Device for shaping plastic preforms into plastic containers

Abstract

The utility model relates to a device for shaping plastic preforms into plastic containers. The utility model relates to a device for forming plastic preforms, comprising a transport device for transporting plastic preforms along a predetermined transport path, the transport device having a transport support on which a plurality of forming stations are arranged, each forming station having an application device for applying a flowable medium to the plastic preforms in order to expand the plastic preforms, the device having at least one first compressed air tank, the utility model relates to a device for producing plastic preforms, comprising a plurality of forming stations, which are suitable and designed to provide compressed air at a first predetermined pressure, and each forming station has a valve assembly, at least one valve device being a pneumatically controlled valve device having a working space for receiving a gaseous medium for applying plastic preforms, the valve device is provided with a working space and a valve piston which can move between at least two positions, the valve device further comprises a control space which can be applied by a gas control medium to move the valve piston, and at least one transition area is arranged between the working space and the control space.

Description

Technical Field

[0001] The utility model relates to a device for molding a plastic preform into a plastic container. Background Art

[0002] Such devices have long been known from the prior art. In this process, usually heated plastic preforms are shaped into plastic containers, in particular plastic bottles, by compressed air. For this purpose, the plastic preforms are subjected to at least two different pressure levels, more recently several different pressure levels. Usually, a number of forming stations are arranged on a rotatable support, the so-called blow molding wheel. The individual forming stations each have a valve block or a valve assembly with a large number of valves. These valves are in part pneumatically controlled valves.

[0003] Recently, blow-moulding machines or forming devices for forming containers under aseptic or sterile conditions have also become known. This means that the forming process is also carried out with sterile air.

[0004] This means that in the prior art, preferably even in the case of the present invention, the blow molding machine is sterilized using a sterilizing medium such as hydrogen peroxide in a sterilizing operation different from the production operation. After the sterilizing operation, the container is formed under sterile conditions with sterile air, in particular filtered air. During the sterilizing operation, the valve block or valve is also sterilized with the sterilizing medium.

[0005] However, the corresponding control air for actuating the valves during working operation is usually not sterile.

[0006] For valve assemblies or valve blocks in sterile spaces or in general aseptic spaces, it should be ensured that the sterile blowing air to be switched is not contaminated by the control air of the valve. For this reason, in the prior art, a tight sealing of the area through which the blowing air flows relative to the control air is partially required. For this purpose, for example, the lifting valve can be sealed to the valve body by means of a bellows or a diaphragm. Blow blocks or valve assemblies known from the prior art are not sterilizable because, on the one hand, the sterilization limits are not defined and, on the other hand, the materials are not properly designed. In particular, in the prior art, if the valve device does not have a separating diaphragm or a separating bellows, it is not sterilizable.

[0007] In practice, such bellows can break. A further disadvantage of such valves is that they require more installation space than valves without bellows. Furthermore, the geometry or material of such bellows is often at their load limit. Furthermore, after autoclaving, the material of the bellows softens, so that defects may occur on the bellows immediately at the start of production.

[0008] Furthermore, such valves require two pilot and / or control pressures to open and close, which results in higher costs and space requirements. Utility Model Content

[0009] The object of the invention is therefore to provide a blow moulding machine which is particularly suitable for use in sterile spaces but which also simplifies the actual blow moulding process, in particular when different pressures are applied.

[0010] The device for molding plastic preforms into plastic containers of the utility model has a transport device, which transports the plastic preforms along a preset transport path. The transport device has a (movable, especially rotatable) transport support, on which a plurality of molding stations for molding the preforms into plastic containers are arranged, and the molding stations have (and / or are suitable for and designed to) apply the plastic preforms to a flowing, especially gaseous medium to expand the plastic preforms.

[0011] Furthermore, the device has at least one first compressed air tank, which is suitable and designed to provide compressed air at a first predetermined pressure, and each forming station has a valve assembly having a plurality of valve devices to apply at least two (in particular different) pressures to the plastic preform.

[0012] Furthermore, at least one of the valve devices is a pneumatically controlled valve device.

[0013] According to the utility model, the valve device has a working space for accommodating a gaseous medium for applying a plastic preform, and has a valve piston that can be moved between at least two positions. In addition, the valve device also has a control space that can be applied with a gaseous control medium to move the valve piston. At least one transition area is provided between the working space and the control space.

