Threaded cap element and method of manufacturing a cap element

PRIORITY CLAIM

The present application claims priority under 35 U.S.C. § 119 to German Patent Application No. DE 10 2023 133 155.8, filed Nov. 28, 2023, the disclosure of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

A threaded cap element and a method of manufacturing a cap element are disclosed.

BACKGROUND

Cap elements having a thread, such as caps for bottles, in particular beverage bottles, are made from a plastics material, in particular polypropylene (PP), in an injection molding process. The corresponding beverage bottles, on the other hand, are usually made of polyethylene terephthalate (PET). PP has proven itself as a material that can be easily worked in an injection molding process. As progress is made in the field of recycling of products and resources, there is an increasing demand for simple solutions that can also be easily recycled. In some countries, it is already required that bottle caps no longer be separable from a container. For further processing in a recycling process, the caps must then be separated from the bottles, as caps and bottles are usually made of different materials. Items made of PET can be recycled more easily than those made of PP because PET is mechanically recyclable. PP requires chemical recycling, where chemolysis allows plastics materials to be completely depolymerized and then resynthesized.

Furthermore, the manufacture of such bottle caps is associated with high costs, since the injection mold tools used are very complex. In addition, a relatively large amount of material is required to produce caps in an injection molding process, since the structure of the cap must be sufficiently strong relative to external influences, for opening the bottle and for compensating for internal pressures (in particular in the case of carbonated drinks).

SUMMARY
Object

It is therefore an object to provide an alternative that provides a varietal purity of packaging systems including a container and a cap, as well as a simple and cost-effective manufacture of cap elements and a reduction of the resources required, while at least maintaining the same properties for the manufacture of cap elements and for cap elements. It is also an object to reduce the manufacturing complexity via an alternative method. Furthermore, it is an object to provide a cap element produced in a thermoforming process that is at least equivalent to known cap elements made of plastics material, for example those produced in an injection molding process, with regard to the required properties.

Solution

The above-mentioned object is achieved by a threaded cap element, where the cap element is manufactured in a thermoforming process, having a threaded portion with a thread, a flange portion, and a central lid portion that is opposite a cap element open region via which the cap element can be applied to a container to close off the container, where the central lid portion has a concavity in the direction of the open region.

The formation of the concavity makes it possible to provide a cap element (e.g., cap) that can withstand high pressures within a container, but is itself molded from a relatively thin film. Until now, thermoformed caps were not able to be used as caps for containers (e.g., bottles) containing carbonated drinks because the caps were deformed due to the high internal pressure (up to 7 bar). However, the formation of a central concavity allows use at pressures up to over 10 bar.

A pressure on the concavity of the cap element leads to an increased pressure on the flange portion, which, when screwed on, runs substantially parallel to the inner wall of the container (e.g., bottle neck) and rests against it. As such, with increased pressure on the concavity, the sealing is even improved.

The cap element is preferably made of PET, which can be mechanically recycled and is therefore easy to recycle and process together with a container made of the same material compared to another plastics material.

In further embodiments, the concavity extends starting from the flange portion, or the sealing flange, towards the open region of the cap element.

In further embodiments, the flange portion can have a diameter adapted to a corresponding portion of a container opening for a non-positive connection with the portion. This further improves the sealing effect because the flange portion is already sufficiently pressed against the inner wall of the container by the prevailing pressure due to the concavity in the central lid portion.

In further embodiments, the cap element can have an edge at an end of the cap element opposite the open region, where the edge is connected to the threaded portion at its external portion and transitions into the flange portion at an inner portion. The edge thus forms a further contact surface that runs substantially orthogonally to the flange portion and, when screwed on, rests against a corresponding portion of a container (e.g., bottle), so that the seal is further improved.

In particular, in interaction with a subregion of the threaded portion running parallel to the flange portion, a cap element region can be shaped that rests against an open container end from three sides.

In further embodiments, the flange portion can have a height of at least 2 mm starting from the edge.

In further embodiments, the flange portion can have a channel or groove that serves to hold items such as disks, etc.

