WO2000053523A1

WO2000053523A1 - Form tool, method and closure for closing containers

Info

Publication number: WO2000053523A1
Application number: PCT/EP2000/001122
Authority: WO
Inventors: Günther Spatz; Hans-Dieter Dubs
Original assignee: Alcoa Deutschland Gmbh Verpackungswerke
Priority date: 1999-03-10
Filing date: 2000-02-11
Publication date: 2000-09-14
Also published as: ES2208283T3; AU2910200A; EP1161399A1; PL351494A1; PL193103B1; DE19910443A1; EP1161399B1; ATE252515T1

Abstract

The invention relates to a form tool for closing containers, more particularly bottles, comprising closures (37) having a closure crown (45) and a jacket (47) starting therefrom, made of deep-drawable material, preferably aluminum sheet or steel sheet, and a sleeve (3) covering the closure (37) during a closing operation, said sleeve having a drawing tool (31) with a deep-drawn section (23) that engages from the outside with the transition area (41) between the closure crown (45) and the sleeve (47) of the closure (37) during closing and that subjects the transition area (41) to a deep-drawing process. The form tool is characterized in that the drawing tool (31) of the sleeve (3) has a formed section (27) contacting the transition area (41).

Description

MOLDING TOOL, METHOD AND LOCK FOR LOCKING

CONTAIN

description

The invention relates to a molding tool for closing containers, in particular bottles, according to the preamble of claim 1, a method for closing containers according to the preamble of claim 9 and a closure made of thermoformable material for closing containers according to the preamble of claim 12.

It is known to close containers or bottles with closures made of deep-drawing material, preferably aluminum or steel sheet. For this purpose, molding tools - the expert also calls them plungers - are used, which form a closure cap having a closure mirror and a jacket extending therefrom onto the mouth region of the container. When closing bottles, the transition region between the closure mirror and the jacket of the closure is subjected to a deep-drawing process in order to optimally mold the seal arranged in the region of the closure mirror to the mouth region of the container or the bottle.

It has been found that when containers are closed with the aid of such tools or methods, cavities with air pockets remain between the seal and the closure. ben. This results in non-uniform sealing values, which means that overpressures that cannot be exactly defined can be sealed within the container. Another disadvantage also arises: the forces required to open the closure for the first time are very uneven.

It is therefore an object of the invention to propose a mold for closing containers, in particular bottles, which does not have these disadvantages.

To solve this problem, a molding tool is proposed, which comprises the features mentioned in claim 1. It is characterized in that it is provided with a sleeve which comprises a drawing mold. This shows a deep-drawing section which, when the container is closed, engages with the transition region between the closure mirror and the jacket of the closure and subjects it to a deep-drawing process. In addition, the drawing mold has a post-molding section, hereinafter referred to briefly as the molding section, which engages with the aforementioned transition region of the closure and subjects it to an additional molding process. The molding tool is therefore intended and suitable for subjecting the transition region of a closure made of deep-drawing material to both a deep-drawing and a molding process when a container is closed. The transition area between the sealing mirror and the jacket is therefore not only brought into a specific shape by the deep-drawing process, but also defined in a defined manner by the molded section. shaped. The design of the transition area can therefore be influenced in a very defined manner. This makes it easy to ensure that cavities and air pockets between the seal and closure are avoided and that the sealing behavior is within a narrow tolerance range. In addition, the forces required to open the closure for the first time are more even.

An embodiment of the molding tool is preferred, which is characterized in that the drawing mold is specially designed. It is namely provided that the deep-drawing section is arranged closer to a front edge of the sleeve than the shaped section. When closing containers, the sleeve is moved towards the closure in such a way that its front edge, as seen in the direction of movement, is at the front. The deep-drawing section is thus also at the front and comes into engagement with the transition region of the closure in front of the molded section. The closure is thus grasped by the deep-drawing section and first subjected to a deep-drawing process before the post-forming is carried out by the shaped section.

An embodiment of the molding tool is particularly preferred, which is characterized in that the molding section has a concave inner surface which is curved in the shape of a circular arc. With this configuration, the transition area can be molded onto the outer contour of the container to be closed in such a way that the seal provided in the interior of the closure is very uniform and in particular without any intermediate spaces or air gaps is pressed against the outer surface of the container and lies close to the inner surface of the closure. Here, too, there are no air gaps or gaps, so that the seal is pressed very evenly onto the mouth region of the container.

Further configurations of the molding tool result from the remaining subclaims.

To solve this problem, a method for closing containers is proposed that has the features mentioned in claim 9. The method is characterized in that a transition region of a closure located between the closure mirror and the casing is deep-drawn when a container is closed, and in that this transition region is subjected to an additional molding process. Due to the deep drawing and subsequent shaping, the closure is molded onto the container in such a way that it is tightly sealed and that the pressure values prevailing in the container, at which the closure is blown off, lie within a narrow tolerance range. In addition, there are more uniform values for the unscrewing forces required when the lock is opened for the first time.

