WO2009046553A1

WO2009046553A1 - Plastic closure

Info

Publication number: WO2009046553A1
Application number: PCT/CH2008/000402
Authority: WO
Inventors: Werner Dubach
Original assignee: Deltona Innovations Ag
Priority date: 2007-10-10
Filing date: 2008-09-26
Publication date: 2009-04-16

Abstract

A plastic closure (1) comprising a bottom part (2) and a lid (6) has an annular retaining bead (10) in the bottom part. A disk (11) having a support surface (12) is held positively or non-positively in said bead. The disk comprises one or more through-passages (13), which open into a chamber (17). A thixotropic fluid present in a flexible container reaches the chamber (12) through the through-passages (13), whereupon the fluid performs a directional change from axial to radial and after a second directional change from radial to axial flows out through the spout opening (5), wherein a constriction (21) between the two directional changes accelerates the flow.

Description

Plastic closure

The present invention relates to a two- or multi-part plastic closure for attachment to the container neck of a flexible bottle for dispensing thixotropic liquids, according to the preamble of claim 1.

Thixotropic liquids are liquids with a non-Newtonian flow behavior. A typical example of such a liquid is ketchup. Also, various liquid soaps have thixotropic behavior, as do many dispersions. Today, such liquids are offered in flexible plastic containers which are provided with closures with a so-called closure membrane. Closures with a so-called closure membrane have become known in many embodiments. For example, see EP-A-545,678, EP-A-442,379, US-A-2,175,052 or WO-A-2006/119315. The great advantage of closures with a sealing membrane is that the already opened container can be kept upside down without the liquid flowing out. By pressure on the flexible bottle, the sealing membrane is deformed and the most slit-shaped opening spreads, and the liquid can be pressed out of the bottle. The problem here is that the tighter the membrane is held, the better the closing force, and the faster the closure closes when the pressure on the container wears off. This creates over time in the container ever greater negative pressure, so that on the one hand the bottle deforms more and more during use and also the pressure required to deliver the liquid must be increased. If the closure membrane is less taut, then at least some of the displaced air can at least partially be returned to the container, but at the same time the closure tends to drip off. In addition, the tighter the sealing membrane is stretched, the more the closure tends to open explosively under pressure, so that a jet emerges at high speed and prone accordingly to spraying.

In order to reduce this problem, various complex closure membrane closures have come on the market, in which the closure membrane in shape is becoming more complex and the extremely small component with respect to the assembly in the closure is becoming more expensive. In these complex closure membranes, however, it is possible to create a closing action or an opening of the slit-shaped closure, as soon as there is a pressure difference between the atmosphere and the internal pressure of the bottle. This possibility thus also ensures the ventilation of plastic bottles. But these plastic bottles with sealing membrane remain alone from the diversity of materials that must be used here, namely on the one hand, the membrane must be made of a silicone rubber and on the other hand, the actual closure is made of a polypropylene, not the possibility this in the same machine to produce at the same injection process at once. In addition, the silicone rubber part is a relatively expensive part and already for this reason one wishes make this part as small as possible. However, the smaller this part is and with its high flexibility, the mechanical assembly is extremely complex and prone to failure.

In the inventive closure, it has been limited to create a closure that is limited in use to thixotropic liquids. Thixotropy refers to the property of a non-Newtonian fluid in which, with constant shear, the viscosity degrades over a period of time. After exposure to the shear stress, the initial viscosity is rebuilt. In other words, the longer a thixotropic liquid is moved, the thinner it gets, and in most cases, the faster the movement is carried out, the faster the viscosity will decrease. In other words, it is ensured that in such a closure, the flow direction is changed and the flow is accelerated, a good flowability of the thixotropic liquid is achieved, while at low viscosity a simple barrier in the flow direction is sufficient to prevent leakage.

From DE-U-20112974 a plastic closure is known in which below the spout an inner cap is used which has two concentric walls and wherein in the mounted state, the spout protrudes within the region of the inner concentric wall. As a result, a discharge labyrinth is formed with a siphon effect wherein the siphon is to be sucked empty in the provision of the flexible bottle. The very complicated outflow path with a large number of changes of direction and several constrictions leads to thixotropic fluids Due to the internal friction, a great resistance arises, which must be overcome during actuation and causes the liquid to jerk out during actuation. At the same time, however, such a labyrinth also leads inevitably always to certain residues which dry up due to the inclusion of air within the labyrinth path. These residues narrow the flow path, which further increases the problems described. It has been found that such closures clog completely over time and accordingly closures of this kind are no longer available on the market today.