In other embodiments, a decorative element can be inserted into the channel or groove to protect the concavity from the outside and/or to indicate the contents, the manufacturer, etc.

In further embodiments, the concavity can have a radius that depends on the inner diameter of a container opening in order to achieve an optimal sealing effect.

In further embodiments, the radius of the concavity can correspond to 1.2 to 1.8 times the inner diameter of a container opening. It was found that an optimal sealing effect is achieved when the radius of the concavity corresponds to 1.5 times+/−20% of the inner diameter of a container opening.

In further embodiments, the cap element can have a further portion with a toothing, via which the cap element can be, for example, rotated and processed in a defined manner in subsequent processing steps during manufacturing. For this purpose, the toothing can be brought into engagement with a drive pinion of a system, for example, which rotates the cap element during, or for, additional processing. In addition, such a toothing can make it easier to open such a cap element (e.g., cap) because it provides slip protection.

In further embodiments, the cap element can have a securing portion with a plurality of hook-like elements (so-called flaps) that, as barbs, can engage behind a corresponding portion of a container and make it difficult or impossible to pull the cap off the container.

In further embodiments, the securing portion can have a perforation via which a part of the cap element can be at least partially separated from a lower ring upon opening, so that the cap element remains on the container even in the opened state.

In further embodiments, the inner diameter of the securing portion and/or the further portion with the toothing can be greater than the inner diameter of the threaded portion, so that demolding of the thermoformed cap element is made easier during manufacture.

The above-mentioned object is also achieved by a method of manufacturing a cap element in accordance with any of the above embodiments, including the following steps:

- providing a plastics film,
- heating the plastics film,
- shaping the plastics film, and
- demolding the shaped plastics film,
  
  where the shaping is carried out by means of a mold tool that has a spindle that is moved out of the shaped region of the plastics film by rotation for the demolding.

Before the plastics film is shaped, the plastics film is fed into a shaping region between a first tool component and a second component, which can be displaced relative to each other. Thereafter, a relative displacement of the first tool component and the second tool component takes place, where regions of the plastics film come into contact with a first mold surface of at least one first mold part of the first tool component, where the first mold surface has at least one first mold portion that has a thread. The shaping of the plastics film takes place in at least one cavity formed between the first mold surface of the at least one first mold part and at least one mold cavity of the second tool component, where at least one cap element with a thread is formed. The demolding of the shaped plastics film, where at least the at least one first mold portion is connected to a spindle and the spindle is connected to a threaded nut, is carried out by jointly displacing the at least one first mold part and the first tool component, where the threaded nut is displaced linearly relative to the first tool component and the spindle is set in rotation together with the at least one first mold portion by the relative displacement of the spindle nut with respect to the first tool component in order to remove the at least one mold part from the shaped cap element.

A spindle can, for example, be designed as a so-called threaded spindle, that is rotated due to a linear displacement of the threaded nut in interaction with its thread. In this respect, the terms “spindle” and “threaded nut” include all designs that involve the rotation of a rotatably mounted spindle or shaft, which is set in rotation by linear displacement of a component connected to it (e.g., threaded nut).

This method makes it possible to manufacture cap elements with a thread in large quantities easily and cost-effectively.

In further embodiments, an edge running substantially orthogonal to the first mold portion can be shaped during the shaping process, which edge is punched, perforated and/or bent to form hook-shaped elements in a subsequent step. In this case, the at least one first mold part and/or the first tool component can have a mold portion for the edge. This edge can then be punched, creating protruding flaps, which can then be further bent to form barb-like elements (flaps). In addition, a region of the shaped cap may be perforated to allow the edge to be torn away from the rest of the cap, for example when the cap is opened for the first time after being applied to a container. Depending on the design of the perforation, the edge with the flaps can, for example, remain on a corresponding portion of a container, with the rest of the cap remaining connected to the edge via a non-perforated region.

In further embodiments, shaped cap elements having a thread can be further processed after formation and, for example, can be opened at a closed end in order to produce, for example, rings or tube portions with an internal and/or external thread.

