DE102018126084A1 - Device for reshaping plastic preforms with changing blow molds - Google Patents

Abstract

Arrangement for producing plastic containers and in particular plastic bottles with a device (1) for shaping plastic preforms into plastic containers (20), the device (1) having a movable support on which a plurality of shaping stations (2) for shaping plastic preforms (10 ) is arranged to plastic containers (20) and these forming stations (2) each have blow mold carrier parts (22, 24) to which blow mold parts (32, 34) can be attached at least indirectly, these blow mold parts (32, 34) being interchangeable. According to the invention, the arrangement has a temperature control device (62) which enables the temperature control of blow mold support parts which are separate from the blow mold support parts (22, 24).

Description

The present invention relates to a device and a method for shaping plastic preforms into plastic containers, and in particular to a retrofitting operation of such devices. Devices for shaping plastic preforms into plastic containers have long been known from the prior art. Plastic preforms are usually first heated and then in a heated state using molds, for example blow molds, to blow or reshape them into plastic containers, in particular plastic bottles.

It is basically known here that the plastic preforms are formed by means of blown air. Recently, devices and methods are also known in which the plastic preforms are formed directly with a product to be filled. This means that the plastic preforms are expanded directly by the pressure of the liquid. The present invention relates to both approaches mentioned here.

In the prior art, it is often necessary to exchange the blow molds or the blow mold parts. This is necessary, for example, if the manufacturer wants to switch to different container formats. In this case, the blow molded parts are removed from their carriers and replaced by other blow molded parts. For this purpose, changing devices, such as changing robots, are also known from the prior art, which carry out such processes semi-automatically or fully automatically. For example, the EP 2 370 368 B1 a method for producing a hollow blow product by means of a forming machine. This machine includes a moving robot. Also the EP 2 852 486 B1 describes a system for manufacturing containers, wherein thermal conditioning of blow molded parts is provided.

Certain manufacturing processes, such as heatset processes, require the blow molds to be heated. The above-mentioned procedures for heating blow molded parts are known from the prior art. It is known, for example, to heat the blow mold parts electrically, or by means of a temperature control medium, such as water or oil under pressure, which is passed through channels in the blow molds. However, this warming up in the work operation poses problems for the changing process.

On the one hand, it is not easily possible to change the still hot blow molds. For this reason, it is known to let the blow molds cool before changing. On the other hand, the blow molds have to be brought back to an operating temperature after a retrofitting process before work can begin. This leads to time losses and thus to higher production downtimes.

Despite the cooling of the blow molds, mold changes take a relatively long time, since a worker cannot change the hot molds safely. A method or device is therefore required which accelerates the change of shape. It is true that changing devices and in particular robots are already known in the prior art, which are able to change the shapes. However, the newly used formulas must first be brought to an operating temperature so that production can be started.

Accordingly, the time it takes for a machine to change shape and be operational again depends on both the time it takes to change the shape and the time it takes to deal with the large temperature difference between the initial temperature of the stored shape and to overcome the temperature of the operating state. For these reasons, it is an object of the invention to accelerate the mold changing process and to reach the operating temperature more quickly, so that the machine comes to a standstill as short as possible.

This object is achieved by the subject matter of the independent claims. Advantageous embodiments and further developments are the subject of the dependent claims.

An arrangement according to the invention for producing plastic containers and in particular plastic bottles has a device for forming plastic preforms into plastic containers, the device having a movable support on which a large number of forming stations for forming plastic preforms into plastic containers is arranged, and these forming stations each have blow molding support parts , to which blow molded parts can be attached at least indirectly, these blow molded parts being interchangeable. According to the invention, the arrangement has a temperature control device which enables a temperature control of blow mold parts separated from the blow mold carrier parts.

It is therefore proposed in the context of the invention that heating of the blow molded parts not only in an assembled state on the Machine is made, but the blow molded parts are already heated in advance, especially in a disassembled state of the machine. Then it is possible to arrange the heated blow mold parts on the machine in order to save time for the heating for the blow molds.

