Device and method for coating a container, in particular by plasma coating

Abstract

The invention relates to a device for coating objects (10), in particular containers (10), comprising at least one first coating station and at least one second coating station (2, 4), each of these coating stations (2, 4) comprising at least one first coating electrode (22, 42) and at least one second coating electrode (24, 44), and a supply device (6) for supplying power to at least one of the coating electrodes (22, 24) in each case. According to the invention, the supply device (6) has a high-frequency generator device (62) for generating an AC voltage and / or voltage pulses (P, P2, P4, P20, P40), and an AC voltage distribution device (64), which distributes the AC voltage and / or voltage pulses (P, P2, P4, P20, P40) to at least one electrode of the first coating station (2) and at least one electrode of the second coating station (4), respectively, wherein the AC voltage distribution device is suitable for and intended to distribute the AC voltage and / or voltage pulses (P, P2, P4, P20, P40) to the electrodes in a time-delayed manner.

Description

Technical Field

[0001] The present invention relates to an apparatus and a method for coating containers, in particular plasma coating. It is well known in the prior art that containers, in particular plastic containers, and in particular their (inner) surfaces, can be coated. This can prevent liquids or gases from diffusing from the interior of the container to the exterior, or prevent gases from entering the product from the exterior. Background Art

[0002] Thus, coating with silicon oxide, for example, is known. For this purpose, for example, one or two electrodes can be introduced into the interior of the container and subjected to voltage pulses. For surface coating with, for example, silicon oxide, plasma methods (PECVD = plasma-enhanced chemical vapor deposition) are usually used. In this case, a silicon-containing precursor (for example, HMDSO, HMDSM, TEOS or other Si-containing compounds) is vaporized and introduced into a vacuum together with oxygen. The gas molecules are then more or less completely broken down into their constituents by the plasma and then reassembled into new compounds, in particular SiO2, which are deposited on the surface.

[0003] For example, plastic bottles are coated to improve their barrier properties to gases, but a wide variety of surfaces are also coated using this method.

[0004] The gas molecules are usually decomposed by supplying energy, for example by means of intensified electromagnetic radiation, such as microwaves, high frequencies or low frequencies (in the form of plasma). The reorganization of the gas and the formation of layered matter mainly occurs outside the plasma and without external energy supply.

[0005] For this purpose, pulsed plasma is usually used. The initial gas is decomposed in a short energy pulse, and then the power supply is turned off. The gas fragments can recombine again. The formed SiO2 can be deposited as a layer on the substrate surface.

[0006] The ideal pulse-to-stop time for the desired coating quality depends on the pressure conditions, the gas supply, and the energy provided in the form of high-frequency or other electromagnetic radiation. Therefore, the pulse length and pulse power can be selected so that the desired degree of dissociation of the precursor molecules present is achieved. If the gas molecules are already dissociated (saturated), longer pulses or particularly high pulse powers will not bring any benefit. Therefore, pulses that are as short as possible and have sufficiently high power can be selected.

[0007] The ideal pulse length depends largely on the existing geometry, process pressure and gas supply. Particularly preferably, after the plasma pulse, everything should be exhausted, the "exhaust gas" should be transported away as much as possible, and the area around the surface should be filled with fresh precursor gas mixture.

[0008] Longer dwell times are disadvantageous because unconsumed gas is then pumped out unnecessarily and the coating time is unnecessarily prolonged. Too short a dwell time results in the precursor concentration still being too low and causes the recombined molecules to dissociate again.

[0009] Thus, for coating a 0.25 L bottle, with a process pressure of, for example, 0.6 mbar and a gas flow rate of approximately 300 sccm (standard cubic centimeters per minute), the entire volume of the container can be replaced in a single pass within approximately 30 ms. Therefore, the dwell time can be selected within this quantitative requirement. As described above, the shortest possible pulse with high power is selected. Particularly preferably, as described in more detail below, pulses with a pulse power of 0.8-1.6 kW and a pulse length of approximately 5-10 ms can be used.

