METHOD AND APPARATUS FOR THE EXPANSION OF CONTAINERS WITH DETERMINING THE GAS PROPORTION

Abstract

A method for filling and expanding of containers includes the following steps: Providing an expandable container and particularly an expandable plastic preform; Filling of the container with a product, wherein the container at least at times during filling is being expanded and wherein the filling is performed by a filling device which is placed against a mouth of the container to be filled and expanded.

According to the process, at least at times a measured value is measured which is characteristic for a gas proportion being located in the filling device.

Claims

1: A method for filling and expanding of containers comprising the following steps: Providing an expandable container and particularly an expandable plastic preform; Filling of the container with a product, wherein the container at least at times during filling is being expanded and wherein the filling is performed by a filling device which is placed against a mouth of the container to be filled and expanded, wherein at least at times a measured value is measured which is characteristic for a gas proportion being located in the filling device.

2: The method according to claim 1, wherein the filling device and particularly a pressure generating device of the filling device is controlled by using the measured value.

3: The method according to claim 1, wherein the measured value is determined in a substantially enclosed volume area of the filling device.

4: The method according to claim 1, wherein the measured value is a pressure value or a measured value which is characteristic for a pressure value.

5: The method according to claim 1, wherein the measured value is a value which is characteristic for a compressibility of a medium and/or from the measured value a value is determined which is characteristic for a compressibility of the medium.

6: The method according to claim 1, wherein the container is transported along a predetermined transport path and at least at times during this transport it is expanded and filled.

7: The method according to claim 1, wherein the liquid medium is supplied to the container by a pressure generating device.

8: The method according to claim 1, wherein at least at times a pressure difference is measured and/or determined.

9: The method according to claim 1, wherein a volume of the liquid to be filled is determined inside a predetermined area.

10: The method according to claim 1, wherein a reference measuring is carried out.

11: The method according to claim 1, wherein at least at times a ventilation of the filling device is carried out.

12: The method according to claim 1, wherein a plurality of measured values is recorded.

13: An apparatus for filling and expanding plastic preforms, wherein the apparatus comprises a filling device configured to fill the plastic preforms with a product and to expand the plastic preforms into plastic containers at least at times during the filling, wherein the filling device comprises a measuring device which is configured to determine at least one measured value that is characteristic for a gas proportion being located in the filling device.

14: The apparatus according to claim 1, wherein the apparatus has a processor device which is configured to determine from at least one pressure value the gas proportion being located in the filling device.

15: The apparatus according to claim 13, wherein the apparatus has a control device configured to control the filling device and particularly the pressure application device in consideration of the measured value.

16: The apparatus according to claim 14, wherein the apparatus has a control device configured to control the filling device and particularly the pressure application device in consideration of the measured value.

Description

[0048] Further advantages and embodiments will be apparent from the attached drawings:

[0049] Which show:

[0050] FIG. 1 a schematic depiction of an apparatus according to the invention;

[0051] FIG. 2 a depiction by way of illustration of the physical principle of the invention;

[0052] FIG. 3 a further roughly schematic depiction of an apparatus according to the invention.

[0053] FIG. 1 shows a roughly schematic depiction of an apparatus according to the invention, more detailed, a transforming station which serves to expand plastic preforms into plastic containers 10 and in particular plastic bottles 10. For this purpose, these filling and transforming stations 2 (above also stated as filling device) comprise a pressure application device 4. This pressure application device 4 has a moveable piston 48 which, more precisely, is movable relative to a receiving volume 42, in which the product to be filled is located. The reference numeral 54 indicates a drive device in order to move this piston device 48. The drive device is in particular an electromotive drive device which moves the piston device in the X direction.

[0054] The reference numeral 56 indicates a path measuring device which at least indirectly determines a position of the piston 48 inside the receiving volume 42.

[0055] Via a feed line 44 a product to be filled is introduced into the receiving volume 42. Here, a valve 46 is provided which can be opened and closed in order to respectively (for example during a backward movement of the piston device 48) allow liquid and in particular product to be filled to flow into the receiving volume 42.

[0056] The product to be filled is transported starting from the receiving volume into the actual filling unit via a feed line 12. In the filling device a receiving volume 26 is provided which is here formed between a closing piston 23 and a peripheral wall 25. Starting from this receiving volume 26 the product to be filled flows via a mouth 10a into the plastic preform and causes in this way also the expansion into the plastic container 10. The reference numeral 28 indicates a contact device, which is able to be placed against the mouth 10a of the plastic preform and thus the liquid can flow into the same. This contact device can be formed as a filling nozzle which in particular is placed against the mouth rim of the plastic preform also in an air-tight manner.

[0057] The reference numeral 22 indicates a stretching rod which serves for stretching the plastic preform in the longitudinal direction L. For this purpose, there is also a drive device 24 provided which causes the movement of the stretching rod 22.

[0058] FIG. 2 shows a schematic depiction by way of illustration of the physical principals. A receiving volume with liquid 42b and air 42a can here again be seen. Inside of this volume 30 there is an air volume V1 and a product volume V2. The air has a compressibility κ1 and the product a compressibility κ2.

[0059] Via a travel length dX a volume difference dV emerges. From the above-stated formula the volume V1 can be deduced in this way which emerges from the compressibilities κ1 and κ2 (which are known), the total compressibility κ.sub.ges (which is determined by change in volume and change in pressure) and the total volume. The reference numeral 32 relates to a pressure measuring device which measures in this case the total pressure Pges, which is equal to the individual pressures p1 and p2. More precisely, the pressure measuring device 32 measures the pressure in various positions of the piston 48 and hereof it can, as mentioned above, deduce the pressure measuring curve.

[0060] The reference numeral 34 indicates a processor device which determines an air proportion of the medium to be filled and/or the air proportion of the liquid on the basis of the measured values. The reference numeral 36 indicates a control device which controls the apparatus on the basis of this air proportion and controls in particular the drive device 54 (compare FIG. 1).

[0061] In addition, the apparatus can also comprise a ventilation device (not shown) which enables ventilation of the apparatus.

[0062] FIG. 3 shows a roughly schematically depiction of an apparatus according to the invention 1 for expanding and transforming plastic preforms. In this case, the apparatus has a rotatable carrier 6 on which a plurality of filling and transforming devices 2 are arranged. The plastic preforms can for example be fed via a feed star (not shown) and the transformed and filled containers can be discharged from the plant via a discharge star (also not shown).

[0063] The Applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided they are novel individually or in combination with respect to the prior art. It is further pointed out that in the individual figures there are features described which per se can be advantageous. The person skilled in the art directly acknowledges that a certain feature described in a figure can also be advantageous without including further features from this figure. Further, the person skilled in the art acknowledges that advantages can also emerge through a combination of features shown in several, individual or different figures.

LIST OF REFERENCES

[0064] 2 Filling device [0065] 4 Pressure application device [0066] 6 carrier [0067] 10 container [0068] 10a mouth [0069] 12 connecting line [0070] 22 stretching rod [0071] 23 closing piston [0072] 25 peripheral wall [0073] 26 receiving volume [0074] 28 contacting device [0075] 30 volume [0076] 32 pressure measuring device [0077] 34 processor device [0078] 42 receiving volume [0079] 44 feed line [0080] 46 valve [0081] 48 piston device [0082] 54 distance measuring device [0083] 56 drive device [0084] X movement direction of the piston device [0085] L longitudinal direction of the container 10 [0086] V1 air volume [0087] V2 product volume [0088] κ1 compressibility of air [0089] κ2 compressibility of product [0090] dV volume difference [0091] p1 pressure [0092] p2 pressure