EP1814603A1

EP1814603A1 - Process and device for sterilising continuously conveyed plastic bottles

Info

Publication number: EP1814603A1
Application number: EP05806747A
Authority: EP
Inventors: Peter Friedrich
Original assignee: SIG Technology AG
Current assignee: SIG Combibloc Services AG
Priority date: 2004-11-18
Filing date: 2005-11-17
Publication date: 2007-08-08
Also published as: WO2006053745A1; DE102004055780A1

Abstract

A process and device are described for sterilising standing plastic bottles with an open top continuously conveyed one behind the other, the inside of the bottles being first sterilised with a sterilising agent, which is then rinsed out. In order to reliably sterilise continuously conveyed plastic bottles, the device according to the invention is characterised by pre-heating and sterilising nozzles (1), each nozzle (1) having one inner tube (2) and at least one outer tube (3). The tubular nozzle formed by the inner tube (2) is used for rinsing with a sterilising agent and the annular gap nozzle formed by the inner tube and outer tube (3) is used for pre-heating with hot air. The device is also characterised by a plurality of tubular nozzles (5) for supplying cool air and by a plurality of nozzles (6) for supplying hot air for drying, the nozzles (1, 5, 6) being lowerable into the bottles.

Description

Method and device for sterilizing continuously moving plastic bottles

The invention relates to a method for sterilizing upright, open at the top and consecutively transported plastic bottles, in particular for receiving beverages, wherein the bottle interior is first sterilized with a sterilizing agent and the sterilant is then rinsed out, and an apparatus for performing this method.

From practice, a variety of different so-called. ^Λ filling machines' are known in which continuously supplied plastic bottles filled with a certain amount of a given product and then sealed. In order for the product so filled to meet the shelf life requirements, the bottles are cleaned prior to filling or even sterilized in the case of aseptic filling in order to reliably kill the germs located inside the still empty containers.

For this purpose, it is known that the filling machines have, in addition to the actual filling unit, a sterilizing unit connected upstream of this, wherein the bottles transported one behind the other and open at the top are moved below the sterilizing unit. In this case, the number of sterilizing nozzles arranged one behind the other and the amount of hot air supplied in addition must be matched to the size of the bottle, transport speed, etc. In the known sterilizing continuously moving plastic bottles peracetic acid is used as a sterilizing agent, which is washed out again after the sterilization process. The use of peracetic acid in addition to the associated odor nuisance also has other procedural problems and in particular does not meet the guidelines of the FDA (Federal Drug Association).

Due to the fact that PET bottles can not be sterilized with the methods known, for example, from the sterilization of glass bottles, since they do not tolerate the temperatures prevailing there, the transfer of these known sterilization methods to the sterilization process for plastic bottles is ruled out.

The present invention is therefore based on the object, the above-mentioned method and the corresponding device in such a way and further, that the aforementioned disadvantages are avoided and in a structurally favorable manner continuously moving plastic bottles are sterilized efficiently and reliably.

Procedurally, the task is solved by the following steps:

Preheat the inner surface of the bottle to one

Temperature up to 80 ° C,

Sterilize the wrong by spraying a

Sterilant, Cool the inner surface of the bottle to one

Temperature <60 ° C and

Dry the bottle by blowing in hot air.

A corresponding device according to the invention is characterized by a first treatment station with a transport wheel, on the radially arranged bottle receiving stations are provided that above each bottle receiving space is lowered into the bottle nozzle for preheating and sterilization is provided that the nozzle has an inner tube and at least one outer tube and in that the tube nozzle formed by the inner tube is provided for rinsing with a sterilizing agent and the annular gap nozzle for hot air preheating formed by the inner tube and outer tube, a second treatment station with a transport wheel on which radially arranged bottle receiving positions are present, can be lowered into the bottle above each bottle receiving position Pipe nozzle is provided for introducing cooling air and a third treatment station with a transport wheel on which radially arranged bottle receiving locations are present that above each bottle receptacle eplatzes a lowered into the bottle nozzle for introducing the hot air is provided for drying.

