EP3710373A1

EP3710373A1 - Plastic closure part with severable membrane

Info

Publication number: EP3710373A1
Application number: EP18804551.2A
Authority: EP
Inventors: Günter Krautkrämer
Original assignee: Bericap Holding GmbH
Current assignee: Bericap Holding GmbH
Priority date: 2017-11-16
Filing date: 2018-11-13
Publication date: 2020-09-23
Also published as: US20200339312A1; US11377271B2; CN111183099A; DE102017126965A1; WO2019096795A1

Abstract

A plastic closure part (10) which can be fastened to a container or to a further closure part to be fastened to the container, having a tubular removal connection (3) of which the cross section is closed by a membrane (7) which has a tear line (8) which runs around over more than 180° along its outer edge, and a corresponding method for producing such a closure. In order to develop a closure part having the features stated at the outset and a method for producing same to the effect that the problems occurring due to narrow flow ducts in injection moulding can be eliminated, there is provision according to the invention that the tear line (8) is formed by a cut which is incorporated into the material of the membrane (7) by a cutting or punching tool.

Description

Plastic closure with detachable membrane

The present invention relates to a plastic closure part which can be fastened to a container or to a further closure part to be fastened to the container, having a tubular extraction nozzle whose cross-section is closed by a membrane which extends over a contact angle of at least 180 ° along its outer edge Has a tear line.

Such closure members are known in the art from numerous closure types. Such a closure member is attached directly or indirectly to the edge of a container opening, such as a bottle or canister neck, optionally together with other closure elements, in a manner that will not be released from the container opening without visible damage or alteration of any parts of the closure can, even if then a lid or a screw cap, which surrounds the closure member with the sampling nozzle, is removed from the closure, the opening cross-section of the sampling nozzle, which may be configured for example as pouring spout, still closed by the membrane, which thus as Guarantee element for the unadulterated contents of the container is used.

For the release of the opening cross-section, the membrane along the tear line, which may be wholly or only partially circumferential, separated from the sampling nozzle and depending on the type of closure either from outside to inside pierced or pushed aside, or it is a handle ring , a grip tab or other actuator that is connected to the membrane, pulled out of the sampling neck.

The closure member according to the invention, the essential element of the invention consists of the opening cross-section closing membrane may form part of a closure, for its attachment to a container neck more part are required, or is still to be provided with an additional cap or the like, or it may also include the necessary parts for attachment, and in particular alone form a complete closure.

The term "membrane" is not limited to a disk-like or film-like element, but includes all an opening cross-section closing elements, although in one piece Are connected to the sampling nozzle, however, which are completely or partially separated by an at least partially circumferential tear line of the cross-section defining sampling nozzle, Accordingly, the sampling nozzle can take many forms and z. B consist of a short pipe section, but also of a plate, of which an inner part forms the separable membrane whose surface defines the maximum opening cross section at the same time.

As used herein, the terms "up", "down", or axially "upwards" or axially "downwards" refer to an orientation of the closure member as it is when the container is upright with the container opening at the top and the closure, which usually either has a screw thread or is designed as a bouncing or Einprell-, screwed onto the neck of the container or bounced or inserted into an opening, in any case is sealed at the edge of a container opening fixed.

For the sake of clarity, the closure member in the present description is described mainly in the variant as a closure for a large container, but is not limited thereto. Large containers in the context of the present invention typically have a volume between 5 and 50 l, usually between 10 and 25 l and are often used for drinking water.

In a large container closure which includes a closure member and which is shown as a possible embodiment in the figures, the membrane is rupturable along the tear line, for example by inserting the leading end of a withdrawal pintle into the withdrawal stub and pushing it axially against the membrane, so that the material of the membrane ruptures along the tear line. Since the tear line is preferably not completely circumferential in this case, the membrane remains connected along an unattenuated or less weakened portion of the defined by the tear line perimeter with the sampling nozzle, so that the membrane is pushed aside only to the inside and folded and the opening cross-section of the Essentially frees sampling outlet.

