WO2019115325A1

WO2019115325A1 - Device and method for molding plastic preforms into plastic containers with a tangential discharge of the plastic containers out of the blow molding machine

Info

Publication number: WO2019115325A1
Application number: PCT/EP2018/083727
Authority: WO
Inventors: Andreas PENSE; Thomas Kitzinger; Christian Betz; Cora Hanesch; Andreas Vornehm; Dominik Meier; Dieter Finger
Original assignee: Krones Ag
Priority date: 2017-12-12
Filing date: 2018-12-06
Publication date: 2019-06-20
Also published as: DE102017129577A1

Abstract

The invention relates to a device (1) for molding plastic preforms (10) into plastic containers (20), comprising a transport device (2) that transports the plastic preforms (10) along a specified transport path (T) and comprising a blow molding machine (5) that is arranged along the transport path (T) and has at least one molding station (8), within which the plastic preforms (10) can be molded and filled simultaneously by supplying a liquid medium to the plastic containers (20), wherein the plastic containers (20) can be transported within the blow molding machine (5) on an at least partly circular transport path (6). According to the invention, the plastic containers (20) are discharged out of the blow molding machine (5) substantially tangentially to the at least partly circular transport path (6) of the blow molding machine (5), and/or the plastic containers (20) are transported out of the blow molding machine (5) on an at least partly linear transport path (7).

Description

Apparatus and method for forming plastic preforms

Plastic containers with tangential discharge of the plastic containers

from the blow molding machine

description

The present invention relates to an apparatus and a method for transforming plastic preforms to plastic containers. Such devices and methods have been known for a long time from the prior art. The plastic preforms are usually heated within a heating device to a temperature necessary for the blow molding process and then fed to the blow molding machine. In the blow molding machine, the plastic preforms are usually reshaped within a blowing station by applying a flowable medium and in particular compressed air and by stretching with a stretching rod to plastic containers and in particular plastic bottles

More recently, the plastic preforms have also been filled simultaneously during the forming, with the plastic preforms being expanded with a liquid medium and, in particular, already with the liquid filling medium. Accordingly, in order to form a container from a preform with the aid of a liquid medium, the preforms heated by an oven are transferred into the forming station or blowing station with the aid of a transfer star with a division delay. After the container has been shaped inside the blow molding machine, which is in particular a rotary, and has been filled simultaneously with the liquid medium, the ferrous Taken, but still unsealed, container again via a transfer star with pitch from the blow molding machine removed and passed on a container transport. Since the direction of rotation of the transfer star is opposite to the direction of rotation of the rotary blow molding machine, the container is subjected to a sudden change of direction when it is transferred to the transfer star. In addition, in such rotary machines, due to the high rotational speeds and output rates, very large peripheral speeds occur. These high peripheral speeds and abrupt changes of direction result in the not yet closed containers, which often have very small headspace volumes, in the removal of the finished molded and filled container, due to the forces acting on the containers centrifugal forces to a very high Überschwappgefahr. In particular, an undefinable amount of the medium escapes from the container, as a result of which the predetermined fill level in the containers can not be reached and the containers consequently have to be sorted out as scrap. In addition, the spilled over liquid could get into the blow mold or the blow molding machine, whereby they are contaminated and must be stopped due to a cleaning. In addition, this over-spun liquid in the blow mold could also damage and even tear the next plastic preform during the forming process.

Furthermore, removal at high circumferential speeds and abrupt changes of direction entail the risk of damage to the container in the wall and neck region due to kinking. With large-volume containers such as gallons there is also the risk that the bottleneck breaks because of the high weight of the container.

