DE102012107811A1 - Device for heating plastic preform, has wall that forms barrier of storage space, where wall is penetrated by electromagnetic radiation, and sensor unit detects physical property of non-contact plastic preform - Google Patents

Abstract

The device has a carrier, at which a heating device is arranged. The heating device has a holding element for holding and transporting the plastic preforms and a heating unit (30), in which the plastic preform is inserted. A wall forms a barrier (S) of a storage space (6), where the wall is penetrated by the electromagnetic radiation. A sensor unit (36) is provided for detecting physical property of a non-contact plastic preform inserted in the heating device. An independent claim is included for a method for heating plastic preform.

Description

In the beverage manufacturing industry, it has long been known to first produce plastic containers, for example by stretch blow molding and then to fill them with drinks. In stretch-blow molding technology, the demand for low-germ and also sterile and / or sterilizable stretch blow-molding machines has increased in recent years. These machines should make it possible, especially in a blocked form, to produce sterile containers for an aseptic filling system in order to eliminate the expensive and expensive sterilization process. Examples of such sterile blow molding machines are for example from DE 10 2008 038 141 or the EP 2 202 047 known.

However, to blow the plastic preform aseptically, it should be previously sterilized. This is done in the known concepts between an upstream of the blowing machine heating device such as an oven and the blow molding machine itself. The reason for this arrangement is that known from the prior art infrared ovens for heating the plastic preforms are practically not aseptic executable.

On the other hand, however, concepts are known which make it possible to sterilize the plastic preforms within a furnace or already produce sterile. However, these concepts fail so far on a non-sterile executable oven for heating the plastic preforms.

The present invention is therefore based on the object to provide a device for heating plastic preforms, which also allows heating of the plastic preforms under sterile conditions.

These objects are achieved by an apparatus and a method according to the respective independent claims. Advantageous embodiments and further developments are the subject of the dependent claims.

A device according to the invention for heating plastic preforms has a carrier to which at least one heating device is arranged, wherein this heating device has a holding element for holding and transporting the plastic preforms and a heating unit into which the plastic preform can be inserted. Furthermore, a movement device is provided, which is suitable for introducing the plastic preform into the heating unit, the device furthermore having a generating device for generating microwaves

Furthermore, the device has a clean room, within which the plastic preforms can be heated by means of the heating unit, this clean room being delimited from an environment by at least one first wall.

According to the invention, at least one wall forming a boundary of the clean room can be penetrated by an electromagnetic radiation. The electromagnetic radiation may be, in particular, microwaves, lasers or infrared radiation and / or radiation in the visible wavelength range.

It is therefore proposed to resort to the concept of microwave heating for the heating of the plastic preforms. The heating of plastic preforms by means of microwaves is known per se from the prior art and has been described, for example, in US Pat EP 958 124 B1 as well as in the DE 10 2007 022 386 described. However, not only the machine itself should be equipped with a clean room, but also the critical parts that are found in the clean room should be sterilizable and be designed according to the latest aseptic requirements. Preferably, the carrier is a movable carrier. The carrier is preferably a wheel to which at least one, but preferably a plurality of said heating devices or heating units is arranged. Advantageously, a drive for driving the carrier outside the clean room is arranged. It is also possible for a movement device, which serves for introducing the plastic preform into the heating unit, to be arranged at least partially outside the clean room.

Preferably, the device comprises a conduit means which directs the microwaves to the heating unit. This conductor device can be, for example, a waveguide.

A problem of such devices is that certain sensor units should be used, for example a pyrometer, which measures contactlessly a temperature of the plastic preforms. However, components known from the prior art, such as pyrometers, are not obtainable in an aseptic form. Therefore, it is necessary to install such components outside of the clean room. By providing a wall through which electromagnetic radiation can pass, a way is provided for measuring such measurements, for example the temperature of the plastic preforms, through a border of the clean room. This means that one appropriate measuring device can also be arranged outside the clean room.

Advantageously, the electromagnetic radiation is light or radiation in the infrared range. These are preferably wavelength ranges which lie between 800 nm and 20,000 nm (ie both NIR and FIR regions).

In this case, this wall, which is penetratable by the electromagnetic radiation, in particular for measuring purposes. However, it would also be possible for the plastic preforms to be heated through such a wall, for example, the microwaves which are intended to heat the plastic preforms should pass through this wall.

Advantageously, however, said wall, through which the electromagnetic radiation can pass through, impermeable to gas.