In practical use, a large container is usually placed upside down, so that the closure (also referred to as cap) is located at the bottom, and it is a removal pin or a removal tube inserted into the withdrawal socket of the then lying down plastic closure, wherein the sampling tube which hits the cross section of the sampling nozzle closing membrane. By applying a sufficient force on the membrane, this ruptures along the tear line and is pushed aside by the removal pin then sweeping through removal pin whose inner end is then connected to the container interior. The extraction nozzle and removal pin are matched to one another such that the removal pin rests tight against the inner wall of the removal nozzle or on the edge surrounding the membrane beyond the tear line.

The extraction plug is essentially a pipe which, in use, projects through the sampling nozzle and into the container interior at an inner end, while an outer portion of the extraction nozzle can be provided with a removal valve. In such large containers is usually drinking water, which can be removed or tapped under the influence of gravity by means of the extraction pin from the overhead container.

However, the present invention extends to all plastic closure parts with a sampling nozzle, the opening cross-section is closed by a first to be opened for use membrane. In addition to the mentioned large containers for drinking water, closures are used with a sealed membrane under but also for oil canisters and other containers for technical or chemical liquids such as paints and the like.

The injection-molded plastic closure part can be designed as a separate attachment or attachment for a container opening, a container neck or else in the form of a screw cap or a Aufprellkappe with a holding bead. The closure is described herein in a position generally present when the closure has been applied and fixed to the container neck of the filled upright container.

An annular head plate, as it defines the closed side of the closure, for example in the case of a closure for large containers, is thus at the top and, for example, an annular cavity of the closure receiving the bottleneck edge faces downwards with its open side.

As a first security feature for large container closures, a dispensing nozzle may generally still be closed and capped by a closure seal, which may be a thin plastic film and either peeled or pierced prior to connection of the closure to a dispensing spigot. As a further security feature, such a plastic closure, when it is designed as a screw cap, usually also have a so-called guarantee strip, which is located at the bottom of the cap skirt and tears off when the closure is removed from the container neck and removed. Finally, closure parts of the type in question have the membrane, which is also referred to as a "membrane seal", and which closes the opening cross-section of the withdrawal nozzle, for example a pouring spout.

These measures ensure that the end user receives the contents of the container, such as drinking water or other drinkable or technical liquids, unadulterated in the originally filled form.

The production of such plastic closures is generally carried out by injection molding in a mold which typically consists of a plurality of so-called cavities, each of the cavities forming the negative mold of the closure into which hot liquid plastic material, generally polypropylene, is produced under high pressure during the manufacture of this closure or polyethylene, is injected. Because many closures, except for smaller details such as e.g. the thread, have a substantially cylindrically symmetrical shape, it is convenient and common to the sprue, i. Place the injection opening of the cavity, which forms a negative mold of the closure, in the center of the closure. Other positions of the gate easily lead to uneven filling of the cavity, so that in other arrangements of the gate, the duration of the injection molding process is extended and / or appropriate closures can not be produced with the required quality and dimensional accuracy, or the closure total with greater wall thickness and greater material consumption would have to be made.

In a closure for large containers, for which the present invention has been developed among other things and typically has a nominal diameter of 50 mm, the geometric center of the cap is at the same time in the center of the membrane, which in turn but one over at least 180 °, usually nearly 360 °, circumferential tear line, along which the membrane is intended to tear during later use, so that it can be pushed laterally out of the cross section of the extraction nozzle or the extraction pin over the remaining, non-weakened portion which acts as a kind of hinge.

In the cavity for a closure part with a membrane that can be torn out or folded out of the opening cross-section of the withdrawal nozzle, the tear line necessarily forms a constriction between the die and the die of the mold, through which the liquid plastic, which is fed via the sprue in the center of the membrane, is pressed through must be in order to fill the remaining parts of the mold, which include the sampling nozzle, the top plate and the circumferential cap shell, optionally including guarantee strip, as well as even sealing elements. This requires on the one hand a good flowable plastic material and thus restricts the avail able to avail supply plastic, and on the other hand also requires very high pressures at which the liquid plastic must be injected into the mold to reach into the most remote from the sprue cavities. This also restricts the possibilities of manufacturing these closures true to scale within small tolerances.

