Container and blow mold

Abstract

The invention relates to a container (1) for receiving a liquid content, comprising a container wall (10) which surrounds a container interior (12) and comprises an opening (8). The container wall has an opening region (2) at the opening, a base region (4) arranged opposite the opening region, and a lateral region (3) which extends between the opening region and the base region, and the container wall has a dimensionally stable central region (22) in the base region and a flexible flat region (24) which encircles the central region. The container wall transitions from the central region into the flat region at an angle such that an edge (26) which encircles the central region is formed in the container wall between the central region and the flat region. The invention further relates to a blow mold (31) for producing such a container.

Claims

1. A container for receiving a liquid, said container comprising a container wall which surrounds a container interior and comprises an opening, wherein the container wall has an opening region at the opening, a base region arranged opposite the opening region, and a lateral region which extends between the opening region and the base region, wherein, in the base region, the container wall has a dimensionally stable central region and a flat flexible region which encircles the central region, wherein the container wall transitions from the central region into the flexible region at an angle such that an edge which encircles the central region is formed in the container wall between the central region and the flexible region, wherein a standing bead is formed in the base region of the container wall outward of the flat flexible region, wherein the container wall in the flexible region is configured to bulge away from the container interior in response to positive pressure in the container such that the bulged flexible region forms a standing ring that extends longitudinally beyond the standing bead, and wherein the diameter of the standing ring becomes smaller with increasing positive pressure in the container.

2. The container according to claim 1, wherein the container wall comprises a thermoplastic material.

3. The container according to claim 1, wherein the container wall is formed in a bead along the edge.

4. The container according to claim 1, wherein the standing bead is in a form of a continuous ring which encircles the flexible region.

5. The container according to claim 1, wherein the container wall has a maximum wall thickness of 0.25 mm in the flexible region.

6. The container according to claim 1, wherein the container wall has a greater wall thickness in the central region than in the flexible region.

7. The container according to claim 1, wherein the container wall has a dimensionally stabilizing contour in the central region.

8. The container according to claim 7, wherein the dimensionally stabilizing contour is curved at least in sections.

9. The container according to claim 8, wherein the dimensionally stabilizing contour is a dome.

10. The container according to claim 8, wherein the dimensionally stabilizing contour is in the form of a spherical cap.

11. The container according to claim 1, wherein a diameter of the central region is within a range of 40 to 70% of a diameter of the base region.

12. The container according to claim 1, wherein the standing bead adjacently surrounds the flexible region or is separated from the flexible region only by an edge which annularly surrounds the flexible region.

13. A blow mold for producing a container according to claim 1, wherein the blow mold is a hollow mold having an inner surface that predetermines a contour of the container wall of the container.

14. The blow mold according to claim 13, wherein the blow mold is not formed in one piece, but rather is formed as several separate and distinct parts.

15. The blow mold according to claim 14, wherein one of the several separate and distinct parts is a base mold for predefining a contour of the base region of the container.

16. The blow mold according to claim 15, wherein the base mold has an edge contour.

17. The blow mold according to claim 15, wherein the base mold is formed in one piece.

18. The container according to claim 1, wherein the container wall has a maximum wall thickness of 0.20 mm in the flexible region.

19. The container according to claim 1, wherein the standing bead is formed at a transition of the flexible region into the lateral region of the container.

Description

(1) The invention is explained below without limiting the general idea of the invention by means of an exemplary embodiment with reference to the drawings. In the drawings:

(2) FIG. 1 shows schematically an exemplary embodiment of a container according to the invention;

(3) FIG. 2a schematically shows a perspective view of the base region of the container from FIG. 1,

(4) FIG. 2b schematically shows a sectional view of a part of the container shown in FIG. 1;

(5) FIG. 3a shows schematically an exemplary embodiment of a base mold for a blow mold according to the invention;

(6) FIG. 3b schematically shows a sectional view of the base mold for forming the base from FIG. 2a; and

(7) FIG. 4 schematically shows a sectional view of the part of the container depicted in FIG. 2b, wherein the flat region is bulged out.

(8) FIG. 1 shows, by way of example, an exemplary embodiment of a container 1 according to the invention, which is formed as a bottle. Apart from an opening 2, the container 1 has a container wall 10, which is divided into an opening region 2 at the opening 8, a base region 4 and a lateral region 3 extending between the opening region 2 and the base region 4. In order to increase the surface stability, the container wall 10 has stabilization ribs 14 in the lateral region 3.

(9) A perspective view of the base region 4 is shown schematically in FIG. 2a, a schematic sectional view of the lower part of the container 2 is shown in FIG. 2b.

(10) The container wall 10 has a circular-symmetrical contour in the base region 4, which extends substantially concentrically around an injection point 23. The injection point 23 is a remnant of an injection-molded workpiece from which the container 1 was produced after thermal conditioning by means of a blow mold 31 in a stretch blow molded body process.

(11) In the immediate vicinity of the injection point 23, the contour of the container wall 10 has a depression, which transitions into a bulged central region 22. In the central region 22, the container wall 10 is otherwise bulged and thus particularly dimensionally stable, wherein the depression around the injection point 23 is designed as far as possible in such a way that it supports or even improves dimensional stability. It is also conceivable to provide a comparatively large wall thickness or a comparatively thick container wall in the central region 22 for further stabilization.