[0014] Preferably, the transition zone is used for the separation or separation of the working space and the control space. In this way, non-sterile air can be applied to the control space without reaching the working space.

[0015] Particularly preferably, the transition area has a transition space. For example, during operation, this transition space can also be filled with a sterile medium. The transition area thus works in the manner of a gray space, separating the sterile workspace from the non-sterile control space. Preferably, non-sterile air can also be applied to the control space. The transition area preferably serves as a hygienic bridge.

[0016] Therefore, a valve device is proposed, which is sterile, preferably bellows-free, and preferably defined or constructed by at least three regions. Preferably, the working space is located in one of the regions, the control space is located in another region, and preferably, the transition region is located between the two regions and / or spaces.

[0017] Preferably, therefore, the first area is a sterile space, in which sterile process air can flow, wherein the valve device is suitable and designed to connect or separate this sterile space or working space to the container to be expanded.

[0018] Particularly preferably, the working space and / or the transitional region, preferably the working space and the transitional region, are sterilizable. Therefore, the working space or the region can be sterilized together with the working space. The transitional region forming the gray space as described above is also preferably sterilizable.

[0019] In another preferred embodiment, the control space is sealed relative to the transition region by at least one first sealing device. For example, this sealing device can be a sealing ring.

[0020] In another preferred embodiment, the transition area is sealed relative to the working space by at least one second sealing device, which is also preferably a sealing ring.

[0021] Particularly preferably, the first sealing device and the second sealing device are opposite one another in the longitudinal direction of the valve device and / or in the direction of movement of the piston device.

[0022] Particularly preferably, at least one further sealing device and preferably two further sealing devices are provided between the first sealing device and the second sealing device.

[0023] In a further advantageous embodiment, the first sealing device, which seals the control space relative to the sealing area and / or the transition area, is arranged such that it never touches the sterile area of ​​the valve assembly (in particular independently of the position of the valve piston).

[0024] Preferably, the gray space or transition area is separated from the sterile space or working space by at least one sealing device. As mentioned above, this gray space is sterilizable.

[0025] Furthermore, as described above, a control space is provided which is separated from the transition region by at least one sealing device, which (particularly in the event of a change in the control pressure) preferably moves the piston device (eg from a closed position to an open position or vice versa).

[0026] As mentioned above, the seal of the control space is designed to never touch the surfaces of the sterile space, ie the surfaces of the working space.

[0027] The transition region preferably serves both as a sanitary bridge and, particularly preferably, as a compression spring for prestressing the valve piston.

[0028] In another advantageous embodiment, another valve device is provided, in particular a pilot valve. This pilot valve preferably controls the control air for opening the piston device. In addition, a lower pilot pressure can be used, for example, to close the piston via an air spring and / or to move the piston to the closed position of the valve device.

[0029] The space controlled by the air spring can preferably be sterilized additionally as follows. Preferably, the pressure in the transition area is lower than the pressure in the working area.

[0030] For example, in the working space the pressure may be between 0 and 10 bar, in the transition region the pressure may be approximately 5 bar.

[0031] In order to sterilize the transition region or the gray space, a sterilization medium is preferably allowed to flow through the transition region or the gray space.

[0032] For this purpose, it is conceivable that the air spring chamber has both an inlet and an outlet, in particular a switchable outlet, so that a uniform flow can be generated.

[0033] The air spring outputs can preferably be connected in parallel. However, preferably one, in particular one, gas flow is provided.

[0034] In another preferred embodiment, the valve device and / or the valve assembly has at least one sensor device. Such a sensor device in the valve device and / or the valve assembly can, for example, detect the pressure in the working space or the control space.

[0035] Furthermore, sensor means can be provided which detect the temperature and / or the concentration of the sterilization medium in order to ensure and / or document whether adequate sterilization has taken place.

[0036] Preferably, the plurality of valve devices of the device of the present invention are formed in the above-mentioned manner.

[0037] A pneumatically controlled valve device is understood in particular to provide control air or the like in order to switch the valve from a closed position to an open position and / or to switch the open position to a closed position. In the open position, the plastic preform is preferably pressurized with the working pressure.