The present invention is therefore based on the object to provide a device and a method, with / in the case of the discharge of the finished molded and filled containers from the blow molding machine, a spillover of the liquid from the container or damage to the Container can be prevented. These objects are achieved according to the invention by the subject matters of the independent claims. Advantageous embodiments and further developments are the subject of the dependent claims. The present invention is directed to a device for converting plastic preforms into plastic containers with a transport device which transports the plastic preforms along a predetermined transport path and with a blow molding machine which is arranged along the transport path and which has at least one forming station in which the plastic preforms can be deformed and simultaneously filled by applying a liquid medium to the plastic containers, wherein the plastic containers can be transported within the blow molding machine on an at least partially circular transport path. According to the invention, the plastic containers are discharged from the blow molding machine substantially tangentially to the at least partially circular transport path of the blow molding machine and / or the plastic containers are removed from the blow molding machine on an at least partially linear transport path. The term "at least partially linear" is understood to mean that the plastic containers are guided on a linear transport path in comparison with the circular transport path of the blow molding machine, and it could also be that the containers only run out of the blow molding machine tangentially to the circulation of the blow molding machine and then guided on a large radius of curvature. However, the plastic containers are particularly preferably discharged tangentially from the blow molding machine and transported away on a linear transport path.

It is therefore proposed according to the invention that the discharge of the finished molded and filled container tangentially to the circulation of the blower "slosh optimized" over a defined curve or on a different plane than the inlet takes place to the direction of delivery, compared to the transport direction within the blow molding machine, not abruptly change. The defined curve is typically a so-called clothoid, i. h a continuous transition of the radius from R = R _ßiasrad to R = 0 (straight line). This is to prevent the medium from spilling over in the container, so that a defined filling level can be produced reproducibly in the finished product. In a preferred embodiment, therefore, the transition from the circular transport _{path of} the blow molding _machine , ie of R _ßiasrad , on the linear transport path is a Klothoidische path. The blow molding machine is particularly preferably a rotary machine, within which the plastic preforms are guided on a circular transport path. In the case of the device according to the invention, therefore, a tangential discharge / discharge of the completely filled and formed containers takes place from a rotary machine or a straight-line transport path of the containers after a rotary machine.

The device according to the invention and also the method according to the invention therefore have the particular advantages that, when the molded and filled containers are removed from the blow molding machine, spilling and buckling of the containers is prevented, so that in particular a defined and predetermined filling level in the condition can be achieved. In addition, this also a, compared to the prior art, gentler handling of the container is provided, this "gentler" removal also favors the prevention of kinking, so-called "Bückling effect", or damage the wall and the neck area of the containers favors.

The discharge from the blow molding machine can preferably also be effected by the transfer to a long stator, a transport star a conveyor chain or the like.

Preferably, the device for forming plastic preforms into plastic containers also has a heating device which heats plastic preforms to a predetermined temperature and in particular to a temperature required for the subsequent forming process. The heating means is preferably an oven known in the art having a plurality of heating elements, such as microwave heating means. The heating device is preferably arranged upstream of the blow molding machine.

The device for forming plastic preforms into plastic containers is preferably a blow molding machine. This means that the plastic preforms are firstly thermally conditioned in a heating section and then expanded by exposure to a liquid or gaseous medium. The flowable medium is preferably under pressure. For the supply of the pressurized medium, the device has a blowing nozzle, which can be applied sealingly to an opening of the plastic preforms in order to expand the plastic preforms with a liquid or gaseous medium. In addition, a valve arrangement is also preferred provided, which controls the supply of the medium to the plastic preforms. The device for converting plastic preforms into plastic containers is particularly preferably a form filling machine in which preferably the expansion of the container takes place by means of the product, so that a simultaneous filling and expansion of the container is carried out.

The blow molding machine or the form filling machine is preferably a stretch blow molding machine, which means that the preforms are stretched in the longitudinal direction before and / or during the expansion by means of a stretching rod. In this case, the blowing stations each have stretching rods which can be inserted into the plastic preforms and stretch the plastic preforms in their longitudinal direction. The stretch rods preferably have an electric drive. However, it is also possible to control the stretching bars via curves. In an advantageous embodiment, a plurality of blowing stations or reforming stations is arranged on a common movable carrier. This carrier is in particular a rotatable carrier. The blowing stations each have a blow molding device, which preferably form a cavity, within which the plastic preforms are expandable to the plastic containers. These blow molding devices are preferably designed in several parts and have two blow mold halves and a bottom mold. Preferably, these blow mold halves are detachably arranged on a mold carrier shell or on the blow mold carriers. The blow mold carriers are pivotable relative to one another in order to open and close the blow molding devices. In addition, the blow mold carrier on locking mechanisms to lock the mold halves against each other during the blowing process.