[0010] However, the technology described here is very expensive, for example due to the power supply units used. Summary of the Invention

[0011] The object of the present invention is therefore in particular to reduce the costs of such an apparatus and its operating method. This is achieved according to the invention by the subject matter of the independent claims.

[0012] Advantageous embodiments and variants form the subject matter of the dependent claims.

[0013] The device according to the invention for coating objects, in particular containers, comprises at least a first coating station and a second coating station, wherein these coating stations each comprise at least a first coating electrode and a second coating electrode, and in each case a supply device for supplying power to at least one of the coating electrodes, that is, in particular to at least one of the two coating electrodes of each coating station.

[0014] According to the invention, the supply device comprises a high-frequency generator device for generating an alternating voltage and / or voltage pulses, and an alternating voltage distribution device, which distributes the alternating voltage to at least one electrode in the first coating station and at least one electrode in the second coating station, respectively. In this case, the alternating voltage distribution device is suitable for and intended to distribute the alternating voltage and / or voltage pulses to the electrodes in a delayed manner, in particular to electrodes of at least two different coating stations and / or to at least two coating stations. In this way, in particular, two electrodes of two coating stations can be supplied with voltage pulses in a delayed manner. In this way, preferably, different coating stations or their electrodes are supplied with voltage pulses in a delayed manner.

[0015] An alternating voltage is hereinafter understood to mean a voltage that changes at least temporarily over time. In particular, voltage pulses, such as those used for plasma coating, can also be understood as alternating voltages.

[0016] In a preferred embodiment, at least one of the electrodes can be introduced into the container. In particular, in this case, the electrode can be introduced into the container through the mouth of the container.

[0017] For this purpose, the device can have a drive device that moves the electrodes and / or the container. In this case, it is possible for the second electrode or the counter electrode to be arranged outside the container. However, it is also possible, in principle, for both electrodes to be introduced into the container simultaneously. In a further preferred embodiment, at least one electrode is designed as a rod-shaped body, in particular, the cross-section of the rod-shaped body is smaller than the cross-section of the container mouth. However, it is also possible for the electrode to be fixed in the chamber and for the container to be guided (in particular in the axial direction) by a lance or the electrode.

[0018] Preferably, the container is a plastic container, in particular a container made of PET.

[0019] In another advantageous embodiment, the system includes a conveyor device that transports the containers and / or the coating stations along a predetermined conveying path. In this case, the conveyor device also transports the containers, in particular during the plasma coating process. Thus, it is possible to introduce at least one electrode into the container while it is being transported along the predetermined conveying path.

[0020] Particularly preferably, the device has a support on which the coating stations are arranged. Particularly preferably, in this case, the support is a rotatable support or a support wheel on which the coating stations are arranged or arranged.

[0021] Alternatively, the coating station can be fixed. Thus, for example, it is possible that the coating station is fixedly arranged in a space and the containers are transported to the plasma chamber of the coating station (and transported away after coating). Thus, in a preferred embodiment, at least one and preferably several coating stations are fixedly arranged and the containers are fed towards them.

[0022] Particularly preferably, the device has at least three, preferably at least four, particularly preferably at least five coating stations.

[0023] As mentioned above, the power supply units described above are costly. However, in the prior art, a single power supply unit is typically required for all plasma stations. The present invention proposes using a single power supply unit for several stations. In the prior art, these power supply units are only activated for approximately 5-10 milliseconds and then remain idle for approximately 30 milliseconds. Therefore, from a hardware perspective, these power supply units operate at less than 25% of their load capacity, resulting in low efficiency. The present invention, however, achieves a more efficient load capacity for the power supply.

[0024] Furthermore, in the prior art, it is not possible to simultaneously use one power supply unit for several plasma stations, because the overall pulse power would have to be higher, which would result in a higher price.