[0038] In a preferred embodiment, the valve device has a movable, in particular linearly movable, valve piston, wherein in a first position of the valve piston, the valve device is closed so that no gaseous medium reaches the application device through the valve device. Preferably, in a second position of the valve piston, the valve device is open and gaseous medium or blowing air reaches the application device.

[0039] The flowable sterilizing medium may be hydrogen peroxide or peracetic acid. In the prior art, there is no valve that is fully sterilizable in this manner.

[0040] The applying device preferably has or is a blow nozzle. These can be placed on the communication opening of the plastic preform to be expanded, or can also be placed on the area of ​​the blow mold, so as to apply a separate pressure to the plastic preform to expand it.

[0041] Furthermore, the shaping station preferably has a blow mould in which the plastic preforms are expanded or blown into plastic containers.

[0042] The blow moulds are particularly preferably at least in two parts, preferably at least in three parts, and have, for example, two side parts and a bottom part.

[0043] Particularly preferred are compressed air tanks which store the air pressure together with the individual valve components or valve blocks, or more precisely store the air pressure in flow connection with the individual valve components, or can be placed therein. This can be done in such a way that the corresponding operating pressure is always present at the valve arrangement.

[0044] In a preferred embodiment, the reservoir is an annular channel. Particularly preferred is at least one reservoir and preferably a plurality of reservoirs arranged on a rotatable support, also referred to below as a blow moulding wheel.

[0045] In a further advantageous embodiment, all materials of the valve device which come into contact with the sterilization medium allow for a corresponding sterilization with the sterilization medium.

[0046] In another preferred embodiment, the device has a sterilizing device suitable for applying a sterilizing medium to the valve device or a plurality of valve devices. In particular, the flow channel or the space of the valve device that conveys a working fluid, in particular blowing air, in the working operation can contact the sterilizing medium.

[0047] Particularly preferably, the above-mentioned valve piston is arranged in a sterile space of the device.

[0048] In a preferred embodiment, the valve device is a sterile or pneumatically controlled valve, and as described in detail below, is a bellows-less valve.

[0049] It is particularly preferred if the control space of the valve device and the working space of the valve device, in which control space the control air is conducted for expanding the plastic preforms and / or for at least temporary storage, are completely sterilizable.

[0050] In the valves known in the prior art, the available control components are usually not sterilizable in terms of material, and the boundaries of the sterile space are not clearly defined. Therefore, within the framework of the present invention, a novel, in particular sterile valve device is proposed.

[0051] In a preferred embodiment, the valve device has a valve, in particular a directional valve, in particular a sterile directional valve. This valve in turn drives the piston valve and / or the above-mentioned valve valve (in particular in order to lock the blowing air or make it reach the application device).

[0052] In this case, the directional valve can be equipped with a bellows or a diaphragm, which allows a sterile separation between the control air and the clean space.

[0053] In a preferred embodiment, the valve device is designed without bellows. In the prior art, bellows are partially provided to separate the sterile area and the non-sterile area of ​​the valve device. These bellows usually have the disadvantage that they are attacked by the sterilizing agent and thus damaged. In addition, such bellows often cannot withstand heating. This means that in the case of rapid operation of the valve after sterilization, the material is still too soft, which can lead to malfunction or damage of the bellows.

[0054] It is particularly preferred that the control space and the working space are completely separated in terms of fluid technology. Non-sterile air is usually used to control the valve. This design prevents this air from contaminating the actual working air and thus prevents the eventually contaminated working air from entering the container.

[0055] In another advantageous embodiment, the device has a clean room in which the plastic preforms to be formed are transported. In particular, the plastic preforms can be transported through the clean room during the expansion process. Preferably, the forming stations can also be transported through the clean room.

[0056] A clean room is understood to be a spatial area or a room in which the air has a higher purity or a lower number of bacteria than in the environment. Different purity levels can be set, for example, a purity level of only 1 / 10 or 1 / 100 of the bacteria concentration compared to the environment. Preferably, this clean room is separated compared to the (non-sterile) environment.

[0057] Particularly preferably, the plastic preforms are transported through the clean room during contact with the gaseous medium in order to expand them.