Further features, embodiments and advantages result from the following illustration of exemplary embodiments with reference to the figures.

BRIEF DESCRIPTION OF THE FIGURES

In the figures:

FIG. 1 depicts a schematic sectional view of a bottle neck with a cap screwed on, according to some embodiments.

FIG. 2 depicts a schematic illustration of a cap in perspective view in an intermediate step, according to some embodiments.

FIG. 3 depicts a schematic illustration of a cap in a perspective view, according to some embodiments.

FIG. 4 depicts a schematic sectional view of a cap, according to some embodiments.

FIG. 5 depicts a further schematic sectional view of a bottle neck with a cap screwed on, according to some embodiments.

FIG. 6 depicts schematic illustrations of a first tool component, according to some embodiments.

FIG. 7 depicts a schematic illustration of a mold tool with a first tool component and a second tool component in a further embodiment, according to some embodiments.

FIG. 8 depicts a schematic illustration of the formation of a groove in further embodiments of a cap, according to some embodiments.

FIG. 9 depicts a schematic illustration of a method of manufacturing caps, according to some embodiments.

DETAILED DESCRIPTION

Various embodiments of the technical teaching described herein are shown below with reference to the figures. Identical reference signs are used in the figure description for identical components, parts and processes. Components, parts and processes that are not essential to the technical teachings disclosed herein or that are obvious to a person skilled in the art are not explicitly reproduced. Features specified in the singular also include the plural unless explicitly stated otherwise. This applies in particular to statements such as “a” or “one.”

FIG. 1 depicts a schematic sectional view of a bottle neck 210 of a bottle 200 (container) only partially shown in FIG. 1, with a screwed-on cap 100, that is used as a cap element for the bottle 200. In the following figure description, the term “cap” is also used as a synonym for “cap element”. Cap elements can also have a different design, as shown in the exemplary embodiments in the figures. For example, instead of an internal thread for closing a container opening from the outside, cap elements can have an external thread that can be screwed into a correspondingly designed container opening.

The bottle neck 210 has a typical design, in particular for plastics bottles made of PET. The bottle neck 210 has at its upper open end a bottle thread 212, which is designed as an external thread. Below the bottle thread 212, a circumferential barb 220 extends at a slight distance therefrom, which, in interaction with barbs of a cap 100—where the barbs are also referred to as flaps 134—makes it difficult to open the bottle 200 after it has been closed for the first time by a cap 100, and makes the opening visible (tamper evidence) by tearing a perforation 150 on the cap 100. Slightly below the barb 220 there is a circumferential ring 224.

The cap 100 has a threaded portion 110, a central lid portion 120, a flange portion and a ring 130. The central lid portion 120 has a concavity 122 that is directed downwards. The flange portion 114 extends from the edge of the concave region of the central lid portion 120 parallel to the bottle neck 210. The flange portion 114 of the cap 100 forms a sealing flange 116, via which the cap 100 is pressed against the inner wall of the bottle neck 210. The pressure on the sealing flange 116 is exerted via the concavity 122. The greater the pressure on the concavity 122, the greater the pressure on the sealing flange 116 and/or the flange portion 114. For example, in particular a bottle 200 containing a carbonated drink may have a high internal pressure, for example in the range of up to 7 bar. This high pressure is transferred to the flange portion 114 via the concavity 122, as shown by the arrows in FIG. 1, so that as the internal pressure in the bottle 200 increases, the pressing effect in the region of the flange portion 114 increases. The height or extension of the sealing flange 116 and/or the flange portion 114 can additionally influence the sealing in the region of the sealing flange 116. For example, the height in flange portion 114 is at least 2 mm.

The radius of the concavity 122 is preferably 1.5 times the inner diameter of the bottle neck 210⁺/₋20%.