In particular, these are interchangeable blow molded parts. For example, it is possible for containers to be manufactured first in a work shop with a specific set of molds. If the retrofitting is necessary, these blow molded parts are dismantled and, at the same time, new blow molds are already installed in a heated state. In this case, work can continue relatively quickly.

The movable carrier is particularly preferably a rotatable carrier and in particular a blowing wheel on which these forming stations are arranged. In addition to the blow mold carriers, the individual shaping stations advantageously also have blow mold carrier shells which hold the blow mold parts. However, it would also be possible for the blow mold parts to be arranged directly on the blow mold carriers.

In a further advantageous embodiment, the forming stations have further elements which serve to expand the plastic preforms. This can be, for example, stretching bars which are each inserted into the interior of the plastic preform to be expanded in order to stretch it in the longitudinal direction thereof. In addition, the forming stations can also have so-called blowing nozzles which are placed on the mouth of the preforms in the work operation in order to pressurize them with a gaseous medium or also with a liquid product, so that the plastic preforms are expanded.

These elements, such as, for example, the blowing nozzles or the stretching rods, can preferably also be replaced in the course of a shaping process. This change can also take place automatically.

The above object is thus achieved by a device and a method for producing containers, which is capable of exchanging hot molds. As mentioned above, a new mold may have been tempered in the temperature control device or by means of a temperature control device which is located inside or outside or in an intermediate region of the container production device. As shown in more detail below, this temperature control device could, for example, be integrated in a magazine, which serves as a bearing for the new and also the replaced blow molded parts.

In other words, the arrangement preferably has a magazine device for storing the blow molded parts. This could be, for example, a magazine that can accommodate a large number of blow molded parts. In this case, holding devices could be provided within the magazine device, which hold the individual blow molded parts. It would be possible for the blow mold parts to be stored individually, for example right side parts, left side parts or bottom parts of the blow molds. However, it would also be possible for the blow molds to be stored in the magazine device in an (at least partially assembled) state.

In a further advantageous embodiment, this magazine device has a housing. In particular, a housing with walls is provided, which at least partially, preferably completely, surrounds and / or closes a receiving space for the blow molds.

In a further advantageous embodiment, the housing is an insulated housing, so that an elevated temperature can be maintained within the housing if necessary. The magazine device and / or the device can particularly preferably be opened and in particular opened automatically, for example by a robot device.

In a further advantageous embodiment, the magazine device has a movement device for moving the blow molded parts. Certain blow molded parts can thus be moved into the effective range of a changing device and then replaced by the changing device, such as a changing robot.

In a further advantageous embodiment, the magazine device itself has the heating device for heating the blow molded parts stored in the magazine device. The heating can take place in different ways, for example by means of electrical heating elements or also by supplying hot air.

In the interior of the magazine device, the blow molded parts are preferably heatable to a temperature which is at least 10 degrees above room temperature, preferably by at least 20 degrees, preferably by at least 30 degrees and preferably by at least 40 degrees. For example, it is possible for blow molded parts to be stored inside the magazine device at temperatures which are higher than 50 degrees, preferably higher than 60 degrees, preferably higher than 70 degrees.

In a further advantageous embodiment, the magazine device also serves to receive further elements of the forming stations, such as the stretching rods and / or the blowing nozzles mentioned above.

The shaping device particularly preferably accommodates the individual blow molded parts individually or in a customizable manner. It is thus possible for a changing device to equip certain forming stations with blow molding parts that are individually provided for this purpose during a changing process.

In a further advantageous embodiment, the device has a changing device for changing blow molded parts. This is preferably suitable and intended for changing heated blow molded parts. In this way, a particularly efficient and quick change of the blow molded parts can be carried out. This changing device is, in particular, a robot or a manipulator. In addition, this changing device preferably has a gripping device which is suitable and intended to grip heated blow molded parts and preferably to hold them firmly during the changing process.

In particular, the changing device is able to change a hot mold, in particular a mold that is too high a temperature for safe processing by the user. The changing device is particularly suitable for changing blow mold parts which have temperatures of more than 60 ° C.

The changing device is preferably suitable for replacing these blow molded parts by other blow molded parts.