In a further advantageous embodiment, the device has at least one sensor device which senses contactlessly at least one physical property of a plastic preform introduced into the heating unit, wherein this sensor device is arranged at least partially outside the clean room. Thus, as mentioned above, this sensor device measures said physical quantity through the wall of the clean room.

Advantageously, this physical quantity is a temperature of the plastic preform that is being heated by the heating unit. Advantageously, this sensor device is suitable for continuously measuring said physical quantity. However, other properties of the plastic preforms could also be measured, such as a transparency of the plastic preform or a wall thickness.

In a further advantageous embodiment, the heating device has a resonator which forms a cavity into which the plastic preform can be inserted. This resonator is thus preferably also the heating unit. In this case, this cavity is also disposed within the clean room and the resonator preferably has a housing which surrounds the cavity, wherein a clean room boundary extends in a region of this housing. An area of this housing is understood to mean that the clean room boundary extends geometrically through the housing or also directly adjoins this housing. Preferably, however, an area of this housing is also provided outside the clean room.

Advantageously, a plurality of sensor devices are provided, and particularly preferably at least one of the above-mentioned sensor devices is assigned to each individual heating unit. Thus, this sensor device is to be mounted in a proximity to the individual resonators. On the other hand, since, as mentioned above, the sensor device is to be arranged outside the clean room, it is proposed that a boundary of the clean room extends into the said region of the resonator housing so as to create a possibility to arrange the sensor device as close as possible to the measuring point.

In a further advantageous embodiment, the housing of the resonator has at least one wall element which can be penetrated by an infrared radiation. It is possible that this wall element is integrated into the housing and / or on an inner wall of this housing, for example, an inner wall, which surrounds the cavity into which the plastic preforms are introduced, is present. It would also be possible for a circumferential wall, for example in the form of a circumferential cylinder, to be provided, which separates the clean space from the actual resonator (which is thus arranged outside the clean room). However, such a wall element advantageously has a high resistance to a cleaning agent. In addition, this wall element should also have a low dielectric loss, so as to be suitable for the penetration of microwaves. Furthermore, this wall element should be transparent to the infrared radiation for the sensor device. Depending on the work area of such a sensor device, which may be in particular a pyrometer, different materials come into question. For a short-wave pyrometer (wavelength ranges <2,000 nm), it would be conceivable to use quartz glass tubes. For longer wavelength pyrometers (which operate in a working range of 8,000 to 14,000 nm) a silicon tube could be used. These two materials are also transparent to microwaves and relatively resistant to chemicals.

Advantageously, the wall element can be penetrated by a radiation emanating from the cavity in a straight-line radiation direction.

Advantageously, as mentioned above, this wall element also forms a boundary of the clean room.

Instead of the above-mentioned cylinder, it would also be conceivable to provide aseptic-capable and infrared-transmittable windows shortly before the sensor device, such as the pyrometer. In this case, at least one preferably at least two windows, which are advantageously sealed according to rules of hygienic design, are preferably arranged outside the actual microwave resonator. The advantage of this approach is that these windows can be very small and do not have to be microwave resistant, as they are not penetrated by the microwave preform heating microwave radiation.

One of the materials would be, for example, slices of silicon or germanium. However, care should be taken in this embodiment, in the resonator itself all shocks (in which materials abut each other) or column are designed hygienically. This can be achieved, for example, by re-coating a finished mounted resonator to seal all such impacts and gaps.

In a further advantageous embodiment, the device has at least one second wall, which limits the clean room, and the first wall is movable relative to the second wall. In this case, a sealing device may be provided in a region between these walls, such as a so-called water lock, a fluid barrier or a slip ring seal. In order to transmit the movements into the interior of the clean room, magnetic couplings can also be provided. Thus, for example, the holding elements which hold the plastic preforms may be holding mandrels, which can be introduced into an opening of the plastic preforms.

Advantageously, the device has a movement device which generates a rotational movement of the plastic preforms with respect to their longitudinal axis. This rotational movement can be initiated for example by a drive device which is arranged outside the clean room. It is possible that this rotational movement is transmitted through a clean room boundary, for example using the above-mentioned magnetic couplings. In addition, however, these holding elements, which hold the plastic preforms, are preferably also movable in a longitudinal direction of the plastic preforms in order to introduce the plastic preforms arranged thereon into the heating units and, preferably, also to carry this out again.

For the implementation of this lifting movement, for example, a long water lock (especially long along the longitudinal direction of the plastic preforms) may be provided or to a fluid barrier or a long bellows, which serves to seal these long strokes. Advantageously, such a water lock is designed such that it permits lifting movements in the longitudinal direction of at least 3 cm, preferably of at least 5 cm and particularly preferably of at least 10 cm.

