DE102008030866B4 - Blowing device, in particular for containers - Google Patents

Abstract

Blowing device for the production of bottles from preforms (44) provided with a threaded neck (46), wherein the blowing device (1) has at least one first shape (50) for shaping the outer contour of bottles to be produced of a first bottle format, determined by first bottle dimensions is, and wherein by means of the blowing device (1) by means of at least one second mold (50) for the shaping of the outer contour of bottles to produce bottles of a second, different from the first, bottle format can be produced, this second bottle format is determined by second Flaschenabmaße, characterized in that a device is provided for the automatic identification of the bottle format or the mold (50) assigned to the bottle format.

Description

The invention relates to a blower device for the production of bottles from preforms provided with a threaded neck, and to a method for the production of bottles from preforms.

In the production of bottles, especially "PET bottles" are known to use preforms, which are already provided with a threaded neck, which corresponds in terms of its contour to the threaded neck of the bottle to be created. These preforms are typically first brought to temperature in a heating section and then supplied in the heated state to a blowing device in which they are shaped into a bottle by means of a pressurized fluid, in particular by means of compressed air.

It is also known that the shaping or deformation takes place in the blowing device in three different stages: In the first stage, the preform is stretched. In a further, subsequent second stage, a pressure is applied by applying a fluid through the opening formed by the threaded neck in a cavity or in the forming cavity of the preform, which causes a deformation or bulging of the present in a mold preform , However, the contour effected in this stage does not yet correspond in contour to the bottle to be formed. In the third stage, the resulting bottle is brought to the final contour, wherein further fluid or compressed air is applied through the opening formed by the threaded neck, in such a way that the outer contour of the preform or the resulting bottle rests against the contour or inner contour of the mold ,

In blowing machines, as a rule, during the blowing process, predetermined parameter sets are used which determine or control the blowing process, and in particular the pressure profile which occurs in each case.

A particular device for controlling the flow rate and the pressure of the fluid is disclosed in US Pat US 6932102 B2 proposed. In this design, various valves and reservoir are provided in a specific arrangement.

Out JP H11-277 617 A For example, a conduit system is known which ensures that fluid is delivered to the front and back of the mold and to a different location.

From the WO 2004/098862 A2 For example, a blowing device is known in which a draw bar, in addition to a tube, has a resilient cover placed over it and partially encasing it, which is in fluid communication with the interior of the tube. After the stretching and after the preforming phase, and before high-pressure air is introduced through an inlet other than the drawbar into the interior of the resulting bottle, liquid is introduced via the drawbar into the interior of the resulting bottle, but by means of the elastic coating is retained and thus claimed volume inside the bottle, without coming into contact with the bottle walls. In order to save high-pressure air - and thus energy -, the liquid in the interior of the bottle is filled by the liquid. A check valve prevents the backflow of this liquid. Subsequently, the high pressure air is introduced through a separate inlet channel.

Continue to show as well DE 1 479 154 B a blow molding machine for producing hollow bodies made of thermoplastic material, in which a plurality of molds are arranged in a circle and the plastic material passed from a reservoir into a arranged in the vertical center axis of the blow molding machine tube and fed from here through connecting pipes of the individual molds in succession and into this by a nozzle located above the molds is squeezed out.

In the aforementioned prior art documents, however, it is not now possible to increase the flexibility of blow molding machines - at least internally known to the applicant. This is that the blow molding machines can be used not only for one, but for different bottle formats. Such, the applicant at least internally known design achieves this so that a blow molding machine from the outset has different shapes for the production of different bottles. Alternatively, it can be provided that the blowing machines are designed so that the molds are interchangeable. The molds are often held by a mold carrier. The Applicant is aware that this mold carrier may be identical for different bottle formats.

The conversion of a blow molding machine from one that can produce a bottle format to one that can produce different bottle formats, is well known by supplies well.

However, in the context of its R & D activities, the Applicant has noticed that blow molding machines which are suitable and intended for the production of different bottle formats can have disadvantages with regard to operational safety compared to those which are suitable and intended only for the production of a bottle format , The following is now a Example, in which there are such disadvantages in terms of reliability, it should be noted that this is a very specific example and problems may well arise in a wider area beyond.

Thus, it has been found in an example specifically examined machine that from a bottle volume of about 2.25 liters upwards it is necessary due to the insufficient in this particular example stability of the mold carrier, the maximum Fertigblasdruck in the software that in this Machine is present, to limit to about 33 bar. The limitation depends essentially on the volume and the shape of the bottle, so that in rare cases even with 2.0-liter bottles already a limit may be necessary, which may be even only 28 bar in part.

