Apparatus and method for forming plastic preforms into plastic containers with improved rinsing rod arrangement

Abstract

An apparatus for forming plastic preforms into plastic containers, includes at least one forming station which forms the plastic preforms into the plastic containers by applying a flowable medium to the plastic preforms, wherein the forming station comprises a blow mold (26), and a rod-like body which is insertable into the plastic preforms via a mouth of the plastic preforms, and a moving device which is configured for moving the rod-like body in the longitudinal direction of the plastic performs. The rod-like body has a channel for guiding the flowable medium, and the forming station has a valve device controlling the supply of the flowable medium into the channel. The said valve device is arranged on the moving device and/or a ratio between an inner diameter of the rod-like body and an outer diameter of said rod-like body is, at least in sections, smaller than or equal to 0.5.

Claims

1. An apparatus for forming plastic preforms into plastic containers, having at least one forming station configured to form the plastic preforms into the plastic containers by being acted upon by a flowable medium, wherein the forming station has a blow mould configured to form a hollow space within which the plastic preforms can be formed into the plastic containers, and wherein the forming station further comprises an application device configured to act upon the plastic preforms with the flowable medium and a rod-like body configured for introduction into the plastic preforms via a mouth of the plastic preforms, and a moving device which is configured to move the rod-like body in the longitudinal direction of the plastic preforms, wherein the rod-like body forms a channel configured for conducting the flowable medium, and the forming station comprises valve device configured to control the feed of the flowable medium into the channel, wherein said valve device is arranged at the moving device, and/or a ratio between an inner diameter of said rod-like body and the outer diameter of said rod-like body is smaller than or equal to 0.5 at least in sections.

2. The apparatus according to claim 1, wherein a movement of the valve device is at least temporarily and preferably completely coupled to the movement of the rod-like body.

3. The apparatus according to claim 1, wherein the valve device is pressure-balanced.

4. The apparatus according to claim 1, wherein the valve device is a pneumatically actuated valve.

5. The apparatus according to claim 1, wherein the valve device is arranged at a portion of the rod-like body.

6. The apparatus according to claim 1, wherein the rod-like body is made of a metal and in particular of a steel.

7. The apparatus according to claim 1, wherein the rod-like body is coated at least in sections.

8. The apparatus according to claim 1, wherein the material of the rod-like body is a semi-finished product.

9. A rod-like body for stretching plastic preforms, wherein the rod-like body has a channel configured for conducting a flowable medium and the rod-like body has a predetermined outer diameter as well as a predetermined inner diameter and the rod-like body has a length of between 500 mm and 1000 mm, wherein the rod-like body is made of a metal and in particular of steel, and a ratio between the inner diameter and the outer diameter is less than or equal to 0.5.

10. A method for forming plastic preforms into plastic containers using a forming station for forming the plastic preforms into the plastic containers by acting upon the plastic performs with a flowable medium, wherein the forming station comprises a blow mould which forms a cavity within which the plastic preforms are formed into the plastic containers, and wherein the forming station further comprises an application device which acts upon the plastic preforms with the flowable medium and a rod-like body which is inserted into the plastic preforms via a mouth of the plastic preforms, and wherein a moving device moves said rod-like body in the longitudinal direction of the plastic preforms, wherein said rod-like body forming a channel for guiding the flowable medium, and a valve device of the forming station controls the supply of the flowable medium into said channel, wherein said valve device is arranged on the moving device, and/or a ratio between an inner diameter of the rod-like body and the outer diameter of the rod-like body is smaller than or equal to 0.5 at least in sections.

11. The apparatus according to claim 2, wherein the valve device is pressure-balanced.

12. The apparatus according to claim 2, wherein the valve device is a pneumatically actuated valve.

13. The apparatus according to claim 2, wherein the valve device is arranged at a portion of the rod-like body.

14. The apparatus according to claim 2, wherein the rod-like body is made of a metal and in particular of a steel.

15. The apparatus according to claim 2, wherein the rod-like body is coated at least in sections.

16. The apparatus according to claim 2, wherein the material of the rod-like body is a semi-finished product.

17. The apparatus according to claim 3, wherein the valve device is a pneumatically actuated valve.

18. The apparatus according to claim 3, wherein the valve device is arranged at a portion of the rod-like body.

19. The apparatus according to claim 3, wherein the rod-like body is made of a metal and in particular of a steel.

20. The apparatus according to claim 3, wherein the rod-like body is coated at least in sections.

Description

[0050] In the drawings:

[0051] FIG. 1 shows a schematic representation of a plant for forming plastic preforms into plastic containers;

[0052] FIG. 2 shows an illustration of a forming station;

[0053] FIG. 3 shows an illustration of a forming station according to the prior art;

[0054] FIG. 4 shows a detailed view of the forming station shown in FIG. 3;

[0055] FIG. 5 shows a detailed representation of a forming station according to the invention;

[0056] FIG. 6 shows a further illustration of a forming station according to the invention;

[0057] FIG. 7 shows a representation of a valve device; and

[0058] FIG. 8 shows a representation of a rod-like body.