[0058] Preferably, the clean room has at least two walls delimiting these, which walls are preferably movable relative to each other.

[0059] Particularly preferably, the device has a sealing device, which seals the clean space from the environment. For example, this can be a hydraulic seal. Particularly preferably, the device has two sealing devices, in particular two water locks, which are suitable and designed to seal the clean space from the environment.

[0060] Particularly preferred is the piston arrangement of the aforementioned valve arrangement which always controls the blowing air in this clean room.

[0061] Particularly preferably, the device is designed in such a way that the pressure of the working air for expanding the container is always greater than the pressure of the control air for actuating the valve device.

[0062] Particularly preferably, the pressure of the working air is greater than 5 bar, preferably greater than 7 bar, preferably greater than 10 bar. Particularly preferably, the pressure of the working air is less than 60 bar, preferably less than 50 bar, preferably less than 40 bar, preferably less than 30 bar.

[0063] The pressure of the control air is particularly preferably greater than 1 bar, preferably greater than 2 bar, preferably greater than 3 bar. Furthermore, the pressure of the control air is less than 15 bar, preferably less than 12 bar, particularly preferably less than 10 bar. The design of these pressure ratios ensures that even in the event of damage to the diaphragm or the bellows, non-sterile control air cannot enter the sterile working air.

[0064] In another advantageous embodiment, the device has a second compressed air tank, which is suitable and designed to provide compressed air at a second predetermined pressure, wherein the second pressure is higher than the first pressure. For example, the second pressure can be a final blow molding pressure, which is preferably used to finally form the container and determine its final shape.

[0065] In a further advantageous embodiment, the device has a third compressed air tank which is suitable and designed to provide compressed air at a third predetermined pressure, wherein the third pressure is preferably greater than the first pressure and preferably less than the second pressure.

[0066] This pressure can be in particular the so-called intermediate blow molding pressure, which is used in newer methods for producing plastic containers. Particularly preferably, the second and third compressed air tanks can also be connected to the application device via a valve device and ultimately supplied to the plastic preform to be expanded.

[0067] The valve device which controls the second pressure and the third pressure of the container is also particularly preferably an above-mentioned valve, which is particularly preferably completely sterilizable.

[0068] Particularly preferably, the second compressed air tank and / or the third compressed air tank are also annular channels arranged on the blowing wheel.

[0069] In a further advantageous embodiment, the shaping stations each have a rod-shaped body, in particular a so-called stretching rod, which can be inserted into the plastic preforms in order to stretch the plastic preforms in their longitudinal direction.

[0070] In another preferred embodiment, the piston of the valve device (or valve piston) is partially or fully pressure-compensated. This means that there is no or only a small resultant force on the piston due to the applied pressure.

[0071] In another advantageous embodiment, a guide for the (valve) piston is provided. It is preferably arranged in such a way that the sterilizing medium can reach anywhere around the piston. A suitable seal can be excluded, since this location can also be sterilized by displacement during the sterilization process.

[0072] Particularly preferably, the valve device has at least one sensor device. For example, the sensor device can be a pressure measuring device, which determines the pressure of the working air and / or the control air in the valve device. This ensures that the pressure of the working air is always higher than the pressure of the control air.

[0073] In another preferred embodiment, a sensor device can be provided on or in the valve device, which for example determines the pressure or temperature and / or concentration of the sterilizing agent. In this way, the sterilization of the valve device can be recorded and / or a check can be made as to whether appropriate sterilization has been carried out.

[0074] The utility model is also directed to a method for molding plastic preforms into plastic containers, wherein a transport device transports the plastic preforms along a predetermined transport path, and the transport device has a movable, especially rotatable transport support, on which a plurality of molding stations for molding the plastic preforms are arranged.

[0075] In each case, the forming stations each have an application device for applying a flowable, in particular gaseous medium to the plastic preforms in order to expand them. In addition, the device has at least one first compressed air tank, which is suitable and designed to provide compressed air at a first predetermined pressure, and each forming station has a valve assembly with a plurality of valve devices for applying at least two pressures to the plastic preforms.

[0076] Furthermore, one of the valve devices is pneumatically controlled and / or operated.