Starting from the flange portion 114, a cap edge 124 extends circumferentially over a corresponding edge of the bottle neck 210. On the outside of the cap 100, the threaded portion 110 with a thread 112 extends around the circumference. The thread of the cap 100, which is designed as an internal thread, corresponds to the bottle thread 212, which is designed as an external thread. Below the threaded portion 110, the cap 100 has a region designed as a ring 130, which has a second portion with a toothing 140 and a securing portion 132. The securing portion 132 has flaps 134 that are bent at the lower end of the cap 100 and that act as barbs and are supported on the underside of the circumferentially shaped barb 220. In addition, the securing portion 132 has a perforation 150 that extends between the region with the flaps 134 and the toothing. The perforation 150 does not run completely around the cap 100. When the cap 100 is opened for the first time, the lower part with the flaps 134 and the portion above it with the toothing 140 separate in the region of the perforation 150. The lower part with the flaps 134 remains on the bottle neck 210 and the remaining cap 100 can be removed from the bottle neck 210, where both parts remain connected to each other via a non-perforated portion.

As shown in the figures, the region of the cap 100 with the ring 130 has a larger diameter than the threaded portion 110. In the illustration in FIG. 1, it should be noted that the flaps 134 are shown in a bent state.

The choice of diameters results from the design of the mold tool and in particular the threaded portion 110, so that during demolding no jamming or locking occurs due to the demolding movement.

In the manufacture of caps 100, a ring is first shaped at the lower, open end of a cap 100. This ring extends substantially in a plane orthogonal to the vertical axis through the cap 100. FIG. 2 depicts a cap 100 in an intermediate step in the manufacture, with a ring that has already been punched.

The formation of the flaps 134 takes place in multiple steps. First, during the shaping, a cap 100 is shaped from a preheated film web, preferably from a PET, with a circumferential edge at the lower end, as shown schematically in FIG. 2 by the dashed line. The edge is then punched in a subsequent processing step, where regions of the edge are cut out. There remain protruding regions, as indicated in FIG. 2. The regions are then bent around and form the inwardly directed flaps 134, which, when a cap 100 is placed on a bottle neck 210, engage behind the barb 220 and thus secure the cap 100 to the bottle neck 210. The curved design of the flaps 134 supports the placement on the bottle neck 210 and the passage over the region of the barb 220.

In a further processing step, the locking portion below the toothing 140 is also perforated. For this purpose, special machines (“slitters”) can be used, such as those already used for slitting injection-molded caps. In further embodiments, slitting can be provided as a subsequent processing step in a machine for manufacturing caps 100. In the embodiment shown, the toothing 140 is provided for mechanical perforation in such machines. The toothing 140 can be brought into engagement with a drive gear or pinion for further processing of the cap 100 and can thus be driven in a controlled manner during further processing.

FIG. 3 depicts a schematic illustration of a cap 100 in a perspective view, illustrating the formation of the perforation 150. The perforation 150 in the embodiment shown extends below the portion with the toothing 140 and has a plurality of longitudinal slots provided on the circumference, where one region has no perforation 150, so that after the cap 100 is opened for the first time, it remains connected to the bottle neck 210 via the lower part.

FIG. 4 depicts a schematic sectional view of a cap 100. There, the formation of the flaps 134 and the perforation 150 can be seen, where the slits of the perforation 150 completely penetrate the material of the film web.

In the embodiment shown, the cap 100 has a substantially uniform thickness over the entire region. During thermoforming with hot mold tools 400, material shrinkage or thinning may occur. Caps 100 can be manufactured from a plastics film in a thermoforming process and by means of a mold tool 400 with different thicknesses, where a film web 300 or plastics film with a thickness of 0.5 mm to 2.0 mm is used.

FIG. 5 depicts a further schematic sectional view of a bottle neck 210 with a screwed-on cap 100. The inner diameter D₁in the region of the ring 130 is greater than the inner diameter D₂in the region of the threaded portion 110, so that a corresponding mold part 440 of a mold tool 400 does not come into contact with the shaped regions of the ring 130 during demolding, as described below. In FIG. 5, the flaps 134 in the securing portion 132 are already fully finished. During demolding, the flaps 134 are not yet shaped, but protrude laterally as a protruding ring, as shown schematically in FIG. 5 by the dashed lines. It is thus clear that during demolding using a correspondingly designed mold part 440, there can be no collision between the mold tool and the shaped film portion.