[0025] Furthermore, the different plasma stations influence one another, and a uniform distribution of the HF pulses to several plasma chambers is almost impossible.

[0026] In fact, in the prior art, if a station has problems with pressure, gas volume, delayed plasma ignition and the like, it can also affect adjacent stations.

[0027] Thanks to the pulse distribution proposed according to the invention, such as the multiplexer described in detail below, this dependency is eliminated, ie the stations are independent of each other.

[0028] It is therefore proposed that several plasma stations or coating stations are supplied with plasma simultaneously and independently of one another by a generator, and that subsequent individual pulses are assigned only to a single station.

[0029] The AC voltage distribution device is preferably a multiplexer. A multiplexer can be understood as a selection circuit in analog and digital electronics that selects one of multiple input signals and switches it to an output. Multiplexers are therefore comparable to rotary switches, which, while not manually adjustable, can be set using electronic signals. In this case, an integrated semiconductor circuit is preferably provided to implement the aforementioned electronic connections.

[0030] The invention therefore proposes the use of a multiplexer which distributes the individual high-frequency pulses to the plasma stations according to a pattern, in particular a predefined uniform pattern.

[0031] Particularly preferably, the pulses are distributed in such a way that at most only a single plasma is active at any one time, wherein preferably individual coating stations or plasma stations can be ignited with a time delay of, for example, a few milliseconds.

[0032] This therefore allows several pulse lengths within a complete cycle time, and thus several coating stations to be operated together on one generator.

[0033] In this way, both space and cost can be saved. Furthermore, the complexity of operation can be reduced. In addition, the load capacity of each generator can be made more efficient.

[0034] In a preferred embodiment, a high-frequency generator is provided, which can generate plasma pulses. The coupled power can be adjusted based on the measured value of the reflected power. This can be achieved, for example, by adjusting the coupled power or adjusting the impedance. This allows the target coupled power value to be achieved.

[0035] In one embodiment, the coupled power of each individual plasma pulse can be individually adjusted based on the measured value of a test pulse. For this purpose, each plasma pulse is preceded by a pre-pulse with lower power, and the power of the plasma pulse is adapted to a single target value based on the measured value of the reflected power. This has the advantage that the desired plasma energy can be applied to each container, regardless of its shape or material composition. This embodiment is particularly advantageous when coating a large number of individually different containers.

[0036] As an alternative to this, another embodiment has proven to be particularly advantageous. In this case, a high-frequency generator is also provided that produces plasma pulses. The coupled power can be adjusted based on the measured value of the reflected power. Unlike the above description, the coupled power of the plasma pulse is based on a measured value, preferably several measured values of one or more previous plasma coatings. This has the advantage that not every plasma pulse must be preceded by a lower-power pre-pulse. In fact, a pre-pulse has the disadvantage that, due to the low energy provided, the coating reaction can be initiated, but the provided chemical reaction cannot continue to completion. This may lead to undesirable intermediate products, higher requirements for the reactants, and / or a weakening of the barrier effect on the deposited material. Another important advantage is that it speeds up the execution of the method, because the pre-pulse, the measurement of the reflected energy, and the setting of the coupled power based on the measured value take several milliseconds. In the method proposed above, plasma coating is carried out in several stations, and the total time of these intervals adds up to a significant slowdown in the coating process. This is particularly disadvantageous in high-throughput processes such as container processing.

[0037] Preferably, the control device is provided with a memory device that uses at least one measured value of a previous coating process to adjust a predetermined target value for a subsequent coating process. In a preferred embodiment, the at least one measured value is selected from at least one of the following: reflected power, supplied power, the difference between supplied power and reflected power, power coupled into the plasma, light emission from the plasma, gas volumetric flow rate, gas composition (e.g., within the vessel, of the feed stream, and / or exhaust gas stream), temperature of the gas lance, and temperature of the vessel surface. These values have proven to be particularly suitable for enabling a particularly accurate prediction of the required power of a future plasma pulse.