Also, US-A-4460101 shows such a labyrinth closure with a support surface mounted under the spout. Also, this closure has the problems described above, in which case the flow path is even more complex, with the result that this closure is even more prone to clogging. In particular, the latter patent mentions the use of thixotropic liquids. Thanks to the many changes in direction and constrictions, the viscosity of the liquid is forcibly improved by the internal friction, however, as already mentioned, the flow path is so complex that the function is only ensured to some extent if the container is vigorously shaken beforehand and the thixotropy is thus reduced Viscosity already changed so that practically the additional changes in direction and narrowing would hardly be required. By appropriate experiments, the Applicant has simplified the inventive closure starting from the known prior art so that the problems mentioned here no longer arise. With only one constriction and only two changes in direction, the thixotropy can be sufficiently reduced during at the same time the force is less and there are hardly any possibilities that the closure sticks with prolonged use or completely closes. Despite the problem of such closures, which has existed for years, no closures on the market which are especially suitable for thixotropic liquids have not yet become sticky, even during prolonged use.

This solution of a closure which uses the flow behavior of thixotropic liquids in a simple manner, it is apparent from the characterizing part of claim 1. Further advantageous embodiments will become apparent from the dependent claims.

In the drawings, two preferred embodiments of the subject invention are shown, and in the following description with reference to the accompanying drawings.

It shows:

1 shows a diametrical vertical section through the lower part of a plastic closure according to a first embodiment of the subject invention.

FIG. 2 shows the same lower part according to FIG. 1 with a view of the underside; FIG.

Fig. 3 shows a variant with a plurality of spouts and

Fig. 4 shows a closure according to Fig. 1 with a snap hinge lid. The plastic closure according to the invention is designated overall by 1. This plastic closure consists of a lower part 2 and an upper part or cover 6. The plastic closure 1 can be designed in two parts or in several parts. Here, a two-part closure is understood to mean a closure in which the lower part and lid are made in one piece and the support surface to be described is a separate pane. However, if lower part and lid are made separately and in addition the mentioned disc exists, it is spoken of a multi-part plastic closure. In the illustration according to Figures 1 and 2, a multi-part plastic closure is shown, while in Figure 4, a two-piece plastic closure is shown, in which the lower part 2 and the cover 3 are made in one piece.

The lower part 2 contains the essential parts of the invention and this lower part can have virtually any shape and design, as is known in plastic closures according to the prior art. Accordingly, the lower part 2 is shown only symbolically and simplified. So lack of the parts shown here, the necessary per se, but in relation to the embodiment of the invention immaterial features. For example, of course, the lower part 2 must have means for fixing the plastic closure 1 on a container. This can, as in the figures, be a thread, but other means, such as retaining beads or retaining cams come into question. Likewise, such plastic closures can be configured with warranty bands.

The particularly simple embodiment of the subject invention is shown in Figures 1 and 2 shown. As already mentioned, only the lower part 2 is shown here in a simplified embodiment. So missing, as already mentioned, the means for fixing the lower part 2 on the container neck, as well as means with which a cover, not shown here is to be attached to the lower part 2 or as this is fixed to the lower part and has any appropriate sealant. The lower part 2 has a circumferential casing wall 3 and the upper end is completely closed by a top surface 4 to a spout opening 5. The top surface 4 is provided in the embodiment shown here with a survey 7. This, cylindrically shaped elevation 7, contains in the embodiment shown here a spout opening 5. To the spout opening 5 extends on the surface of the elevation 7 an annular groove 9. This forms a spout 8 extending through the top surface 4 'of the elevation 7 therethrough extends and at the bottom has an extension 18.

On the underside of the top surface 4, an annular retaining bead 10 is formed. This retaining bead 10 is larger in diameter than the diameter of the elevation 7. Between the annular retaining bead and the jacket wall 3 remains a gap in which a bottleneck comes to rest. This bottleneck can be sealed externally by the jacket wall 3, while the inside of the bottle neck can be sealed either by the annular retaining bead 10 or between the annular retaining bead 10 and the shell wall 3 can be arranged a separate sealing ring wall. This ring wall, not shown here would of course be concentric with the casing wall 3. Between this jacket wall or the annular retaining bead 10 and the top surface 4 may be present more sealing means.