Advantageously, a bellows is used to seal this lifting movement and a sliding seal to seal the rotational movement. Also advantageous is the above-mentioned long water lock, which itself seals both the rotational movements and the lifting movements.

Advantageously, the resonator, or its housing, designed so that it complies with the rules of a hygienic design. Thus, it is conceivable that transitions between components of the resonator or joints and connections which are in contact with the clean room, are closed with a seal aseptikfähigen, for example, are provided with an aseptifähigen layer.

In a preferred embodiment, the heating unit has a first opening, via which the plastic preform can be inserted into the heating unit and at least one second opening, which is spaced from the first opening. This second opening can be used for example for cleaning the heating unit or the interior of the resonator.

In a further advantageous embodiment, the device has a line for conducting a flowable medium, which is in flow communication with the second opening. By means of this line, a cleaning process or rinsing process of the resonator interior is conceivable.

In a further advantageous embodiment, at least one bellows is provided to seal at least one relative movement occurring in the device, and in particular a lifting movement.

In a further advantageous embodiment, the generating means for generating electromagnetic waves outside the clean room is arranged. In this embodiment, it would be possible for the electromagnetic waves, which serve to heat the plastic containers, to pass through the radiation-permeable wall.

The present invention is further directed to a heating device for heating plastic preforms, wherein the heating device comprises a resonator, the forming a cavity into which the plastic preform is insertable, and this resonator further comprises a housing and a sensor device which detects contactlessly at least one physical property of a plastic preform introduced into the heating device.

According to the invention a gas-impermeable wall is arranged between the sensor device and the cavity, which is permeable to electromagnetic radiation in an infrared wavelength range. It is therefore also proposed for the individual heating devices that they detect through a wall through the physical parameters of the plastic preforms and in particular their temperature. Advantageously, the sensor device is a pyrometer.

The present invention is further directed to a method of heating plastic preforms, wherein the plastic preforms are transported along a predetermined transport path and heated during this transport. The plastic preforms are each introduced into heating units and heated in these heating units, so that each plastic preform to be heated is assigned to a heating unit. Furthermore, the heating units are at least partially moved along a transport path and for heating the plastic preforms microwaves are introduced into the heating unit.

According to the invention, the plastic preforms are transported at least temporarily during their heating within a clean room, this clean room being delimited from an environment by at least one first wall and at least one second wall, which is preferably movable relative to the first wall, and wherein at least one physical property a plastic preform located in a heating unit is detected by a sensor device arranged outside the clean room.

Therefore, it is also proposed in terms of the method that the said physical parameter, in particular a temperature, is detected through the clean-room boundary. Advantageously, the above-mentioned transport movement of the plastic preforms is a rotary movement or a movement along a circular line.

Further advantages and embodiments will be apparent from the attached drawings:

Show:

1 A representation of a resonator according to the invention;

2 a representation of a resonator according to the invention in a second embodiment;

3 a schematic representation of a device according to the invention;

4 a further illustration of a device according to the invention;

5 a representation of a device according to the invention in a further embodiment;

6 a further illustration of a device according to the invention; and

7 a further illustration of a device according to the invention.

1 shows a representation of a heating unit according to the invention 30 or a resonator 30 , This resonator 30 has a resonator housing 34 on and forms a cavity 32 from which plastic preforms (not shown) can be inserted. As you can see, this is the resonator housing 34 constructed in several parts, ie it has several housing parts 34a . 34b on. These housing parts can be screwed together. The reference numerals 36 refer to pyrometers, with the help of which a temperature of the plastic preforms (not shown) can be measured without contact. These pyrometers 36 are here outside the clean room 6 arranged.

The clean room is here in its entirety by the reference numeral 6 and includes, inter alia, the cavity 32 which is inside the resonator 30 is trained. The reference symbol S denotes the sterile room boundary, here by an infrared-transmitting cylinder 66 is formed, which fully encloses this cavity. There is, as mentioned above, this cylinder 66 that also makes it part of a wall 64 of the clean room, made of a non-microwave absorbing material. In this way it is possible for the case 34 the resonator itself is outside the clean room and in this way no sterile conditions must be met for this resonator.