[0038] In a preferred embodiment, several of the above-mentioned parameters are determined, and their influence on the calculation of the required power is weighted using a single factor for future plasma pulses. Thus, a single factor is assigned to the power calculation for one, several, or all of the above-mentioned parameters. This facilitates simple normalization of the calculation based on previously calculated empirical values.

[0039] In another preferred embodiment, an evaluation device is provided for determining a factor with which a parameter is included in the calculation for determining a couplable power. Preferably, the evaluation device uses a comparison of parameters measured in the past to determine the factor for a future coating process. Particularly preferably, the factor determined by the evaluation device is dynamically variable. Particularly preferably, the determined factor is determined again after a predetermined number of coating processes. In this regard, it is conceivable that older measured values of the parameter are taken into account to a lesser extent when determining the factor. Thus, if appropriate, it can be ensured that the evaluation device determines the factor again at predetermined intervals and adjusts it.

[0040] Particularly preferably, the evaluation device includes an AI system. This allows the evaluation device to, for example, recognize patterns and adjust the factors accordingly. Pattern recognition allows predictions to be drawn about how an incoming single pulse, an incoming pulse sequence, and / or further processing will behave. These predictions can be taken into account when adjusting the factors.

[0041] Preferably, a calibration device is provided that compares actual values of the pulse and / or coating process with target values. This comparison can be used, for example, to protect the system. For example, if the supplied power is too high, such that the reflected power is extremely close to the power limit of the generator (e.g., less than 10% of the upper power limit), a mandatory power limit can be implemented.

[0042] Preferably, the verification device is suitable for checking whether the change of the factor has brought about an improvement in the process. For example, the coating result is taken into account in the verification. Preferably, a channel can be defined within which the parameter to be verified must move. In this way, it can be ensured that the process is not permanently damaged (for example, due to an erroneous process, an interruption before the process or an interruption during the process). Therefore, when the channel limit is reached or approached, the coating process that produces defective products can be prevented at an early stage. A system with such a verification device recognizes that at least one parameter is outside the permitted range before reaching an unauthorized value outside the channel. It can then initiate a countermeasure. In particular, in combination with an AI system and / or data derived from previous measurements and stored in the system, at least one factor can be adjusted to keep the process within a defined channel or redirect it back to a defined channel.

[0043] In a preferred embodiment, the evaluation device can take into account several measured values of the same parameter in a single pulse mode. This is particularly advantageous because various parameters (e.g., the amount of fresh gas and / or the educt / product rate (e.g., gas volume) in the chemical process during coating) can change during each pulse. Several parameters are influenced by the plasma itself, which can change the plasma impedance. When considering multiple measured values of a single parameter in a single pulse mode, the evaluation device can adjust factors so that the coupled power particularly effectively offsets or supports such changes in the considered parameter. It is particularly advantageous if the AI system takes these parameters into account during the pulse and learns how to optimally provide the coupled power.

[0044] In a further advantageous embodiment, the apparatus comprises a medium supply device adapted and intended to deliver a flowable, in particular gaseous, medium into the container. In particular, in this case, this gaseous medium is ultimately used to coat the interior surface. Particularly preferably, a gas or medium containing at least silicon (Si) and / or oxygen (O2) is used for coating. Thus, for example, SiO2 can be deposited.

[0045] In a further advantageous embodiment, the high-frequency generator device outputs the voltage in the form of voltage pulses. In this case, rectangular pulses are particularly preferably used, which can be sent to the individual coating stations in a time-delayed manner as described above.

[0046] As described above, the high-frequency generator device can also output the voltage in the form of a combination of several voltage pulses. In this case, it is particularly preferred that it can be several rectangular pulses, such as a pre-pulse with a lower power and a main pulse (plasma pulse), which, as described above, can be emitted one after another with a time delay.

[0047] In a further advantageous embodiment, the AC voltage distribution device distributes the pulse output generated by the high-frequency generator device completely to each electrode. In other words, each pulse is preferably assigned to exactly one coating station. Preferably, there is no overlap between the pulses sent to the various coating stations.