Further embodiments of the method result from the remaining subclaims.

To achieve the stated object, a closure made of deep-drawing material is also proposed, which has the features mentioned in claim 12. points. It is characterized by the fact that it is deep-drawn and shaped in a transition area located between the closure mirror and the jacket. Compared to only deep-drawn closures, this has the advantage that the container to be closed can be optimally sealed. This makes it possible to safely achieve tightly tolerated pressure values within the container.

In a preferred embodiment of the closure, it is provided that parts of the transition region are deep-drawn and additionally shaped, while others are exclusively deep-drawn. In this way it is possible to optimally adapt the transition area to the desired circumstances.

The invention is explained in more detail below. Show it:

FIG. 1 shows a molding tool 1, also called a plunger, which is used for closing containers, in particular bottles, by means of closures made of thermoformable material,

Figure 2 shows the lower part of a sleeve in longitudinal section and

Figure 3 shows a part of a closure in longitudinal section.

Molding tools of the type mentioned here are known in principle. They serve the one Applying the closure mirror and a closure having a jacket extending therefrom onto a container, the seal provided in the interior of the closure being pressed onto the mouth region of the container. To anchor the closure, a thread is rolled out from the outside into the outer surface of the closure using a suitable tool.

Forming tools and rolling tools required for producing the thread are known, so that their basic function will not be discussed in more detail here.

The molding tool 1 shown in longitudinal section in FIG. 1 has a sleeve 3 which engages over the closure to close a container during the closing process and processes the transition region between the closing mirror and the jacket. The inner diameter of the sleeve 3 is therefore selected so that the sleeve, at least with its area lying in FIG. 1, engages over the closure. The sleeve shows a front edge 5, which represents the lower limit.

The sleeve 3 encloses an interior space 7, in which an ejector 9 is accommodated so as to be displaceable in the direction of the central axis 11 of the molding tool 1. In Figure 1, the plate-shaped ejector 9 is in its lowermost position, so that it is at the smallest distance from the front edge 5. In this position, the ejector 9 is secured against falling out of the interior 7 by a pin 13. The ejector 9 is actuated by at least one spring element ment 15, which is designed here as a coil spring, with a downward biasing force. In the exemplary embodiment shown here, a plurality of spring elements 15, 15 ′ arranged around the central axis 11 are provided. These are accommodated here in recesses or bores 17, 17 'which run essentially parallel to the central axis 11 and which are introduced into the base body 19 of the sleeve 3. The arrangement and configuration of ejectors 9 of the type mentioned here is known, so that they are not discussed in more detail here.

Near the front edge 5 of the sleeve 3 there is an inlet slope 21 which, as shown in FIG. 1, widens conically from top to bottom, the inner surface of which thus describes a conical jacket section. The inlet slope 21 serves to facilitate its entry into the sleeve 3 when the molding tool 1 is applied to a closure.

A deep-drawing section 23 adjoins the inlet bevel 21, which has a deep-drawing radius 25 which projects in the direction of the central axis 11 and is also referred to as a deep-drawing bead, the outer surface of which is convexly curved, that is, it projects into the interior 7. It is provided here that the inner surface of the deep-drawing radius 25 forms a circular arc in longitudinal section, which in particular has a radius of 0.8 mm.

A molded section 27 adjoins the deep-drawing section 23, the inner surface of which — as seen from the interior 7 — is concavely curved. The curvature This mold section 27 is 1.0 mm to 2.0 mm, preferably 1.3 mm to 1.7 mm. A radius of curvature of 1.5 mm is particularly preferred, since particularly good sealing values and very uniform opening forces result here. This applies to bottles that are closed with a screw cap made of deep-drawing material and have a diameter of approx. 25 mm in the mouth area. The radius of curvature given in the shaped section 27 can be selected depending on the dimensions of the containers to be closed. The figures given here relate to the commercially available glass beverage bottles for juices and carbonated drinks, especially mineral water.

The lower region of the sleeve 3, which is identified by a circular line 29, is also referred to as a drawing mold 31, which is explained in more detail with reference to FIG. 2.

Figure 2 shows in longitudinal section the lower part of a sleeve 3, in particular its front edge 5 with the adjoining drawing mold 31. The same parts are provided with the same reference numerals, so that reference is made to the explanations for Figure 1.