This elevated temperature can, as mentioned above, be achieved by the heating device.

The changing device is preferably able to exchange both entire blow molds and individual mold parts. This changing device can have gripping devices which are selected from a group of gripping devices which contains electromagnetically acting gripping devices, suction cups, vacuum gripping devices, clamps and the like. If the exchange device is a robot, it can also perform other tasks in addition to the changeover processes.

In one embodiment, the device can also have measuring devices for determining physical properties and in particular temperature measuring devices. On the basis of appropriate temperatures, in particular of the blow molded parts, actions can be initiated, such as a further tempering of the blow molded parts or the like.

It is possible for such temperature measuring devices to be built into the blow molded parts themselves, but it would also be possible for such temperature measuring devices to be arranged in the changing device or on the changing device. Such measuring devices and in particular temperature measuring devices can also be provided in the magazine device. In addition, it would also be possible for such temperature measuring devices to be provided at several points.

In a further advantageous embodiment, the changing device is designed as a changing robot which is suitable and intended to arrange blow molded parts essentially independently at the forming stations. This changeover device is preferably also capable of making any connections between the blow molded parts and in the respective forming stations, such as flow agent connections for temperature control media for temperature control of the blow molded parts, electrical connections for controlling temperature sensors or also heating elements and the like.

The changing device is preferably also suitable and intended to connect or disconnect all electrical and / or hydraulic and / or pneumatic connections. This can advantageously be done without user intervention.

Furthermore, a so-called manipulator could also be used as a changing device, which is operated by hand and essentially serves to make it easier for the user to lift heavy weights, in particular the blow molded parts.

In a further advantageous embodiment, the magazine device is designed to receive the blow molded parts in isolated cases.

In a further advantageous embodiment, the entire arrangement has a heating device for heating plastic preforms, and waste heat from this heating device is also used for heating the blow molded parts.

As mentioned above, it is known from the prior art that the plastic preforms are first heated in an oven. The oven is usually used in the prior art Infrared ovens used. These stoves naturally generate a very high amount of waste heat. In the context of this embodiment, it is proposed that this waste heat be used to heat blow molded parts or to bring them to a certain temperature.

In a further advantageous embodiment, the temperature control device for the blow molded parts also has a regulating device with which, in particular, a user can regulate or control a specific target temperature to which the blow molded parts are brought.

By using a changing device that is able to change the hot molds and replace them with molds that have already been pre-heated, the time for changing the mold is significantly reduced. When using a robot as a changing device, tasks can be performed faster and usually more reliably than if a normal user would perform them.

It is also advantageous that the robot can largely perform its tasks automatically. Accordingly, only one control person is required, who is exposed to a lower risk at work. In the event that the robot, in addition to changing the mold, is also able to connect and disconnect at least one, preferably several, and particularly preferably all lines, the user does not have to use hot molds and / or lines that contain hot media or electrical currents are handled. Accordingly, the risk of injury is reduced.

This is especially the case if the lines are still under high pressure, as the hot liquids will spray out of the line at high pressure in the event of a leak or damage. Likewise, the robot preferably always works in a fixed sequence, so that the robot does not run the risk that the coupling and uncoupling of cables or components is forgotten due to unfocused work.

This in turn ensures that the risk of component damage due to worker errors is significantly reduced since there is no risk that the machine will be put into operation without all the components (such as a temperature sensor). Another advantage of using a robot is that it can be equipped with various means for measuring certain physical or chemical values or states, or at least can receive signals or instructions based on the measurement results that trigger a reaction in the robot , such as a retrofitting process or the removal of a damaged component.

This enables a quicker reaction to problems that occur or the prevention of certain problems or damage, which can prevent machine failures or at least shorten their times.

If a manipulator is used instead of a robot as a changing device, the mold change can nevertheless be accelerated, since the user can exchange the hot molds himself using the gripping device without having to touch it. The task can thus be fulfilled and the operator is protected. Unlike a robot, the task is not solved automatically, but the purchase costs are lower.