[0048] Thus, the multiplexer does not switch during a pulse, but rather the pulse is completely transmitted to a specific coating station. Particularly preferably, this involves the rectangular pulse described above.

[0049] In a further preferred embodiment, the AC voltage distribution device is activated by the generator device.

[0050] Particularly preferably, the time interval between two pulses is shorter than the duration of the individual pulses.

[0051] The present invention further provides a method for coating objects, in particular containers, wherein at least a first coating station and a second coating station are used. In this case, each of these coating stations has at least one first coating electrode and one second coating electrode, and at least one of the coating electrodes is supplied with electrical energy by a supply device.

[0052] According to the present invention, the supply device provides an AC voltage, particularly voltage pulses, via a high-frequency generator, and the AC voltage distribution device distributes the AC voltage and / or these voltage pulses to at least one electrode of the first coating station and at least one electrode of the second coating station. In this case, the AC voltage distribution device distributes the AC voltage to each electrode and / or coating station in a time-delayed manner. Preferably, the AC voltage is distributed to each electrode of both coating stations in a time-delayed manner.

[0053] According to this method, the individual voltage pulses necessary for generating the plasma are distributed to the individual coating stations. As a result, the individual coating stations do not influence each other, so that, for example, a possible defect in an individual coating station does not lead to malfunctions in other coating stations.

[0054] In a further preferred method, the control device controls the high-frequency generator device in such a way that voltage pulses are emitted at predetermined time intervals. Particularly preferably, in this case, the length of the voltage pulses is longer than the time interval between two pulses.

[0055] By suitable selection of the individual pause times between the individual voltage pulses, the generator arrangement can thus be made to operate as many coating stations as possible.

[0056] Preferably, the pulses have a pulse length of greater than 2 ms, preferably greater than 3 ms, preferably greater than 4 ms and particularly preferably greater than 5 ms.

[0057] Particularly preferably, the voltage pulse has a temporal length of less than 40 ms, preferably less than 30 ms, preferably less than 20 ms, preferably less than 15 ms, and preferably less than 10 ms. In a further preferred method, the pulse power of the voltage pulse is greater than 0.4 kW, preferably greater than 0.5 kW, preferably greater than 0.6 kW, and preferably greater than 0.7 kW.

[0058] In a further preferred embodiment, the pulse power of the pulses is less than 4 kW, preferably less than 3 kW, preferably less than 2 kW, and particularly preferably less than 1.7 kW.

[0059] The pause time between two pulses is preferably less than 20 ms, preferably less than 15 ms, preferably less than 10 ms, preferably less than 7 ms, preferably less than 5 ms and particularly preferably less than 3 ms.

[0060] However, the dwell time between two pulses from the high-frequency generator also depends on the number of stations to be supplied.

[0061] Thus, for example, a pulse pause duration of 30 ms and a pulse duration of 8 m are possible for each individual coating station. Ideally, the pulses emitted by the generator arrangement and subsequently distributed to the stations are spaced far enough apart in time to enable them to be evenly distributed.

[0062] If, for example, only two stations are fed, the second pulse is centered at the dwell position of the first station. The pulse sequence of the generator is then 8 ms "on" - 11 ms "off" - 8 ms "on" - 11 ms "off", etc. In this case, each individual station sees 8 ms "on" - 30 ms "off".

[0063] Preferably, the two electrodes or the electrodes of the two coating stations are operated independently of one another.

[0064] In a further preferred method, the high-frequency generator device outputs the AC voltage in the form of voltage pulses, which are preferably rectangular pulses.

[0065] In a further preferred method, the control device controls the high-frequency generator device in such a way that the voltage pulses are emitted at predetermined time intervals. Particularly preferably, the voltage pulses are emitted at substantially constant time intervals.

