CA2289464A1 - Device for sterilizing beverage containers using a plasma - Google Patents

Abstract

The invention relates to a device for filling, closing and/or checking the smell of beverage containers comprising processing stations for the treatment of said containers and devices for transporting the objects to be treated taking the shape of containers or closures, in addition to devices for disinfecting the objects, said devices for disinfecting having at least one processing station located upstream. The invention is characterized in that at least one disinfecting station provides a disinfection area synchronously in relation to the flow of objects, said area being configured to receive an object between two electrodes which are connected to a high frequency generator to produce plasma pulses between said electrodes.

Description

DEVICE FOR STERILIZING BEVERAGE
CONTAINERS USING A PLASMA
The invention relates to an apparatus of the type referred to in the precharacterising portion of Claim 1.
Beverages are filled into beverage containers, such as metal cans, glass bottles or, recently, increasingly plastic bottles. The containers are supplied cleaned to an apparatus of the type referred to above, that is to say come either from a washing machine, when e.g. re-used multiple use bottles are concerned, or come, when new bottles are concerned, e.g. direct from a plastic blow moulding machine or out of a rinser, which merely washes the bottles out.
The containers supplied to the apparatus of the type referred to above are clean but not sterile. If there are relatively high sterility requirements, as are to be fulfilled by apparatus of the type referred to above, the containers and also the closures for closing the containers must be sterilised before the filling or closing process. The germ count in the finished filled and closed containers is thus reduced and the storage life of the beverage prolonged. Some drinks, which are currently becoming increasingly widespread, such as iced tea or uncarbonated fruit juices, can only be filled into sterile containers with limited storage life.
The apparatus of the type referred to above can be only a filling machine or only a closing machine. Commonly, it is a filling and closing machine in which the containers are firstly filled and are then closed. Disinfection devices must be provided which sterilise the processed articles, that is to say the containers and/or closures.

Superheated steam treatment stations are primarily known in the prior art as the disinfection devices but also chemically operating sterilising devices, which use e.g. H2O2.
Of disadvantage with these known disinfection devices are residues, such as drops of water, at the end of the superheated steam sterilisation or H2O2 residues, which can impair the beverage to be filled. Furthermore, the sterilisation results are unreliable with the known devices. Unreliable sterilisation results can occur as a result of non-uniform gas supply or e.g.
non-uniform steam temperatures. Since the parameters of the sterilisation process may not be directly monitored in the article to be treated, that is to say e.g. a bottle, there remains a sterilisation risk which necessitates continuous sterility checks. Thermal or chemical loadings on the container material are also disadvantageous.
Subsequently published Application PCT/CH96/00406 proposes the disinfection of containers by means of plasma, but without going into the special requirements of the beverage technology.
There is a further difficult problem with odorous containers, particularly plastic bottles. Disruptive residues remain, even after cleaning in conventional washing machines, in returned multiple use bottles which have come into contact during inappropriate treatment e.g. with urine, petrol or similar substances. An odour check is thus necessary with a so-called sniffer which is associated with a high expense on apparatus and strongly odorous containers must be sorted out, which results in scrap containers.

