APPARATUS FOR EXPANDING PLASTICS MATERIAL CONTAINERS WITH DOUBLE-ACTING PRESSURE GENERATING DEVICE

Abstract

Apparatus is provided for expanding plastics material parisons into plastics material containers by a liquid medium, having at least one transforming station, which fills and expands the plastics material parisons with the liquid medium with at least one pressure generating device, which is suitable and intended to deliver the liquid medium to at least one filling device, which filling device fills the plastics material parisons with the liquid medium, wherein the pressure generating device has a pressure outlet which at least at times can be fluidically connected to the plastics material parison to be filled. The apparatus has a removal device which is suitable and intended at least at times to remove a flowable medium from a plastics material container, wherein the pressure generating device has a suction intake which at least at times can be fluidically connected to this removal device in order to remove the flowable medium.

Claims

1. An apparatus for expanding plastics material parisons into plastics material containers by a liquid medium having at least one transforming station, which fills and expands the plastics material parisons with the liquid medium with at least one pressure generating device, which is suitable and intended to deliver the liquid medium to at least one filling device, which filling device fills the plastics material parisons with the liquid medium, wherein the pressure generating device has a pressure output which at least at times can be fluidically connected to the plastics material parison to be filled, wherein the apparatus has a removal device which is suitable and intended at least at times to remove a flowable medium from a plastics material container, wherein the pressure generating device has a suction intake which at least at times can be fluidically connected to this removal device in order to remove the flowable medium.

2. The apparatus according to claim 1, wherein the pressure generating device has a piston element which is movable relative to a liquid chamber.

3. The apparatus according to claim 1, wherein the apparatus has a movable or stationary carrier on which the transforming stations are arranged.

4. The apparatus according to claim 1, wherein the apparatus has a receiving device for liquid medium removed from the container.

5. The apparatus according to claim 1, wherein the apparatus has a closing device in order to close a flow path of the liquid medium from the container.

6. The apparatus according to claim 1, wherein the apparatus has a rod-like body for expanding the containers, wherein this rod-like body has a channel for conveying the liquid medium.

7. The apparatus according to claim 1, wherein the apparatus has a further receiving container to receive the liquid medium and this further receiving container is advantageously arranged below the plastics material container to be expanded.

8. The apparatus according to claim 7, wherein the further receiving container is fluidically connected at least at times to the container to be expanded.

9. A method for expanding plastics material parisons into plastics material containers by a liquid medium, with at least one transforming station, which fills and expands the plastics material parisons with the liquid medium, wherein at least one pressure generating device delivers the liquid medium to at least one filling device, which filling device fills the plastics material containers with the liquid medium, wherein the pressure generating device has a pressure output which at least at times is fluidically connected to the plastics material parison to be filled, wherein the apparatus has a removal device which at least at times removes a flowable medium from a plastics material container, wherein the pressure generating device has a suction intake which at least at times is fluidically connected to this removal device in order to remove the flowable medium.

10. The method according to claim 9, wherein the removal of the flowable medium from the container takes place at least in part through a rod-like member, wherein this rod-like member is introduced at least at times into the plastics material container in a longitudinal direction thereof.

11. The method according to claim 9, wherein venting takes place at least at times by the rod-like member, wherein this venting takes place in particular using the Venturi effect.

Description

BRIEF DESCRIPTION

[0050] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0051] FIG. 1 shows a schematic representation of an arrangement;

[0052] FIG. 2 shows a detail of the arrangement shown in FIG. 1;

[0053] FIG. 3 shows a plan view of the representation shown in FIG. 2; and

[0054] FIG. 4 shows a rough schematic representation of an apparatus.

DETAILED DESCRIPTION

[0055] FIG. 1 shows a schematic representation of a transforming station 2 according to embodiments of the invention. In this case the reference numeral 10 relates to a container which is expanded and simultaneously filled with the filling material. The reference numeral 16 designates a so-called stretching rod which can be introduced into the container via the mouth of the container, in order also to stretch it in its longitudinal direction during the stretching process. This stretching rod has a channel in its interior and in particular a channel which extends in the longitudinal direction of the stretching rod and through which the liquid medium can flow.

[0056] The reference numeral 4 designates a pressure generating device as a whole. This pressure generating device has a piston 46 which is movable in the direction x relative to a liquid chamber 48, in order thus to convey the liquid by means of a pressure outlet 42 via a conduit 32 to a filling device designated as a whole by 12. Starting from the filling device the liquid enters the container 10. The filling device 12 serves simultaneously as a pressure application device, in order to apply a pressure to the plastics material parisons in order to expand them.

[0057] The reference numeral 44 designates a suction intake of the pressure application device. In a movement of the piston element downwards in FIG. 1, medium is drawn in via this suction intake 44. For this purpose, a conduit 34 is provided which leads from the outlet of the filling device 12 and likewise to the mouth of the container 10. In addition, liquid can also be drawn off by means of the hollow stretching rod 16 into the connecting conduit 54. The reference numeral 14 designates a receiving container for (intermediate) storage of liquid. The reference numeral 52 designates a further conduit device. Together with the filling device which also serves here for removal of liquid, the totality of these individual conduits forms the removal device 6.

[0058] Furthermore, a conduit 38 is provided, by means of which liquid can enter a receiving container 50 due to the siphon effect. The reference numeral 36 designates a valve, in order to allow or to block this fluid stream. Thus, it would be possible to draw off liquid by means of the hollow stretching rod 16 and possibly a switchable non-return valve which could be arranged in the stretching rod. This non-return valve could prevent filling material from entering the stretching rod again. In this way, after or during the collapse of the plastics material container the container could be vented due to the siphon effect and thus the container could be brought again into its original state. A resulting temporary negative pressure due to the siphon effect could open the non-return valve and by means of a feed conduit air from the environment or also a neutral gas such as nitrogen or carbon dioxide from a tank could be supplied.

