TW201841803A - Method and device for manufacturing peel-off lids as well as a peel-off lid - Google Patents

Abstract

A peel-off lid with a rolled-in section around the extraction opening (15) is formed in such a way that before forming the rolled-in section a thin plastic strip (32) is applied onto the collar of the lid ring. After forming the rolled-in section, the plastic strip is melted in order to reach a good adhesion of the plastic on the upper side and the underside of the peel-off lid in the rolled-in section. In this way it is possible to reach a practically hermetic sealing of the cutting edge (31) of the peel-off lid in an inexpensive way and with the possibility to manufacture with high cadence.

Description

   Method and device for manufacturing tear-open cover and tear-open cover    [Cross-reference related applications]

This application claims the priority of the Swiss patent application 0536/17 filed on April 21, 2017, the disclosure of which is incorporated herein by reference.

The invention relates to a method for manufacturing a tear-open cover according to the preamble of item 1 of the scope of the patent application. Furthermore, the present invention relates to a device for manufacturing a tear-open cover according to the preamble of item 9 of the scope of patent application, and a tear-open cover according to item 15 of the scope of patent application.

Tear-off covers are known, for example, from DE-U 298 17 592 or from DE-U 92 03 953. If the container closed by the tear-open lid is filled with liquid, corrosive filling contents, such as saline, the bare cutting edge of the lid opening may corrode. If a tear-off cap with a so-called retort-curl is encountered, a certain protective effect on the filling content is achieved by rolling out towards the top and out of the section with the cutting edge And by covering it with the torn foil. In addition, the exposed or potentially corroded cutting edges are invisible, respectively. However, despite this, the traces of corrosion may become visible, depending on the aggressiveness of the filled contents and the storage time of the filled container. EP-A 1 153 840 proposes to also seal the ripped foil on the pressure roller itself, with the result that the cutting edge is protected from hitting the contents of the can by the seal. However, it has been noted that the sealing system is difficult to control perfectly at the sealing flange and also at the press roller during production at high steps. WO-A 02/790041 mentions incidentally that the gap established during the roll-in can be filled with the heat-sealing cladding of the ripped foil, and does not describe how this would be possible during the industrial manufacture of the ripped lid Really implemented. It is known that the ripped foil only has a very thin heat sealing layer, and if heat sealing known to those with ordinary knowledge in the technical field of the present invention is performed, how can those with ordinary knowledge in the technical field of the present invention This layer is not obvious for gap filling systems. The possibilities mentioned in WO-A 02/790041 are therefore practically impossible. It is known from EP-B 2 055 736 how to provide outward rolling of the container at the opening of the container so that the cutting edge does not come into contact with water. It is proposed here to protect the cutting edge with a modified hotmelt material containing a thermoplastic elastomer. WO 2015/164986 A1 discloses a method and device according to the preamble of the independent items of these patent applications, which makes it possible to effectively protect the cutting edge. In rare cases, insufficient protection of the cutting edge can also occur with this conventional method.

The present invention has the purpose of establishing an improved method by which the tear-open cap can be manufactured industrially at a very high pace and at low cost, and for this reason the actual number of defective caps with insufficient cutting edge protection The upper limit is reduced to zero.

In this way, after rolling into the free end of the collar, the purpose of using the tear-open cover manufacturing method mentioned in the beginning is to achieve the purpose that the rolled-in section is based on a plastic that occurs at least in the strip The material is heated by partial melting.

The rolled-in section contains at least the actual curl of the flask, followed by the section that forms the cover ring of the sealing surface, and in particular contains the entire section where a strip of plastic material is present. The heating is understood in such a way that the rolled-in section is brought to a temperature that allows the plastic material to melt, wherein it is not necessary, but preferred, that the entire rolled-in section is brought uniformly to the same temperature. Melting the plastic material is not understood in such a way that the entire plastic material of the strip must be brought to the melting temperature. It may be sufficient that the material layer bordering the plastic material and the cover material melts to ensure that the plastic material adheres to the cover ring material. The heating system is also not limited to the rolled-in section, which can heat the entire cover ring, however, it is substantially limited to or concentrated on the rolled-in section of the strip with plastic material, respectively The heating system is preferred. For this purpose, various heat sources can be used.

It has been noticed that the best adhesion of the plastic material to both sides of the cover ring can be achieved by heating the rolled-in section and melting the strip of the plastic material, its side and the rolled-in section The plastic materials of the strips border. A complete seal of the rolled-in section with respect to the contents of the container is achieved, and the tear-off cap is applied on the rolled-in section. In this way, corrosion at the cutting edge can be reliably avoided at the cutting edge used for the tear-off cap produced according to the invention.