,_ . 3 The object of the present invention is to provide an apparatus of the type referred to above which makes highly sterile filling of beverages possible with increased security and with high throughput.
This object is solved in accordance with the invention with the features of Claim 1.
Provided in the apparatus in accordance with the invention there is a disinfection station with at least one disinfection location at which the articles, that is to say containers or closures, are acted on between electrodes with a high frequency generated plasma. This disinfection station makes the treatment location or the plurality of treatment locations available in synchronism with the moving flow of articles. The disinfection station can thus be operated synchronously with a filling or closing machine and is thus suitable for high throughputs, as are nowadays required in the beverage industry. Furthermore, the disinfection station may be integrated in this manner directly before the filling or closing station so that the risk of reinfection is slight on the very short pathway between the disinfection station and the subsequent treatment station.
A single disinfection location can be provided through which the articles move in cyclical motion or in continuous motion or a plurality of disinfection locations can be arranged, for instance for achieving higher throughputs, in a disinfection station, for instance rotating on a carousel, as with filling elements of a rotating filling machine. The disinfection station can also be equipped for multi-track operation with a plurality of parallel disinfection locations, e.g. in a cyclical operation in the manner of the operation of a series filler. The disinfection locations are very simply defined with only two electrodes which can be constructionally integrated in conventional container treatment machines, such as transporters, filling machines or closing machines.
Disinfection by means of plasma has produced very good results in preliminary tests which resulted in lower residual germ counts with comparable constructional expense than the known sterilisation methods using superheated steam or H2O2. Complete absence of germs may be achieved with high reliability with a suitable design of the disinfection station. No residues remain in the container as with superheated steam sterilisation or H202 sterilisation. It has further transpired that plasma treatment has a strongly deodorising action.
Expensive odour testing can therefore, under certain circumstances, also be omitted or the rejects reduced if a disinfection station is arranged before the sniffer. The time required for the plasma treatment process is so short that the throughput performance of modern container treatment machines is achieved with very small cycle times, even with single track movement of the articles.
The articles to be disinfected are containers which are open at a mouth and whose interior with germs suspended therein and whose inner surface with germs deposited thereon is to be sterilised. The conventional closures, such as screw caps for bottles, are also of cup-shaped construction with a mouth open to the exterior whose interior and inner surfaces must be disinfected. The features of Claim 2 are advantageously provided for this purpose. In such a construction, the plasma is produced in a large volume in the interior of the article and results in uniform action of plasma on the inner wall of the article which produces a sterilising action at that point. The high voltage electrode can be arranged projecting into the internal space through the mouth or, preferably, outside the article in front of its mouth.

The features of Claim 3 are advantageously provided. The insulating layer results in a more uniform distribution of the plasma which is produced over the entire internal surface of the article whilst avoiding excessively high local plasma concentrations which could result in surface damage.
The earth electrode is preferably constructed in accordance with Claim 4 surrounding the article in the manner of a cup for empty containers or for closure caps for particularly uniform plasma action on the inner surface of the article.
With the construction of Claim 5 a further sterilisation can be performed in a filled container, advantageously shortly before sealing the head space, which is at risk of infection on the way from the filling station to the closing station.
In accordance with Claim 6, the earth electrode is advantageously matched to the shape of the article in order to improve the uniform plasma action.
A disinfection location can be equipped completely with the two electrodes.
However, at relatively high throughputs it is then difficult to move the article correctly and with a form-locking fit between the electrodes in the time available for exchanging articles. The features of Claim 7 are therefore advantageously provided. The earth electrodes are moved with the articles so that sufficient time is available during the movement for moving the articles into and out of engagement with the earth electrodes. The high voltage electrode remains, however, stationary. This has the advantage that the high frequency generator and the expensively constructed and geometry sensitive connecting line between the high voltage electrode and the high frequency generator and optionally the necessary shields against electrical disturbances can be stationarily arranged.
In the case of earth electrodes, which are stationarily disposed at the disinfection location and engage around the article to be treated, particularly in a form-locking manner, exchanging the article is difficult and requires a lifting process e.g. in the case of cup-shaped earth electrodes. The features of Claim are therefore advantageously provided. With this construction of the earth electrode, which may be moved out of engagement in divided form, the replacement of the article is considerably simplified. The articles can move e.g.
straight on whilst the portions of the earth electrode can be moved into and out of engagement in e.g. lateral cyclical movements.
The features of Claim 9 are advantageously provided. The form-locking accommodation of the articles in the earth electrode may be effected very simply in this manner with the usual constructional means in container treatment machines, advantageously, in accordance with Claim 10, by constructing the half shells on transport stars which result in complete surrounding of the article at their transfer point at the position of the treatment location with the half shells engaging in one another.
The features of Claim 11 are advantageously provided. In this manner both an article can be sterilised and also an object situated in the vicinity of the second earth electrode can be sterilised simultaneously at one location. In accordance with Claim 12, this can be the filling element situated above the container to be filled so that its outlet, which is at risk of infection, is sterilised at the same time as the container. Optimally sterile filling is thereby ensured.