[0059] FIG. 1 shows a schematic representation of a forming device 1 for forming plastic preforms 10 into plastic containers and in particular plastic bottles 40. A feed device such as a feed starwheel 32 is provided, which transfers heated plastic preforms to a plurality of forming stations 20. These are thereby arranged on a rotatable carrier 25, such as in particular a so-called blowing wheel. In these forming stations, the plastic preforms 10 are formed into the plastic containers 40 and then transported away by a discharge device 34, such as a discharge starwheel.

[0060] The reference sign 26 roughly schematically indicates a blow mold arranged in the forming station 20. This blow mould can have two side parts which can be pivoted relative to one another with respect to an axis in order to open and close the plastic preforms.

[0061] FIG. 2 shows a representation of a forming station 20, which has a rod-like body 24 such as a stretching bar, which can be inserted into the interior of the plastic preforms for stretching them. The reference sign 4 indicates a movement device which moves this stretching bar for this purpose.

[0062] The reference sign 2 indicates an application device which acts upon the plastic preforms with a flowable medium and in particular with compressed air. The reference signs 14a and 14b indicate side part carrier which are suitable and intended for supporting and holding the blow-molded parts of the blow mold 26. The reference sign 16 indicates a locking device which holds the two blow mould parts or their side part carrier 14a and 14b together or locks them together during an expansion of the plastic preforms.

[0063] FIG. 3 shows a detailed representation of a forming station according to the prior art. Here, a carrier is provided on which a movement element 52 is arranged. The rod-like body 124 is in turn arranged on this movement element 52. The reference sign 108 indicates a valve device, which is connected to the rod-like body via a conduit 126 such as a hose. The interior of this hose forms a dead space volume, which is to be reduced according to the invention.

[0064] FIG. 4 shows a detailed view, wherein only the valve means 108, the conduit means 126 and the rod-like body 24 are shown.

[0065] FIG. 5 shows a forming station according to the invention. Here again, a movement element 52 such as a stretching carriage is provided. This movement element can be a component of the movement device mentioned above. However, in this embodiment the valve device 8 is arranged directly on the rod-like body 24. The reference sign 46 indicates a working air feed line which is connected to a connection 44 of the valve device 8 via a connection line 42 which, however, is preferably rigid in this case. In this way, the connecting hose 126 shown in FIG. 4 can be dispensed with and in this way the dead space volume is significantly reduced. More specifically, the valve device is preferably arranged directly on the rod-like body 24. Thus, preferably the valve device also moves with the rod-like body 24.

[0066] FIG. 6 shows a further illustration of a forming station according to the invention. The reference sign 46 refers to a control air feed line in the event that the valve device is designed as a pneumatic valve.

[0067] FIG. 7 shows a detailed representation of an advantageously used valve device, which is designed here as a pressure-balanced valve. Here, the reference sign 82 indicates the valve device and the reference sign 84 indicates a valve seal.

[0068] The reference sign 85 indicates a pilot valve, which is used in particular for actuating the valve device. Reference signs 90 and 92 indicate a control chamber and in particular the control chamber controlled by the pilot valve.

[0069] The reference sign 88 indicates a connecting space between a sealing side and a piston rear side, via which the pressure compensation is effected, and the reference sign 94 indicates the pressure chamber of the piston rear side. Reference sign 86 indicates the piston of the valve device.

[0070] FIG. 8 shows a sectional view of a rod-like body 24 or a stretching bar. Here, the reference signs di and da refer to the inner diameter and the outer diameter of this rod-like body. It can be seen that the rod-like body 24 preferably has a cylindrical profile. Also, the cavity or channel 62, which here is in the form of a bore, is preferably cylindrical in shape.

[0071] The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they are individually or in combination new compared to the prior art. It is further pointed out that the individual figures also describe features which may be advantageous in themselves. The skilled person immediately recognizes that a particular feature described in a figure can be advantageous even without adopting further features from that figure. Furthermore, the skilled person recognizes that advantages can also result from a combination of several features shown in individual figures or in different figures.

LIST OF REFERENCE SIGNS

[0072] 1 forming device [0073] 2 application device [0074] 4 movement device [0075] 8 valve device [0076] 10 plastic preform [0077] 14a side part carrier [0078] 14b side part carrier [0079] 20 forming stations [0080] 24 rod-like body, stretching rod [0081] 25 carrier [0082] 26 blow mold [0083] 32 feeding starwheel [0084] 34 discharge device [0085] 40 plastic bottles [0086] 42 connection line [0087] 44 connection [0088] 46 working air feed line [0089] 52 movement element, stretching carriage [0090] 62 channel [0091] 82 valve output [0092] 84 valve seal [0093] 85 pilot valve [0094] 92 control chamber [0095] 90 control chamber [0096] 88 connection chamber between seal side and piston rear side [0097] 86 piston [0098] 94 pressure chamber rear side of piston [0099] 108 valve device (state of the art) [0100] 124 rod-like body (state of the art) [0101] 126 conduit means [0102] di internal diameter [0103] da outside diameter