The invention has recognized that plastic bottles can also be sterilized by means of hot hydrogen peroxide, when the bottles are cooled to a temperature <60 ° C immediately after spraying the hydrogen peroxide. In this way, the - inevitable - associated with the heat treatment shrinkage of the bottle at a value <3 vol .-%. By the preheating of the inner surface of the container with hot air is reliably ensured that condensation of the sprayed sterilant on the container wall is almost impossible.

According to another teaching of the invention, the temperature of the sterilizing agent at the nozzle outlet between 180 and 300 ° C, preferably about 190 ° C, and the temperature of the hot air at the nozzle exit during preheating 180 to 220 ° C, preferably about 200 ° C. Zum Reaching the necessary cooling, it suffices that the used cooling air has room temperature. It goes without saying that sterile air is used for cooling. The temperature of the hot air at the nozzle outlet is preferably in a range of 120 to 150 ° C, in particular at about 135 ° C.

According to a further embodiment of the invention, the volume flow (at room temperature) of the

Sterilizing agent between 3 and 7 Nm ³ / h, preferably at 5 Nm ³ / h, and the volume flow of the hot air required for preheating between 8 and 12 Nm ³ / h, preferably at 10 Nm ³ / h. The volume flow of the cooling air and the hot air used for drying is between 10 and 15 Nirι ³ / h, preferably 12 Nm ³ / h.

A further embodiment of the invention provides that the time for preheating is 2 to 4 seconds, preferably 3 seconds. Sterilization requires 1 to 3 seconds, preferably 2 seconds, for cooling 2 to 4 seconds, preferably 3 seconds, and for drying 6 to 10 seconds, preferably 8 seconds. It can be seen that the total treatment duration of all three process steps is relatively short. By doing that, the individual steps run on separate, consecutively connected transport wheels, the different treatment time can be elegantly solved by different sized transport wheels with a correspondingly different number of bottle receiving stations at the same transport speed of the bottles.

The amount of sterilizing agent needed to sterilize a bottle is, for example, 250 μl / s with a bottle volume of 11. For sterilization, a mixture containing hydrogen peroxide (H ₂ O ₂ ), for example H ₂ O ₂ / steam mixture, is used as the sterilizing agent. However, other sterilants can be used.

The nozzles used dive into the plastic bottles to a depth of 100 mm during treatment to achieve optimal effect. Plastic bottles provided with a screw cap can be sterilized by the method of the invention according to a preferred teaching of the invention by reversing the air escaping from the bottle opening during the individual treatment steps or the vapor mixture of air and sterilizing agent in order to sterilize the thread as well. For this purpose, the "double nozzle" consisting of pipe nozzle and annular nozzle and the nozzle for drying have a deflector which is open at the bottom and engages in the bottle thread in the lowered position of the respective nozzle In this way, reliable sterilization is also provided for diverting the air flow to the bottle thread an externally located on the bottleneck external thread possible.

According to a further preferred embodiment of the invention, the clear cross-sectional areas of pipe nozzle and annular die are the same size. In order to achieve an optimal detection of the entire bottle interior, in the machining position, as described above, each nozzle plunges into the bottle to a depth of 100 mm. According to another teaching of the invention, the inner tube at the nozzle outlet is longer than the outer tube to achieve on the one hand uniform heating of the bottle body during preheating and on the other hand sterilization from bottom to top. The inner diameter of the inner tube is according to a further preferred embodiment of the invention 8 to 11 mm, preferably 10 mm, and that of the outer tube 16 to 20 mm, preferably 18 mm. The diameter of the nozzle for introducing the cooling air, however, is only in the range of about 4 to 8 mm.

For the nozzle for introducing the hot air for drying, it has proved to be particularly advantageous to provide openings distributed over its circumference, in order to bring the hot air not primarily to the bottom of the bottle, but also to the bottle wall. These may be holes, slots or the like. Act.

The invention will be explained in more detail with reference to a drawing illustrating only preferred embodiments. In the drawing show 1 shows a nozzle for preheating and sterilization in side view,

2 the nozzle of FIG. 1 in vertical section,

3, the nozzle of FIG. 1 in plan view from below,

4 is a nozzle for introducing cooling air in side view, partially broken,

Fig. 5 is a nozzle for introducing the hot air for drying in side view, partially broken, and

Fig. 6 in an enlarged view, another

Embodiment of a provided for sterilizing the bottle thread diverter.