In accordance with Claim 13, directly before closing a container, the closure moving downwardly onto the container and the head space situated above the liquid in the container can advantageously be sterilised simultaneously so that optimum sterility is ensured even directly before the closing of the container.
In accordance with Claim 14, the closing element supporting a closure can advantageously be constructed as an earth electrode so that the disinfection of the closure in the closing apparatus is possible directly before the closing process, e.g. the screwing on process.
The features of Claim 15 are advantageously provided. It is possible in this manner to supply a plurality of disinfection stations with only one sufficiently powerful high frequency generator, whereby the constructional complexity and the cost of the entire apparatus are reduced. The treatment stations supplied by the high frequency generator can thus be supplied simultaneously or sequentially, e.g. via switchover devices.
The plasma can be produced in various gases or gas mixtures. Vacuum apparatus is not necessary since a plasma can be produced with a suitably designed high frequency generator, even at pressures in the region of normal atmospheric pressure. If the plasma generation is effected, in accordance with Claim 16, in the open atmosphere, the apparatus is simplified since gas-tight spaces, valves and the like are not required.
A foreign gas is preferably supplied in accordance with Claim 17 which can facilitate the plasma generation. The supply can preferably be effected in accordance with Claim 18 in an aimed manner through the mouth of the article directed into its interior, through the suitably constructed high voltage electrode.
The features of Claim 19 are advantageously provided. In contrast to the known sterilisation processes by means of superheated steam or H202, the sterilisation process with a plasma pulse may be monitored very well. The electrical parameters can be tapped off at the generator, such as the pulse duration, voltage, current and frequency. The plasma generation can also be monitored directly at the disinfection location, for instance by optically monitoring the light phenomenon which is produced or by acoustically monitoring the gentle pop which is produced. The monitoring device can make a determination with high reliability from the measured parameters whether the treated article was treated with a plasma pulse within the permitted parameter values, that is to say whether the sterilisation was effected reliably. In the event of a misfunction, the incorrectly treated article can be followed on its further transport path and sorted out of the article flow at a suitable position.
Maximum infection security is produced in this manner.
The invention is illustrated schematically and by way of example in the drawings, in which:
Fig. 1 is an axial sectional view of a disinfection location for empty plastic bottles, Fig. 2 is an axial sectional view of a disinfection location for closure caps, Fig. 3 is an axial sectional view of a disinfection location for the head space of filled bottles, Fig. 4 is a sectional view on the line 4-4 in Figure 5 of a disinfection location with two transport stars, Fig. 5 is a sectional view on the line 5-5 in Fig. 4 of the disinfection location of Figure 4, Fig. 6 is a sectional view on the line 6-6 in Fig. 8 of a disinfection location for an empty bottle and the associated filling element, Fig. 7 is a sectional view on the line 7-7 in Fig. 8 of a disinfection location for the head space of a filled bottle and for the associated closure cap and Fig. 8 is a plan sectional view on the lines 8-8 in Figures 6 and 7 of a filling and closure machine with three disinfection locations.
Figure 1 shows a disinfection location for disinfecting the inner surfaces of a plastic bottle 1, e.g. of the material PET which is commonly used nowadays for these purposes. The bottle 1 is standing on its base and its open mouth 2 is pointing upwardly. The bottle 1 is positioned in a cup-shaped upwardly open earth electrode 3, which is formed e.g. of electrically conductive metallic plate.
The earth electrode 3 is lined on its inner surface with an insulating layer 4 of suitably insulating material. An earth line 5 is shown with which the earth electrode 3 is earthed. The earthing can of course also be effected by means of constructional elements to which the earth electrode 3 is connected.