Particularly preferably, the blow molding machine or the carrier and the blow mold arrangements are arranged within a clean room which delimits the blow molding machine from an unsterile environment. Drive devices for the closure, locking and / or opening of the blow molds are preferably arranged outside the clean room.

The blow molding devices are preferably transported within the clean room. The clean room is preferably limited by several walls. Preference is given to the clean room thereby limited by at least one standing wall and a standing against this wall moving wall. The cleanroom delimits the blow molds, in particular, from an unsterile environment. Advantageously, the clean room is designed like a ring or torus around the blow molding stations or forming stations and / or the transport path of the plastic containers.

In a preferred embodiment, on the at least partially linear and in particular tangential transport path of the plastic containers, a capper is arranged, which applies a closure to the plastic containers. Accordingly, after the removal of the already formed and filled plastic container from the blow molding machine and the tangential discharge, the container is preferably closed, this preferably taking place during the linear movement or the linear transport of the plastic containers. Preferably, the container is therefore closed during this linear guide and then forwarded to subsequent machines. Before closing, in particular, it is not necessary to cool the container, so that the closing can be directly followed by the mold filling process. The fact that the container before passing on to subsequent transport devices or container treatment plants, which are in particular again designed as a transport stars or rotary, is also closed, the risk of spillover of the liquid is further reduced. These downstream of the capper machines are preferably a packaging machine, a Behälterinspektionsma- machine or the like.

In a further preferred embodiment, the capper can be moved along with the plastic containers during the transport of the plastic containers. The plastic containers are therefore advantageously closed during transport. The closure is particularly preferably a screw cap or a snap closure (snap-on). The screw cap has a thread, which can be screwed onto the mouth region of the container.

In a preferred embodiment, the transport means is selected from a group of transport means which includes transfer stars, pitch warp stars, conveyor belts, air transporters, chains, belts, long stators and the like. In a preferred embodiment, the device has at least one holding device, which holds the plastic containers at a neck area at least during the forming and closing process. This holding device is preferably a clamp which encloses the plastic containers in their neck area. However, a holding device with actively or passively controlled gripping devices would also be conceivable here. A neck region is understood to mean an area below the support ring of the plastic container or directly on the support ring. Such holding of the plastic containers is also referred to as neck-handling. Particularly preferably, the device has a plurality of such holding devices, wherein the holding devices are preferably moved with the containers.

In a further preferred embodiment, the at least one retaining device can be guided circumferentially between the blow molding machine and a deflection wheel. This means that the holding devices are guided in a closed circuit within the device for forming plastic preforms into plastic containers. Advantageously, therefore, the plastic preform and the holding device are supplied together to the blow molding machine and the plastic container and the holding device are also removed together again from the blow molding machine. Particularly preferably, the holding device removes the plastic preform from the heating device and moves together with the preform to the blow molding machine and is then guided along with the finished molded and filled container along the linear transport path and the capper. At the deflecting wheel, the holding device advantageously transfers the containers to a diverting device or removal device or to a downstream machine, such as a packaging machine or an inspection system, and then removes a new plastic preform from the heating device.