In the area defined by the annular retaining bead 10, a disc 11 is inserted, which forms a support surface 12. This disk 11 or support surface 12 is held positively and / or non-positively in the annular retaining bead 10. At the annular retaining bead 10 additional means may be present, which improve the positive retention. These may be, for example, annular retaining beads or a plurality of cams directed towards the center, via which the disc 11 is held in the correct end position. The positioning of the disc 11 is effected by the annular retaining bead 10 in axial alignment. A radial alignment is not required.

In the disc 11 a plurality of through holes 13 are arranged. If the disk 11 is a circular disk, the passage openings 13 are usefully arranged on a circle. The passage openings 13 are radially offset so far that they come to lie outside the range of the inside diameter of the outlet opening 5. Also, the through holes 13 are like a dull up the survey 7 extended. However, these extensions 14 terminate below the extension 18 of the shell 8 of the spout opening 5 in the elevation 7. By these spout-like extensions 14 forms a kind of centric elevation on the disc 11. At the same time remains a central recess 15. This is caused by the fact that spout-like extensions 14 touch each other or merge into one another and so practically form a star-shaped annular wall 16. The of the star-shaped annular wall 16th formed central recess 14 is located directly below the spout opening 5. Between the top of the disc 11, which forms the support surface 12, and the underside of the top surface .4 'of the elevation 7 remains a space 17. This space 17 can also be formed when in the top surface 4 no elevation 7 is present by the annular retaining bead in the axial direction extends further down and the support surface 12 and the disc 11 is held further down. In any case, the presence of the space 17 is ensured.

The disc 11 is referred to as a support surface 12, as this, when the bottle is placed on the plastic closure is upside down, the static hydraulic pressure of the non-Newton's see fluid rests. Even if the spout opening 5 is not closed, the thixotropic liquid is unable to hydrate out. However, if pressure is exerted on the flexible bottle, the thixotropic liquid flows through the passage openings 13 into the tree 17 in the axial direction. In this case, a first change in direction of the flow from axial to radial occurs. The space 17 is filled and the thixotropic liquid undergoes a radial movement toward the center, whereupon the thixotropic liquid exits through the spout opening 5 by a further change of direction. During this flow, shearing forces occur in the liquid, which lead to the thixotropic liquid becoming more fluid and thus having an improved flow behavior.

Between the two changes of direction, when flowing from the bottle into the space 18 and when flowing out of the space 18 between the disc 11 and the top surface 4 and the raised top surface 4 ', is exactly one Constriction 21 is present, which causes a flow rate increase.

In principle, this constriction could be accomplished by an annular aperture. Here, however, preferably and particularly easily the constriction is formed by the approximate extensions 14 and 18 of the spouts 13 in the disc 11 and the spout 8 of the spout.

In this case, the sleeve edges may only approach, but the free radial passage must be ensured.

As soon as the pressure on the flexible bottle is removed, a negative pressure is created by the reshaping of the flexible bottle in the same and the outlet jet is stopped abruptly and the liquid in the spout 8 is sucked back into the chamber 17 and through the through-openings 13 with the spout-like extensions 14 sucked back into the bottle. Due to the cross-sectional constrictions occurs in both the spout opening and in the through holes 13 a Bernoulli effect, and accordingly the space 17 is emptied according to the Venturi principle. Experiments have shown that this first embodiment of the subject invention allows an absolutely drip-free flow, the jet is terminated immediately after completion of the pressure on the bottle, and practically in the spout opening-near area is sucked back into the spout opening 5. This keeps the mouth of the spout opening absolutely clean. Due to the Venturi principle, the space 17 is also completely emptied and thus residues in the space 17 can not dry and thus clog the closure. This effect can only be achieved with a sufficient flow velocity and this can only be ensured if a labyrinth seal is avoided. Thus The object of the invention is fully achieved by a plastic closure without silicone rubber membrane is formed, but has all the advantages of such a closure, but realized much cheaper and safer. In addition, the disk 11 as a support surface 12 is a very simple plastic part, which is inexpensive to manufacture and thanks to its strength is also much easier to assemble, as a membrane made of silicone rubber. It should be noted, however, that the cross-sectional area of the spout opening must be smaller than the sum of the cross-sectional areas of the through holes 13.