[0077] According to the utility model, the valve device has a working space for accommodating and / or providing a gas medium for applying a plastic preform, and has a valve piston that can be moved between at least two positions (in particular, for switching the valve device between a closed position and an open position), wherein the valve device also has a control space that can be applied by a gas control medium to move the valve piston, and a transition area is arranged between the working space and the control space.

[0078] In a further preferred method, during working operation, the pressure in the working space of the valve device for accommodating the gaseous medium acting on the plastic pre-form is higher than the pressure in the control space for accommodating the control fluid for moving the valve piston of the valve device.

[0079] Preferably, the device is temporarily operated in a working operation for shaping plastic preforms into plastic containers and in a sterilization operation in which parts of the device, in particular the valve device, are sterilized.

[0080] The utility model is also directed to a forming device, in particular a stretch blow molding machine, for forming plastic preforms into plastic containers using a pneumatically controlled valve device.

[0081] According to the utility model, the valve device has a working space for accommodating a gaseous medium for applying a plastic preform, and has a valve piston that can be moved between at least two positions, and the valve device also has a control space that can be applied by a gaseous control medium to move the valve piston, and a transition area is arranged between the working space and the control space. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Further advantages and embodiments can be seen from the accompanying drawings:

[0083] in:

[0084] Figure 1 A schematic diagram of a device according to the utility model is shown;

[0085] Figure 2 a schematic diagram showing the valve arrangement in a closed position; and

[0086] Figure 3 A schematic diagram showing the valve arrangement in the open state. DETAILED DESCRIPTION

[0087] Figure 1 The device 1 for molding plastic preforms 10 into plastic containers 15 is shown. The device has a transport device 2 for transporting plastic preforms, on which a rotatable support 22 of a plurality of forming stations 20 is arranged. The individual forming stations each have a blow molding device 82 in which a cavity is formed for expanding the plastic preform.

[0088] Reference numeral 84 denotes an application device for expanding the plastic preforms 10. This can be, for example, a blow-moulding nozzle which can dock at the opening of the plastic preforms in order to expand these plastic preforms 10. Furthermore, it is also conceivable that the blow-moulding nozzle is sealed to the blow-moulding device. The application device is preferably movable in the longitudinal direction and preferably only in the longitudinal direction of the plastic preforms.

[0089] Reference number 4 describes a valve assembly, such as a valve block, which preferably has a plurality of valve devices which control the application of the plastic preforms at different pressure levels. Preferably, each molding station has such a valve block.

[0090] Preferably, a throttling device is provided on each of the valve assemblies, which controls the flow cross section of the compressed air supplied to the plastic preforms at at least one pressure. As mentioned above, at least a part of the valve devices is sterilizable, and preferably all of these valve devices.

[0091] In a preferred method, the plastic preform is first exposed to a pre-blowing pressure P1, then to at least one intermediate blowing pressure Pi higher than the pre-blowing pressure, and finally to a final blowing pressure P2 higher than the intermediate blowing pressure Pi1. Particularly preferably, the plastic preform is covered by a further intermediate blowing pressure Pi2 which is greater than the pressure Pi1 but less than the pressure P2.

[0092] After the plastic container has expanded, the pressurized or compressed air is preferably fed back from the container to the respective pressure tank.

[0093] Therefore, preferably, the device has an air recirculation device which is suitable and designed to recirculate the compressed air from the various forming stations to the compressed air tanks, in particular those absorbing lower pressure levels.

[0094] Reference numeral 88 denotes a stretching rod for stretching the plastic preform in its longitudinal direction. Preferably, all molding stations have such a blow mold 82 and a stretching rod 88. Such a stretching rod is preferably a component of the stretching device with reference numeral 30. The stretching rod is (preferably also only) movable in the longitudinal direction of the plastic preform 10.

[0095] Preferably, the number of forming stations 4 is between 2 and 100, preferably between 4 and 60, preferably between 6 and 40.

[0096] The plastic preforms 10 are fed to the device by a first transport device 62 , in particular but not exclusively a transport star. The plastic containers 15 are transported out by a second transport device 64 .

[0097] Reference numeral 7 denotes a pressure supply device, such as a supercharger or a compressed air connection. Compressed air is delivered to a rotary distributor 74 via a connecting line 72 and from the distributor via another line 76 to the first compressed air reservoir 32, here an annular channel.