Are now from the same machine also z. B. 0.5-liter bottles driven, it may be that you would need more than the limited 33 bar here. For small bottles, for example, it may be necessary to use a maximum pressure of 38 bar.

In other words, limiting the pressure to a relatively low value, necessary in view of the stability of the bottle carrier, could not easily produce smaller bottles requiring a higher pressure to produce. Conversely, if the pressure is limited to the higher value, for example 38 bar in the above-mentioned example, there would be a risk that the reliability in the production of larger bottles would be impaired, which could end in damage or destruction of the mold carrier, if it is dimensioned accordingly is.

The invention is an object of the invention to provide a way for the bubbles of bottles provided with a threaded neck preforms, which enables reliable production of different bottle formats.

According to the invention, a blowing device according to claim 1 is now proposed. An inventive method is the subject of claim 7. Preferred developments are subject of the dependent claims.

The blowing device according to the invention has at least a first shape for shaping the outer contour of the bottle to be produced of a first bottle format. The first bottle format is determined by (first) bottle dimensions. Furthermore, bottles of a second bottle format can be produced by means of the blowing device, this second bottle format being different from the first bottle format. The second bottle format is also determined by Flaschenabmaße, by second Flaschenabmaße.

To give an example of such different bottle formats, it should be noted that, for example, one bottle format is designed so that the volume of the bottle associated with this bottle format is 2.5 liters, while another bottle format is designed such that the volume associated with this bottle format is 0 , 5 liters. In this case, in particular, the volume of the bottles would differ.

However, it can also be provided that differ different bottle formats only in terms of their shape, without being different in terms of their bottle volume.

The categorization of different bottle formats may in particular be such that all bottle dimensions are taken into account or so that predetermined bottle formats are taken into account. It can also be provided, for example in a rough subdivision, that only a distinction is made with regard to the volume of the bottles in terms of the bottle format.

According to the invention, a device is provided for the automatic identification of the bottle format or the shape associated with the bottle format.

The bottles, for the production of which the blowing device according to the invention or the method provided according to the invention, which will be mentioned in the following, is intended, may in particular be plastic films, preferably PET bottles.

In an advantageous embodiment, it is provided that the blowing device has at least one pressure line, said pressure line in particular for supplying a fluid through the threaded neck of the preform or the resulting bottle for applying a pressure acting on the preform or the resulting bottle for the deformation of this Preform or this resulting bottle is provided. In this case, provision is made in particular for this pressure to be applied to the preform or the resulting bottle via the walls bounding the interior space or the resulting interior space.

The blowing device is referred to herein as such, typically using gases, and less fluids than fluid for blowing become. It should be noted, however, that for the purposes of the present invention, both liquids and gases may be used for blowing. In a particularly preferred embodiment, the blowing device is such that gases, in particular air, preferably exclusively gases or exclusively air, are used for the blowing. But it can also be provided that instead of gases or air, a liquid is used. Combinations of gases and liquids can also be provided.

In a particularly preferred development, a fluid flow meter, which is preferably a gas flow meter and / or air flow meter, is provided. This fluid flow meter can be arranged in particular in the already mentioned pressure line for supplying the fluid through the threaded neck. It can be provided that the blowing device has several stations, in particular several stations for one or more bottles (multi-mold carrier) separate bottles. It can be provided that a fluid flow meter or air flow meter is provided at one of these stations or at all of these stations.

However, it can also be provided that such a fluid flow meter or air flow meter is provided at a main air connection of the blowing device, in particular at the rear of the main air connection. In a particularly preferable embodiment, it is provided that by means of the measured value of the fluid flow meter or air flow meter, the bottle format that is to be finished or is currently being produced is closed. Furthermore, provision can be made for this bottle format or the bottle format currently being installed in the machine to be closed on the basis of the measured value taking into account further characteristic values, such as, in particular, the measured finish blow pressure and the machine output, or the corresponding bottle format is automatically recognized. Thus, the fluid flow meter is preferably a component of the device for the automatic identification of the bottle formats.

For measuring the Fertigblasdrucks may be provided in a preferred embodiment, a pressure sensor. In an alternative embodiment can be provided that the Fertigblasdruck is determined in other ways, for. B. mathematically.