FIG. 6 depicts schematic illustrations of a first tool component 410 of a mold tool 400, which can be used in a thermoforming machine for shaping and manufacturing caps 100 from a thermoformable film material, in particular PET. The embodiment depicts a tool table 412 of the first tool component 410, which is coupled to a first drive. Via the first drive, the tool table 412 and thus the components connected thereto can be displaced in a displacement direction relative to a second tool component 450 to close a mold tool 400. A first drive can, for example, include a spindle drive or toggle lever.

A tool body 414 is connected to the tool table 412 and can be displaced together with the tool table 412 via the first drive. The tool body 414 has a frame that serves to hold additional components. The tool body 414 and/or the frame has a tool plate 428 that is fixed to the tool body 414 and cannot be displaced relative to the tool body 414 and the tool table 412. The tool plate 428 has openings in that drive rods 424 are guided, which are connected at their lower end to a drive plate 422. The drive plate 422 can be moved independently of the first drive via a second drive, e.g., a linear drive 430. The second drive may be coupled to a movement of the tool table 412 so that the components for displacement by the second drive may be displaced together with a displacement of the tool table 412. However, the displacement of the second drive can take place independently of the first drive. In further embodiments, the components for displacement by the second drive may not be connected to the tool table 412.

The drive rods 424 are connected to a threaded plate 416 at their upper end. The threaded plate 416 has an opening that has an internal thread that serves as a threaded nut 418 for a threaded spindle 420. Alternatively, a separate threaded nut 418 can be arranged on the threaded plate 416. The threaded spindle 420 is rotatably mounted on the drive plate 422. For this purpose, the drive plate 422 can, for example, have an opening into which a lower end of the threaded spindle 420 is inserted. In further embodiments, the drive plate 422 can have a pin, bolt or shaft onto which a threaded spindle 420 with a corresponding receptacle is placed, which can be rotated via it. The position of the threaded spindle 420 relative to the drive plate 422 cannot be changed. The threaded spindle 420 is only rotatably mounted.

An upper end of the threaded spindle 420 is guided through a corresponding opening in the tool body 412 and connected at its upper end to a mold part 440, or the threaded spindle 420 is shaped at its upper end as a mold part 440. In the embodiment shown, the mold part 440 is located on a contact surface 415 of the tool body 414.

When the drive plate 422 is displaced by the linear drive 430, a guided, linear displacement of the threaded plate 416 with the threaded nut 418 occurs. The displacement of the threaded plate 416 leads to a rotation of the threaded spindle 420 and thus to the rotation of the mold part 440. At the same time, for demolding, the entire tool table 412 with the mold part 440 can be displaced via the first drive, for example downwards, so that a first mold portion 442 with a thread 443 of the mold part 440 is unscrewed while the mold part 440 is simultaneously displaced downwards. This allows for demolding of thermoformed threads.

In the embodiment shown, the mold part 440 has a second mold portion 444, which has a toothing 445, and a third mold portion 446. In the embodiment, the second mold portion 444 and the third mold portion 446 are not rotatable, unlike the mold portion 442 with the thread 443. In such embodiments, the second mold portion 444 and the third mold portion 446 may, for example, be fixed to the tool body 414. In further embodiments, the second mold portion 444 and the third mold portion 446 can be reversibly connected to the tool body 414 and secured against twisting by locking features. In still further embodiments, the second mold portion 444 and the third mold portion 446 may form a unit. The second mold portion 444 and the third mold portion 446 can have a through-opening in which a shaft or the like is guided, which connects the first mold portion 442 to the threaded spindle 420, so that a rotation of the threaded spindle 420 only leads to a rotation of the first mold portion 442 with the thread 443, but not of the second mold portion 444 and the third mold portion 446 of the mold part 440. This ensures that a toothing 445 is not rotated during demolding and thus a correspondingly shaped region of the cap 100 with a toothing 140 is maintained.

The mold part 440 has a depression 448 in a central region as a mold surface for shaping a concavity 122.

