WO2019025080A1

WO2019025080A1 - Stretch blow moulder with thermal insulation

Info

Publication number: WO2019025080A1
Application number: PCT/EP2018/066828
Authority: WO
Inventors: Florian Geltinger; Harald Steinberger; Thomas Spitzer; Bernhard Sternkopf
Original assignee: Krones Ag
Priority date: 2017-08-03
Filing date: 2018-06-22
Publication date: 2019-02-07
Also published as: DE102017117683A1

Abstract

An apparatus (1) for shaping plastic preforms into plastic containers, with a main carrier (2) on which a rotatable station carrier (4) is arranged, wherein a multiplicity of shaping stations (6) for shaping plastic preforms into plastic containers is arranged on said rotatable station carrier (4), and wherein a mounting device is provided in order to mount the rotatable station carrier (4) rotatably in relation to the main carrier (2). According to the invention, the apparatus has a thermal insulating device which at least partially thermally insulates at least one portion of the shaping stations (6) and/or a region (4b) of the station carrier (4) in relation to at least one further region (4a) of the rotatable station carrier (4).

Description

Stretch blow moulder with thermal insulation

description

The present invention relates to an apparatus for forming plastic preforms into plastic containers. In particular, the present invention relates to a blow molding machine, in particular a so-called stretch blow molding machine. Such machines have been known from the prior art for a long time. These usually have a movable and in particular rotatable carrier, a so-called blowing wheel on which a plurality of forming stations is arranged.

In each case, these forming stations have blow mold carriers and blow molds which can be unfolded and folded and, in a folded state, form a cavity within which the plastic preforms can be formed by applying a flowable medium to the plastic containers. Such blow molding machines are available for different power ranges. For the middle and upper power range, these blow molding machines are usually designed as rotary machines. In recent years, the station performance of these machines has continued to increase and thus inseparable was also an increase in the speed of the respective blower. These steadily increased speeds also lead to higher load of storage of this blowing wheel. The speeds are now so high that the storage in a continuous operation reaches a significant increase in temperature to more than 60 ° C. This increase in temperature leads in the long run to a considerable increase in temperature in the blowing wheel. The Applicant In elaborate investigations it was found that this temperature increase even led to a measurable positional shift of the blowing wheel. Such a positional shift, in connection with a high speed and also increasingly plastic preforms for the containers, can sometimes lead to problems during a transfer within the machine.

The present invention is therefore based on the object to avoid positioning problems, especially when using high speeds of a blowing wheel. This object is achieved by the subject matters of the independent claims. Advantageous embodiments and further developments are the subject of the dependent claims.

A device according to the invention for forming plastic preforms into plastic containers has a main carrier on which a (with respect to the main carrier) rotatable station carrier is arranged. In this case, a plurality of forming stations for forming plastic preforms to plastic containers is arranged on this station carrier and further provided a storage device to rotatably support the rotatable station carrier relative to the main carrier. According to the invention, the device has a thermal insulation device which at least partially insulates at least a portion of the transformation stations and / or the station support thermally with respect to the station support and / or other areas of the station support. It is therefore proposed that the heating occurring be blocked by means of thermal insulation and thus prevents certain areas of the station carrier or the conversion stations are excessively heated. In this way, it is also possible that at higher speeds of the blowing wheel or the station support nevertheless no excessive heating in sensitive areas of the station carrier is introduced.

The device for forming plastic preforms into plastic containers is preferably a blow molding machine. This means that the plastic preforms are first thermally conditioned in a heating section and then to be expanded with 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 in such a way with liquid or gaseous medium. In addition, a valve arrangement is preferably provided which controls the supply of the blowing air to the plastic preforms.

The blow molding 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. 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. In an advantageous embodiment, a plurality of blowing 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 each other to open and close the blow molds. In addition, the blow mold carrier has locking mechanisms in order to lock the mold halves against one another during the blowing process.

The blow molding machine or the carrier and the blow mold arrangements are particularly preferably 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 of 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 clean room 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.