Another problem that has been found in the practical use of these closures is the force required to rupture and push aside the membrane along the tear line.

This applies both to large containers when a removal pin has to be introduced into the withdrawal socket of the closure of a container., As well as when the membrane via a connected thereto handle ring, in which typically only a finger of a hand can be pulled out of the sampling neck must become. On the other hand, it is hardly possible because of the above-described problems in injection molding, the tear line, along which the wall thickness of the plastic material is typically at least 0.15 mm, even further gene einzuen.

The invention also relates to a method for producing a Kunststoffver closing part with a sampling nozzle and a cross-section of the sampling nozzle ver closing membrane according to any one of claims 1-13, which comprises the injection molding of the plastic closure part in an injection mold

Compared to this prior art, the present invention, the object of developing a closure member having the features mentioned and a method for its production to the effect that at least one of the problems listed above is taken besei.

According to one aspect of the present invention, this object is achieved by a closure part having the features of claim 1, which is characterized in particular by the tear line being formed from a cut introduced into the material of the membrane after completion of the injection molding process with a cutting or punching tool . consists of the below the section BED Benden, thin wall portion of the membrane. "After completion of the injection molding process" means in practice after ejecting the closure part of the injection mold, but it would also be conceivable to perform the cutting or punching process still within the injection mold, even if the plastic is not fully cured.

The surface of a tear line introduced by cutting or punching differs from corresponding surfaces produced by constriction of a shape, so that the subsequent production of the tear line due to the surface structure and usually also on the cross-sectional shape of the tear line on the finished closure part is recognizable.

The plastic closure member may thus be initially manufactured in the injection mold without any tear line, i. the membrane has a relatively large and expediently uniform wall thickness, including its connection with the withdrawal nozzle continuously. The injected in the center of the membrane liquid plastic can therefore easily through this cavity flow through without bottlenecks and spread over the entire volume of the injection mold or the respective cavity. Only in the thus finished sprayed closure part is then in the vicinity of the outer edge of the membrane, i. at or near their connection to the sampling nozzle, a cut introduced, which detects the material of the membrane with a well-defined depth and this material is severed to a very small remaining wall thickness. The remaining wall thickness in the region of this dividing line, i. the thickness of the remaining in the region of the cut wall of the membrane, it can be set very accurately, and in particular less than 0.15 mm and they can preferably be reduced to a maximum of 0, 1 mm thickness. In one embodiment, the wall thickness of the membrane remaining below the incision is between 0.06 and 0.1 mm, in particular 0.08 mm.

However, the depth of cut can also be variably adjusted, in particular with a punching tool along the circumference of the membrane, in order, for example, to retain a greater material thickness along a short section in the circumferential direction, so that the relevant section can serve as a hinge, or around an initial section of the tear line, in the vicinity of which, for example, a grip ring attaches to be made particularly thin, since the membrane can be relatively easily separated along the remaining tear line when a starting section is already torn open.

The design of the tear line in the form of a subsequently introduced into the membrane incision has several advantages. On the one hand, as already mentioned, during production of the closure in the injection mold, the plastic flow unhindered in the region of the tear line, since there is initially still a sufficiently large wall thickness of the membrane. Thereby, the pressures used in the injection can be reduced and one also has a greater freedom in the choice of the plastic material used. Also, the mold is simplified, because considerably less effort is required than in the case in which a precisely defined, very narrow flow gap has to be set for the tear line between die and punch.

Furthermore, you can significantly reduce the force required for tearing the tear line by the depth of the incision or by the remaining smaller wall thickness and adjust to a precise desired level. The lower pressures, the simplification of the mold production and also the greater freedom in the selection of appropriate plastic materials in turn lead to better compliance with dimensional tolerances and allow the production of closures with integrated sealing elements for which no separate seal is required.

According to a preferred embodiment of the invention it is provided that the tear line of the membrane is cut in a region in which the wall thickness of the membrane (by the way), i. outside the area thinned by the incision itself, at least 0.5 mm. Furthermore, according to one embodiment, the membrane in the region of the cut tear line is reduced to a thickness of less than 0.15 mm, preferably to a maximum of 0.1 mm thickness.

