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 the plastic preforms along a predetermined transport path, the transport device having a transport support on which a plurality of forming stations for forming the plastic preforms are arranged, the forming stations each having an application device for applying a flowable medium to the plastic preforms in order to expand the plastic preforms, and wherein the transport support has a transport device for transporting the plastic preforms along the transport path. The device has at least one first compressed air tank, which is adapted and designed to provide compressed air at a first predetermined pressure, and each forming station has a valve assembly, which has a plurality of valve devices for applying at least two pressures to the plastic preforms, characterized in that the valve devices are arranged in the first compressed air tank. At least one of the valve devices is a pneumatically controlled valve device sterilizable by a sterilising medium or a magnetically and / or magnetically operable valve device sterilizable by a sterilising medium.

Description

Technical Field

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

[0002] Such devices have long been known from the prior art. Usually heated plastic preforms are formed 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 molding machines or forming devices for forming containers under aseptic or sterile conditions have also become known. 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.

[0004] However, the corresponding control air for actuating the valves during working operation is usually not sterile.

[0005] 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 sterile boundaries 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.

[0006] 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.

[0007] 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

[0008] 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.

[0009] The device for forming 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 forming stations for forming the preforms into plastic containers are arranged, wherein each forming station has an applying device for applying a flowable, especially gaseous medium to the plastic preforms to expand them.

[0010] Furthermore, the device has at least one first compressed air tank, which is suitable and designed to store and / or 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 (different) pressures to the plastic preform.

[0011] According to the invention, at least one of the valve devices is a pneumatically controlled valve device sterilizable by a sterilizing medium or a magnetic and / or magnetically operable valve device sterilizable by a sterilizing medium. The sterilization is performed in a sterilization operation different from the production operation.

[0012] 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.

[0013] In a magnetically and / or magnetically operable valve arrangement, it is understood that at least one of these valve movements is achieved or executed by magnetic force. This will be explained in more detail with reference to the accompanying drawings.

[0014] It is also conceivable that the valve device is actuated by the control air and that the actual movement of the valve piston is effected by magnetic forces or that a corresponding force transmission is effected by magnetic forces.

[0015] In a preferred embodiment, the valve device has a movable, in particular linearly movable, valve piston, in a first position of which 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.

[0016] The flowable sterilizing medium may be hydrogen peroxide or peracetic acid.

[0017] 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.

[0018] Furthermore, the shaping station preferably has a blow mould in which the plastic preforms are expanded or blown into plastic containers.

[0019] 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.

[0020] Particularly preferred are compressed air tanks which provide a flowable medium for forming a container with a single valve assembly or valve block, more specifically a single valve device with a flow connection or a container which can be placed therein. This can be done in such a way that the corresponding operating pressure is always applied to the valve device.

[0021] The pressure tank can be a container. In addition, the tank can also consist of hoses, channels or pipes. The concept of a tank is not primarily about storage capacity, but about commonality (for all forming stations). In this way, a ring boiler or a ring channel can be omitted and the forming stations can be reached directly via hoses. A hose with a T-piece or a central distributor connects at least two forming stations to each other so that they can be "connected" in terms of pressure.

[0022] In a preferred embodiment, the reservoir is an annular channel. It is particularly preferred that at least one reservoir and preferably a plurality of reservoirs are arranged on a rotatable support, also referred to below as a blow moulding wheel.

[0023] In a further advantageous embodiment, all parts of the valve device which come into contact with the sterilization medium are made of a material which is resistant to the sterilization medium and the sterilization temperature and has a sufficient surface finish to allow sterilization. Furthermore, materials which are resistant to the sterilization medium are preferred.

[0024] In another preferred embodiment, the device has a sterilizing device suitable for applying a sterilizing medium to the valve. In particular, the flow channel or the space of the valve device that conveys a working fluid, in particular blowing air, during the working operation can contact the sterilizing medium.

[0025] Particularly preferably, the valve device has a valve piston which is preferably movable in a predetermined linear direction. Thus, this movable piston is used to control the blowing air (partially referred to as working air in this application) and can close the valve in one position and open the valve in another position.

[0026] Particularly preferably, such a valve piston is arranged in the sterile space of the device.

[0027] In a preferred embodiment, the valve device is a sterile or pneumatically and / or magnetically controlled valve, and a bellows-free valve as described in detail below.

