WO2014154310A1

WO2014154310A1 - Method and device for producing filled containers

Info

Publication number: WO2014154310A1
Application number: PCT/EP2014/000077
Authority: WO
Inventors: Christian Rommel; Arne Wiese
Original assignee: Khs Corpoplast Gmbh
Priority date: 2013-03-29
Filing date: 2014-01-15
Publication date: 2014-10-02
Also published as: DE102013007411A1

Abstract

The present invention relates to a method and a device for producing filled containers, in which method a preform made from a thermoplastic material is shaped into the container, after thermal conditioning along a transport path, in the region of a heating section within a mould by way of the action of pressure by means of a fluid, is filled with a filling medium and is closed with a closure element, and is characterized in that the container volume is reduced after the closure of the container (10), by heat being introduced into the container wall (11) and/or into a label (20) which is attached to the container wall (11) and shrinkage therefore being carried out locally.

Description

Method and device for producing filled containers

Description:

The invention relates to a method for producing filled containers, in which a preform made of a thermoplastic material after thermal conditioning along a transport path in the region of a tempering within a mold by pressure by means of a fluid is transformed into the container, filled with a filling medium and with a closure element is closed.

Furthermore, the invention relates to an apparatus for filling a container made of a thermoplastic material, in particular for carrying out the method according to the invention, the at least one arranged along a transport path of a preform tempering with at least one tempering device, a handling device for the preform for transport through the tempering, one with a blowing station provided with blowing station, and having a filling station either integrated in the blowing station or subsequently provided, the filling station having a device for pressure-tight sealing of the container or the device for pressure-tight sealing of the container after the filling station is provided.

In case of container molding by blowing pressure, preforms are made of a thermoplastic material, for example preforms of PET

CONFIRMATION COPY (Polyethylene terephthalate), supplied to different processing stations within a blow molding machine. Typically, such a blow molding machine has a heating device and a blowing device, in the region of which the previously tempered preform is expanded by biaxial orientation to form a container. The expansion takes place with the aid of compressed air, which is introduced into the preform to be expanded. The procedural sequence in such an expansion of the preform is explained in DE-OS 43 40 291. The introductory mentioned introduction of the pressurized gas also includes the introduction of compressed gas into the developing container bubble and the introduction of compressed gas into the preform at the beginning of the blowing process.

The basic structure of a blowing station for container molding is described in DE-OS 42 12 583. Possibilities for temperature control of the preforms are described in DE-OS 23 52 926.

According to a typical processing method, the blow-molded containers produced as described above are fed to a subsequent filling device and filled here with the intended product. As a rule, a separate blowing machine and a separate filling machine are thus used. It is also already known to directly couple a separate blowing machine and a separate filling machine and to provide a so-called blocked blow-filling device.

Moreover, it is already known to make the shaping of the container by the filling material to be filled. A correspondingly tempered preform is used for this purpose in a suitable form and then the liquid filling medium is introduced into the preform and the resulting from this preform container bubble. The container bladder is in this case expanded until a complete contact with the inner contour of the mold is achieved and the container is filled. Such a process is also referred to as a hydraulic molding process.

In addition, it is known that certain contents, such as fruit juices or ice tea, are filled into the thin-walled containers in a so-called "hot-fill" process For this purpose, the contents are strongly heated in order to prevent any germs present in the contents before they are filled After heating, the hot product is filled into containers and then immediately closed to prevent germination by germs during cooling. A disadvantage of this known method is that the volume of the filling material during cooling is reduced (so-called volume shrinkage). Since the container is closed, it creates a negative pressure, which causes the thin-walled container to deform inwards. To avoid this, in the hot-fill method, for example, in the prior art, a drop of liquid nitrogen is added to the container via a nitrogen dew point before it is closed. The evaporating droplet leads to a nitrogen gas quantity with a larger than the drop volume and thus generates an overpressure which compensates for the negative pressure created by the cooling product.

The disadvantage of this known method is that the pressure generated by the nitrogen is difficult to regulate. As a rule, the nitrogen drop is therefore oversized to ensure that the negative pressure is compensated by volume shrinkage due to the overpressure. Owing to the oversizing of the nitrogen droplet, an overpressure is created in the container. This has the consequence that the walls of the container must be made larger, so that the container reliably withstands the additional load due to the overpressure. Correspondingly, more material has to be used for the container walls than without overpressure in the container, as a result of which the material weight to be used and the associated material costs rise.

A change in the internal pressure to the negative pressure also arises when there are temperature differences between filling and subsequent storage, as this also causes a change in volume. Furthermore, this also occurs through a diffusion of gases or product components out of the container, or by chemical reactions in the product itself. This also allows the product volume within the container to decrease and the internal pressure to drop. These deformations by existing in the interior of the container negative pressure is also met with an increase in the wall thickness of the container. This is disadvantageous because it is desired to reduce the packaging material used. One way of reducing is to make the wall of the container with a smaller wall thickness. This leads to a weakening of the container and thus to a deformation of the container when a negative pressure arises in the container. As a further disadvantage, the reduction of the wall thickness leads to the reduction of the possible ballast, which a container can carry. The problem of reducing the load is met by either expensive additional outer packaging is necessary or by stabilizing the container by increasing the internal pressure as described above with liquid nitrogen. A slightly higher internal pressure leads to significant stabilization of the bottle.