FIG. 2 clearly shows that, starting from the front edge 5, a run-in slope 21 is provided which runs conically towards the central axis 11 and which here adjoins the front edge 5 and widens towards the front edge 5 in a quasi funnel shape. The inlet slope preferably goes into a substantially cylindrical one Centering section 33 over. Above this centering section 33 is the deep-drawing radius 25, the inner surface of which, as said, projects in a longitudinal section in the form of a circular arc into the interior of the sleeve 3. The deep-drawing radius 25 of the deep-drawing section 23 projects at an angle of 90 ° with respect to the centering section 33. However, angles that are larger or smaller than 90 ° are also conceivable here. In the exemplary embodiment shown here, the deep-drawing radius 25 merges directly into the concavely curved shaped section 27 via a cylindrical partial region 35, which is also attributable to the deep-drawing section 23.

In the embodiment shown here it is clear that when placing the sleeve 3 on a closure, not shown here, the inlet slope 21 is effective, which ensures with the centering section 33 that the closure runs centered into the interior of the sleeve 3. Immediately after the sleeve 3 has been placed on a closure, the transition region between the closure mirror and the jacket is located within the sleeve in the region of the centering section 33.

FIG. 3 shows in longitudinal section part of a closure 37 which is placed on a container 39, for example on a glass bottle. The transition region 41 can clearly be seen here, which lies between the closure mirror 45 closing the mouth region and the jacket 47 of the closure 37 extending therefrom. Between the closing mirror 45 and parts of the transition Reichs 41, a seal 49 is arranged in the interior of the closure 37, which not only closes the horizontal region of the mouth region 43, but extends to the side surface 51 of the container. Below the transition region 41, a circumferential bead 53 can be seen, which is preferably provided with knurling which serves on the one hand to reinforce the closure 37 and on the other hand to improve the grip.

The inner diameter of the sleeve 3, of which only parts of the drawing mold 31 are visible here, is matched to the outer diameter of the closure 33. Before the sleeve 3 is placed on the closure 37, its outer diameter is larger than the inner diameter in the cylindrical partial region 35. This dimensioning means that the deep-drawing radius 25 of the deep-drawing section 23 engages with the closure 37 or with its transition region 41 such that it is subjected to a deep-drawing process can be.

A thread 57 is rolled out into the jacket 47 of the closure 37 after the deep-drawing and shaping or post-forming of the transition region 41 in order to form the jacket onto the external thread 58 of the container 39 and to securely fasten the closure 37 to the container 39.

The function of the molding tool 1 explained with reference to the figures, the method for closing containers by means of deep-drawn closures and the closure 37 are discussed in more detail below: To close a container 39, a closure 37 is placed on its mouth region 43. The jacket 47 of the closure 37 is not yet provided with a thread. The circumferential bead 53 is at most present.

After the closure 37 has been placed on a container 39, the molding tool is lowered onto the closure 37. Figure 1 shows that a hold-down 59 of the mold 1 secures the closure 37 until the sleeve 3 engages with it. First, it is ensured with the help of the bevel 21 that the closure 37 runs centrally into the interior 7 of the sleeve 3. Before the closure 37 is machined with the aid of the molding tool 1, the outer diameter of the transition region 41 is larger than the inner diameter in the cylindrical partial region 35. As a result, the deep-drawing radius 25 engages with the transition region 41, which, when the sleeve 3 is further lowered, is capable of being deep-drawn Material, in particular made of aluminum or steel sheet closure 37 is deep-drawn. It is only a question of a relative movement between the closure 37 and the sleeve 3. It would also be theoretically possible to retract the closure 37 into the interior 7 of the sleeve 3.

It is clear from the explanations relating to FIG. 2 that the deep-drawing radius 25 engages with the transition region 41 before the molding section 27 takes effect. During the lowering of the sleeve 3 relative to the closure 37, the transition region 41 only deep-drawn as long as the deep-drawing radius 25 and the cylindrical partial area 35 are in engagement with the transition area 41. In the case of a further lowering, however, the concavely curved shaped section 27 also engages with the transition region 41 and reshapes this region. Finally, the sleeve 3 is opposite the closure 37 in the position shown in Figure 3. It has thus reached the maximum displacement compared to its starting position, the deep-drawing process, like the molding process, has ended.

In the case of commercially available closures and containers or bottles, a drawing depth of about 2.6 mm is aimed for. It follows from this that when the sleeve 3 is lowered relative to the closure 37 over a first distance of approximately 0.8 mm, only a deep-drawing of the transition region 41 takes place by means of the deep-drawing radius 25 and a deep-drawing by means of the cylindrical partial region 35 over approximately 0.3 mm . After this depth of drawing, the curved inner surface area of the mold section 27 reaches the transition area 41, so that while the transition area is being deep drawn, a molding process takes place in the area of the transition area 41. In order to achieve the drawing depth of approximately 2.6 mm, a radius of approximately 1.5 mm is selected for the shaped section 27.

