MOULDING AND FILLING STATION OF AN INSTALLATION FOR PRODUCING FILLED CONTAINERS FROM PREFORMS BY MEANS OF FILLING MATERIAL INTRODUCED INTO THE PREFORM UNDER PRESSURE

Abstract

The invention relates to a moulding and filling station of an installation for producing filled containers from preforms (2) by means of liquid filling material introduced into the preform (2) under pressure, said moulding and filling station comprising a stretch rod (1) and a liquid duct (3), which can be controlled by means of a filling valve (22), passes through at least part of the stretch rod (1) and ends in at least one outlet opening (4a, 4b, 4c, 4d, 5) in the stretch rod (1), and being characterised in that a gas barrier (6, 6a, 6b) is provided in the liquid duct (3) between the filling valve (22) and the outlet opening (4a, 4b, 4c, 4d, 5). The invention also relates to a stretch rod (1) for a moulding and filling station, having a filling material duct (3) and at least one outlet opening (4a, 4b, 4c, 4d, 5) for discharging filling material, a gas barrier (6, 6a, 6b) being provided in the filling material duct (3).

Claims

1-14. (canceled)

15: A molding and filling station of an installation for producing a filled container from a preform by introducing a liquid filling material under pressure into the preform, the molding and filling station comprising: a stretch rod; a liquid duct that passes at least partially through the, stretch rod; and a filling valve for controlling a flow of the liquid filling material through the liquid duct; wherein at least one outlet opening is provided in an end portion of the stretch rod, and wherein a gas barrier is disposed in the liquid duct between the filling valve and the at least one outlet opening.

16: The molding and filling station according to claim 15, wherein the gas barrier comprises an insert provided with a plurality of flow passages, and wherein each said plurality of flow passages has a cross-sectional area that is smaller than a cross-sectional area of the liquid duct.

17: The molding and filling station according to claim 16, wherein the plurality of flow passages in the gas barrier are round or polygonal in cross-section.

18: The molding and filling station according to claim 16, wherein the plurality of flow passages in the gas barrier are triangular or hexagonal in cross-section.

19: The molding and filling station according to claim 16, wherein some of the plurality of flow passages in the gas barrier are arranged in rings that are coaxial relative to each other and to the stretch rod.

20: The molding and filling station according to claim 19, wherein each of the plurality of flow passages through the gas barrier has a length that is greater than the cross-sectional area of said flow passage.

21: The molding and filling station according to claim 15, wherein the gas barrier is disposed in the liquid duct directly upstream from the at least one outlet opening disposed in the end portion of the stretch rod.

22: The molding and filling station according to claim 15, wherein at least one further outlet opening is provided in the stretch rod other than in the end portion, and wherein a further gas barrier is disposed upstream from the at least one further outlet opening.

23: A stretch rod for use in a molding and filling station of an installation for producing a filled container from a preform by introducing a liquid filling material, said stretch rod comprising a filling material duct that passes at least partially through the stretch rod, wherein at least one outlet opening is provided in an end portion of the stretch rod for the discharge of filling material, and wherein a gas barrier is disposed in the filling material duct.

24: The stretch rod according to claim 23, wherein the gas barrier comprises an insert provided with a plurality of flow passages, and wherein each of said plurality of flow passages has a cross-sectional area that is smaller than a cross-sectional area of the filling material duct.

25: The stretch rod according to claim 24, wherein the plurality of flow passages in the gas barrier are round or polygonal in cross-section.

26: The stretch rod according to claim 25, wherein the plurality of flow passages in the gas barrier are triangular or hexagonal in cross-section.

27: The stretch rod according to claim 23, wherein some of the plurality of flow passages in the gas barrier are arranged in rings that are coaxial relative to each other and the stretch rod.

28: The stretch rod according to claim 27, wherein each of the plurality of flow passages through the gas barrier has a length that is greater than the cross-sectional area of said flow passage.

29: The stretch rod according to claim 23, wherein the gas barrier is disposed in the liquid duct directly upstream from the at least one outlet opening disposed in the end portion of the stretch rod.

30: The stretch rod according to claim 23, wherein at least one further outlet opening is provided in the stretch rod other than in the end portion, and, wherein a further gas barrier is disposed in the filling material duct upstream from the at least one further outlet opening.