[0028] 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.

[0029] With regard to valves known in the prior art, no known valve piston is completely sterilizable.

[0030] 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).

[0031] This directional valve can be equipped with a bellows or a diaphragm, which allows a separation between sterile and non-sterile control air.

[0032] In a preferred embodiment, the valve device is designed without bellows. In the prior art, bellows are partially provided to separate the valve device into a sterile area and a non-sterile area. 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.

[0033] In a preferred embodiment, the valve device has a working space which is suitable and designed to at least intermittently accommodate a gaseous medium for expanding the plastic preform. In addition, the valve has a control space for accommodating a gaseous medium, in particular air, for controlling the valve device. Preferably, both the working space and the control space can be sterilized with a sterilizing medium.

[0034] Particularly preferably, the control space and the working space are completely separated in terms of fluid technology. In the prior art, non-sterile air is 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.

[0035] Preferably, sterile air is also used for controlling the valves. Therefore, there is no risk of contaminating the working air or the blowing air.

[0036] 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.

[0037] 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.

[0038] Particularly preferably, the plastic preforms are transported through the clean room during contact with the gaseous medium in order to expand them.

[0039] Preferably, the clean room has at least two walls delimiting the clean room, which walls are preferably movable relative to each other.

[0040] 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.

[0041] Particularly preferred is the main piston of the aforementioned valve arrangement, which always controls the blowing air in a space which can (in particular always) be flushed with sterile air.

[0042] The valve device preferably consists of a control valve and a main valve and / or has these elements. The control valve actuates the main valve with a valve piston so that the container is filled with blowing air.

[0043] In another advantageous embodiment, the control valve is a 3 / 2 directional valve or a 5 / 2 directional valve. As described below, such a 5 / 2 directional valve has or requires a smaller stroke. In this case, a bellows or a diaphragm can also be realized more easily because it occupies a smaller area. The control pressure here is also smaller.

[0044] When a 3 / 2 directional valve is used, the bellows or more specifically the provided diaphragm may be the separation point between the sterile control air and the non-sterile pilot air which effects the movement of the valve and / or the movement of the valve piston mentioned above. This sterile control air is preferably used to control the valve piston which releases the blowing air.

[0045] In another preferred embodiment, the valve piston 54 of the valve device is pressed into the closed position by a pneumatic spring. The reset can also be performed by another 3 / 2-way valve.

[0046] Preferably, the reset device is a spring device, particularly an air spring device. In addition, the reset device also can be another valve device.

[0047] Particularly preferably, the device is designed in such a way that the pressure of the blowing air for inflating the container is always greater than the pressure of the control air for actuating the valve device.

[0048] 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.

[0049] 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.

[0050] The utility model achieves that one movement of the main piston of the valve device is carried out completely in the sterile space. Therefore, even in the event of a leak, there is no risk of contamination. If the diaphragm in the control valve leaks, due to the pressure conditions, non-sterile air cannot enter the sterile control air, because the pressure on the sterile control side is higher than the pressure on the non-sterile side. However, the switchability can be given by different area ratios. Particularly preferred is an area on the sterile side (smaller than the area on the non-sterile side), which allows higher pressures.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Particularly preferably, the valve device which allows the second pressure and the third pressure to be applied to the container is also a valve as described above, which is particularly preferably fully sterilizable.

[0055] Particularly preferably, the second compressed air tank and / or the third compressed air tank are also annular channels arranged on the blowing wheel.

[0056] 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.

[0057] In another advantageous embodiment, the valve device has a magnetic actuator. Preferably, the magnetic actuator of the valve device is separated from the piston of the valve device or the valve piston by a magnetically permeable wall. In this way, a magnetic actuation of the valve device is proposed, preferably also generating a sterile space boundary through the wall.

[0058] In a preferred embodiment, the valve device has a permanent magnet component, in particular a movable permanent magnet component. Such a permanent magnet component can also cause a movement of the valve piston by movement.

[0059] Particularly preferably, such a permanent magnet assembly is movable, in particular linearly movable.

[0060] In a preferred embodiment, the valve device has a movable piston which is movable and in particular has a floating bearing. This can be connected to the actuator by magnetic forces. Particularly preferably, as described above, the actuator has a magnetically permeable but sterile and dense boundary layer, i.e. the above-mentioned wall separating the piston and the air space. Such a wall can be a plastic shell, in particular, but not completely made of polytetrafluoroethylene.