The container is therefore preferably kept in a holding device during the entire pass, from the exit of the oven until it is closed. In the areas between the rotary machine or the blow molding machine and the deflection wheel, the holding devices are preferably guided on a kind of long stator. Instead of a long stator, a chain guide (Caterpillar) would also be conceivable here. Preferably, however, the holding device could also be transferred together with the plastic container to the subsequent system, wherein the holding devices could then be fed again via a feed device of the device. Advantageously, at least the forming and the closing process take place within a clean room, so that preferably at least the blow molding machine and the capper are arranged within a clean room. Particularly preferably, the transport path of the holding devices also runs within a clean room. The present invention is also directed to a method for converting plastic preforms to plastic containers, comprising a transport device which transports the plastic preforms along a predetermined transport path and with a blow molding machine which is arranged along the transport path and which has at least one forming station in which the plastic preforms are formed by applying a liquid medium to the plastic containers and filled at the same time, wherein the plastic containers are transported within the blow molding machine on an at least partially circular transport path.

According to the invention, the plastic containers are discharged from the blow molding machine essentially tangentially to the at least partially circular transport path of the blow molding machine and / or the plastic containers are removed on an at least partially linear transport path.

Therefore, it is also proposed on the method side to make the discharge of the finished molded and filled container tangential to the circulation and in particular to the circular transport path of the blow molding machine and to subsequently guide the containers on a linear transport path in order to prevent them from spilling over in the unclosed container contained liquid or damage to the container to avoid. In a preferred method, the plastic containers are also closed on the at least partially linear transport path. Advantageously, the containers are thereby closed during the transport of the containers, so that the capper moves along the linear transport path with the plastic containers and in particular is moved with them. In a further preferred method, the plastic containers are held at a neck area at least during the forming and closing operation. Preferably, a holding device removes the plastic preforms from a heating device, which heats the preforms to a predetermined temperature. In particular, the container is held by this holding device during the entire passage, from the outlet of the heating device to the closure, wherein the holding device transfers the containers on a deflection wheel to a subsequent machine, such as an inspection system or a packaging machine. Further advantages and embodiments will be apparent from the attached drawings:

Show:

1 shows a first embodiment of a device according to the invention for reshaping of plastic preforms into plastic containers;

2 shows a second embodiment of a device according to the invention for reshaping plastic preforms into plastic containers. FIG. 1 shows a first embodiment of a device 1 according to the invention for reshaping plastic preforms 10 into plastic containers 20. The plastic preforms 10 are heated to a predetermined temperature within a heating device 3, which has a plurality of heating elements, and subsequently Passing means of a transport device 2 to a blow molding machine 5. The blow molding machine 5 has at least one and preferably a plurality of transformation stations 8. Within the blow molding machine 5 or within the forming stations 8, the plastic preforms 10 are formed into plastic containers 20 and also filled at the same time, these being guided during the forming and filling along a circular transport path 6.

As shown in FIG. 1, the plastic containers 20 are removed from the blow molding machine 5 tangentially to the circular transport path 6 of the blow molding machine 5, in order to prevent spilling over of the liquid arranged in the container. the. In particular, the subsequent further transport of the containers takes place on a linear transport path 7. The reference numeral 25 denotes a closure, which is preferably also applied to the containers 20 during the linear transport of the containers along the transport path 7.

FIG. 2 shows a second embodiment of a device 1 according to the invention for reshaping plastic preforms 10 into plastic containers 20, wherein the plastic preforms 10 are here heated again within a heating device 3 to a temperature required for the blow molding. Subsequently, the plastic preforms 10 are transported on a predetermined transport path T to the blow molding machine 5, wherein the plastic preforms 10 are held by a holding device 30 during transport and also during the subsequent blow molding and closing operation. At a deflection wheel 8, the plastic preforms 10 are transferred from the holding device 30 to a subsequent machine (not shown here). The holding devices 30 themselves reach via the deflection wheel 8 again to the heating device 3 and take here again a plastic preform 10.

It can be seen in particular from FIG. 2 that the holding devices 30 are guided between the blow molding machine 5 and the deflecting wheel 8 on a circulating transport path, which is constructed in particular in the manner of a long stator 32. As already shown in FIG. 1, a closure 25 is also applied to the containers during the linear transport of the containers 20. The closure 25 shown in FIGS. 1 and 2 is a screw or rotary closure, although it would also be conceivable for other types of closure to be applied to the containers 20 at this point.