FIG. 6 depicts the state after demolding, where a cap 100 has been shaped from a PET film in a region of a film web 300 and the shaped cap 100 has been demolded. The film web 300 with the cap 100, which is substantially not yet finally shaped, is then further processed and, for example, punched, and then punched-out regions are bent around to form flaps 134 and the cap 100 is perforated in the region of the ring 130.

To form caps 100 from PET, a preheated film web 300 is first brought into a shaping region between a first tool component 410 and a second tool component 450 of a mold tool 400. Thereafter, the mold tool 400 is closed by relative displacement of the first tool component 410 and the second tool component 450, where the film web 300 comes into contact with the contact surface 415 and the mold surface of the mold part 440. Subsequently, the film web 300 is sucked in at least in the region of the caps 100 or the mold part 440 and/or pressed onto the mold surface of the mold part 440 by means of overpressure, where the film is applied to the surface of the mold part 440 and partially to the contact surface 415 and assumes the shape of the mold surface. In addition, the film cools down on the relatively cold surface of the mold surfaces, so that the film hardens. The cap 100 must then be demolded, where a combined movement via the first drive and the second drive takes place.

In this case, the first drive and the second drive can be coupled to one another, where a forced control is provided. In this case, a linear movement of the drive plate 422 and thus of the threaded plate 416 as well as a rotation of the threaded spindle 420 and thus of the first mold portion 442 with the thread 443 can be dependent on and determined by a displacement of the tool table 412.

During the movement of the tool table 412 away from the shaping region, e.g., downwards, the first mold portion 442 rotates so that the thread 443 is unscrewed from the shaped threaded portion 110 of the cap 100. The dimensions of the cap 100 and its thread 112 must be taken into account. Accordingly, the travel movements of the first drive and the second drive must then be coordinated with each other. Furthermore, the pitch of the thread of the threaded spindle 420 must be designed and adapted to the required movement and rotation.

The rotation of the first mold portion 442 with the thread 443 and the displacement of the tool table 412 are to be designed such that the mold portion 442 can be unscrewed without damaging the shaped threaded portion 110 of the cap. After the first mold portion 442 has been unscrewed from the threaded portion 110, further rotation can be interrupted and the mold part 440 can be moved by moving the tool table 412 alone. Since the diameters D₁and D₂(see FIG. 5) are selected accordingly, no blockage or damage occurs when the mold part 440 is displaced via the different portions 442, 444, 446.

The displacement via the tool table 412 can be divided into two portions, where the two portions can be travelled on at different speeds. For example, a displacement of the tool table 412 can take place more quickly after the first mold portion 442 has been unscrewed from the threaded portion 110.

After demolding, the region of the film web 300 with the molded cap 100 is moved out of the shaping region, and a new portion of the film web 300 can be shaped as described above. For this purpose, the mold tool 400 moves back into a closed position. In order to be able to repeat the demolding in a corresponding manner as described above, the threaded plate 416 must first be returned to its starting position by displacing the drive plate 422 by the linear drive 430. In the starting position, depending on the design of the thread (left- or right-hand thread), the threaded plate 416 can be located in an upper region or in a lower region of the tool body 414.

FIG. 7 depicts a schematic illustration of a mold tool 400 with a first tool component 410 and a second tool component 450 in a further embodiment.

The mold tool 400 of FIG. 7 is designed to simultaneously shape a plurality of caps 100. For this purpose, the first tool component 410 has a drive plate 422 which, like the drive plate 422 of the embodiment of FIG. 6, can be linearly displaced via a linear drive 430. The drive plate 422 is guided over a plurality of columns 426. The columns 426 are connected at their lower end to the tool table 412 and at their opposite upper end to the tool plate 428. The tool plate 428 has openings through which drive rods 424 are guided. The drive rods 424 are connected to the drive plate 422 and to a threaded plate 416. The threaded plate 416 has a plurality of openings. Threaded nuts 418 are located in the region of the openings. The threaded nuts 418 engage with threaded spindles 420. The threaded spindles 420 are rotatably mounted on the tool plate 428 and are connected at their upper end to mold parts 440 and/or a first mold portion 442 of the mold parts 440.