Supported above the mouth 2 of the bottle 1 by means which are not shown is a high voltage electrode 6 which is connected by means of a line 7 to the high voltage pole of a high frequency generator 9 which is earthed via a line 8.
If the electrodes 3 and 6 are dimensioned and arranged approximately as shown and with a plastic bottle 1 of about one litre volume a high frequency generator can be used which applies a high frequency of e.g. of 2 Mhz at a voltage of a few kV across the electrodes 3,6 for a pulse time of e.g. 20 ms.
A plasma is generated between the electrodes, substantially on the axis of the bottle 1, which fills the internal space, diffuses to the inner walls of the bottle 1 and acts on them with chemically highly reactive ions and radicals. Biological materials, particularly such as bacteria etc., suspended in the internal space and resting on the internal surface of the bottle 1 are thus destroyed. Odorous substances, which would impair the beverage, are removed in this manner so that under certain circumstances sniffing and sorting out of odorous bottles can be avoided.
The illustrated disinfection location can be enclosed in a predetermined atmosphere, for instance by a chamber, which is not shown, and inlet and outlet transfer ports etc. In the illustrated exemplary embodiment, the plasma generation occurs, however, in the open atmosphere, that is to say in air. It can be necessary to introduce a foreign gas, e.g. argon, into the bottle before the plasma ignition.
For this purpose, the high voltage electrode 6 is constructed in the illustrated exemplary embodiment in the form of a nozzle with a passage 11 which is connected via a hose 12 and a controllable valve 13 to a gas supply, which is not shown.
After the necessary plasma pulse, which is, as mentioned, very short, the bottle 1 can be immediately removed and replaced by a new bottle. The pulses can be produced at a rate of about 10 Hz so that the bottles can be disinfected at a very high processing rate.
Beaker-shaped containers, as shown in Figure 5, can also be disinfected in the disinfection station shown in Figure 1 and, for instance, also upwardly open metal cans, glass bottles or other containers used for beverage filling.
Figure 2 shows a disinfection location for the internal disinfection of a closure cap 21 with an internal thread, as is used e.g. as a screw cap for bottles. It is a cup-shaped article with a lower mouth 22 whose internal surfaces are to be disinfected, that is to say an article which is geometrically similar to that represented by the bottle 1 in Figure 1.
An earth electrode 23, which surrounds the closure cap 21 in the manner of a cup is again provided, in this case also which is constructed in this case as a holder for the cap 21 with which, driven by means of a shaft 24, the cap 21 can be screwed onto a bottle immediately after termination of the sterilisation, whereby the shaft 24 is to be rotated in the direction of the arrow.
Disposed in front of the mouth 22 of the cap 21 is a high voltage electrode 26 which is connected via a line 27 to a high frequency generator 29, which is earthed by means of a line 28.