Preferably, the heating system of the rolled-in section is made before sealing the ripped foil onto the lid ring, so that this is a separate work step during lid manufacturing. In this way, it is possible to perform the heating and melting of the plastic material separately from the heat guide during the sealing of the ripped foil, and the effect of heating the rolled-in section on the seal can also be avoided. It may also provide cooling of the cover ring, for example by air flow, between the heating of the rolled-in section and the seal, so as not to affect the seal or the sealing parameters, respectively, for the tear-off foil in the Seal on the cover ring.

Preferably, an induction-operated heating mechanism is used to heat the rolled section. It generates eddy currents in the metal cover material, which causes it to heat up. The heating can act on the entire cover ring. Due to the configuration of the induction heating mechanism and potentially the concentration of the magnetic field lines of the induction heating by pole shoes, mainly the eddy current generated in the rolled-in section can be provided. The very rapid heating of the plastic material to a temperature that causes the melting of the plastic material can be caused by the inductive heating of the metal material of the cover ring. Induction heating mechanisms have been used in this industrial environment for a long time to heat materials, and they are known to those of ordinary knowledge in the technical field of the present invention and are also commercially available. Alternatively, the heating can also be made by infrared radiation or hot air.

Furthermore, it is alternatively or additionally possible to perform the heating of the rolled-in section while sealing the ripped foil. In this case, the heating mechanism contacting the rolled-in section is preferably provided in the sealing tool so that direct heat transfer from the heating mechanism to the rolled-in section occurs. In this way, the heating of the rolled-in section can be performed separately from the sealing of the ripped foil on the cover ring, so that the seal is not disturbed in a disturbing manner by the heating of the rolled-in section influences. It is possible in two steps to perform the heating on the outside of the sealing tool, and also additionally inside the sealing tool, especially inductively.

During the sealing of the tear foil on the cover ring, it is known to perform dual heating so that the pre-sealing of the tear foil first occurs on the cover ring, and in the second step, the tear foil occurs The main seal of the material on the cover ring, wherein the temperature of the pre-seal is lower than the temperature of the main seal. In this case, it is preferable that the heating of the strip or the plastic material rolled into the section is performed in the second step, respectively, during the main sealing period of the ripped foil. In this way, from a lower temperature point of view, the effect of the pre-sealing by additional heat guidance and by heating the rolled section can be avoided. This heat conduction can be well controlled with the higher sealing temperature during the main sealing period.

The term plastic material of the strip includes the current situation where the strip contains or consists of a polymer or resin, and the rolled into section is heated at least to the melting temperature of the plastic material of the strip occur. In particular, the heating of the rolled-in section occurs to a temperature in the range of 100 ° Celsius to 200 ° Celsius, and in particular to a temperature in the range of 140 ° Celsius to 180 ° Celsius. If the upper side of the blank for forming the heat-sealed sealing surface of the ripped foil is a polypropylene modified varnish system or contains this system, or it is a polypropylene composite coating, or another contains polypropylene The coating material, and the bottom side of the blank material have a coating material made of an inner varnish for a tank body with polyester or acrylic or epoxy resin or polyvinyl chloride, which is particularly advantageous of. The selection of the mentioned material of the plastic strip and the mentioned section for heating leads to a difference between the cover material of the cover blank or the cover ring and the plastic strip respectively Very good connection.

It is possible to add a blowing agent to the plastic material of the strip, so that the foaming occurs during heating of the rolled-in section, which can increase the adhered section or surface, respectively.

Furthermore, the present invention has the purpose of providing a manufacturing device for a tear-open cover. The tear-open cover can be manufactured in a high-step and inexpensive manner by the manufacturing device, which provides the cutting edge of the tear-open cover with corrosion resistance Actually no fault protection.

This object is achieved by the device mentioned in the beginning, which has the characteristic features of item 9 of the patent application.

By means of the at least another processing station, which is arranged after the third processing station in the transport direction, it is designed to be suitable for heating the rolled-in section of the tear-open lid to at least at least the plastic strip The melting temperature is obtained by heating the rolled-in section and melting the plastic material of the strip. The optimal adhesion of the plastic material on both sides of the cover ring can be obtained by the device, and both sides are adjacent to the quilt The plastic material of the strip rolled into the section. For a tear-off lid made by the device, the complete seal of the rolled-in section is achieved with respect to the contents of the container, the tear-off lid being applied to the container. In this way, for the tear-off cap made by the device according to the invention, the corrosion of the cutting edge can be reliably avoided.