[0061] Particularly preferably, the separating wall or separating shell is thermally and chemically stable to cleaning agents and high temperatures. For example, sterilization can be performed using H2O steam at a specific concentration above 60° or 80°, particularly preferably above 100°C.

[0062] In another preferred embodiment, the actuator device is directly magnetic. Thus, it is envisaged that a current-carrying coil assembly (directly or with a metal plate regulating the magnetism of the coil) generates a magnetic field which moves the piston of the valve device.

[0063] Furthermore, it is conceivable that the piston device itself has no permanent magnets, but rather is similar to an asynchronous linear motor, with an external coil exciting a current in the piston device, and this mutual inductance and the resulting magnetic field acting as the actuator force.

[0064] In another preferred embodiment, permanent magnetic, electromagnetic and inductively induced magnetic forces can also be combined and / or combined with other forces such as mechanical springs.

[0065] In a preferred embodiment, the magnet is actuated above the (valve) piston, which means that the lifting unit is pressed down and sealed, for example on a soft gasket. In addition, it is also possible to actuate the magnet from below, so that the lifting unit or the piston is pushed to the top.

[0066] In a further preferred embodiment, the valve device has a sealing seat for the valve body. Such a sealing seat made of a soft material is particularly preferred. This means that, in contrast to a conventional blow-molded piston design, which has, for example, a metal sealing seat, the plastic piston seals directly onto it, for example using a metal such as aluminum, in particular surface-treated aluminum or stainless steel or titanium or a plastic piston.

[0067] The plastic piston may be composed of a material selected from the group consisting of PEK, PEI, POM or PTFE. The piston may seal on a soft seal thermodynamic seal seat.

[0068] This reduces the force required to seal.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] In a further preferred embodiment, the valve device has a control valve and a main valve.

[0074] Preferably, the sterile boundary runs in the control valve or is arranged in the control valve.

[0075] In a further preferred embodiment, the main piston of the valve device which controls the blowing air is always located in a space which can be flushed with sterile air.

[0076] In a further preferred embodiment, the pilot valve is located upstream of the control valve, wherein all valves are preferably designed to be sterile.

[0077] In a further preferred embodiment, the device can be operated both in a working operation for shaping the plastic pre-forms and in a sterilizing operation for the sterilizing device and / or the valve device.

[0078] The utility model is also directed to a method for forming 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, in particular rotatable transport support, on which a plurality of forming stations for forming the plastic preforms are arranged.

[0079] 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 stores and / or supplies 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 different pressures to the plastic preforms.

[0080] According to the utility model, at least one of the valve devices is a pneumatically controlled valve device which can be sterilized by a sterilizing medium or a magnetically controlled valve device which can be controlled by a sterilizing medium.

[0081] In a further preferred method, a higher pressure prevails in the working space of the valve device for accommodating the gaseous medium applied to the plastic preform during working operation than in the control space for accommodating the control fluid which moves the valve piston of the valve device.

[0082] In another preferred method, in at least one operating mode, in particular during a sterilization operation, the parameters of the operation are monitored. These parameters can be monitored using a sterilization medium-valve circuit. This allows monitoring of valve position and / or flow and / or pressure and / or temperature and / or concentration.

[0083] This ensures sterilization of the entire system.

[0084] The characteristic data of these processes are preferably stored, ie in particular stored and saved in a database. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] For further advantages and embodiments, please refer to the attached drawings.

[0086] in:

[0087] Figure 1 A schematic diagram of a device for forming a plastic preform into a plastic container is shown;

[0088] Figure 2 , Figure 3 Two illustrations of a device with a 3 / 2-way valve and a gas spring are shown;

[0089] Figure 4a , Figure 4b Two further illustrations of the valve device of the present invention are shown;

[0090] Figure 5a , Figure 5b Two diagrams showing an arrangement with two 3 / 2-way valves; and

[0091] Figure 6a , Figure 6b Two illustrations of a magnetically actuated valve arrangement are shown. DETAILED DESCRIPTION

[0092] Figure 1 The device 1 for shaping 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 shaping stations 20 is arranged. The individual shaping stations each have a blow molding device 82 in which a cavity is formed for expanding the plastic preform.