[0066] In a further preferred method, the voltage distribution device distributes the voltage pulses in such a way that no more than one coating station is supplied with voltage at a predetermined time.

[0067] Particularly preferably, the individual stations are supplied in a predetermined sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The accompanying drawings show further beneficial effects and implementation methods. In the accompanying drawings of the specification:

[0069] Figure 1 The configuration method in the prior art is shown.

[0070] Figure 2 A schematic diagram of an embodiment of the present invention is shown.

[0071] Figure 3 Another schematic diagram of the device according to the present invention is shown. DETAILED DESCRIPTION

[0072] Figure 1A schematic diagram of an embodiment known from the prior art is shown. In this case, a high-frequency generator 62 is provided, which generates a voltage P which is output to the coating stations 2 in each case at predetermined time intervals. In this case, each coating station is provided with a high-frequency generator.

[0073] Figure 2 1 shows a schematic diagram of a device according to the invention. Here again, a high-frequency generator 62 is provided which outputs voltage pulses P. However, it can be seen here that these voltage pulses are spaced apart from each other by a time substantially shorter than Figure 1 Output as shown.

[0074] Furthermore, an AC voltage distribution device is provided, in particular a multiplexer 64 , for example, which distributes the individual pulses P into pulses P2 , P4 , P20 and P40 with a time delay relative to one another, in this case to the four coating stations 2 , 4 , 20 , 40 .

[0075] In this case, the reference symbol T represents the interval between all emitted pulses. It can be seen that the individual pulses P2, P4, P20 and P40 are delayed with respect to one another.

[0076] Figure 3 1 is a schematic diagram showing further details of the device 1 according to the invention. In this case, reference numeral 6 relates to a supply device having a high-frequency generator 62 and an AC voltage distribution device 64.

[0077] In the embodiment shown here, the voltage pulses are distributed with a time delay to two coating stations.

[0078] Each coating station 2, 4 has a first electrode 22 or 42, which can be introduced into the container 10 to be coated. In addition, each coating station 2, 4 has a second electrode 24, 44, which is arranged outside the container 10. Here, the second electrode 24, 44 is preferably grounded.

[0079] Reference numeral 32 denotes a medium storage tank, for example, a gas mixture, such as a mixture of HMDSO and O. Reference numeral 34 denotes a feed conduit for delivering the medium to the container. Reference numeral 36 denotes a control device that controls the delivery of the medium into the container 10. SiO is first generated in the plasma within the container, more specifically, between two plasma pulses.

[0080] The applicants hereby reserve the right to include in the claims all technical features disclosed in this application document, if they contribute substantially to the present invention, provided that they are novel, individually or in combination, compared to the prior art. It should also be noted that features that may be advantageous individually have been depicted in a single figure. Even without reference to further features in the figures, a person skilled in the art would immediately recognize that a particular feature depicted in a figure may be advantageous. A person skilled in the art would also recognize that combining multiple features shown in a single figure or in different figures may also produce beneficial effects.