In the figure 3, an additional variant is shown- In contrast to the previously described embodiment, the disk 11 here only has a central passage opening, which is designated by 13 '. Also, this through hole 13 'may have a tüllenförmige extension 14. Also in this variant, the top surface 4 has a survey with a corresponding top surface 4 '. In this cover surface 4 ', in contrast to the previously described embodiment, a plurality of spouts 8' are arranged. At least two approximately diametrically opposite spouts 8 'should be present. But this can be any number of arranged on a circle grommets. The central recess 21 in the top surface 4 'of the survey essentially serves to form the spout. This room can also be designed filled with material.

Finally, only the sake of completeness in the figure 4, a two-part closure mentioned above is shown. Here, the lower part 2 is connected to the lid 6 via a film hinge 20 and straps 19 with each other, so that the entire closure a Represents snap hinge closure. In the cover 6, a sealing pin 6 'is formed, which is able to engage in the spout 8 and thus causes a largely hermetic seal.

Reference number:

1 plastic closure

2 lower part 3 shell wall

4 top surface 4 'top surface of the survey

5 spout opening

6 lids

6 'sealing pin 7 elevation

8 grommet

9 ring groove

10 annular retaining bead

11 disc 12 support surface

13 passages

14 spout-like extension

15 central recess

16 star-shaped ring wall 17 space

18 Extension of the spout to the disc 11

19 tension bands

20 movie hinge

21 flow restriction

Claims

Claims:

1. Two or more parts plastic closure (1) for attachment to the container neck of a flexible bottle for

Dispensing of thixotropic liquids, with a lower part (2) having a jacket wall (3) and a top surface (4) in which at least one spout opening (5) is formed, wherein below the top surface (4) and from this in the axial direction a support surface distanced (12) is present, which blocks the free axial passage from the container neck to the spout opening (5), and in that at least one axially extending through hole (13) is arranged in the support surface (12) which is radially offset with respect to the at least one outlet opening (5) is, and in that on the underside of the top surface (4) an annular retaining bead (10) or - wall is formed and therein a separate disc (11) as a support surface (12) is held positively and / or non-positively, characterized in that in a space (17) between the support surface (12) and the top surface (4) in both flow directions in each case only a change in direction from axial to radial and a success end change of direction from radially to axially and between the two changes in direction a flow constriction (21) is present.

2. Plastic closure according to claim 1, characterized in that the sum of the cross-sectional areas of all the axially extending passage openings (13) is equal to or greater than the cross-sectional area of the outlet opening (5).

3. Plastic closure according to claim 1, characterized in that the cover surface (4) has a protrusion (7) in which the spout opening (5) is arranged like a spout (8).

4. Plastic closure according to claim 3, characterized in that the support surface (12) below the elevation (7) is arranged.

5. Plastic closure according to claim 1, characterized in that the axial passage openings (13) are arranged on at least one circle which is concentric with the spout opening (5) and whose diameter is so large that the axial passage openings (13) completely outside the range of the spout opening (5) lie.

6. Plastic closure according to claim 1, characterized in that the spout opening is formed by a formed in the survey spout (8), which covers up below the survey cover surface (4 ') by means of an extension (18) to the disc (11) extends, and so the flow constriction (21) forms.

7. Plastic closure according to claims 6 and 7, characterized in that the disc (11) has a central elevation which is smaller in diameter than the elevation (7) in the top surface (4) of the lower part (2) and therein a centric Recess (15) is present around which the axial passage openings (13) are arranged in the central elevation and thus spout-shaped extensions (14) extending to near the level of the lower edge of the extension of the spouts, thus forming a radially free but restricted (21) flow passage.

8. Plastic closure according to claim 3, characterized in that in the top surface (4 ') of the elevation (7) to the spout opening (5) an annular groove (9).

9. Plastic closure according to claim 1, characterized in that in the separate disc (11) only one

Through hole (13) is present and to this radially offset a plurality of spout openings (5) are present.