[0093] Reference numeral 84 denotes an application device for expanding the plastic preforms 10. This can be, for example, a blow nozzle which can be docked at the opening of the plastic preforms in order to expand these plastic preforms 10. Furthermore, it is also conceivable that the blow opening is sealed on the blow molding device. The pressure device is preferably moved in the longitudinal direction and preferably only in the longitudinal direction of the plastic preforms.

[0094] Reference numeral 4 denotes a valve arrangement, such as a valve block, which preferably has a plurality of valves which control the impact of different pressure levels on the plastic preforms. Preferably, each forming station has such a valve block.

[0095] 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.

[0096] 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.

[0097] After the plastic container has expanded, the pressure or pressurized air is preferably fed back from the container to the respective pressure accumulator.

[0098] 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.

[0099] Reference numeral 88 denotes a stretching rod for stretching the plastic preform in its longitudinal direction. Preferably, all forming 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.

[0100] Preferably, the number of forming stations 4 is between 2 and 100, preferably between 4 and 60, preferably between 6 and 40.

[0101] 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 .

[0102] Reference numeral 7 denotes a pressure supply device, such as a supercharger or a pressurized 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.

[0103] These rotary distributors are therefore preferably used to direct air from the stationary part of the device to the rotating part of the device.

[0104] 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.

[0105] Reference numeral 33 denotes a connection 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 connection line. The connection line 33 is preferably arranged in the rotating part of the device.

[0106] 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 is sealed off from the non-sterile environment by a sealing device, preferably with at least two pressure storage tanks.

[0107] In addition, the device preferably has ( Figure 1The 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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 forming stations.

[0113] A further flow measuring device can also be allocated between a further compressed air tank and the respective forming station.

[0114] Furthermore, a position detection device is preferably provided, which can detect the position of the stretching rod of each forming station.

[0115] 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.

[0116] 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 pressure device, i.e. the blow molding nozzle. As mentioned above, the control device can also preferably adjust the settings of the individual throttling devices.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] Reference numeral 28 generally and schematically indicates an inspection device for inspecting manufactured containers.

[0121] 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.

[0122] Figure 2 and Figure 3 Another valve device of the utility model is shown, wherein: Figure 2 The closed position of the valve device 50 is shown. Figure 3 The open position of the valve arrangement 50 is shown.

[0123] Reference numeral 52 denotes a valve body, in which a valve piston 54 is in a first position ( Figure 2 ) and the second position ( Figure 3 ) between the linear movement to close or open the valve. Preferably, the valve piston is arranged so that it can be continuously flushed by the sterilizing medium during the sterilization operation.

[0124] Reference numeral 56 denotes a working space for receiving the blowing air of the valve device 50. This working space can be sterilized with a sterilizing medium.

[0125] Reference numeral 32 denotes a tank for supplying the blowing air. Reference numeral 57 denotes an outlet of the valve body 52 through which the blowing air reaches the container 10 or the plastic preform.

[0126] Reference numeral 59 relates to a control space to which a control fluid, in particular control air, can be applied in order to move the valve piston relative to the housing 52 in one direction, here from the closed position to the closed position. Figure 3 The open position is shown. The control fluid supplied from the air source 43 is sterile control air.

[0127] Reference numeral 42 denotes a control valve which controls the supply of control air to the control space 59. Non-sterile pilot air is preferably supplied to the control valve 42 via an inlet 45. In the control valve 42, there is a sterile boundary which is preferably formed by a diaphragm. In this way, non-sterile pilot air can be prevented from coming into contact with sterile sterile air in the working space.

[0128] The sterile boundary preferably represents a plane or division between the sterile area and the non-sterile area of ​​the device.

[0129] Preferably, the sterile boundary is formed by one element. Preferably, the sterile boundary is airtight to prevent pathogens from entering the sterile area from the non-sterile area.

[0130] Alternatively or additionally, the sterile boundary can also be produced by a laminar flow from the sterile area to the non-sterile area. The sterile boundary can also be achieved by a higher pressure in the sterile area relative to a lower pressure in the non-sterile area.

[0131] Reference numeral 44 denotes an air suspension device which supplies air to the air suspension space 55 to reset the valve piston 54 .

[0132] Figure 4a and 4b A detailed view of the control valve 42 is shown.