(12) Radially outside the central region 22, a flat region 24 is provided in the container wall 10, which encircles the central region 22. Within the scope of the invention, it is advantageous if the flat region 24 is oriented substantially concentrically around the central region 22. It is also advantageous if the central region 22 and the flat region 24 are formed to be rotationally symmetrical, in particular circular symmetrically within the usual production tolerances.

(13) According to the invention, the flat region 24 is configured flexibly. For this purpose, it is provided in particular that an edge 26 is formed between the central region 22 and the flat region 24 in the container wall 10, against which the central region 22 and the flat region 24 abut one another at an angle. It may also be provided to configure the wall thickness of the container wall 10 in the flat region 24 comparatively thin. If the container wall consists substantially of PET, a wall thickness in the flat area 24 of about 0.16 mm has proved to be useful in practice for the container 1 shown. However, the person skilled in the art will take into account that this is a value optimized for a single exemplary embodiment of the invention from which it is possible to deviate within the scope of the invention, and in particular also depends on the material used.

(14) According to experience, the wall thickness in the flat region 24 should not exceed 0.25 mm, wherein wall thicknesses of 0.2 mm or less have proved to be useful for a wide range of different containers, e.g. wall thicknesses of 0.18 mm or less.

(15) In the bottle shown by way of example, the edge 26 is also formed as a reinforced bead, so that the edge forms a bending-resistant ring between the central region 22 and flat region 24. This increases the stability of the central region 22 and favors a deformation of the flat region 24 under pressure, since a flow of force from the flat region 24 to the central region 22 is deflected at the edge 26 and thereby interferes with a stabilizing support of the flat region 24 at the central region 22. Radially outside the flat region 24, a standing bead 28 is formed in the container wall 10, which adjacently surrounds the flat region 24 as a stabilized ring.

(16) Overall, according to the invention, this results in a contour in which the annular flat region 24 extends between two comparatively stable rings and thus achieves a functionality similar to a rolling bellows, so that the dimensionally stabilized central region 22 can be moved when the flat region 24 is deformed.

(17) In particular, the central region 22 can move upwards for volume reduction of the container interior 12 and downwards for a volume increase and thus at least partially compensate pressure differences occurring between the container interior 12 and the surroundings.

(18) Typically, the container 1 formed as a bottle will thereby be standing securely on the annular standing bead 28. However, in the case of the present invention, the stability is also ensured if the flat region 24 bulges downwards beyond the standing bead 28 when the volume of the container interior 12 increases. In this case, an annular ridge results in the bulged out flat region 24, which however is in any case at least as big as the ring formed by the edge 26, and thus always provides sufficient footprint.

(19) A bead-like stabilization of the edge and/or the presence of a standing bead 28 is advantageous for this mode of action according to the invention. The described mode of action of the base region according to the invention is, however, already achieved substantially when the inner ring is formed as a simple bend between the central region 22 and flat region 24 and the outer ring is formed by the transition of the flat region 24 into the substantially vertical side wall of the container.

(20) In the bottle shown by way of example in FIG. 2b, the edge 27, i.e., the edge between the flat region 24 and the standing bead 28, is formed as a step so that the edge forms a bending-resistant ring between the flat region 24 and the standing bead 28. This increases the stability and favors a deformation of the flat region 24 under pressure, since a flow of force from the flat region 24 to the standing bead 28 is deflected at the edge 27 and thereby interferes with a stabilizing support of the flat region 24 at the standing bead 28.

(21) FIG. 4 shows, by way of example, an exemplary embodiment of the container 1 according to the invention from FIG. 2b, wherein the flat region 24 is bulged out of the container interior in the longitudinal direction of the container 1 beyond the standing bead 28 by a volume increase of the container interior. The flat region 24 thereby forms a standing ring 29, which encircles the central region 22 or the edge 26 and can serve as a secure footprint for the container 1. The central region 22 is formed dimensionally stabilized in the form of a dome and usually does not bulge out of the container interior.

(22) According to the invention, there is also a base mold 30 by means of which the described base contour according to the invention of a container 1 can be produced or molded in the base region 4. An exemplary base mold 30 for molded body the base region 4 shown FIGS. 2a and 2b is shown in FIGS. 3a and 3b, wherein FIG. 3a shows a schematic side view and FIG. 3b shows a schematic sectional view.

(23) The base mold 30 substantially consists of a molded body which is formed, for example, from a metal, such as aluminum or steel. Mold surfaces 22, 26 and 28 are provided in this molded body, which predefine the contour of the container wall in the base region 4, in particular of the central region 22, the flat region 24 and the standing bead 28. In addition, there is an edge contour 26 for molding the edge 26 between the central region 22 and the flat region 24. Advantageously, the edge contour 27 can also be provided, which serves molding the edge between the flat region and the standing bead.

(24) In addition, the molded body has bores 34 for forming cooling passages as well as bores 32 for forming ventilation passages, wherein the bores 34 for the cooling channels are closed by a closure 35 on the outside.

REFERENCE NUMERALS

(25) 1 Container 2 Opening region 3 Lateral region 4 Base region 8 Opening 10 Container wall 12 Container interior 14 Stabilizing rib 22 Central region 22 Molding surface for the central region 23 Injection point 24 Flat region 24 Molding surface for the flat region 26 Edge 26 Mold contour for edge 27 Edge between the flat area and standing bead 27 Mold contour for edge between flat area and standing bead 28 Standing bead 28 Molding surface for standing bead 29 Standing ring 30 Base mold 31 Blow mold 32 Bore for venting passage 34 Bore for cooling passage 35 Closure