Disadvantages with regard to the use of liquid nitrogen are the associated costs.

The object of the present invention is to provide a process improved in this respect for producing filled containers and an improved apparatus for producing filled containers. This object is achieved with respect to the method in that the container volume is reduced after closing the container by heat is introduced into the container wall and / or in a mounted on the container wall label. As a result, the volume of the container is reduced in a simple manner by shrinkage, preferably locally, and thereby an internal pressure is built up, which stabilizes the container and / or counteracts a possible pressure drop within the container.

Another teaching of the invention provides that the temperature control section is a heating section.

Another teaching of the invention provides that the heat is introduced by radiation, convection heat and / or heat transfer by contact of the heat source with the surface of the container and / or the label. It is advantageous that the radiation is infrared, near-infrared, ultraviolet and / or microwave radiation. This makes it possible to supply a corresponding amount of energy for shrinking the wall of the container within a short time.

A further teaching of the invention provides that the heat is introduced locally, preferably uniformly over the circumference of the container and / or the label. This ensures that the shrinkage is correspondingly uniform.

Another teaching of the invention provides that the heat is introduced in the region of the side wall of the container. As a result, the head and bottom of the container and closure area are kept stable.

A further teaching of the invention provides that the heat is introduced in strongly drained areas of the container. Here is a possible advantageous embodiment that it the stiffened areas are stiffening ribs, preferably horizontal, vertical, and / or curved.

A further teaching of the invention provides that during the volume reduction, the pressure in the container is measured without contact, preferably optically. This makes it possible to determine the optimum shrinkage point. Furthermore, the container or its minimum or optimally necessary wall thickness can be determined in accordance with the internal pressure, since over-dimensioning of the wall thickness of the container can be avoided by the pressure monitoring.

A further teaching of the invention provides that the fluid is a gas, preferably air, and / or a liquid, preferably the filling medium.

Another teaching of the invention provides that the heat input is made until the wall reaches a temperature of at least 60 ° C, preferably at least 65 ° C. As a result, the contents are not affected, but quickly introduced the necessary amount of heat for the deformation.

This object is achieved with respect to the device according to the invention in that after the device for pressure-tight sealing of the container, a shrinking station is provided, with which the pressure in the container is increased.

A further teaching of the invention provides that the temperature control section is a heating section and the temperature control device is a heating device.

Another teaching of the invention provides that the shrinking station has a device for introducing heat into the container.

A further teaching of the invention provides that the shrinking station has a device for non-contact pressure measurement in the container, preferably for optical pressure measurement.

In the drawings, embodiments of the invention are shown schematically. Show it:

1 is a side view of a first container according to the invention, 2 is a side view of a second container according to the invention,

3 is a schematic representation of a container according to the invention in a first schematic embodiment of a shrinking station according to the invention,

4 shows a schematic representation of a container according to the invention in a second schematic embodiment of a shrinking station according to the invention,

Fig. 5 is a schematic representation of a container according to the invention in a third schematic embodiment of a shrinking station according to the invention, and

Fig. 6 is an arrangement diagram of an embodiment of a device according to the invention.

1 shows a side view of a first container 10 according to the invention. The container 10 has a bottle body 11 which is subdivided into a head region 15, a side wall 13 and a bottom 14. In the head region 15, an opening 12 is provided with thread 19 for attaching a closure 21. An arrow 16 shows the largest extent of the container, the so-called bumper. The side wall 13 has horizontal stiffening ribs 17 and vertical stiffening ribs 18. Furthermore, the side wall 13 has a region 25 to which a label 20 is applied.

After filling the container 10 with a product 22, the opening 12 is closed pressure-tight with a closure 21. In this case, a level 23 is present, which represents the boundary of the filling material 22 from an above dead space, the so-called headspace 24.

Subsequent to the filling and closing, the label 20 is placed on the label area 25. This is shown in Fig. 2. The container according to FIG. 2 differs from that shown in FIG. 1 in that the vertical stiffening ribs 18 are not provided. However, the label can also be applied to such stiffening ribs 18.

In Fig. 3 to 5 different variants of the shrinkage of the container 10 are shown. The shrinkage takes place so that the contour of the container 10 remains substantially unchanged. In each case, a differently designed heat emitter 30 is provided, which is composed of an emitter element 35 or of a plurality of emitter elements 35 and connecting elements 36. The heat emitter 30 is in each case arranged in the region of the shrinkage region 31 of the container 10. By the term heat emitter is meant both a radiation source for example for microwaves, UV, IR and NIR radiation as from a heating element or a hot air source or the like.

Provided in each case is a pressure sensor 32, with which the optically acting in the container 10 pressure is measured. Other types of pressure measurement are possible. Additionally or alternatively, it is also possible to control the fill level 23 or the increase 33 of the fill level.