1 to 3, a nozzle 1 for preheating and sterilizing is shown, wherein a provided inside the nozzle 1 inner tube 2 for introducing a sterilizing agent and a concentrically arranged around outer tube 3 for introducing hot air through the annular gap between the inner tube 2 and outer tube 3 serve.

In the upper region of the nozzle, a downwardly open deflecting body 4 can be seen, which engages around the upper edge of the bottle neck in the processing position in order to also sterilize this edge. For this purpose, the nozzle is lowered correspondingly deep inside the bottle. Not shown is that a plurality of nozzles 1 is arranged radially on a transport wheel of a first treatment station, in accordance with the number of provided on the transport wheel bottle receiving stations. The continuously moving bottles are thereby transferred to the bottle receiving stations of the transport wheel, where there is then first the lowering of the nozzles 1 and the treatment by the process steps preheat and sterilize. Thereafter, the bottles are transferred to another transport wheel, not shown, on which, as described above, distributed over the circumference arranged nozzles 5 are provided, which, as shown in Fig. 4, can be formed as a simple pipe nozzle. In the illustrated and insofar preferred

Embodiment, the nozzle 5 is closed to its outlet, but it is also possible to provide over its circumference distributed openings (slots, holes or the like) to achieve a quick and more uniform cooling of the plastic bottle body.

Fig. 5 finally shows the nozzle which is used in the last treatment step for introducing the hot air for drying the bottle interior. Again, a plurality of nozzles 6 are arranged on a transport wheel, not shown, which are then moved continuously in rotation with the already sterilized plastic bottles, so that during this time the drying and thus the removal of the sterilizing agent can take place from the inside of the bottle. Again, as in the nozzle 1, a deflecting body 4 is provided, which also serves the Opening a plastic bottle F or a provided there external thread to dry reliably. With designed as holes 7 openings on the circumference of the nozzle 6 can be optimally adapted to the bottle shape flow conditions.

Finally, it is shown in FIG. 6 that the shape of the deflecting body can also be designed differently, there is a deflecting body 4 'is shown, which has a conically tapered edge to the emerging in the direction of the arrows from the annular gap between the nozzle and bottleneck Air (resp.

Air / sterilant mixture) even better to exploit. In order to reliably preclude the avoidance of dead spaces in the region of the thread, deflecting elements, such as a web 8 shown in FIG. 6, can be present to specifically direct the air or the air / sterilant mixture onto the thread of a bottle F. conduct.

Claims

P A T E N T A N S P R E C H E

Method for sterilizing upright, open-topped and successively transported plastic bottles, in particular for receiving beverages, wherein the bottle interior is first sterilized with a sterilizing agent and then the sterilizing agent is rinsed out, characterized by the following steps:

Preheating the inner surface of the bottle to a temperature of up to 80 ° C,

Sterilizing the wrong one by spraying a sterilizing agent,

- Cool the inner surface of the bottle to a temperature <60 ° C and

Drying the bottle by blowing in hot air,

wherein the preheating and sterilizing is carried out in a first step by means of a common nozzle lowered into the bottle, wherein the sterilizing agent is passed through a pipe nozzle and the hot air through an annular gap nozzle arranged around the pipe nozzle, wherein the cooling and drying by means of a further in the Bottle lowered nozzle takes place and wherein the movement of containers and nozzles in each processing step is carried out together continuously.

2. Method according to claim 1, wherein the temperature of the sterilizing agent at the nozzle outlet is in the range between 180 and 300 ° C, preferably at about 190 ° C, the temperature of the sterilizing agent.

3. The method according to claim 1 or 2, wherein the temperature of the hot air at the nozzle outlet during preheating is 180 to 220 ° C., preferably about 200 ° C., the temperature of the hot air at the nozzle outlet is.

4. The method of claim 1, wherein the cooling air used for cooling has room temperature.

5. The method of claim 4, wherein a sterile air is used for cooling.

6. The method according to any one of claims 1 to 5, wherein the temperature of the hot air at the nozzle outlet during drying is 120 to 150 ° C, preferably about 135 ° C, d.