[0133] In this control valve, the valve piston 154 can again move in a linear direction. In the open position, sterile control air enters the control valve as shown by arrow P1, and enters the control space 159 in the valve body 152 from the control valve as shown by arrow P2. Reference numeral 33 accordingly denotes the valve inlet, and reference numeral 156 denotes the valve outlet.

[0134] Reference numeral 159 indicates that non-sterile pilot air for moving the valve piston 154 of the control valve is supplied to the inlet of the control valve. Reference numeral 49 indicates a diaphragm which also separates the sterile space or aseptic area of ​​the valve device from the control space.

[0135] In addition, the pressure of the blow molding air supplied is always greater than the pressure of the control air. Like this, even when diaphragm 49 is damaged, the working air can not be polluted by the control air.

[0136] Figure 5a and 5b Another design of the valve device 50 of the present invention is shown, wherein: Figure 5a The closed position is shown again, Figure 5b The open position is shown.

[0137] and Figure 4a , Figure 4b The embodiment shown differs in that a further pneumatic valve 73 is used here instead of the pneumatic spring 44 shown there in order to also control the return of the valve piston 54 .

[0138] Figure 6a , 6b Another valve device 50 is shown, wherein Figure 6ashows the closed state of the valve device, Figure 6b The valve arrangement is shown in its open state. Reference numeral 54 again relates to a valve piston which is movable between two positions.

[0139] Reference numeral 56 designates a working space which can come into contact with a gaseous medium for expanding the plastic pre-forms 10 .

[0140] The valve piston 54 is guided by the guide device 104. Figure 6a , 6b In the embodiment shown, a plurality of permanent magnets 106, 108 are provided, which are also linearly movable. The valve piston is magnetically coupled to these permanent magnets and thus follows the movement of the permanent magnets.

[0141] A wall is also provided between the valve piston and the permanent magnet, which wall, on the one hand, forms a boundary of the sterile space, in particular prevents the passage of gas, and, on the other hand, exerts a magnetic attraction force via the wall.

[0142] On the other hand, the movement of the permanent magnet can be caused by a number of actuator means, for example by an electric drive or for example by a pneumatic drive.

[0143] The applicant reserves the right to claim all features disclosed in the application documents that are essential to the utility model, as long as these features are new compared to the prior art individually or in combination. It is further noted that features that 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 using other features in the drawing. In addition, the skilled person sees 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 a plurality of forming stations (20) for forming the plastic preforms (10) are arranged, 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 tank (32), which is suitable and designed to provide compressed air at a first predetermined pressure, and each forming station (20) has a valve assembly (4), which has a plurality of valve devices (50) for applying at least two pressures to the plastic preforms, It is characterized in that At least one of the valve devices (50) is a pneumatically controlled valve device sterilizable by a sterilization medium or a magnetically and / or magnetically operable valve device sterilizable by a sterilization medium.

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

3. The device (1) according to claim 1, It is characterized in that The valve device has a working space suitable and designed to at least intermittently accommodate a gaseous medium for expanding the plastic preform (10), and a control space for accommodating air for controlling the valve device, wherein both the working space and the control space can be sterilized with a sterilization medium.

4. The device (1) according to claim 1, It is characterized in that The device (1) has a clean room (18) in which the plastic preforms to be formed are transported.

5. The device according to claim 1, It is characterized in that The control valve (42) is a 3 / 2-way valve or a 5 / 2-way valve.

6. The device according to claim 1, It is characterized in that The valve device (50) is equipped with a reset device for resetting a valve piston of the valve device, wherein the reset device has an air suspension device (44) or another valve device (73).

7. 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.

8. 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).

9. The device according to claim 1, It is characterized in that The magnetic actuator of the valve device is separated from the piston of the valve device by a magnetically permeable wall.

10. The device according to claim 1, It is characterized in that The valve device has a permanent magnet assembly (106, 108).

11. The device according to claim 1, It is characterized in that The valve device (50) has a control valve (42) and a main valve, wherein a main piston of the valve device which sets a sterilization boundary in the control valve and / or controls the blowing air is always located in a space which can be flushed with sterile air.

12. The device according to claim 11, It is characterized in that The pilot valve is located upstream of the control valve, wherein all valves are designed to be sterile.

13. 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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