APPARATUS FOR FORMING PLASTIC PREFORMS INTO PLASTIC CONTAINERS WITH A COVER DEVICE ARRANGED ON THE STRETCHING DEVICE

Abstract

An apparatus for forming plastic preforms into plastic containers, includes a transport device, which has a rotatable transport carrier on which a plurality of forming stations is arranged. The forming stations each have application devices for applying fluid medium to the plastic preforms. The forming stations each have stretching devices for stretching the plastic preforms in the longitudinal direction thereof. The stretching devices each have at least one stretching rod which can be moved in the longitudinal direction of the plastic preforms. The apparatus has a clean room, within which the plastic preforms are expanded into the plastic containers, and a sealing device in order to seal the clean room from a non-sterile environment. The sealing device has at least one circumferential channel which can be filled with a liquid, characterized in that the clean room is closed with a cover device, and this cover device is fastened at least to at least one stretching device by fastening devices.

Claims

1. An apparatus for forming plastic preforms into plastic containers, comprising a transport device, which transports the plastic preforms to be formed along a predetermined transport path, wherein the transport device has a rotatable transport carrier on which a plurality of forming stations is arranged, wherein these forming stations each have blow molding devices within which the plastic preforms can be formed into the plastic containers by applying a fluid medium thereto, and the forming stations each have application devices in order to apply the fluid medium to the plastic preforms, wherein the forming stations each have stretching devices for stretching the plastic preforms in the longitudinal direction thereof, and these stretching devices each have at least one stretching rod which can be moved in the longitudinal direction of the plastic preforms and which can be inserted into the plastic preforms, and wherein the apparatus has a clean room, within which the plastic preforms are expanded into the plastic containers, and a sealing device configured to seal the clean room from a non-sterile environment, wherein the clean room is closed with a cover device, and this cover device is fastened by fastening devices at least to at least one stretching device and/or the cover device is designed as a non-supporting device.

2. An apparatus for forming plastic preforms into plastic containers, comprising a transport device, which transports the plastic preforms to be formed along a predetermined transport path, wherein the transport device has a rotatable transport carrier on which a plurality of forming stations is arranged, wherein these forming stations each have blow molding devices within which the plastic preforms can be formed into the plastic containers by applying a fluid medium thereto, and the forming stations each have application devices in order to apply the fluid medium to the plastic preforms, wherein the forming stations each have stretching devices for stretching the plastic preforms in the longitudinal direction thereof, and these stretching devices each have at least one stretching rod which can be moved in the longitudinal direction of the plastic preforms and which can be inserted into the plastic preforms, and wherein the apparatus has a clean room, within which the plastic preforms are expanded into the plastic containers, and a sealing device configured to seal the clean room from a non-sterile environment, wherein the clean room is closed with a cover device, and this cover device is arranged by fastening devices to at least one supporting element within the clean room.

3. The apparatus according to claim 1, wherein the cover device is designed as a non-supporting device.

4. The apparatus according to claim 1, wherein the cover device is fastened at least to multiple stretching devices.

5. The apparatus according to claim 1, wherein the cover device is fastened to multiple stretching devices by a plurality of connecting elements.

6. The apparatus according to claim 1, wherein the connecting elements are designed to be bendable in order to absorb a thermally induced expansion of the cover device.

7. The apparatus according to claim 1, wherein the cover device is mounted in a floating manner.

8. The apparatus according to claim 1, wherein the stretching device and the cover device are thermally decoupled from one another.

9. The apparatus according to claim 1, wherein the sealing device has a circumferential wall which projects into a circumferential channel, wherein this wall is designed to be rotatable.

10. The apparatus according to claim 9, wherein the circumferential channel is fastened to at least one stretching devices.

11. The apparatus according to claim 1, wherein the cover device has a substantially circular or annular shape and/or the cover device has a material thickness that is smaller than 50 mm, and/or the cover device has a material thickness that is greater than 1 mm.

12. A method for forming plastic preforms into plastic containers, wherein a transport device transports the plastic preforms to be formed along a predetermined transport path, wherein the transport device has a rotatable transport carrier on which a plurality of forming stations is arranged, wherein these forming stations each have blow molding devices within which the plastic preforms are formed into the plastic containers by applying a fluid medium thereto, and the forming stations each have application devices which apply the fluid medium to the plastic preforms, wherein the forming stations each have stretching devices for stretching the plastic preforms in the longitudinal direction thereof, and these stretching devices each have at least one stretching rod which can be moved in the longitudinal direction of the plastic preforms and which is inserted into the plastic preforms, and wherein the apparatus has a clean room, within which the plastic preforms are expanded into the plastic containers, and a sealing device configured to seal the clean room from a non-sterile environment, and this sealing device has at least one circumferential channel filled with a liquid, wherein the clean room is closed with a cover device, and this cover device is fastened by fastening devices at least to at least one stretching device and/or the cover device is designed as a non-supporting device.

13. The method according to claim 12, wherein the cover device is thermally insulated from at least one stretching device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Further advantages and embodiments can be seen in the accompanying drawings:

[0055] In the figures:

[0056] FIG. 1 shows a schematic representation of a apparatus according to the invention; and

[0057] FIG. 2 shows a partial view of an apparatus according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0058] FIG. 1 shows an apparatus 1 for forming plastic preforms 10 into plastic containers 15. This apparatus has a rotatable carrier 22 on which a multitude of forming stations 4 is arranged. These individual forming stations each have blow molding devices 82, which in their interior form a cavity for expanding the plastic preforms.

[0059] Reference sign 84 denotes an application device which serves for expanding the plastic preforms 10. This can be, for example, a blowing nozzle which can be placed onto an opening of the plastic preforms in order to expand the latter. In addition, it is also conceivable to seal the blowing nozzle on the blow molding device.