Also, the length of the tear line along the circumference can be adjusted very precisely in this way, wherein according to one embodiment it is provided that the tear line is more than 270 ° and less than 360 °, but in particular not more than 355 ° and preferably more than 330 ° extends.

With a reduction in the remaining, non-weakened portion of the membrane which effectively acts as a hinge upon engagement with the extraction peg, the membrane will no longer resist tearing if the hinge region is restricted to less than 30 ° along the circumference. On the other hand, a hinge portion of 10 ° circumferential length still securely holds the membrane to the dispensing nozzle, so there is no danger of the membrane being completely torn off the dispensing nozzle and then lying loosely within the container.

The radial distance of the tear line from the inner wall of the sampling nozzle in its directly adjacent to the membrane region according to an embodiment between 0.1 and 1 mm or corresponds exactly to the inner radius of the sampling nozzle, so is the cross section of the sampling nozzle in its adjacent to the membrane area adjusted as much as possible. The membrane is expediently arranged at the lower end (ie at the end facing the interior of the container) of the withdrawal nozzle. Furthermore, it has proven to be expedient if the incision of the tear line is introduced from the inside of the closure part. The membrane is in general more easily accessible from the inside of the closure part (which faces the interior of the container), in particular if it is attached to the lower end of the extraction nozzle, so that from here it is also possible to easily attach a corresponding tool which forms the recess the tear line produces. The withdrawal nozzle runs according to an embodiment of the invention at least partially tapered conically from the top plate to the lower end. This conical taper facilitates the insertion of a removal pin. Conveniently, however, the lower, adjacent to a membrane portion of the sampling nozzle is cylindrical, which facilitates a tight contact of the outer surface of a sampling pin on the inner wall of the sampling nozzle.

Furthermore, according to one embodiment of the invention, the closure part has a sealing neck, which extends axially downwards between the withdrawal nozzle and the cap jacket, for engagement with the inner wall of a container neck.

The sealing neck then forms, together with an outer portion of the top plate and the cap skirt, an annular peripheral U-shaped cavity, also referred to as a "closure foot", in which the upper edge of a bottle neck is sealingly receivable when the sealing neck sealingly engages the interior engages the container neck. In addition, at the bottom of this U-shaped cavity also annular circumferential sealing elements may be provided which engage with the front side or the upper edge of the container neck. The base of the U-shaped cavity is formed in this case by the lying between the cap skirt and the sealing piece portion of the top plate.

The gasket may be formed, for example, by a cylindrical gasket projecting downwardly from the top plate between the cap skirt and the extraction nozzle, which has a radially outwardly bulging sealing bead which is capable of sealingly engaging the inner surface of a container neck.

In addition, according to an embodiment of the present invention in which the closure has an internal thread for screwing onto a threaded container neck, the lower edge of the cap skirt has a tamper-evident band connected to the cap edge by easily breakable bridges.

The partially filigree structure of such a guarantee strip as well as the respective sealing elements and their dimensional accuracy can be due to the inventive measures, ie by providing flow channels in the membrane area with a larger cross section and optionally also by using appropriate plastic materials, accomplish easier than conventional closures.

With regard to the method, the object underlying the invention is achieved in that after injection molding and at least partial curing of the plastic closure part, an at least partially circumferential incision is made in the membrane.

According to a variant of the method, the tear line is introduced only after the injection molding through an incision by means of a cutting or punching tool.

Conveniently, the incision may be introduced while the plastic closure member is still in the closed or partially opened injection mold prior to final ejection.

The method proves to be particularly advantageous when the sprue for filling the cavities of the injection mold in the region of the membrane, preferably in the center, because then the full material cross section of the membrane for the flow of the liquid plastic in all the associated areas of the Cavity is available and there are hardly any bottlenecks.