[0098] These rotary distributors are therefore preferably used to direct air from the stationary part of the device to the rotating part of the device.

[0099] Preferably, in addition to the annular channel 32 shown in the figure, other annular channels are also provided. Figure 1 In the illustration shown, these annular channels are shielded by the annular channel 32, for example bounded by the annular channel 32. For example, there is preferably a pressure tank for storing the pressure P2 and the intermediate blowing pressures Pi1 and Pi2 and the pressure P1.

[0100] Reference numeral 33 denotes a connecting line for delivering compressed air to the forming station 20 or its valve block 4. Preferably, each of the annular channels is connected to all the forming stations via a corresponding connecting line. The connecting line 33 is preferably arranged in the rotating part of the device.

[0101] Reference numeral 18 schematically denotes an optional clean room, which preferably forms a ring and surrounds the transport path of the plastic preforms 10. Preferably, a (geometric) rotation axis around which the transport support 22 can rotate is arranged outside the clean room 18. Preferably, the clean room 18 has a sealing device, preferably with at least two water locks, and is sealed compared to the non-sterile environment. The clean room is preferably ring-shaped or toroidal.

[0102] In addition, the device preferably has ( Figure 1 The cover device of the top limiting clean space 18 (not shown in FIG. 1 ) is preferably arranged on at least one of the stretching devices 30.

[0103] The device has a plurality of measuring and / or sensor devices for controlling the device. Reference numeral 14 denotes a pressure measuring device for measuring the air pressure in the compressed air tank 32. Preferably, the other compressed air tanks also have corresponding pressure measuring devices.

[0104] Reference numeral 16 denotes a further pressure measuring device which measures the air pressure, in particular the pressure inside the container of the plastic preforms to be expanded. Preferably, each forming station is assigned such a pressure measuring device.

[0105] Preferably, the valve device itself also has at least one and preferably a plurality of sensor devices, such as pressure measuring devices. In addition, the valve device can also have a sensor device for detecting the concentration of the sterilization medium.

[0106] Preferably, the device has a sterilizing device, which is suitable and designed to apply a flowable sterilizing medium to the respective valve device. Preferably, this sterilization is carried out in a sterilizing operation different from the working operation of the device.

[0107] Reference numeral 19 also schematically indicates a flow measuring device for determining the flow of the blowing air from the compressed air tank to the valve block 4 of the forming station 20. Preferably, corresponding flow measuring devices are respectively arranged between the compressed air tank and all the forming stations.

[0108] A further flow measuring device can also be allocated between a further compressed air tank and the respective forming station.

[0109] Furthermore, a position detection device is preferably provided, which can detect the position of the stretching rod of each forming station.

[0110] Reference numeral 24 designates a control device which controls, in particular regulates, the device 1. The control device is preferably also able to vary operating parameters of the device, in particular the setting of the throttle device.

[0111] The control device thus controls in particular the individual valve devices and thus the individual pressure levels of the plastic preforms. In addition, the control device preferably also controls the movement of the stretch rods of the individual forming stations. Preferably, the control device also controls the movement of the application device, i.e. the blow molding nozzle. As mentioned above, the control device can also preferably adjust the settings of the individual throttling devices.

[0112] The control device is preferably suitable for controlling the time at which the application device applies pressure to the plastic preform and / or the time at which the blow moulding device lifts off the plastic preform again, in particular also for varying these times.

[0113] Reference numeral 26 denotes a storage device in which in particular measured values, in particular pressure values ​​and flow values, but also corresponding operating parameters are recorded. Preferably, these values ​​are stored together with a time allocation.

[0114] Preferably, these values ​​can be stored continuously, in particular over a long period of time while the machine is in operation. The control device also takes these recorded measured values ​​into account for controlling or regulating the device.

[0115] Reference numeral 28 generally and schematically indicates an inspection device for inspecting manufactured containers.

[0116] Reference numeral 25 denotes a display device for outputting information to the machine operator. Via this display device, an approximately measured pressure (distribution) curve can be output.