[0081] Reference numerals

[0082] 1 Equipment

[0083] 2,4 coating stations

[0084] 6 Supply device

[0085] 10 containers

[0086] 22,42 First electrode

[0087] 24,44 Second electrode

[0088] 32 medium storage tanks

[0089] 34 medium conduit

[0090] 36 Control Device

[0091] 62 High frequency generator device

[0092] 64 AC voltage distribution devices, multiplexers

[0093] P voltage pulse

[0094] P2, P4, P20, P40 assigned voltage pulses

[0095] T cycle

Claims

1. A device for coating objects (10), in particular containers (10), comprising at least one first coating station (2) and at least one second coating station (4), wherein each of these coating stations (2, 4) comprises at least one first coating electrode (22, 42) and at least one second coating electrode (24, 44), and a supply device (6) for supplying power to at least one of the coating electrodes (22, 24); characterized in that The supply device (6) has a high-frequency generator device (62) for generating AC voltage pulses (P, P2, P4, P20, P40), and an AC voltage distribution device (64), which distributes the AC voltage pulses (P, P2, P4, P20, P40) to at least one electrode of the first coating station (2) and at least one electrode of the second coating station (4), respectively, wherein the AC voltage distribution device is suitable and intended to temporally shift the AC voltage pulses (P, P2, P4, P20, P40) to the electrodes, wherein the voltage pulses have a time length of less than 40 ms; wherein the device (1) has a conveying device, which conveys the containers (10) and / or the coating stations (2, 4) along a predetermined conveying path; wherein the individual voltage pulses are distributed to the individual coating stations; Where there are several pulse lengths within a complete cycle time, several coating stations are operated together on one generator.

2. The device (1) according to claim 1, characterized in that The AC voltage distribution device (64) is designed as a multiplexer.

3. The device (1) according to claim 1, characterized in that The device (1) has a rotatable conveying device on which coating stations (2, 4) are arranged.

4. The device (1) according to claim 1, characterized in that The coating stations (2, 4) are fixedly arranged.

5. The device (1) according to claim 1, characterized in that The device has a medium supply device (32, 34, 36) which is suitable and intended to convey a flowable, in particular gaseous, medium to the container.

6. The device (1) according to claim 1, characterized in that The time interval between two pulses is shorter than the duration of each pulse.

7. The device (1) according to claim 1, characterized in that The AC voltage distribution device distributes the pulse output generated by the high-frequency generator device completely to the individual electrodes in each case.

8. The device (1) according to claim 1, characterized in that The coupleable power of the high-frequency generator device can be adjusted based on the measured value of the reflected power.

9. The device (1) according to claim 1, characterized in that It comprises a control device with a memory device, by means of which at least one measured value of a preceding coating process can be used to adjust a predetermined target value for a subsequent coating process.

10. The device (1) according to claim 9, characterized in that The at least one measurement is selected from at least one of the following: reflected power, supplied power, the difference between supplied and reflected power, power coupled into the plasma, light emission from the plasma, gas volume flow rate, gas composition, temperature of the gas lance, and temperature of a container surface.

11. The device (1) according to claim 1, characterized in that It comprises an evaluation device which is able to determine a factor with which the parameter is included in the calculation for determining the coupleable power.

12. The device (1) according to claim 11, characterized in that The factors are dynamically variable.

13. The device (1) according to claim 11, characterized in that The evaluation device includes an AI system that recognizes patterns and adjusts factors based on the recognized patterns.

14. A method for coating objects (10), in particular containers (10), comprising at least one first coating station and at least one second coating station (2, 4), wherein each of these coating stations (2, 4) comprises at least one first coating electrode (22, 42) and at least one second coating electrode (24, 44), and a supply device (6) for supplying power to at least one of the coating electrodes (22, 24); characterized in that The supply device (6) provides AC voltage pulses (P, P2, P4, P20, P40) via a high-frequency generator device (62), and the AC voltage distribution device (64) distributes the AC voltage pulses (P, P2, P4, P20, P40) to at least one electrode of the first coating station (2) and at least one electrode of the second coating station (4), respectively, wherein the AC voltage distribution device temporally shifts the AC voltage pulses (P, P2, P4, P20, P40) to the electrodes; wherein the voltage pulses have a time length of less than 40 ms, and wherein the conveying device conveys the containers (10) and / or the coating stations (2, 4) along a predetermined conveying path; wherein the individual voltage pulses are distributed to the individual coating stations; Where there are several pulse lengths within a complete cycle time, several coating stations are operated together on one generator.

15. The method according to claim 14, wherein The time interval between two pulses is shorter than the duration of each pulse.

16. The method according to claim 14, wherein The control device controls the high-frequency generator device (62) in such a way that voltage pulses are emitted at predetermined time intervals.

17. The method according to claim 14, wherein The AC voltage distribution device distributes the voltage pulses in such a way that no more than one coating station (2, 4) is supplied with voltage at a predetermined time.

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