2 shows a further embodiment of a resonator according to the invention 30 , In this embodiment, the clean room extends 6 not only in the area of the cavity 32 , but also in a vertical area 33 , Instead of in 1 shown transparent cylinder are here aseptic and IR-transparent windows 68 provided, through which the sensor device 36 can detect a temperature of a plastic preform (not shown). This embodiment of the window 68 Although cheaper, but requires that certain parts of the housing 34 must be kept sterile, for example, by the above-mentioned coatings. A wall of the region perpendicular to the cavity 33 here also forms a border of the clean room 6 out.

3 shows a representation of a device according to the invention. Here is the resonator again 30 shown, as well as a movement device here 24 which plastic preforms 10 in the cavity 32 of the resonator can introduce. In this case, the reference numeral refers 22 on a holding element, which is designed here as a holding mandrel, in the mouth of the plastic preform 10 is introduced. The reference number 28 indicates a bellows which serves to seal a lifting movement of the plastic preform, ie a movement in the direction of the double arrow L. The reference number 52 indicates a carrier inside this bellows and thus outside the clean room 6 is arranged. This carrier 52 is here arranged rotatable with respect to the longitudinal axis L.

Via a coupling device 54 , which may be, for example, a sliding seal or a magnetic coupling, the rotation of the carrier 52 on the holding element 22 transfer. Furthermore, a (not shown) drive is provided outside of the clean room, which is for generating the rotational movement of the carrier 52 serves.

The reference numerals 40 refer to two sealing devices or water locks, which a stationary arranged wall 64 opposite a movable wall 63 caulk. These water locks each have circumferential channels 41 into which a sword 43 which is on the movable wall 63 is arranged, dips.

In the embodiment shown here is only a heating device 20 However, they are actually presented in their entirety 2 characterized carrier arranged a plurality of such heating units. This carrier 2 thus also provides a (rotatable) transport device for transporting the plastic preforms 10 The reference number 7 schematically indicates a conduit means, via which the microwaves in the resonator 34 be coupled. The reference number 64 denotes a stationary wall, which is also the clean room 6 limited. In this stationary wall, it is also possible to arrange locks which are used for introducing and / or carrying out the plastic preforms 10 serve. The clean room 6 is thus designed so that it the transport path of the plastic preforms 10 surrounds channel-like.

The reference number 70 refers here to a radiation-permeable wall, which also forms a sterile room boundary. In this embodiment, the radiation or microwaves which heat the plastic preforms also pass through this wall. Accordingly, here the microwave generating device (see. 4 ) outside the clean room 6 arranged. Also the management device 7 for conducting the microwaves is arranged here outside the clean room. This wall 70 is therefore permeable here in particular for microwave radiation. Advantageously, this wall is made of an aseptic material. As a material for the wall, for example Teflon comes into question.

4 shows another illustration of in 3 shown device. In addition to the management device 7 Here is also the microwave generating device 4 , about a magnetron, shown. It is possible that each individual heating unit has its own magnetron, but it would also be possible for a magnetron or a microwave generating device to have a multiplicity of resonators 34 provided. The reference number 72 refers to tuning units, such as tuning pins, in the ductwork 7 can be introduced so as to control the microwave power.

5 shows a further embodiment of a device according to the invention. In this embodiment, the microwave generating device 4 below the transport device and the plastic preforms 10 arranged. Here, too, moves the microwave generating device 4 with the individual containers or plastic preforms with. Unlike the previous embodiment, however, here is the power device 7 arranged radially outside of the individual resonators.

6 shows an embodiment similar to that in FIG 5 shown embodiment, but here the microwave generating device 4 is arranged radially within the individual resonators.

At the in 7 In the embodiment shown, a microwave generating device is again shown which transmits the microwaves via the line device 7 in the heating unit 30 or the resonator 30 introduces.

The Applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, if they are new to the prior art individually or in combination.

LIST OF REFERENCE NUMBERS

2

carrier

4

Microwave generator

6

cleanroom

7

line device

10

The plastic preforms

20

heater

22

retaining element

24

mover

28

bellow

30

Heating unit, resonator

32

cavity

33

to the longitudinal direction L vertical area

34

Resonator / resonator

34a, 34b

housing parts

36

Sensor device / pyrometer

40

Sealing devices / surge tanks

41

circumferential channels

43

sword

52

carrier

54

coupling device

64

stationary wall

63

movable wall

66

Cylinder (as part of the wall limiting the clean room)

68

IR-permeable windows (as part of the wall bordering the clean room)

70

wall

72

Tuning Units / tuning pins

S

Sterile room boundary

L

Double-headed arrow direction / longitudinal axis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008038141 [0001]
• EP 2202047 [0001]
• EP 958124 B1 [0009]
• DE 102007022386 [0009]