The second tool component 450 has a tool table 452, which carries out a displacement of the second tool component 450 via a separate drive or a drive coupled to or synchronized with the first drive. A tool body 454 is arranged on the tool table 452. The tool body 454 has a hold-down bracket 480. The hold-down bracket 480 has a number of openings corresponding to the number of mold parts 440, which define a mold cavity 456 in interaction with the mold parts 440.

The first tool component 410 further includes a clamping frame 432 mounted on springs 433. The clamping frame 432 has a number of mold parts corresponding to the number of openings.

To form caps 100, a film web is first introduced into the shaping region between the first tool component 410 and the second tool component 450 of the opened mold tool 400. FIG. 7 depicts an opened mold tool 400. The film web 300 preheated via an upstream preheating station of a thermoforming system is then in contact with the contact surface 415 or extends over the contact surface 415 at a small distance therefrom.

Subsequently, the first tool component 410 and the second tool component 450 are displaced relative to each other, where the film web 300 comes to rest on the contact surface 415. Upon further relative displacement of the first tool component 410 and the second tool component 450, the hold-down bracket 480 comes into contact with the film web and presses it against the mold surface 415, where the clamping frame 432 is pressed downwards against the force of the springs 433 via the hold-down bracket 480 as the mold tool 440 is further closed. The mold parts 440 protrude from the mold surface 415 of the clamping frame 432 and pre-form the film web. In the closed state of the mold tool 440, the regions of the film web 300 to be deformed are held against the mold surface 415 by the edges of the openings of the hold-down bracket 480. Inside the openings of the hold-down bracket 480, the regions of the film web are held on the one hand by the hold-down bracket 480 and on the other hand are pre-shaped by the mold parts 440 protruding from the mold surface 415. The film is then sucked into the regions held by the hold-down bracket 480 via corresponding suction channels of the first tool component 410. Alternatively or additionally, an overpressure can be generated in the mold cavity 456. In the above variants, the film is pressed onto the surfaces of the mold parts 440 and partially onto the mold surface 415 in the respective regions, so that the film is shaped accordingly. Since the mold surface 415 and the surfaces (mold portions) of the mold parts 440 are not actively heated, a sudden cooling occurs, where the film takes on the shape of the mold parts 440. In further embodiments, at least some regions of the tool components can be actively cooled to support rapid cooling. For this purpose, the tool components are made of a metal or a metal alloy (e.g., aluminum) with high thermal conductivity to dissipate the thermal energy introduced via the film web 300.

After the shaping, the demolding of the shaped caps 100 in the film web 300 is carried out, as already described for the embodiment of FIG. 6, where a linear displacement of the first tool component 410 simultaneously causes a rotation of the first mold portions 442 of the mold parts 440. In the embodiment shown in FIG. 7, the displacement of the drive plate 422 and the rotation of all threaded spindles 420 as well as the associated mold parts 440 or the rotatable parts of the mold parts 440—in the embodiment of FIG. 7, the first mold portions 442 with the thread 443—are carried out via a single second drive or via a single linear drive 430. It is not necessary to provide a separate drive for each of the threaded spindles 420. As such, a variety of caps 100 can be produced with a simple tool design, where thermoformed caps 100 with a thread can be manufactured.

The design of the mold tool 400 and the tool components 410 and 450 may differ from the embodiment shown in FIGS. 6 and 7 in further embodiments.

Instead of displacement via a threaded spindle 420, an equivalent drive can also be used that translates a linear movement of a second drive, e.g., a linear drive 430, into a rotational movement for a mold part 440 or a first mold portion 442 with thread 443. As such, the second drive or linear drive 430 also includes the use of equivalent drives.

Additionally or alternatively, as schematically indicated in FIG. 8, a groove 180 (channel) can be formed in the region of the flange portion 114, into which, after the cap 100 has been manufactured in a thermoforming process, decorative elements such as disks can be inserted in order to protect the concavity 122 from the outside and/or to indicate a designation of the contents, the manufacturer, etc.