[0117] Figure 2 and Figure 3 The valve device 50 of the utility model is shown, which is in a closed state ( Figure 2 ), once in the open state ( Figure 3). In this case, reference numeral 56 relates to the working space to which the gaseous medium for expanding the plastic preform can be applied. Preferably, the blowing pressure is permanently applied to this working space 56. Reference numeral 57 denotes the outlet opening of the valve device, which is in flow connection with the application device and thus ultimately with the plastic preform.

[0118] Reference numeral 54 denotes a closed position of the valve device 50. Figure 2 as shown and in the open position as Figure 3 Valve piston shown.

[0119] Reference numeral 58 designates a control space to which (non-sterile) control air can be supplied in order to move the valve piston 54 .

[0120] The valve device can be divided into three areas by the structure thereof, namely a first area where the working space 56 is located, a transition area or a second area or a transition area and a third area where the control space is located.

[0121] Reference numeral 94 denotes a sealing device, in particular an O-ring, which seals the working area relative to the intermediate area 60. Reference numeral 96 denotes a sealing device, and preferably an O-ring or the like, which also seals the control space 58 relative to the transition area 60.

[0122] In the transition region a circulation volume 60 is formed, to which sterile air is preferably applied. Reference numerals 92 and 98 denote additional sealing means which seal the transition region 60 at two locations relative to the control space 58 .

[0123] The applicant reserves the right to claim all features disclosed in the application documents as essential features of the utility model, as long as these features are new compared to the prior art individually or in combination. Further, it is to be pointed out that features which can be advantageous per se are also described in individual drawings. It is immediately apparent to a person skilled in the art that a certain feature described in a drawing can be advantageous even without the use of other features in the drawing. In addition, it is apparent to the skilled person that advantages can also be obtained by combining several features shown in a single drawing or in different drawings.

Claims

1. A device for forming plastic preforms (10) into plastic containers, comprising a transport device (2) for transporting the plastic preforms (10) along a predetermined transport path, wherein: The transport device (2) has a transport support (22), on which are disposed a plurality of forming stations (20) for forming the plastic preforms (10), wherein each of the forming stations has an application device (84) for applying a flowable medium to the plastic preforms to expand them, and wherein the device (1) has at least one first compressed air storage tank (32), which is suitable and designed to provide compressed air at a first predetermined pressure (p1), and each forming station (20) has a valve assembly (4), wherein the valve assembly (4) has a plurality of valve devices (50) for applying at least two pressures to the plastic preforms, wherein at least one valve device (50) is a pneumatically controlled valve device (50), It is characterized in that The valve device (50) has a working space (56) for accommodating a gaseous medium for applying the plastic preform (10), and has a valve piston (54) that can be moved between at least two positions, and the valve device (50) also has a control space (58) that can be applied by a gaseous control medium to move the valve piston (54), and at least one transition area (60) is arranged between the working space (56) and the control space (58).

2. The device (1) according to claim 1, It is characterized in that The working space (56) and / or the transition region (60) are sterilizable.

3. The device (1) according to claim 1, It is characterized in that The control space (58) is sealed relative to the transition area (60) via at least one first sealing device (96, 98), and / or the transition area (60) is sealed relative to the working space via at least one second sealing device (92, 94).

4. The device according to claim 3, It is characterized in that The first sealing means (96, 98) sealing the control space relative to the transition area (60) is arranged to never touch the sterile area of ​​the working space.

5. The device (1) according to claim 1, It is characterized in that The transition region (60) serves as a compression spring for prestressing the valve piston (54).

6. The device (1) according to claim 1, It is characterized in that The valve component and / or the valve device has at least one sensor device.

7. The device (1) according to claim 1, It is characterized in that The valve device is designed without a bellows.

8. The device (1) according to claim 1, It is characterized in that The device (1) has a clean room in which the plastic preforms to be formed are transported.

9. The device according to claim 1, It is characterized in that The control pressure for actuating the valve device is lower than the pressure of the gaseous medium for expanding the plastic pre-forms.

10. The device according to claim 1, It is characterized in that The device has a second compressed air tank adapted and designed to provide compressed air at a second predetermined pressure (pi), wherein the second predetermined pressure is higher than the first predetermined pressure (p1).

11. The device (1) according to claim 1, It is characterized in that The device (1) can be operated both in a working operation for shaping the plastic preforms (10) and in a sterilizing operation for sterilizing the device (1) and / or the valve device.

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