. . 12 The earth electrode 23 should be earthed in a suitable manner, for instance by means of an earth contact spring 25, which maintains the earth electrode 23 earthed in sliding contact, even whilst it is rotated.
An auxiliary gas can be introduced into the interior of the cap 21 through the high voltage electrode 26 or in some other manner before the plasma generation in the construction of Figure 2 also. The high frequency generator 29 can have similar characteristics to the high voltage generator 9 referred to above.
Other closures, such as can lids or crown tops, can also be plasma sterilised in a similar manner. The earth electrode surrounding them can be constructed as an earthed closure element in order to simplify the construction.
Figure 3 shows a disinfection location for a bottle which is arranged in the treatment sequence of the bottle after the filling process and before the closure process. The illustrated bottle 1 is previously sterilised, e.g. at the disinfection location shown in Figure l, filled to the level 31 and is now to be closed.
Its head space above the level 31 can, however, be recontaminated on the way from the filling station to the closure station and must now be post-sterilised.
This is effected by the disinfection location which is illustrated in Figure 3.
An earth electrode 33 with an internal insulating layer 34 surrounds the upper region of the bottle 1 in a rotationally symmetrical and form-locking manner with the throat region, that is to say the top region of the bottle in which the head space, which is not filled with liquid, is disposed. The earth electrode 3 is earthed with an earth line 35. Arranged above the mouth 2 of the bottle 1 is a high voltage electrode 36 which is connected by a line 37 to a high frequency generator 39, which is earthed with a line 38.
With this construction, the interior space and the internal surface of the bottle 1 S are sterilised with a plasma in a similar manner to that with the construction of Figure l, but only in the liquid-free head space with the construction of Figure 3.
As Figures 1 to 3 show, the earth electrode 3, 23, 33 should be form-lockingly matched to the outer shape of the article to be disinfected, that is to say the bottle 1 or the closure cap 21, in order to achieve a favourable plasma formation in the interior of the article. The replacement of the bottle 1 disinfected with a plasma pulse by the next bottle to be disinfected is difficult in the embodiments of Figures 1 and 3 with cup-shaped or annular closed earth electrodes 3 and 33, respectively.
In order to make bottle replacement less complicated at the possible cycle frequency referred to of 10 Hz, a disinfection station can be constructed as shown in Figures 4 and 5. A cup-shaped container 41 is shown therein but the bottle l, which is shown in Figures 1 and 3, can also be treated with this treatment station.
Containers 41 come in a single line in a continuously moved flow to the illustrated treatment station which has two transport stars 43 and 44 rotating synchronously in opposite directions about vertical shafts 42. The two stars have pockets on their periphery and correspond in the plan view of Figure 4 to the conventional transport stars used in bottle treatment machines. Containers . . 14 move in, for instance, on the transport star 43, situated in its pockets, pass the disinfection location situated at 45 and move out with the transport star 44, rails 46 holding the containers 41 in the pockets.
All the pockets of both stars are, as shown particularly in Figure 5, formed with cylindrical half shells 47, whereby, as shown in Figures 4 and 5, the transfer of the containers 41 from the one star to the other star occurs at the disinfection location 45, at which the two stars 43 and 44 are in engagement with one another, two respective half shells 47 from the two stars defining a cylinder which engages completely around the container 41 and is closed at the bottom with a sliding plate 48 to form a cup-shaped earth electrode 47, 47, 48.
This earth electrode is earthed by way of an earth line 49 on the sliding plate 48.
The transport stars 43 and 44 are earthed by sliding contacts 50 in contact with the sliding plate 48 so that the half shells 47 are also earthed.
Situated above the mouth of the container 41 there is a high voltage electrode 56, which is fixedly disposed above the sliding plate 48, that is to say above the disinfection station 45 which, as indicated in Figure 5, projects out of an insulator head 58. A line 57 leads to the high frequency generator.
In the disinfection station illustrated in Figures 4 and 5, containers 41 are transported successively in a row with the transport stars 43 and 44. They reach the disinfection location 45 beneath the high voltage electrode 46. At this position, a cup-shaped earth electrode is closed around the container 41 by the half shells 47 on the stars 43 and 44 and the sliding plate 48 and a plasma discharge can take place here with substantially the same geometrical IS
conditions as described in relation to Figure 1.
As shown in Figures 4 and 5, the half shells 47 are provided with an insulating layer 54 which, if necessary, can also be provided on the sliding plate 48.
Figures 6 to 8 show an apparatus for filling and closing and twice disinfecting bottles 61 which are shown (Figure 6) with a throat collar 62 and mouth 63 but in other respects can correspond to the shape shown in Figure 1. The bottles can be commercially available PET bottles. An odour testing station is provided upstream.
The bottles 61 move, as shown in Figure 8, on a transport belt 80 to an inlet star 81 which transfers the bottles onto the filling locations 82 of a filling machine whose filling table 84 rotates about a shaft 83. The bottles rotate, whilst situated at the filling locations 82, with the filling table 84 and are transferred with a transfer star 85 to the rotating table 86 of a closer from which they are transferred after one rotation with the aid of an outlet star 87 onto a removal transport belt 88. The filling table 84 and the closer table 86 and the transport belts 80, 88 and the stars 81, 85 and 87 are coupled to move in synchronism.
Figure 6 is an axial sectional view of a filling location 82 on the filling table 84 with the filling element 89, which is arranged above each filling location, of conventional construction with a liquid outlet 90, container edge seal 91 and return gas tube 92.
Secured to each filling location 82 on the filler table 84 is a radially outwardly open semi-cylindrical half shell 93.