Further advantages, features and possible applications of the present invention will become apparent from the following description of a preferred embodiment and the associated figures. Show it:

1 is a perspective view of a plastic closure according to the invention in a view obliquely from below,

FIG. 2 shows a cross-section of a closure according to FIG. 1, FIG. 2A shows an enlarged section of FIG. 2, showing the closure axis

3 shows a view of the closure along the closure axis from below,

Figure 4 is a view along the closure axis on the closure from above.

Figure 5a-c a closure in different stages with closed and opened membrane and with an introduced removal pin and

Figure 6 shows a cross section through the container standing on an overhead with an applied closure together with an introduced through the closure removal pin. 1 shows a closure part according to the invention, in this case a complete closure 100 in a perspective view obliquely from below, ie from the closure opening into the interior of the closure 100. The following description refers simultaneously to FIGS. 1 to 4.

It can be seen above all in Figures 3 and 4 and in the sectional view of Figure 2, an annular top plate 1, at the outer edge of an approximately cylindrical cap casing 2 attaches, which extends axially downwards. At the inner edge of the top plate 1 downwardly extends an initially downwardly conically tapered portion of a sampling nozzle 3 axially downwards, followed by a cylindrical portion at the end of which one recognizes the cross section of the sampling nozzle 3 closing membrane 7.

The membrane 7 is along most of its circumference only over a weakened by an incision material portion 8, which is referred to here as a "tear line, with a thin ring-shaped edge of the membrane 7, outside the tear line 8 and directly to the lower edge of Entnahmestutzens 3 connected. The incision thus runs along a circle of maximum diameter within the cross section of the sampling nozzle.

The tear line 8 is interrupted only by a very short, in the circumferential direction about 10 ° making hinge section 9, which holds the membrane to the sampling nozzle. On the inside of the top plate 1 can be seen further between the sampling nozzle 3 and the cap casing 2 a circumferential sealing nozzle 1 1 and another, annular umlau fende seal 12 between the sealing nozzle 1 1 and the cap shell 2. The cap coat also has an internal thread 13 and is connected via its lower edge with a folded guarantee band 14, a so-called flex band.

Figure 4 is a view of the plastic closure 100 from above, in which also the top plate 1, the cap skirt 2, the sampling nozzle 3 and the membrane 7 recognizes. The section of Figure 2 with the enlarged section 2A corresponds to the section line A-A in Figure 4.

In Figure 5, the plastic closure 100 can be seen in a perspective view from the inside in three different stages ver, namely in Figure 5A in an intact, unused state, in Figure 5B with a partially separated and folded out membrane 7 and in Figure 5C with a at completely unfolded membrane through the sampling nozzle 3 hindurchgeführ th removal pin 20th

FIG. 6 shows a cross-section containing the axis in the state according to FIG. 5C. The embodiment of a closure for large containers shown in the figures has a thread 13 which is screwed onto a matching thread of a large container. The neck of such a large container has a radially outwardly facing securing ring (only indicated in FIG. 6), which is engaged behind by a flexible band 14. The flex band 14 is an upwardly folded, axial extension of the cap skirt 2. End projections of the flex band 14 are supported on the retaining ring 24 of the container neck and thus prevent unscrewing of the closure 100 of the container neck, wherein in the event of a violent twisting and the entire Flexband breaks off, which is connected by easily breakable bridges with the un direct edge of the cap skirt.

As can be seen in FIG. 6, the upper edge or the upper portion of the container neck (which lies at the bottom in FIG. 6) is accommodated in an annular circumferential cavity, which is enclosed in a U-shape by the cap jacket 2, an outer portion of the annular head plate 1 and the sealing nozzle 1 1, which has the shape of a short hollow cylindrical portion with an outwardly projecting bead 16. A further annular lip seal 12 extends downwardly between the seal neck 11 and the cap skirt 2 from the head plate 1 and communicates with the top of the bottle neck rim while the bead 16 sealingly abuts the inner surface of the neck of the container.