Claims (11)

Contraption ( 1 ) for heating plastic preforms ( 10 ) with a carrier ( 2 ), to which at least one heating device ( 20 ), this heating device ( 20 ) a holding element ( 22 ) for holding and transporting the plastic preforms ( 10 ) and a heating unit ( 30 ) into which the plastic preform ( 10 ) is insertable, and wherein a movement device ( 24 ) is provided, which is suitable, the plastic preform ( 10 ) into the heating unit ( 30 ), the device ( 1 ) a generating device ( 4 ) for generating electromagnetic waves, wherein the device ( 1 ) a clean room ( 6 ) within which the plastic preforms ( 10 ) by means of the heating unit ( 30 ) are heatable and this clean room ( 6 ) of at least one first wall ( 66 . 68 . 70 ) with respect to an environment (U) is characterized in that at least one of a boundary (S) of the clean room ( 6 ) forming wall ( 66 . 68 . 70 ) is permeable to electromagnetic radiation Contraption ( 1 ) according to claim 1, characterized in that the device ( 1 ) at least one sensor device ( 36 ), which contactlessly at least one physical property of a plastic preform introduced into the heating device ( 10 ), this sensor device ( 36 ) at least partially outside the clean room ( 6 ) is arranged. Contraption ( 1 ) according to claim 1, characterized in that the heating device ( 20 ) a resonator ( 30 ) having a cavity ( 32 ) into which the plastic preform ( 10 ) is insertable and this cavity ( 32 ) within the clean room ( 6 ) is arranged and this resonator ( 30 ) a housing ( 34 ) having the cavity ( 32 ) and a clean room boundary in an area of this housing ( 34 ) runs. Contraption ( 1 ) according to claim 3, characterized in that the housing ( 34 ) of the resonator ( 30 ) at least one wall element which can be penetrated by an infrared radiation (US Pat. 66 . 68 . 70 ) having. Contraption ( 1 ) according to claim 4, characterized in that the wall element ( 66 . 68 . 70 ) in a straight line radiation direction starting from the cavity ( 32 ) is penetratable by the electromagnetic radiation. Contraption ( 1 ) according to at least one of the preceding claims, characterized in that the device ( 1 ) at least one second wall ( 64 ), which the clean room ( 6 ) and the first wall ( 66 . 68 . 70 ) opposite the second wall ( 64 ) is movable. Contraption ( 1 ) according to at least one of the preceding claims, characterized in that the heating unit ( 30 ) has a first opening, over which the plastic preform of the heating unit ( 30 ), and at least one second opening which is spaced from the first opening. Contraption ( 1 ) according to at least one of the preceding claims, characterized in that at least one bellows ( 28 ) is provided to at least one in the device ( 1 ) seal occurring relative movement. Contraption ( 1 ) according to at least one of the preceding claims, characterized in that the generating device ( 4 ) for generating electromagnetic waves outside the clean room ( 6 ) is arranged. Heating device ( 20 ) for heating plastic preforms ( 10 ), wherein the heating device ( 20 ) a resonator ( 30 ) having a cavity ( 32 ) into which the plastic preform ( 10 ) is insertable and this resonator ( 30 ) a housing ( 34 ), and a sensor device ( 36 ), which contactlessly at least one physical property of one in the heating device ( 20 ) introduced plastic preform ( 10 ), characterized in that between the sensor device ( 36 ) and the cavity ( 32 ) a gas-impermeable wall ( 66 . 68 . 70 ), which is permeable to electromagnetic radiation in an infrared wavelength range. Method for heating plastic preforms ( 10 ), wherein the plastic preforms ( 10 ) are transported along a predetermined transport path and heated during this transport, wherein the plastic preforms ( 10 ) in each case in heating units ( 30 ) and in these warming units ( 30 ), so that each plastic preform to be heated ( 10 ) a heating unit ( 30 ) and the heating units ( 30 ) are moved at least in sections along the transport path, and for heating the plastic preforms ( 10 ) Microwaves in the heating units ( 30 ), characterized in that the plastic preforms ( 10 ) at least temporarily during its heating within a clean room ( 6 ), this clean room ( 6 ) of at least one first wall ( 64 ) and at least one second wall ( 66 . 68 . 70 ), which are movable relative to the first wall ( 64 ) is executed, is demarcated from an environment and at least one physical property of one in a heating unit ( 30 ) plastic preform ( 10 ) from outside the clean room ( 6 ) arranged sensor device ( 36 ) is detected.

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