The insulating device may be a thermal insulator which is arranged, for example, between adjacent components. However, the isolating device can also be a device which tempers and in particular cools a specific section, in particular of the station carrier, and thus enables the thermal insulation between the heating area of the station carrier and other areas.

However, it would also be conceivable to actively cool certain areas of the blow molding machine, and in this way to achieve that the unwanted heating of certain parts of the station carrier or blowing wheel does not occur. In another embodiment of the invention, an apparatus for forming plastic preforms to plastic containers on a main carrier on which a rotatable station carrier is arranged, wherein at this rotatable station carrier a plurality of forming stations for forming plastic preforms is arranged in plastic containers and wherein a storage device provided is to rotatably support the rotatable station carrier relative to the main carrier.

According to the invention, the device here has a cooling device for cooling at least one component of the rotatable station carrier and / or at least one forming station, and this cooling device in turn has conducting means which emit a gaseous medium and / or liquid medium emerging from the forming station onto at least one component of the rotatable Carrier and / or at least one component of the forming station and / or at least one component of the storage device directs.

In such forming processes of plastic preforms to plastic containers by means of blown air usually comes to exhaust air. This occurs in particular when unloading the plastic preforms, that is, when the plastic preforms have already been reshaped and are removed again from the blow molds. The invention proposes Here before, to use this exhaust targeted, in order to direct them to the station support or certain areas of the conversion stations and so as to achieve a corresponding cooling effect. Preferably, therefore, these conducting means or (air flow) conducting means are suitable for conducting exhaust air occurring during the blowing process to the station carrier and / or the forming stations.

It would also be possible to directly cool the storage facility where the largest temperature rise is to be measured. In the simplest case, the guide means can also be the air outlets of the conversion stations, for example nozzles or the like, which are aligned such that the air exiting through these nozzles reaches the areas to be cooled

In an advantageous embodiment, the forming stations each have two side member carriers, on which at least indirectly blow molding parts are arranged, these blow moldings forming a cavity within which plastic preforms are deformable to the plastic containers. In a further advantageous embodiment, these conversion stations each have loading devices, which act on the plastic preforms with a flowable medium. In particular, this flowable medium is air and in particular blowing air. However, it is also conceivable that the loading device, the plastic preforms directly with a liquid, in particular but not exclusively a beverage to be filled, applied to expand the plastic preforms through this liquid.

In a further advantageous embodiment, the conversion stations each have rod-like bodies, so-called stretching rods, which can be inserted into the interior of the plastic preforms in order to stretch them in their longitudinal direction.

Furthermore, the devices preferably have a valve block which controls the supply of the flowable medium into the plastic preforms. As mentioned above, this may also be a valve block which is suitable and intended to fill liquid into the plastic preforms so as to expand them.

In a further advantageous embodiment, the insulating device has a between the rotatable station carrier or a first region of the station carrier and less at least one forming station and / or a further region of the station carrier arranged insulating element, which causes the thermal insulation and / or thermal separation. It is also possible that this insulating element is arranged between a first region of the station carrier and a second region of the station carrier.

As mentioned above, the transfer points should not shift within the machine, but must remain stable in each operating condition. In order to achieve this, certain solutions have already been known in the internal state of the art. One solution aimed to use the wind of the blower as a passive cooling medium for the storage device. Although this is possible in principle, the cooling capacity is relatively limited here.

Therefore, in the second embodiment described below, it is concretely proposed not to easily relieve the already existing relief air of the already blown bottles in an inner region of the blowing wheel, whereby this expensive high-pressure air is finally lost, but specifically down particularly on the storage device in which it For example, it is a rotary ball connector, to guide and thus actively cool it. Due to the fact that this air was previously highly compressed and suddenly relieved after the blowing process was completed, this air also contains a certain amount of expansion forces, which in a sense amounts to active cooling. The use of these expansion forces would also slightly improve the energy efficiency of the machine. The fact that in non-production, that is, in standby mode, due to the non-existent discharge air no active cooling can take place, is not critical, since at this low rotational power also no correspondingly high temperature occurs in the storage device.