To connect the closure or a closed with the closure 100 Großbehäl age 30 with the outside of the container, a removal pin 20 from the outside, i. from the side of Kopfplattel ago, inserted into the sampling nozzle 3 (see Figure 6). By corre sponding pressure of the sampling nozzle on the membrane 7 tears this along the tear line 8 from the lower edge of the sampling nozzle 3 and remains only along a short crowd nierabschnittes 9 hang on the sampling pipe so the membrane can axially downwards and laterally from the cross section of the withdrawal nozzle out into the position shown in Figure 5B. This is done by inserting the removal pin 20, which has pushed aside in the position shown in Figures 5C and 6, the membrane 7 and sealed with its outer surface close to the lower inner wall of the sampling nozzle 3 and possibly an annular edge of the membrane 7 outside the section line 8 is applied.

As can be seen with reference to FIG 6, the liquid (drinking water) in the container 30 through openings at the inner end of the sampling nozzle 20 through the sampling nozzle flow from, in the not shown further course of the extraction pin outside the Behäl age 30 and the closure 100th a valve may be provided to dose the liquid tapped from the container 30 in a desired manner.

Claims

Patent claims

1. plastic closure part (10) which can be fastened to a container or to the container to be fastened tes further closure part, with a tubular sampling nozzle (3) whose cross-section is closed by a membrane (7), the one over 180 ° along having its outer edge circumferential tear line (8), characterized in that the tear line (8) is formed by a cut with a cutting or punching tool in the material of the membrane (7) cut.

2. plastic closure part according to claim 1, characterized in that the tear line of the membrane (7) is cut in an area in which the wall thickness of the membrane is at least 0.5 mm

3. Plastic closure part according to one of the preceding claims, characterized in that the wall thickness of the membrane by the incised tear line to a thickness of less than 0.15 mm, preferably to a maximum of 0.1 mm thickness, in particular to a thickness between 0.06 and 0.1 mm, preferably 0.08 mm is reduced.

4. Plastic closure part according to one of the preceding claims, characterized in that the tear line extends along the circumference of the membrane over more than 270 ° and less than 360 °, in particular over at most 355 ° and more than 330 °.

5. Plastic closure part according to one of the preceding claims, characterized in that the radial distance of the tear line (8) of the inner wall (12) of the removal rod cens (3) in which the membrane (7) adjacent region between 0.0 and 1 , 0 mm

6. plastic closure part according to one of the preceding claims, characterized in that the membrane is arranged at the lower end of the sampling nozzle.

7. Plastic closure part according to one of the preceding claims, characterized in that the incision of the tear line is introduced from the inside of the closure part ago

8. Plastic closure part according to one of the preceding claims, characterized in that the immediately adjacent to the membrane portion of the sampling nozzle is cylindrical

9. plastic closure part according to one of claims 1-8, characterized in that it comprises a the sampling nozzle annular comprehensive, in cross section U-shaped Ver closing foot, which forms out for receiving an annular bottle neck end

10. Plastic closure part according to one of the preceding claims, characterized in that the closure foot has a sealing neck with a radially outwardly projecting, circumferential sealing bead

1 plastic closure part according to one of the preceding claims, characterized in that it has a cap coat with an internal thread or a radially projecting inner bead for bouncing on a container neck.

12. Plastic closure part according to claim 13, characterized in that adjoins the lower edge of the cap skirt a guarantee strip which is connected via easily breakable bridges with the lower cap edge.

13. Plastic closure part according to one of the preceding claims, characterized in that the cap jacket has a nominal diameter of 50 mm.

14. A method for producing a plastic closure part with a sampling nozzle and the cross-section of the sampling nozzle closing membrane according to any one of claims 1-13, which comprises the injection molding of the plastic closure in an injection mold, characterized in that after injection molding and at least partially curing of the plastic closure part an at least partially circumferential incision is made in the membrane.

15. The method according to claim 14, characterized in that the incision is introduced by means of a cutting or punching tool.

16. The method according to claim 14 or 15, characterized in that the incision is introduced, while the plastic closure part is still in the partially opened injection mold before the final ejection.

17. The method according to any one of claims 14 to 16, characterized in that the filling of the cavities of the injection mold takes place in each case via a gate, which lies in the region of the membrane, preferably in the center thereof