The heat emitter element 30 in FIG. 3 is annular. The container 10 is used either from above / below or the emitter element 30 is at least made in two parts and closes around the container 10. In Fig. 3 shows the variant of the inventive method in which the shrinkage of the container 10 is not or not exclusively is done by a deformation of the container itself, but by shrinking the label 20 takes place. The heat is introduced from the emitter 30 into the label 20 until it begins to shrink due to the thermal stress and thereby compresses the wall of the container 10 and thus reduces the volume of the container 10, so that an increase in pressure takes place in the interior of the container 10. This causes a level increase 33 and a reduction of the headspace 24th

4, a punctiform heat emitter 30 is shown. The heat emitter 30 delivers the energy necessary for the shrinkage to the bottle body 11. It is divided into emitter elements 35 and connecting elements 36. Here is also the possibility that the heat emitter is elongated and the container is moved past this. In order to allow uniform heating, it is necessary to rotate the container, as shown by the direction of rotation 34 in Fig. 4. The heat emitter 30 can also be provided on both sides, for example along a transport path (not shown). In Fig. 5, a bottle body 11 contacting heat emitter 30 is shown. This is designed to be annular surface. Other versions for example for Point contact in the case of a flap along a stiffening rib 17, 18 and thereby as an elongate element or as a doctor blade or the like are also possible.

FIG. 6 shows a possible embodiment of a device 100 according to the invention as a flowchart. This is composed of a arranged along a transport path of a preform heating section 101 with at least one heater 102, a handling device 103 for the preform for transport through the heating section 101, provided with a blow mold 105 blowing station 104, and one in Fig. 6 separately from blow station 104 has a separate filling station 106, which is provided with a closure station 107. Subsequent to the closure station 107, a shrinking station 108 is provided, which can be designed as described above. After the shrinking station, a decorating station is provided for labeling. The shrinking station 108 and the labeling station 109 can also be provided in the reverse order, for example if the shrinkage takes place at least partially over the label.

*****

LIST OF REFERENCE NUMBERS

Container 103 Handling device Bottle body 104 Blowing station

Opening 105 Blow mold

Sidewall 106 filling station

Bottom 107 Closing station Head section 108 Shrinking station

Bumper 109 decorating station

stiffening rib

thread

label

shutter

filling

level

headspace

Labeling area heat emitter

shrinking range

pressure sensor

level increase

direction of rotation

emitting element

Connecting element device

heating section

heater

Claims

claims:

1 . Method for producing filled containers, in which a preform made of a thermoplastic material is thermoformed after a thermal conditioning along a transport path in the region of a tempering within a mold by pressure by means of a fluid in the container, filled with a filling medium and sealed with a closure element , characterized in that the container volume after closing the container (10) is reduced by heat in the container (1 1) and / or in a on the container wall (11) attached label (20) is introduced.

2. The method according to claim 1, characterized in that it is a heating section in the tempering.

3. The method according to claim 1 or 2, characterized in that heat is introduced by radiation, convection heat and / or heat transfer by touching the heat source (30) with the surface of the container (10) and / or the label (20).

4. The method according to any one of claims 1 to 3, characterized in that the heat locally, preferably over the circumference of the container (10) and / or the label (20) evenly introduced.

5. The method according to any one of claims 1 to 4, characterized in that the heat in the region of the side wall (13) of the container (10) is introduced.

6. The method according to any one of claims 1 to 5, characterized in that the heat in strongly degenerated areas (17, 18) of the container (10) is introduced.

7. The method according to any one of claims 1 to 6, characterized in that during the volume reduction of the pressure in the container (10) without contact, preferably optically, is measured.

8. The method according to any one of claims 1 to 7, characterized in that it is the fluid is a gas, preferably air, and / or a liquid, preferably the filling medium (22).

9. The method according to any one of claims 1 to 8, characterized in that the

Heat input is made until the wall reaches a temperature of at least 60 ° C, preferably at least 65 ° C.

10. The method according to any one of claims 3 to 9, characterized in that it is the radiation to infrared, Nahinfrarot-, ultraviolet and / or microwave radiation.

11. An apparatus for filling a container made of a thermoplastic material, in particular for carrying out the method according to one of claims 1 to 10, the at least one arranged along a transport path of a preform tempering with at least one tempering device, a handling device for the preform for transport through the tempering a blowing station provided with a blow mold, and having a filling station either integrated in the blowing station or subsequently provided, the filling station having a device for pressure-tight sealing of the container or the device for pressure-tight sealing of the container after the filling station, characterized in that according to the device for pressure-tight sealing the container a shrinking station (108) is provided, with which the pressure in the container is increased.

12. The device according to claim 11, characterized in that it is a heating device in the temperature control and a heating device in the tempering.

13. The apparatus according to claim 11 or 12, characterized in that the

Shrinking station (108) has a device for introducing heat into the container.

14. Device according to one of claims 11 to 13, characterized in that the shrinking station (108) comprises a device for non-contact pressure measurement in the container (10), preferably for optical pressure measurement.

*****