The Applicant reserves the right to claim all features disclosed in the application documents as essential to the invention insofar as they are novel individually or in combination with respect to the prior art. It is further pointed out that features have also been described in the individual figures, which in themselves can be advantageous. The person skilled in the art immediately recognizes that a specific feature described in a figure can also be obtained without taking over further features from this figure. can be liable. Furthermore, the person skilled in the art recognizes that advantages can also result from a combination of several features shown in individual or in different figures.

LIST OF REFERENCE NUMBERS

1 device

2 transport equipment

3 heating device

4 heating element

5 blow molding machine

6 circular transport path

7 linear transport path

8 transformation station

10 plastic preform

20 plastic container

25 closure

30 holding device

32 Langstator

T transport path

Claims

Apparatus and method for forming plastic preforms to plastic containers with tangential discharge of plastic containers from the blow molding machine claims

1. Device (1) for forming plastic preforms (10) into plastic containers (20) with a transport device (2) which transports the plastic preforms (10) along a predetermined transport path (T) and with a blow molding machine (5). which is arranged along the transport path (T) and which has at least one forming station (8), within which the plastic preforms (10) can be deformed and simultaneously filled by applying a liquid medium to the plastic containers (20), wherein the plastic containers (20) can be transported within the blow molding machine (5) on an at least partially circular transport path (6),

characterized in that

the plastic containers (20) are removed from the blow molding machine (5) substantially tangentially to the at least partially circular transport path (6) of the blow molding machine (5) and / or the plastic containers (20) are removed from the blow molding machine (5) takes place on an at least partially linear transport path (7).

2. Device (1) according to claim 1,

characterized in that

on the at least partially linear transport path (7) of Kunststoffbehält- nisse (20) a closer is arranged, which applies a closure (25) on the plastic containers (20).

3. Device (1) according to claim 2,

characterized in that

the capper during movement of the plastic containers (20) with the plastic containers (20) is mitbewegbar.

4. Device (1) according to at least one of the preceding claims,

characterized in that

the closure (25) is a screw cap or a snap closure.

5. Device (1) according to at least one of the preceding claims,

characterized in that

the transport device (2) is selected from a group of transport devices which includes transfer stars, split delay stars, conveyor belts, air transporters, chains, belts, long stators and the like.

6. Device (1) according to at least one of the preceding claims,

characterized in that

the transition from the circular transport _path (6) of the blow molding _machine (5), ie of R _ßiasrad , on the linear transport path (7) is a Klothoidische path.

7. Device (1) according to at least one of the preceding claims,

characterized in that

the device (1) has at least one holding device (30) which holds the plastic containers (10, 20) at a neck area at least during the forming and closing operation.

8. Device (1) according to claim 6,

characterized in that

the at least one retaining device (30) revolving between the blow molding machine (2) and a deflecting wheel (8) can be guided.

9. A method for forming plastic preforms (10) to plastic containers (20), wherein the plastic preforms (10) along a predetermined transport path (T) to a blow molding machine (5) are transported and with a blow molding machine (), which along of the transport path (T) is arranged and which we least one Umformungsstation (8), within which the Kunststoffvorform- Lingen (10) are transformed by applying a liquid medium to the Kunststoffbe- (20) and simultaneously filled, the Kunststoffbehält- nes (20) within the blow molding machine (5) on an at least partially circular transport path (6) are transported

characterized in that

the plastic containers (20) are removed from the blow molding machine (5) substantially tangentially to the at least partially circular transport path (6) of the blow molding machine (5) and / or the plastic containers (20) are removed on at least one of them sectionally linear transport path (7).

10. The method according to claim 8,

characterized in that

the plastic containers (20) are closed on the at least partially linear transport path (7).

1 1. A method according to at least one of the preceding claims,

characterized in that

the plastic containers (10, 20) are held at a neck area at least during the forming and closing process.