The present invention is further directed to magazine device for storing blow molded parts, the magazine device having a heating device for heating the blow molded parts arranged or to be arranged in this magazine device.

The present invention is further directed to a method for operating an arrangement for shaping plastic preforms into plastic containers and in particular plastic bottles. This arrangement has a device for shaping plastic preforms into plastic containers and in particular plastic bottles.

This device has a movable and, in particular, rotatable carrier, on which a multiplicity of shaping stations for shaping plastic preforms into plastic containers are arranged, and these shaping stations each have blow mold carrier parts to which blow molded parts are at least indirectly attached, with plastic preforms by means of blow molding devices in one working mode which have blow molded parts, are formed into plastic containers and in particular plastic bottles, and the blow molded parts are exchanged in a changeover operating mode and are preferably replaced by other blow molded parts.

According to the blow mold parts are heated in a disassembled state from the blow mold carrier part.

It is therefore also proposed on the process side that, for the purpose of changing the blow mold, blow mold parts which have already been heated are replaced at the forming stations. As mentioned above, the time period for such conversion processes can be reduced in this way. As mentioned above, it is possible that complete Blow molded parts, in particular both the side parts and the base parts, are to be replaced, but it would also be possible for only parts of a blow mold to be replaced, such as only the base parts or only the side parts.

In a preferred method, the blow molded parts are exchanged by means of an exchange device and in particular by means of an exchange robot.

In a further preferred method, the blow molded parts are stored within a magazine device. The blow molded parts are particularly preferably also heated or preheated within the magazine device. It is possible that the blow molded parts are already preheated to a working temperature. However, it would even be possible for the blow molded parts to be heated to a somewhat higher temperature in order in this way to compensate for temperature drops which occur during the actual changing process. In addition, it would also be possible for the blow molded parts not to be fully temperature-controlled to the working temperature, but only then to be in a state in which they are mounted on the shaping stations and in particular indirectly on the blow mold carrier parts.

• 1 eine schematische Darstellung einer erfindungsgemäßen Vorrichtung.

Further advantages and embodiments can be seen from the attached drawing:

• 1 is a schematic representation of a device according to the invention.

1 shows a rough schematic representation of an arrangement according to the invention 50 for forming plastic preforms into plastic containers. This arrangement has a device 1 for forming plastic preforms into plastic containers, here in the form of a stretch blow molding machine. This device 1 has a basic carrier 28 on which a rotatable carrier 4th , in particular a so-called blowing wheel, is arranged.

There are a number of forming stations on this blowing wheel 2nd arranged. These forming stations have blow mold carrier parts (only shown at one forming station) 22 and 24th on. In turn, blow mold side parts are on these blow mold carrier parts 32 and 34 (shown in another forming station for clarity).

In addition, blow mold carrier shells (not shown) can be provided, which are mounted on the blow mold carrier parts and which, in turn, serve to assemble the blow mold parts.

The reference number 36 indicates a bottom part of the respective blow molds. In this case, a base part carrier (not shown) is also provided, which serves to support this base part.

These blow molds are closed in a working operation, so that they form, in particular, a cavity in the interior, within which the plastic preforms are expanded to form the plastic containers. As mentioned above, this can be done by blowing air or directly by a product to be filled.

Here, the blow molding device, as indicated by the arrow, plastic preforms 10th supplied, and after the expansion process plastic containers, in particular plastic bottles 20th dissipated. This can be done, for example, by using a feed wheel (not shown) which is plastic preforms 10th to the carrier wheel 4th and the individual forming stations 2nd feeds and through a discharge wheel (not shown), which the manufactured containers 20th dissipates.

The reference number 8th identifies a changing device and in particular a robot that is used to replace the individual blow molded parts. This change robot 8th has a gripping device here 82 on, which serves to hold the individual blow molded parts.

For this purpose, the gripping device 82 have special gripping elements which can engage in corresponding gripping elements of the blow molded parts. The gripping device and in particular also the changing device 8th In its entirety, it is suitable and intended to transport blow molded parts that have already been heated and also to the respective forming stations 2nd to assemble.

