterized in that the same substance is provided as the sterilizing agent and the main sterilizing agent.

4. Method according to one of the preceding claims, characterized in that hydrogen peroxide is used as sterilizing agent.

5. Method according to one of the preceding claims, characterized in that the containers (1) in the form of bottles or preforms made of plastic are held in the region of a neck ring (9) during their transport.

6. Method according to one of the preceding claims, characterized in that the sterilizing agent is provided on the return path (7) as a gas or mist and condenses or deposits on the container receptacles (3).

7. Method according to one of the preceding claims, characterized in that the sterilizing agent is discharged as a vapor mixture of water vapor, hydrogen peroxide vapor and air at a vapor temperature between 110°C and 150°C, in particular about 120°C, preferably continuously.

8. Method according to one of the preceding claims, characterized in that the sterilizing agent is applied as a liquid to the container receptacles (3).

9. Method according to claim 8, characterized in that the sterilizing agent is applied to the return path (7) with a surface-specific amount of 0.2 pl / cm 2 (microliters per square centimeter) to 3 pl / cm 2is applied to a contact surface of the container receptacles (3).

10. Method according to one of the preceding claims, characterized in that the container receptacles (3) are cooled before being exposed to the sterilizing agent.

11. Sterilization system for carrying out the method according to one of the preceding claims, with a circulating transport device having a plurality of container receptacles (3), which has a receiving area (4) and a delivery area (6) and is designed to transport containers (1) to the receiving area (4) with an associated Container receptacle (3) to be received, transported with the container receptacle (3) along a transport path (5) and delivered to the delivery area (6), and wherein a return path (7) for the container receptacles (3) is provided between the delivery area (6) and the receiving area (4), wherein a sterilization device for the containers (1) is arranged on the transport path (5) and wherein a first discharge device (8) is provided on the return path (7) in order to apply a sterilizing agent to the container receptacles (3).

12. Sterilization system according to claim 11, wherein the container receptacles (3) are designed as grippers.

13. Sterilization system according to claim 12, wherein the grippers each have flat contact surfaces for the flat support of a neck ring (9).

14. Sterilization system according to one of claims 11 to 13, wherein the transport device has a star wheel (2) which carries the container receptacles (3).

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