In a preferred embodiment, it is provided that from the quotient
Total air flow: finished blowing pressure: engine power
is closed to the bottle volume or the result of the quotient is equated with the volume of the bottle.

In a preferred embodiment, the blowing device on a control, which may be formed for example as a PLC (programmable logic controller) or as part of a PLC.

It can be provided that the aforementioned quotient is stored in the controller, in particular in the PLC. Furthermore, it can be provided that the quotient, which is stored in particular, is used to automatically limit the preset blow-down pressure given or released for the respective bottle to the top. As a result, it can be ensured, for example, that the machine or the blowing device in continuous operation with an example 3-liter bottle does not run at 38 bar and thereby break the mold carrier. It should be noted that these values with regard to the volume of the bottle and the pressure can also be designed differently, in particular depending on the specific design or dimensioning of the machine and the mold carrier.

It can be provided that, during a settling time, which can be, for example, about one minute, of the flowmeter, it may occur that the mold carrier is being subjected to too much pressure inappropriately; Without monitoring or air flow meter, however, this circumstance could drag on over a longer period of time, for example over several days, provided the mold carriers are able to withstand this at all. The pressure could also be limited for the duration of the settling time.

In an advantageous embodiment, a pressure limiting device is provided for limiting the fluid pressure acting on the preform or the resulting bottle. The pressure limiting device may be, for example, electronic type or have a data processing program or be part of a data processing program. In a preferred embodiment, it is provided that the pressure limiting device limits the pressure, in particular the finished blowing pressure, in particular automatically, as a function of the bottle format determined or detected, in particular using the fluid flow meter or air flow meter. The actual bottle format to be produced is preferably determined by means of the fluid flow meter or air flow meter or the values measured by the fluid flow meter or air flow meter and by means of the preform.

It should be noted that the blowing device has been described with respect to two different bottle formats, it being understood that it may also be provided that the blowing device is suitable or intended for three or four or five or six or more than six bottle formats. In this case, it can further be provided that the device for the automatic identification of the bottle format or the shape assigned to the bottle format can distinguish all of these bottle formats or shapes. It is provided in particular that the fluid flow meter or air flow meter is part of the device for the automatic identification of the bottle format or the shape associated with the bottle format.

In a preferred embodiment, a control device is provided, which was incidentally already mentioned. In particular, it is provided that the air pressure is controlled and / or regulated during the blowing of the bottles by means of the control device.

It can be provided that this control device has in a memory and / or arithmetic unit a control program, which can be designed as software or as hardware, by means of which the pressure or pressure curve during the blowing of the bottles is controlled and / or regulated.

Embodiments of the invention will now be explained in more detail, wherein it should be noted that the invention should by no means be limited thereto. Showing:

1 a first exemplary embodiment of a blowing device according to the invention in a partial schematic view, in particular a side view of a mold carrier or a pressure pad is shown; and

2 a second exemplary embodiment of a blowing device according to the invention in a schematic view.

At the in 1 illustrated design of a partially illustrated blowing device 1 is in particular a mold carrier 10 or a blow mold 50 represented. This is exemplary here so that here two bottle sizes - for better distinctness than 14 and 16 - are shown, with the one bottle by the dashed line 14 is limited and intended for 0.5 liter bottles, and the other bottle by the dashed line 16 is limited and intended for 3.0 liter bottles. In this design, a device, not shown, is provided for the automatic identification of the bottle format or the shape associated with the bottle format. In operation, exactly one of the two blow molds is used.

2 shows a second exemplary embodiment of the invention in a schematic view.

In particular, an air connection is shown there 30 , a pressure reducer 32 , a drive motor 34 , a blow mold 36 , a flow meter or air flow meter 38 , a control device 40 , which is exemplified here as a PLC, as well as a touch screen 42 , via which a preset blow-molding pressure set by the operator can be specified.

The control device 40 stands with the flow meter 38 and the pressure reducer 32 and the drive motor 34 in signal connection. The flow meter 38 is in the fluid or air transmission path 52 between the air connection 30 and the blow mold 36 intended. Within the fluid transmission path 52 between the flow meter 38 and the blow mold 36 is the pressure reducer 32 ,

The preform (not shown) is a threaded neck 46 provided, which corresponds to the bottle to be produced or from the outset has the final contour.