In a further advantageous embodiment, the insulating device has a plate-shaped body made of a thermally insulating material or at least one coolant channel. If a plate-shaped body is used, this can be arranged, for example, between a first region of the station carrier and a second region of the station carrier. In this way, this second area of the station carrier can be insulated from the first area and even with a high occurring heating of the first area there is no corresponding heating of the second area. It would also be possible that this plate-shaped insulator between the station carrier and the individual transformation stations is mounted in order to prevent excessive heating of the conversion stations. Also, at least one and preferably a plurality of coolant channels may be provided. In this case, for example, a closed coolant loop can be provided in a region of the station carrier. The said insulating plate may be formed annularly or it may be provided a plurality of insulating elements.

In a further advantageous embodiment, the plate-shaped body is formed of a thermally insulating material, such as stainless steel.

In a further advantageous embodiment of the rotatable station carrier is rotatably mounted relative to the main carrier by means of a ball slewing. Such rotary ball connectors are known per se from the prior art. These may have a plurality of rolling elements such as balls, which may extend as in an angular contact ball bearings on annular tracks or treads, for example, an inner ring. In this way, these rolling elements can absorb axial forces and tilting moments. Preferably, the entire camp is protected by seals against grease leakage and contamination. Preferably, therefore, the storage device has a bearing inner ring and a bearing outer ring. Advantageously, these bearing inner rings and bearing outer rings also form running surfaces for a large number of rolling elements. Preferably, these rolling elements are balls.

The present invention is further directed to a method of forming plastic preforms into plastic containers. In this case, plastic preforms are transferred to forming stations and reshaped by these forming stations by exposure to a flowable medium to the plastic containers. Furthermore, as part of the forming process from the forming stations, a flowable medium, and the conversion stations are arranged on a station carrier which rotates relative to a stationary main carrier and which is rotatably mounted relative to this main carrier by means of a bearing means, wherein at least a portion of the forming stations or Storage device and / or the station carrier is cooled and / or thermally insulated. According to the invention, this thermal insulation is achieved by a thermal insulation device comprising at least a portion of the transformation stations and / or a region of the station support and / or the storage device at least partially thermally relative to the station carrier and / or a further region of the station carrier and / or at least a portion of Forming stations isolated and / or the cooling is achieved by means of emerging from the forming stations flowable medium.

It is therefore also proposed on the method side that at least one region of the device is thermally insulated from another region or that at least one region of the machine is actively cooled by a flowable and in particular gaseous medium emerging from the transformation stations. In this way, a higher temperature gradient can be achieved between the storage device and further components of the station carrier and / or the conversion stations than without the said measures, that is, without the cooling and / or insulation. In particular, the said area of the station carrier and / or the conversion stations can be kept at a lower temperature than without the said measures.

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

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

Fig. 2 is a detail view for illustrating the invention.

1 shows a roughly schematic representation of a device 1 according to the invention. In this case, a station carrier 4 is shown, which is in particular a blowing wheel. This is rotatably mounted with respect to a rotation axis Z. At this station carrier a plurality of forming stations 6 is arranged. These forming stations 6 each have (not shown) side member support on which blow moldings can be attached. These side member carriers can be pivoted with the blow mold parts arranged thereon, for example by a pivoting operation, opened and closed. In a closed state, the plastic preforms with the gaseous Applied medium so as to be expanded to plastic containers and plastic bottles in particular can.

Figure 2 shows a detail of the present invention. Here, the stationary main carrier 2 is shown on which the station carrier 4 is rotatably shown. The reference numeral 8 denotes a rolling element, which is part of a storage device, which serves for the rotatable mounting of the station carrier 4. This station carrier 4 has a first area 4a and a second area 4b. The reference numeral 22 denotes a thermal separating element, which is arranged between the area 4a of the station carrier and the area 4b of the station carrier. In this way, the high heating, which occurs in the storage device 8 and is also transmitted to the area 4a, can be prevented from wandering into the area 4b.

In addition, a cooling channel 16 is also shown in the region 4b, which serves to cool this region 4b.