. 16 A disinfection location is designated 94 in Figure 8 and is disposed fixedly, that is to say not rotatably with the filler table 84. Arranged at this disinfection location 94 adjacent the filler table 84 there is a counter-rotating star 95 with pockets constructed as half shells 96.
Figure 6 shows the disinfection location 94 constituted in this manner on which, as also shown in Figure 8, a half shell 96 on the star 95 and a half shell 93 on the filling table 84 are closed around the bottle 61 and together with the filling table 84 define a cup-shaped earth electrode surrounding the bottle 61, in a manner similar to the earth electrode 3 shown in Figure 1.
Fixedly arranged at this position, that is to say at the stationary disinfection location 94, there is a high voltage electrode 97 with an insulator 98 which is connected via a schematically indicated line 99 to a high frequency generator 101, which is earthed by means of a line 100. The stationary high voltage electrode 97 has upwardly and downwardly projecting tips 102 and 103.
Both the earth electrode 93, 96, 84 defined at the disinfection location and also the filling element 89 are earthed in a suitable manner, as shown in Figure 6.
If a pulse is supplied to the high voltage electrode 97, a plasma is produced simultaneously both in the bottle 61 and also with respect to the filling element 99. The interior of the bottle is thus sterilised and the filling element 89 is sterilised at the critical points, that is to say at the return gas tube 92 and in the outlet 90. On further rotation of the filling table 84 after the disinfection location 94, the filling element 89 can be lowered directly onto the mouth 63 of the bottle 61 and the filling process commenced.

Bottles 61 filled to a level 104 (Figure 7) now move on the closer table 86 to a disinfection location 105 provided there, which is shown in detail in Figure 7.
The bottles 61 are situated at closing locations on the closer table 86. Each of these closing locations is equipped with a half shell 106, which is connected to the closing table 86, e.g. by means of a disc 107. Further half shells 108 are connected to the pockets of a star 109 which is arranged to counter-rotate synchronously adjacent the closing table 86.
The half shells 106 on the closing table 86 and the half shells 108 on the star 109 are mounted at an appropriate height and constructed with an appropriate shape so that when two of them are closed around the bottles 61 they define an earth electrode of a shape and construction as is shown in Figure 3, optionally also with the internal insulation shown therein. Both half shells should be earthed, as indicated in Figure 7, for instance via the closing table 86 and via the star 109.
Disposed above the closing locations on the closing table 86 are, as shown in Figure 7, closing elements 23 with shafts 24 for holding closure caps 21. They correspond to the construction in Figure 2.
Arranged stationarily, that is to say not rotating, at the position of the disinfection location 105, there is a high voltage electrode 97 which corresponds to the high voltage electrode illustrated in Figure 6 and is provided with the same reference numerals including the entire high voltage portion.