[0059] By means of the pressure in the container, during opening of this valve of the feed conduit the displaced volume in the container could be adjusted. If the feeding of the air takes place during the pressure relief, the stretching rod position would have to be deeper than 50% of the bottle height in order to prevent the gas from being flushed out of the container in the direction of the receiving container 50. Since the pressure relief takes place relatively quickly, despite the supply of air the air still cannot rise upwards so quickly that it is flushed by the siphon effect in the direction of the receiving container.

[0060] In this case a pressure below 4 bars could be maintained and no further means would be necessary for reduction of pressure.

[0061] Alternatively, the sealing of the stretching rod could also be carried out by means of contact between the ridge of the plastics material parison and the stretching rod during longitudinal stretching.

[0062] Pressing of the piston 46 would also be conceivable when pressure is relieved in a tank located further down. By pressing of the piston 46 with an opened valve 72 (cf. FIG. 2) in the filling device 12, the positive pressure which would be produced by the piston travel could prevent the collapse of containers due to the lower tank and the occurring siphon effect.

[0063] The valve 36 in the direction of the container 50 could be closed prematurely.

[0064] The last positive pressure could then be reduced by return travel of the piston 46 and/or the stretching rod. This could be controlled and/or regulated by a pressure sensor in the filling device 12 or in the container.

[0065] Furthermore, it would also be possible, that the connection 54 between the stretching rod and the receiving chamber above the piston 46 is used in order to clean the piston drive, in order for example to move the piston 46 into a position in which there is no contact with the side wall and a cleaning medium is introduced by means of a feed conduit 47 and/or a separate supplying into the connection or the individual feed conduits. The reference numeral 49 designates a valve in this feed conduit.

[0066] Overall, in this way it is possible to save a vacuum pump and the process engineering conditions of the piston drive of the piston 46 can be used. Furthermore, in this way a controlled collapse of the container is made possible by a stretching rod device or pressing of the piston 46.

[0067] Furthermore, it would also be possible to deliver a neutral gas. In the method proposed here, however, a negative pressure in the head would not be injected by the stretching rod but by the filling piston 46. The venting also would be affected by this. As mentioned above, an alternative would be to provide a non-return valve (in particular in the stretching rod) which in the event of negative pressure frees the gas path in the interior of the stretching rod. In addition, the negative pressure could also be achieved by means of the above-mentioned siphon effect. The negative pressure could also be achieved via openings in the application device or filling nozzle.

[0068] Air supplied with positive pressure can be admitted in the container, through venting holes arranged in particular horizontally in the stretching rod, and the filling level can also be adjusted on the basis of the filling level. In addition, it would also be conceivable that these venting holes are arranged vertically or are also arranged obliquely.

[0069] In a further procedure it would also be conceivable to make the container 10 and/or the filling device 12 and/or the pressure application device 4 pressureless (or to supply them with a slight positive pressure), before the removal operation and/or extraction operation is started. In this way, through the stretching rod (in particular their channel) or also through an additional conduit between the container 10 and the receiving chamber (not shown), the negative pressure is used (in particular during return travel of the piston element 46) in order to adjust the filling level.

[0070] FIG. 2 shows a detail of the filling device according to embodiments of the invention. This shows in particular the valve 72 which can also adjoin the stretching rod. The reference numeral 62 designates an outlet by means of which liquid can be drawn off from the container and can be fed for example to the conduit by the valve 36. The reference numeral 10a designates a rim of the mouth of the plastics material parison to which the filling device 12 is applied. For this purpose, the filling device can have an abutment edge 76 which is applied peripherally to the mouth of the plastics material parison.

[0071] FIG. 3 shows a detail of this region of the filling device and of the edge of the plastics material parison. This again shows in particular the openings 62, by means of which medium can be drawn off from the container, or can be removed in the event of positive pressure, and can be fed to the receiving container 50 by the siphon effect.

[0072] The reference numeral 75 likewise designates an opening through which liquid can flow. The reference numeral 74 designates the filling material flowing into the container 10, i.e. the liquid to be filled.

[0073] FIG. 4 finally shows a rough schematic representation of an apparatus 1 according to embodiments of the invention. This has a rotatable carrier 22 on which a plurality of transforming stations 2 are arranged. In this case, as mentioned above, it would also be possible that a container is shaped or filled by a first transforming station 2 and liquid is drawn off from a container which is just being handled by a further transforming station.

[0074] In this way it is possible that an individual piston or an individual pressure application device 4 is associated with each transforming station. However, it would also be possible that a pressure application device is associated with several transforming stations. In addition, flow connections can also be provided between a transforming station 2 and the pressure application device which is associated with a further transforming station.

[0075] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0076] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements. The mention of a unit or a module does not preclude the use of more than one unit or module.

LIST OF REFERENCE SIGNS

[0077] 1 apparatus [0078] 2 transforming station [0079] 4 pressure generating device [0080] 10 container [0081] 10a rim of the mouth [0082] 12 filling device [0083] 14 receiving container [0084] 16 stretching rod [0085] 22 carrier [0086] 32 conduit [0087] 34 conduit [0088] 36 valve [0089] 38 conduit [0090] 42 pressure outlet [0091] 44 suction intake [0092] 46 piston [0093] 47 feed conduit [0094] 48 liquid chamber [0095] 49 valve [0096] 50 receiving container [0097] 52 conduit device [0098] 54 connecting conduit [0099] 62 outlet, opening [0100] 72 valve [0101] 74 liquid to be filled [0102] 75 opening [0103] 76 abutment edge [0104] X direction of movement