It should be noted that alternatively either the plate-shaped element 22 or the insulating element 22 and the cooling channel 16 can be provided. The reference numeral 18 denotes a further region of the station carrier, which may also be thermally insulated by means of an insulating element 22. At this station carrier 4, the conversion stations 6 are shown only schematically. By virtue of the thermal insulation shown here, it is achieved, as mentioned above, that the areas 4a of the station carriers, in particular, are not excessively heated and, as a result, thermally induced misalignments or mispositioning can not occur.

Furthermore, it would be possible (not shown) for the individual forming stations, in particular with their exhaust air, to cool areas of the storage device 8 or also areas 4a, 4b of the station carrier and / or the station carrier 4. This would in particular mean active cooling of said areas, which however could also lead to a proper cooling of the same.

The Applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they are novel individually or in combination with respect to the prior art. It is further noted that in the individual figures also features have been described, which in itself can be advantageous. The person skilled in the art immediately recognizes that a particular feature described in one figure can also be advantageous without taking over further features from this figure. 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 according to the invention

2 stationary main beams

4 station carriers

6 transformation stations

8 rolling elements

8 storage facility

16 cooling channel

18 further area of the station carrier

22 Thermal separator

22 plate-shaped element or insulating element

4a First area of the station carrier

4b Second area of the station carrier

Z axis of rotation

Claims

Stretch blow molding machine with thermal insulation Claims

Device (1) for converting plastic preforms to plastic containers with a main carrier (2) on which a rotatable station carrier (4) is arranged, wherein arranged on this rotatable station carrier (4) a plurality of forming stations (6) for forming plastic preforms to plastic containers and wherein a bearing device (8) is provided for rotatably supporting the rotatable station carrier (4) in relation to the main carrier (2), characterized in that

the apparatus comprises a thermal insulation device which at least partially thermally insulates at least a portion of the transformation stations (6) and / or a region (4b) of the station support (4) from at least one further region (4a) of the rotatable station support (4).

Device (1) for converting plastic preforms to plastic containers with a main carrier (2) on which a rotatable station carrier (4) is arranged, wherein arranged on this rotatable station carrier (4) a plurality of forming stations (6) for forming plastic preforms to plastic containers and wherein a storage device is provided to the rotatable station carrier (4) rotatable relative to the main carrier

(2) store,

characterized in that

the device has cooling means for cooling at least one component of the rotatable station carrier and / or at least one conversion station, and this cooling device has conducting means which direct a gaseous medium leaving the forming station onto at least one component of the rotatable carrier and / or at least one element of the forming stations and / or or direct at least one element of the storage device (8).

3. Device (1) according to claim 1 or 2,

characterized in that

the conversion stations each comprise at least two side sub-carriers (14, 16). sen, where arranged at least indirectly blow molding, these blow moldings form a cavity within which plastic preforms are deformable to the plastic container.

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

characterized in that

the insulation device (20) has an insulating element (16, 22) arranged between the region (4a) of the rotatable station support and at least one transformation station (6) and / or the further region (4b) of the station support, which thermal insulation and / or thermal insulation Separation effected.

5. Device (1) according to claim 3,

characterized in that

the insulation device (22) has a plate-shaped body made of a thermally insulating material or at least one coolant channel (16).

6. Device (1) according to claim 4,

characterized in that

the plate-shaped body is made of stainless steel.

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

characterized in that

the rotatable station carrier is rotatably mounted relative to the carrier (2) by means of a ball slewing connector.

8. A method for forming plastic preforms to plastic containers wherein plastic preforms are transferred to forming stations and are transformed from these forming station by applying a flowable medium to the plastic containers and at least temporarily as part of the forming process from the forming stations a flowable medium exits and wherein the forming station a station carrier (4) which rotates with respect to a stationary main carrier and which is rotatably mounted relative to this main carrier (2) by means of a bearing device, wherein at least a portion of the forming stations or the storage device is cooled and / or thermally isolated,

characterized in that

this thermal insulation is carried out by a thermal insulation device (16, 22) which at least partially thermally opposite at least a portion of the forming stations (6) and / or a region (4b) of the station carrier (4) to at least one further area (4a) of the rotatable station carrier isolated and / or cooling takes place by means of emerging from the forming stations flowable medium.