Ig The closure cap 21 and, downwardly, the head space of the bottle 61 above the liquid level 104 are simultaneously sterilised at the disinfection location when a pulse is supplied to the high voltage electrode 97. Directly thereafter the closing process can be effected by the closer.
A supply path 110 is also indicated in Figure 8 with which the closure caps 21 are supplied to the closer at which they are inserted into the closure elements 23, in a manner which is not illustrated.
As indicated in Figure 8, the high voltage electrodes 97 of the two disinfection locations 94 and 95 can be supplied by one high voltage generator 101 via lines 99, namely via a distributor 111 which supplies pulses to the two high voltage electrodes either simultaneously or successively with a suitable switch-over device with appropriate synchronisation.
Figure 8 also shows an installation provided upstream of the transport belt 80 for odour testing plastic bottles. As may be seen from the highly schematic view, the bottles 61 arrive on a transporter 120 and move firstly into a disinfection station 121, which can be constructed as illustrated in Figures 4 and 5. The disinfected bottles move from the disinfection station 121 via a transporter 122 to a sniffer 123 which checks the interior of the bottles for odour loading and discharges excessively loaded bottles onto a transporter 124.
Non-odour loaded bottles continue to move on the transport belt 80.
The disinfection station 121 operates, for instance, as shown in Figures 4 and 5, with plasma generation and is connected via a line 99 to the distributor 111.
In the case of the plasma generation in the bottles 61, there is not only a - . , , 19 preliminary disinfection but also a considerable reduction in the odour loading.
Rejection onto the transporter 124 is thus substantially reduced.
The upstream odour testing installation can also be omitted if the bottles are not odour loaded or if, for instance, at only low odour loading the action of the plasma at the disinfection station 94 is sufficient for complete deodorisation.
Care should be taken in all the illustrated exemplary embodiments that the high voltage electrode always has a pulse applied to it by its associated high frequency generator to produce the plasma when it is situated in front of the mouth of an article, that is to say a bottle, a container or a closure cap.
For this purpose, the high frequency generator should be synchronised in a suitable manner with the movement of the articles so that the production of the pulses always occurs at the right time.
In the illustrated exemplary embodiments the earth electrodes are connected to the generator via earth lines, that is to say, for instance, machine components and the like. The earth electrodes can, however, also be in contact with the corresponding pole of the high frequency generator unearthed, that is to say insulated, although earth connections are generally more suitable, particularly for the purpose of electrical disturbance shielding.
The earth connections are difficult in the illustrated embodiments with moved earth electrodes, such as the moved half shells 47 in Figure 5. Sliding contacts must be used, such as the two resilient sliding contacts 50 shown in Figure 5.
Rotating contact points on the shafts can also be used. Another type of contact, which is possible in the light of the high frequency used in this case for plasma - , , , 20 generation, is, however, advantageous. Capacitative coupling can be used which operates contactlessly and thus does not suffer from disruption and wear.
For instance, the sliding plate 48 in Figure 5 can be earthed via a fixed earth line 49. The earth contact between the sliding plate 48 and the stars 43 and can, however, be effected contactlessly by capacitative coupling between the sliding plate 48 and the rotating discs of the star wheels 43 and 44, which can be arranged with a suitable size and a small spacing between them.
The sterilisation of plastic containers is discussed in the illustrated embodiments. Glass containers, e.g. glass bottles, may be treated in the same manner. Metallic objects, such as beverage cans or metallic closure caps, may also be sterilised with plasma in an easily modified manner.
Impermissible variations in the plasma generation can occur during plasma sterilisation as a result of electrical disturbances in the high frequency generator or as a result of inhomogeneities in the objects to the treated, for instance if a filled bottle is present when an empty bottle is expected. An incorrectly treated object is not sterile and must be sorted out. A monitoring device, which is not illustrated, can be provided for this purpose which e.g. measures the electrical parameters of the plasma pulse at the high frequency generator or, for instance, monitors the plasma generation at the sterilisation location by means of optical or acoustic remote observation. After comparing each individual plasma generation with permissible parameter threshold values, a decision can be made as regards correct disinfection. If there is imperfect treatment, the imperfectly treated object is detected and can be followed in the synchronously moving flow of articles and discharged at a suitable position.

' 21 Disinfection locations are shown in Figs. 6 and 7 in which a high voltage electrode 97 with the tips 102 and 103 simultaneously produces a plasma upwardly towards the filling element 89 or towards the closure cap 21 and downwardly into the bottle 61. These views are selected only schematically in order to illustrate the possibility of simultaneous sterilisation of two articles at a disinfection location. In fact, the simultaneous application of plasma to two articles from one electrode meets technical problems. Instead of the one high voltage electrode 97 illustrated in Figs. 6 and 7, it is better to provide two high voltage electrodes which are individually supplied by high frequency generators, e.g. successively. The tips of the these high voltage electrodes can be directed towards their respective plasma application location in a manner similar to the tips 102 and 103. They can be energised, for instance, shortly after one another or optionally even simultaneously.

Claims (19)

CLAIMS:

1. Apparatus for filling, closing and/or odour testing of beverage containers (1, 41, 61) including treatment stations (filling table 84, closing table 86, sniffer 123) for treating and devices for transporting (transport belts 80, 88, stars 81, 85, 87) the articles to be treated in the form of containers or closures and including devices for disinfecting the articles which are provided upstream of at least one treatment station, characterised in that at least one disinfection station is provided which makes at least one disinfection location (45, 94, 105, 121) available, which is constructed to receive an article (bottle 1, 41, 61, closure cap 21) between two electrodes (high voltage electrode 6, 26, 36, 56, 97, earth electrode 3, 23, 33, 47, 48, 93, 96, 84, 106, 108), which are connected to a high frequency generator (9, 29, 3 9, 101) to produce a plasma pulse between the electrodes.

2. Apparatus as claimed in Claim 1, characterised in that one of the electrodes is earthed to constitute an earth electrode (3, 23, 33, 47, 48, 93, 96, 84, 106, 108) and is constructed with a large area and rotationally symmetrically with respect to the axis of the article (bottle 1, 41, 61, closure cap 21) to surround it whilst the other is disposed as a high voltage electrode (6, 26, 36, 56, 97) in the region of the mouth (2, 22, 63) of the article connected to the high voltage pole of the high frequency generator (9, 29, 39, 101).