The draw depth for standard closures 37 for bottles with a diameter of 25 mm is set to 2.6 mm as standard. The height of the cylindrical measured in the direction of the central axis 11 Partial region 35 therefore depends on the choice of the radii of the deep-drawing radius 25 and the shaped section 27. If radii larger than those specified above are selected, the height of the cylindrical partial region 35 can also be practically 0 mm. In this case, the deep-drawing process takes place through the deep-drawing radius 25 and, if appropriate, through the first adjoining region of the shaped section 27.

The closure 37 is thus characterized in that a part of the transition region 41 directly adjacent to the jacket 47 is only deep-drawn. This is the cylindrical part of the transition region 41, which adjoins the circumferential bead 53. Above this part, the transition region 41 has been subjected to both a deep-drawing and a molding process.

Figure 3 clearly shows that the seal 49 on the one hand is applied or pressed to the exterior of the container 39, also on the side surface 51, and that there are also no cavities between the inside of the closure 37 or the transition region 41 and the seal 49 . The seal is thus pressed everywhere in the transition area 41 from the outside of the container 39 so that it is sealed. The seal 49 rests on the surface F of the container 39 which extends horizontally around the mouth region 43, and also in the region of the side surface 51 which is arranged below this surface F. This arrangement of the seal 49 ensures a so-called side seal of the container 39. Since there are no cavities or air pockets on the one hand between the container 39 and the seal 49 and on the other hand between this and the inside of the transition region 41, there are better unscrewing forces. In addition, there is a tightly tolerated sealing value, which means that, at most, if the overpressure in the container 39 is clearly above a tolerance range, so-called blowing can take place, in which liquids and / or gases from inside the container 39 on the seal 49 can exit over.

Claims

Expectations

1. Molding tool for closing containers, in particular bottles, with a closing mirror (45) and a starting jacket (47) having closures (37) made of deep-drawing material, preferably made of aluminum or steel sheet, with one during the closing process Closure (37) engaging sleeve (3), which has a drawing shape (31) with a deep-drawing section (23) which is connected to the transition region (41) between the closing mirror

(45) and jacket (35) of the closure (37) engages from the outside during the closure and subjects the transition region (41) to a deep-drawing process, characterized in that the drawing mold (31) of the sleeve (3) has a molded section (27) comprises, which engages with the transition region (41).

2. Molding tool according to claim 1, characterized in that the drawing mold (31) is designed such that the deep-drawing section (23) is arranged closer to a front edge (5) of the sleeve (3) than the molding section (27).

3. Molding tool according to claim 1 or 2, characterized in that the deep-drawing section (23) and the mold section (27) adjoin one another directly.

4. Molding tool according to one of the preceding claims, characterized in that the molding section (27) is concave.

5. Molding tool according to claim 4, characterized in that - seen in longitudinal section - the inner surface of the shaped section (27) is curved in the form of a circular arc.

6. Forming tool according to claim 5, characterized in that the radius of curvature of the circular arc is 1.0 mm to 2.0 mm, preferably 1.3 mm to 1.7 mm, in particular 1.5 mm.

7. Molding tool according to one of the preceding claims, characterized in that the drawing mold (31) has an inlet slope (21) which is arranged between the front edge (5) of the sleeve (3) and the deep-drawing section (23).

8. Molding tool according to one of the preceding claims, characterized in that the run-in slope (21) and the deep-drawing section (23) merge directly or preferably via a centering section (33).

9. A method for closing containers, in particular bottles, with a closure mirror (45) and a closure (37) with closures (37) therefrom, made of thermoformable material, preferably of aluminum. sheet metal or steel, with a sleeve (3) which engages over the closure (37) during the closure process and which has a drawing shape (31) with a deep-drawing section (23) which is connected to the transition region (41) between the closure mirror (45) and the jacket ( 47) of the closure engages from the outside during the closure and subjects the transition region (41) to a deep-drawing process, in particular by means of a molding tool (1) according to one of Claims 1 to 8, characterized in that the transition region (41) is subjected to an additional molding process becomes.

10. The method according to claim 9, characterized in that a part of the transition region (41) is first deep-drawn and then molded.

11. The method according to claim 9 or 10, characterized in that a part of the transition region (41) is deep-drawn and additionally shaped.

12. Closure made of deep-drawing material, preferably aluminum or steel sheet, for closing containers, in particular bottles, with a closing mirror (45), a jacket (47) extending therefrom and a transition area (41) between the closing mirror and jacket, which is deep-drawn , characterized in that the transition region (41) is additionally shaped.

3. Closure according to claim 12, characterized in that the part of the transition region (41) adjoining the closure mirror (45) is deep-drawn and additionally shaped, and that the part of the transition region (41) adjoining the jacket (47) is only deep-drawn .