The reference number 6 refers to a storage device, such as a magazine, in which the blow molded parts can be stored. This storage facility 6 has a temperature control or heating device 62 on which causes an interior of the storage device 6 there is a higher temperature, in particular compared to the room temperature, and the blow molded parts located therein are heated.

The reference numbers 64 identify individual holding devices, which each serve to hold the individual side parts and / or blow molded parts. An individualized removal of the blow molded parts from the storage device is preferred 6 possible.

In addition, a temperature measuring device can be located within the storage device 66 be provided, which measures the temperature in the interior and thus indirectly also the temperature of the respective blow molded parts. However, it would also be possible for the blow mold parts themselves to have temperature measuring devices in order to directly measure the temperature, for example, of the blow mold side parts and, in particular, of those surfaces which face the plastic preforms during operation. Depending on these temperatures, the actual heating of the blow molded parts can be controlled in the blow molding process.

Reference list

1

contraption

2nd

Forming stations

4th

rotatable carrier / carrier wheel

6

Storage facility

8th

Exchange device / robot

10th

Plastic preforms

20th

Plastic containers, plastic bottles

22, 24

Blow mold carrier parts

28

Basic rack

32, 34

Blow mold side parts

36

Bottom part of the blow mold

50

arrangement

62

Temperature control or heating device

64

Holding devices

66

Temperature measuring device

82

Gripping device

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• EP 2370368 B1 [0003]
• EP 2852486 B1 [0003]

Claims (10)

Arrangement for producing plastic containers and in particular plastic bottles with a device (1) for shaping plastic preforms into plastic containers (20), the device (1) having a movable support on which a plurality of shaping stations (2) for shaping plastic preforms (10 ) is arranged to plastic containers (20) and these forming stations (2) each have blow mold carrier parts (22, 24) to which blow molded parts (32, 34) can be attached at least indirectly, these blow molded parts (32, 34) being exchangeable, characterized in that the arrangement has a temperature control device (62) which enables the temperature control of blow mold support parts which are separate from the blow mold support parts (22, 24). Arrangement after Claim 1 characterized in that the arrangement has a magazine device (6) for storing the blow molded parts (32, 34). Arrangement after Claim 2 , characterized in that the magazine device has the heating device (62) for heating the blow molded parts (32, 34) stored in the magazine device (6). Arrangement according to at least one of the preceding claims, characterized in that the arrangement has a changing device for changing the blow molded parts (32, 34), which is suitable and intended for changing heated blow molded parts (32, 34). Arrangement (50) according to the preceding claim, characterized in that the changing device (12) is designed as a changing robot which is suitable and intended to arrange the blow molded parts (32, 34) essentially automatically at the forming stations (2). Arrangement according to at least one of the preceding claims, characterized in that the changing device has gripping means for gripping the blow molded parts (32, 34), these gripping means being suitable and intended for holding the blow molded parts (32, 34) on heated elements of these blow molded parts (32, 34). 34) to grip Arrangement according to at least one of the preceding claims, characterized in that the magazine arrangement is designed for singly receiving the blow molded parts (32, 34). Arrangement according to at least one of the preceding claims, characterized in that the arrangement has a heating device for heating plastic preforms and waste heat of this heating device serves for heating the blow molded parts (32, 34, 36). Magazine device (6) for storing blow molded parts (32, 34), characterized in that the magazine device (6) has a heating device (62) for heating the blow molded parts arranged in this magazine device (6). Method for operating an arrangement (50) for shaping plastic preforms (10) into plastic containers (20), the arrangement comprising a device (1) for shaping plastic preforms (10) into plastic containers (20) with a movable support on which a A large number of shaping stations (2) for shaping plastic preforms into plastic containers is arranged, and these shaping stations (2) each have blow mold carrier parts (22, 24) to which blow molded parts (32, 34) are at least indirectly attached, whereby in a working mode of operation plastic preforms by means of blow molding devices the blow molded parts (32, 34) are formed into plastic preforms and the blow molded parts (32, 34) are replaced in a changeover operating mode, characterized in that the blow molded parts (32, 34) are heated in a state disassembled from the blow mold carrier parts.

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