3. Apparatus as claimed in Claim 2, characterised in that the earth electrode (3, 33, 47) is provided on its inner surface with an insulating layer (4, 34, 54).

4. Apparatus as claimed in Claim 2, characterised in that the earth electrode (3, 23, 47, 48, 93, 96, 84) at a disinfection location for closure caps (21) or empty containers (1, 41, 61) surrounds the closure cap or the body of the container in the manner of a cup whilst leaving the mouth region exposed.

5. Apparatus as claimed in Claim 2, characterised in that a disinfection location is provided after the filling and before the closing of the containers (1, 61) which surrounds the head space of the container above the liquid level (31, 104) with a substantially annular earth electrode (33, 106, 108).

6. Apparatus as claimed in Claim 2, characterised in that the earth electrode (3, 23, 33, 47, 48, 93, 96, 84, 106, 108) is form-lockingly matched to the external shape of the article (1, 21, 41, 61).

7. Apparatus as claimed in Claim 2 with continuously moved articles, characterised in that a plurality of earth electrodes (3, 23, 33, 47, 93, 96, 84, 106, 108) are moved with the articles (bottles 1, 41, 61, closure caps 21) through the disinfection location (45, 94, 105) at which the high voltage electrode (6, 26, 36, 56, 97) is stationarily arranged, the high frequency generator (9, 29, 39, 101) being so controlled that a pulse is produced when the mouth (2, 22, 63) of an article is situated in front of the high voltage electrode.

8. Apparatus as claimed in Claim 2, characterised in that the earth electrode is divided into a plurality of portions (47, 47; 93, 96; 106, 108) which may be brought separately out of engagement for the purpose of replacing the article.

9. Apparatus as claimed in Claims 7 and 8, characterised in that the earth electrodes are divided on the central line of the path of movement of the articles (containers 41, bottles 61) into two respective half shells (47, 47;
93, 96; 106, 108) which are secured to separator transporters (stars 43, 44; filling table 84, star 94; closing table 86, star 109), which move synchronously with the articles so that when a pulse is applied two half shells surround the article at a disinfection location (45, 94, 105).

10. Apparatus as claimed in Claim 9, characterised in that the half shells (47) are constructed in the form of pockets in transport stars (43, 44) in engagement with one another at the disinfection location.

11. Apparatus as claimed in Claim 2, characterised in that at least one high voltage electrode (97) is disposed between the mouth (63) of the article (bottle 61) surrounded by the earth electrode (93, 96, 84; 106, 108) and a second, earthed electrode (filling element 89, closer 23).

12. Apparatus as claimed in Claim 10, characterised in that the article is an empty container (bottle 61) and the second earthed electrode is a filling element (89) for filling the container.

13. Apparatus as claimed in Claims 5 and 11, characterised in that the earth electrode (half shells 106, 108) surrounds the head space of the filled container (bottle 61) and the second earthed electrode (closer 23) surrounds a closure cap (21) to be sealed onto the container (bottle 61).

14. Apparatus as claimed in Claim 2, characterised in that an earth electrode surrounding the closure cap (21) is constructed as a closing element (23) for sealing the closure cap.

15. Apparatus as claimed in Claim 1 including a plurality of disinfection stations (94, 105, 121) for disinfecting empty or filled containers or closures caps, characterised in that the disinfection stations (94, 105, 121) are connected to a common high frequency generator (101).

16. Apparatus as claimed in Claim 1, characterised in that the plasma is produced in the open air.

17. Apparatus as claimed in Claim 16, characterised in that a foreign gas, preferably argon, is supplied to the location of the plasma generation before applying the pulse.

18. Apparatus as claimed in Claims 2 and 17, characterised in that the foreign gas is conducted into the mouth (2) of the article (bottle 1) through the high voltage electrode (6), which is constructed as a nozzle.

19. Apparatus as claimed in Claim 1, characterised in that a monitoring device is provided which monitors the parameters of each pulse and associates them individually with the disinfected articles.