7. The method according to any one of claims 1 to 6, characterized in that the volume flow (at room temperature) of the sterilizing agent is between 3 and 7, preferably 5 NmVh.

8. A process according to any one of claims 1 to 7, wherein the volumetric flow rate (at room temperature) of the hot air for preheating is between 8 and 12, preferably 10 NmVh, for the preheating.

9. The method according to any one of claims 1 to 8, characterized in that the volume flow (at room temperature) of the cooling air between 10 and 15, preferably 12 Nm ³ / h, is located.

10. A process according to any one of claims 1 to 9, wherein the volume flow (at room temperature) of the hot air for drying is between 10 and 15, preferably 12 NmVh, for drying.

11. Method according to one of claims 1 to 10, wherein the time for preheating is 2 to 4 seconds, preferably 3 seconds, for the preheating process.

12. Method according to one of claims 1 to 11, wherein the time for sterilization is 1 to 3 seconds, preferably 2 seconds.

13. The method according to any one of claims 1 to 12, characterized in that the cooling time is 2 to 4 seconds, preferably 3 seconds.

14. A process according to any one of claims 1 to 11, wherein the drying time is 6 to 10 seconds, preferably 8 seconds.

15. Method according to one of claims 1 to 14, wherein the amount of sterilizing agent required for the sterilization of a bottle is 100-400 μl / s, preferably 250 μl / s.

16. The method according to any one of claims 1 to 15, characterized in that as a sterilizing agent hydrogen peroxide (H ₂ O ₂ ) containing mixture is used.

17. A method according to any one of claims 1 to 16, wherein the nozzles used are immersed in the bottles to a depth of 100 mm.

18. The method according to any one of claims 1 to 17, wherein the plastic bottles are equipped with screw cap, characterized in that the emerging at the individual treatment steps from the bottle opening air is redirected to sterilize the thread.

19. An apparatus for sterilizing upright, open-topped and successively transported plastic bottles, in particular for receiving drinks, with at least one nozzle for introducing a sterilizing agent into the bottles and with a transport device for the continuous transport of the bottles, characterized by

a first treatment station with a transport wheel on which radially arranged bottle receiving stations are provided, above each bottle receiving station a nozzle (1) which can be lowered into the bottle for preheating and sterilizing, wherein the nozzle (1) comprises an inner tube (2) and at least one Having outer tube (3) and wherein the tube nozzle formed by the inner tube (2) is provided for rinsing with a sterilizing agent and the annular gap nozzle formed by the inner tube and outer tube (3) for preheating with hot air,

- A second treatment station with a transport wheel, on which radially arranged bottle receiving stations are present, above each bottle receiving location a lowered into the bottle pipe nozzle (5) is provided for introducing cooling air and

- A third treatment station with a transport wheel, on the radially arranged bottle receiving stations are provided, above each bottle receiving space is provided in the bottle lowerable nozzle (6) for introducing the hot air for drying.

20. Device according to claim 19, wherein the clear cross-sectional areas of the pipe nozzle and the annular gap nozzle are the same.

21. Device according to claim 19, wherein the inner tube (2) at the nozzle outlet is longer than the outer tube (3).

22. The device according to claim 19, wherein the inner diameter of the inner tube (2) is 8 to 11 mm, preferably 10 mm, according to one of the claims.

23. Device according to claim 19, wherein the inner diameter of the outer tube (3) is from 16 to 20 mm, preferably 18 mm, according to one of claims 19 to 22, characterized in that the inner diameter of the outer tube (3) is.

24. The device according to claim 19, wherein the diameter of the nozzle is 5 to 8 mm.

25. Device according to one of claims 19 to 24, characterized in that the nozzle (6) distributed over its circumference openings (7).

26. Device according to one of claims 19 to 25, wherein the plastic bottles are equipped with screw cap, characterized in that the nozzles (1) and (6) have a bottom open deflecting body (4, 4 ') which in the lowered position of the nozzles ( 1) or (6) overlaps the bottle thread.

27. Device according to claim 26, characterized in that inside the outer body (4, 4 ') webs (8) are provided for deflecting the air flow onto the bottle thread.