The fluid connection 52 between the flow meter 38 and the blow mold 36 is such that the fluid or air in the preform 44 via the associated opening or bottle opening 48 is supplied and thus in the inner volume or growing inner volume of the bottle or the preform 44 generates the appropriate pressure to inflate the bottle. This pressure is from the controller 40 controlled or regulated. For the shaping is the form 50 provided, which is part of the blow mold 36 is.

By means of the flow meter 38 measured values sent to the controller 40 is transmitted by the controller 40 Determines which bottle format or bottle formats are currently being produced (should). Depending on this detected bottle format the Fertigblasdruck is limited. It should be noted that in an advantageous embodiment, the bottles, in the production of a new bottle format was recognized for the first time, are supplied to the Committee.

The air flow meter 38 and the controller 40 are part of a device for automatic detection of a bottle format that is currently being manufactured.

The embodiments explained with reference to the exemplary embodiments make it possible to use the desired or required higher blow-off pressure (for example 38 bar) for small bottles, but nevertheless adequate protection is provided for larger or larger bottles.

All disclosed in the application documents features are claimed as essential to the invention, provided they are new individually or in combination over the prior art.

LIST OF REFERENCE NUMBERS

1

blower

10

mold carrier

12

blow

14

dashed line for 0.5 liter bottle

16

dashed line for 3.0 liter liter bottle

30

air connection

32

pressure reducer

34

drive motor

36

blow

38

Flowmeter

40

Control, PLC

42

Touch Screen

44

preform

46

threaded neck

48

Opening of 46

50

Form as part of 36

52

Fluid transfer line

Claims (10)

Blowing device for the production of bottles with a threaded neck ( 46 ) preforms ( 44 ), wherein the blowing device ( 1 ) at least a first form ( 50 ) for the shaping of the outer contour of bottles to be produced of a first bottle format, which is determined by first Flaschenabmaße, and wherein by means of the blowing device ( 1 ) by means of at least one second mold ( 50 ) for the shaping of the outer contour of bottles to be produced bottles of a second, different from the first bottle format, this second bottle format is determined by second Flaschenabmaße, characterized in that a means for the automatic identification of the bottle format or the bottle format associated shape ( 50 ) is provided. Device according to claim 1, characterized in that the blowing device ( 1 ) at least one pressure line ( 52 ) for supplying a fluid through the threaded neck ( 46 ) for applying one to the preform ( 44 ) acting pressure for the deformation of the preform ( 44 ) having. Device according to the preamble of claim 1 or claim 2, characterized in that a fluid flow meter ( 38 ) is provided. Device according to one of the preceding claims, characterized in that a pressure limiting device for the limitation of the preform ( 44 ) acting fluid pressure is provided. Device according to one of the preceding claims, characterized in that at least one mold carrier ( 10 ) for the inclusion of the first ( 50 ) and / or second form ( 50 ) is provided. Device according to one of the preceding claims, characterized in that a control device ( 40 ) is provided. Process for the production of preform bottles ( 44 ) in a device in which bottles of different formats can be produced, in particular in a device according to one of the preceding claims, with the steps: - mounting, in particular by means of the threaded neck ( 46 ) Screwing, one with a threaded neck ( 46 ) preform ( 44 ) in a blowing device ( 1 ), in particular in a blower device designed according to one of the preceding claims ( 1 ); Applying a pressurized fluid, in particular pressurized air, to the interior of the preform ( 44 ) by one of the threaded neck ( 46 ) of the preform ( 44 ) formed opening ( 48 ); wherein - the volume and / or the volume flow of the applied in or in the direction of the preform fluid, in particular air, in particular total air flow, determined, in particular measured, and - depending on the determined or measured value for the volume and / or the volume flow, the Bottle format of the bottle to be produced by means of the currently existing preform. A method according to claim 7, characterized in that the bottle format of the means of the currently existing preform ( 44 ) to be produced bottle depending on the total air flow rate and depending on the used in the currently used preform Fertigblasdrucks and in dependence of the engine power, in particular engine power of an engine ( 34 ) of the blowing device ( 1 ), is determined. Method according to claim 7 or claim 8, characterized in that, depending on the ascertained bottle format, the fluid pressure, in particular air pressure, or the fluid pressure profile, in particular air pressure curve, and / or the Fertigblasdruck for the next to be produced bottle or the next preform is set. A method according to claim 9, characterized in that a bottle is assigned to the committee if, depending on the determined bottle format, the fluid pressure, in particular air pressure, or the fluid pressure curve, in particular air pressure curve, and / or the Fertigblasdruck for the next bottle to be manufactured or the next preform is changed.

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