The formation of a groove 180 is shown schematically and can, for example, be carried out analogously to the formation of undercuts, which are known in caps or cups made of plastics material in the thermoforming process. Usually, no moving tool parts are required for such undercuts because, due to the appropriate design of the depth, radius, etc., they are sufficiently flexible to be pulled out of a corresponding mold channel, etc. during demolding.

The illustration in FIG. 8 depicts schematically the formation of a groove 180. In embodiments, a groove 180 protrudes only so far inwards, i.e., from the central lid portion 120 with the concavity 122 in the direction of the threaded portion 110 with the thread, as shown in FIG. 8, that the cap 100 can still rest against a bottle neck 210 or the like substantially over its entire surface in the region of the flange portion 114. In further embodiments, a groove 180 can also be shaped only by a taper, so that the flange portion 114 rests completely against a bottle neck 210 or another container interior portion on the side facing the latter.

FIG. 9 depicts a schematic illustration of a method 600 of manufacturing caps 100. In the manufacture of caps 100, in a first step 610, a plastics film, for example a PET film web 300, with a layer thickness in the range of 0.5 mm to 2.0 mm is first provided. In a subsequent step 620, the film web 300 is then fed to a first station of a thermoforming system and preheated there to the shaping temperature. The feed takes place in cycles. Subsequently, in a subsequent step 630, the preheated film web 300 is introduced in cycles into a shaping region of an open mold tool 400 (see, for example, FIG. 7).

Subsequently, in a step 640, a relative displacement of a first tool component 410 and a second tool component 450 of the mold tool 400 takes place. In a step 650, the film web 300 is then shaped in regions with mold parts 440 to form caps 100. In a subsequent step 660, the molded caps 100 are demolded. The demolding process step 660 includes sub-steps such as the displacement of the tool components 410 and 450 in a step 661, a displacement of the drive plate 422 in a step 662, and a rotation of the threaded spindles 420 and the first mold portions 442 connected thereto in a step 663.

After demolding in step 660, the mold tool 400 is opened and the film web 300 with the shaped caps 100 is removed from the shaping region in cycles. Subsequently, further processing steps can be carried out in a step 670. For example, punching out 671 of the cap 100 from the film web 300 can take place. Further processing can then be carried out in the thermoforming system or in a downstream, separate processing station. Post-processing may include, for example, perforating 672 an edge of the cap 100 and bending 673 flaps 134.

The solution presented offers the formation of thermoformed caps 100 in high quantities with a simple tool structure and thus provides an alternative to injection-molded caps. The solution is significantly more efficient in terms of costs and material usage compared to conventional caps and manufacturing methods, as well as the tool required.

LIST OF REFERENCE SIGNS

- 100 Cap
- 110 Threaded portion
- 112 Thread
- 114 Flange portion
- 116 Sealing flange
- 120 Lid portion
- 122 Concavity
- 124 Cap edge
- 130 Ring
- 132 Securing portion
- 134 Flaps
- 140 Toothing
- 150 Perforation
- 180 Groove
- 200 Bottle
- 210 Bottle neck
- 212 Bottle thread
- 220 Barbs
- 224 Ring
- 300 Film web
- 400 Forming tool
- 410 First tool component
- 412 Tool table
- 414 Tool body
- 415 Contact surface
- 416 Threaded plate
- 418 Threaded nut
- 420 Threaded spindle
- 422 Drive plate
- 424 Drive rod
- 426 Column
- 428 Tool plate
- 430 Linear drive
- 432 Clamping frame
- 433 Spring
- 440 Mold part
- 442 First mold portion
- 443 Thread
- 444 Second mold portion
- 445 Toothing
- 446 Third mold portion
- 448 Mold depression
- 450 Second tool component
- 452 Tool table
- 454 Tool body
- 456 Mold cavity
- 480 Hold-down bracket
- 600 Method
- 610-673 Method steps

Threaded cap element and method of manufacturing a cap element

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