Description

[0022] Various embodiments of stretch rods according to the invention are explained in greater detail below on the basis of the accompanying illustrations which show the following:

[0023] FIG. 1 shows schematically the elements of a molding and filling station in the context of a machine for simultaneous molding and filling of containers;

[0024] FIG. 2 shows a sectional view of a stretch rod during according to the invention simultaneous molding and filling of a preform to form a container in a sectional view;

[0025] FIG. 3 shows a sectional view of the stretch rod from FIG. 1 at the start of a molding and filling operation in a pressureless state;

[0026] FIG. 4 shows a perspective partially cutaway diagram of a stretch rod according to the invention with a gas barrier;

[0027] FIG. 5 shows a stretch rod like that in FIG. 1, wherein the stretch rod has a plurality of outlet openings at different levels.

[0028] All the diagrams are understood to be illustrations of the principle of the invention. They are also represented in simplified form in some cases and include only the components required to illustrate the invention. Based on their technical knowledge, those skilled in the art can readily vary the size ratios of the individual components to one another or adjust them to specific needs.

[0029] FIG. 1 shows a longitudinal section through a preform 2 into which a stretch rod 1 is inserted. The stretch rod 1 serves to guide the preform 2 at least temporarily while it is being reshaped to form the container. Typically there is contact between the tip 18 of the stretch rod 1 and the bottom 19 of the preform 2. Further insertion of the stretch rod 1 into the preform 2 causes longitudinal stretching of the preform 2. After the end of the stretching operation or even while the stretching operation is being carried out, filling material 21 taken from a storage device 20 is introduced into the preform 2 through the liquid duct 3 in the interior of the stretch rod 1. The liquid stream can be controlled by the filling valve 22.

[0030] The preform 2 can be ventilated by using a vent valve 26. The vent valve 26 is connected to an outflow opening 27 arranged in the area of a molding and filling head 8 acting on the preform 2. The stretch rod 1 can be positioned by means of the molding and filling head 8. The preform 2 is sealed with respect to the molding and filling head 28 by a gasket 29, which may be designed as an 0-ring, for example. An interior space 30 of the preform 2 can be connected by an annular gap 31 to the outflow opening 27. The annular gap 31 thereby encloses the stretch rod 1 in some areas.

[0031] With the filling valve open, the filling material can flow through the outlet openings 4a, 4b into the preform 2. According to the invention, a gas barrier 6 is arranged upstream from the outlet openings.

[0032] FIG. 2 shows a stretch rod 1 according to the invention in a sectional view during the simultaneous molding and filling of a preform 2 to form a container. The molding and filling head 8 of a molding and filling station of an apparatus for simultaneous molding and filling of bottles from preforms is placed on the mouth 7 of the preform. The preform 2 is in a mold (not shown here) which defines the shape of the bottle to be molded.

[0033] A liquid duct 3 through which filling material can be introduced into the preform 2 under a high pressure is situated in the interior of the stretch rod 1. To this end, the filling valve (not shown in this figure), which is situated above the stretch rod in the liquid stream, is opened. Filling material is introduced through the outlet openings 4a, 4b and 5 into the preform 2. The pressure prevailing in the preform ensures the shaping to form a container, as indicated by the arrows.

[0034] A gas barrier 6 is situated directly upstream from outlet openings 4a, 4b and 5.

[0035] FIG. 3 illustrates the same arrangement as in FIG. 1, but at the start of a molding and filling operation. The stretch rod 1 is already inserted into the preform 2 but is still pressureless because the filling valve (not shown) is not yet closed. The gas barrier 6 prevents the filling material present in the liquid duct 3 from flowing through the outlet openings 4a, 4b, 5 into the stretch rod as long as the station is pressureless.

[0036] To this end, as illustrated in FIG. 4, a gas barrier 6 may be arranged in the stretch rod 1, which is illustrated here in a partially cutaway view. The gas barrier 6 consists of a plurality of ducts 9 each having a round cross section and a length L corresponding to a multiple of the duct diameter. Which dimensions and ratios between the duct diameter and duct length L are suitable depends to a significant extent on the filling material and its surface tension. Those skilled in the art can easily ascertain suitable dimensions theoretically or experimentally.

[0037] FIG. 5 shows a stretch rod 1 like that in FIG. 1, where the stretch rod has a plurality of outlet openings 4a, 4b, 5 and 4c, 4d at different levels. In this way, the filling material can be introduced at different levels into the container being molded. A gas barrier 6a is thus located directly upstream from the lower outlet openings 4a, 4b, 5 as well as upstream from the upper outlet openings 4c, 4d. The upper gas barrier 6b prevents filling material from running out of the liquid duct in the stretch rod from above when the liquid has flowed out after closing the filling valve beneath the gas barrier 6b through the outlet openings 4c, 4d and there is a small unfilled region in the stretch rod in the area of the upper outlet openings 4c, 4d.