[0060] Reference sign 90 denotes a valve arrangement, such as a valve block, which preferably has a plurality of valves which control the application of different pressure levels to the plastic preforms.

[0061] In a preferred method, first a pre-blowing pressure P1, then at least one intermediate blowing pressure Pi that is higher than the pre-blowing pressure, and finally a final blow molding pressure P2 that is higher than the intermediate blowing pressure Pi are applied to the plastic preforms. After the expansion of the plastic containers, the pressures or the compressed air are preferably returned from the container to the individual pressure reservoirs.

[0062] Reference sign 88 denotes a stretching rod which serves to stretch the plastic preforms in their longitudinal direction. Preferably, all forming stations have such blow molds 82 and stretching rods 88. This stretching rod is preferably a component of a stretching device denoted by 30.

[0063] The number of these forming stations 4 is preferably between 2 and 100, preferably between 4 and 60, preferably between 6 and 40.

[0064] The plastic preforms 10 are fed to the device via a first transport device 62, such as, in particular but not exclusively, a transport star. The plastic containers 15 are transported away via a second transport device 64.

[0065] Reference sign 7 denotes a pressure supply device, such as a compressor or a compressed-air connection. The compressed air is conveyed via a connecting line 72 to a rotary distributor 74 and delivered from the latter via a further line 76 to the reservoir 2a, which is here an annular channel. This rotary distributor is thus preferably used to guide air from a stationary part of the apparatus into a rotating part of the apparatus.

[0066] In addition to this annular channel 2a shown, further annular channels are preferably provided, which are however covered by the annular channel 2a in the illustration shown in FIG. 1, for example are below it. Reference sign 98 denotes a connecting line which delivers the compressed air to a forming station 4 or the valve block 90 thereof. Preferably, each of the annular channels is connected to all forming stations via corresponding connecting lines. This connecting line is preferably arranged in the rotating part of the apparatus.

[0067] Reference sign 8 schematically denotes a clean room, which is preferably annular and surrounds the transport path of the plastic preforms 10. Preferably, a (geometric) axis of rotation with respect to which the transport carrier 22 can be rotated is arranged outside the clean room 8. Preferably, the clean room is sealed from the non-sterile environment by means of a sealing device, which preferably has at least two water locks.

[0068] Furthermore, the apparatus has a cover device (not shown in FIG. 1), which delimits the clean room 8 upward. This cover device is preferably arranged on at least one of the stretching devices 30.

[0069] FIG. 2 shows a side view of an apparatus according to the invention. In this case, a forming station which has a stretching device 30 is shown partially. This stretching device has a stretching rod 82 which can be inserted into the plastic preforms by a movement in the longitudinal direction L (which is, in particular, also a longitudinal direction of the plastic preforms to be expanded).

[0070] Reference sign 17 denotes a carrier of the stretching device 30. This carrier is preferably dimensioned such that it can support the stretching device. Reference sign 18 denotes a valve block or a valve arrangement, which preferably has a plurality of valves by means of which pressure is applied to the plastic preforms.

[0071] Reference sign 19 denotes a blow mold carrier on which a blow molding apparatus (not shown) is arranged.

[0072] Reference sign 25 denotes a cover device, which delimits the clean room upward. This cover device is arranged via, here two, connecting elements 16, in particular connecting bolts 16, on the stretching device 30 and also on further stretching devices (not shown). These connecting elements are furthermore arranged on the carrier 18 of the stretching device 30.

[0073] Reference sign P1 denotes the direction in which the cover device is movably and/or floatingly mounted and in which (thermally induced) expansions of the cover device can also be absorbed.

[0074] The connecting elements are preferably designed as bolts and in particular as elongated bolts.

[0075] Preferably, these connecting elements are arranged in the longitudinal direction L or substantially in the longitudinal direction L (the latter means that an extension direction of the connecting elements deviates by less than 10, preferably by less than 8 preferably by less than 6 and particularly preferably by less than 4 from the longitudinal direction.

[0076] The connecting elements preferably have a length that is greater than 1 cm, preferably greater than 1.5 cm, preferably greater than 2 cm, and preferably greater than 2.5 cm.

[0077] The connecting elements preferably have a length that is smaller than 20 cm, and preferably greater than 10 cm.

[0078] Reference sign 50 denotes a sealing device which delimits the clean room from the environment. This sealing device preferably has a circumferential channel 52 which is arranged in particular in a stationary manner. A circumferential wall 54 preferably dips into this circumferential channel or into the liquid (not shown) located therein. This circumferential wall 54 is preferably arranged on the cover device 20.

[0079] The sealing device 50 preferably also has at least one further circumferential channel which is not shown in FIG. 2 and which is preferably located below the circumferential channel 52 shown. These channels are preferably connected to one another by a circumferential wall.

[0080] Furthermore, the cover device is preferably fastened to further devices of the apparatus, which can take place, for example, by means of a fastening plate 23. In this case, for example, such a connection can be established with the column on which the transport carrier, i.e., the blowing wheel, is arranged.

[0081] Reference signs 2a and 2b denote two reservoirs and in particular annular channels, which serve for storing compressed air.

[0082] In a further, preferred embodiment, components of the stretching devices 30 and in particular a housing of the stretching device 30 extends through the cover device 25.

[0083] The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they are novel over the prior art individually or in combination. It is also pointed out that features which can be advantageous in themselves are also described in the individual figures. The person skilled in the art will immediately recognize that a particular feature described in a figure can be advantageous even without the adoption of further features from this figure. Furthermore, the person skilled in the art will recognize that advantages can also result from a combination of several features shown in individual or in different figures.