The rolled-in section usually follows the curling of the flask following the section of the cover ring forming the sealing surface. The heating achieved by the processing station is understood in such a way that the rolled-in section is brought to a temperature that allows the plastic material to melt, which is not required, but preferably the entire rolled-in area The segments are brought to the same temperature in a uniform manner. The melting of the plastic material is not understood in such a way that the entire plastic material of the strip must be brought to the melting temperature. It may be sufficient that the material layer of the plastic material adjoining the cover material melts to ensure the adhesion of the plastic material to the cover ring material. The heating system is also not limited to the rolled-in section, which may be heated for the entire cover ring, however, the heating system that is substantially concentrated on the rolled-in section is preferable. Any heat source can be used for this purpose.

In the subsequent processing station, the induction heating mechanism is preferably provided as a heat source. This allows the cover ring, and in particular its rolled into section, to be heated particularly quickly to the desired temperature, which is required for melting the plastic strip. In this way, the high manufacturing pace for tearing the cover can also be maintained with additional processing stations. The further processing station can be located anywhere along the transport path of the device between the processing station that manufactures the rolled-in section and the sealing station. It can be arranged before or after the conversion station of the device. The configuration before the conversion station is advantageous because, as a result, the cover ring is cooled again until the sealing station. For cooling them, additional cooling stations can potentially be supplied, which cool the cover ring, for example, with airflow. The cooling before the sealing station has the advantage that the sealing parameters are not affected by the previous heating of the cover ring.

However, the further processing station integrated into the at least one sealing station and having a heating mechanism in the sealing tool that contacts the rolled-in section can also be provided. The device for continuously having two sealing stations in the transport direction, in order to perform the pre-sealing of the ripped foil and the main sealing, the other processing station is preferably integrated in the second sealing station.

The other sealing station is specifically designed to be suitable for heating the rolled section in the temperature range from 100 ° C to 200 ° C, and in particular in the range from 140 ° C to 180 ° C. Furthermore, it is preferred that a strip having a substantially uniform thickness, especially in the range from 0.05 mm to 0.5 mm, and in particular having a thickness of about 0.1 mm, is produced for applying the strip In the form of a plastic strip, the application station is designed to be suitable for applying the plastic strip. The low thickness of the strip is advantageous for quickly reaching the melting temperature.

Furthermore, the present invention relates to a tear-off cover, including a circumferential attachment section, a sealing flange having a tear-off foil sealed thereto, and a rolled-in section extending circumferentially around the sealing flange, which The extraction opening is laterally limited, wherein the rolled-in edge has a seal made of plastic, the term plastic means a polymer or resin, which is melted by melting the rolled-in section in an adhesive manner Plastic is connected to the upper and lower sides of the tear-open cover. This tear-open cover has the advantages mentioned.

1‧‧‧ embryo

2‧‧‧ Cover ring

4‧‧‧collar

5‧‧‧Curved bottle curl

6‧‧‧ edge

7‧‧‧ Sealing flange

8‧‧‧Tear foil

10‧‧‧ tear open the cover

11‧‧‧Wall parts

12‧‧‧Stacked storage

15‧‧‧ extraction opening

18‧‧‧Tear off the latch

20‧‧‧Manufacturing device

22‧‧‧Conveying device

23‧‧‧ Stamping processing station

24‧‧‧ processing station

25‧‧‧ Rolling into the station

26‧‧‧ Conversion station

27‧‧‧Pre-sealing station

28‧‧‧Main sealing station

29‧‧‧ Processing station

30‧‧‧ embryo

31‧‧‧cutting edge

32‧‧‧ribbon strip

34‧‧‧Upper

35‧‧‧ processing station

35’‧‧‧ processing station

36‧‧‧Bottom

38‧‧‧Heating mechanism

39‧‧‧Heating element

40‧‧‧Inside

42‧‧‧ Heat transfer layer

43‧‧‧ unit

With the aid of this drawing, further embodiments, advantages, and applications of the present invention are derived from the appendages of these patent applications and the now subsequent description. This is shown in: Figures 1 to 5 are upright cross-sectional views through the blank, cover ring and tear-off cover, used to describe the processing steps when manufacturing the tear-off cover; Figure 6 is the tear-off process according to the present invention An upright cross-sectional view of the cover ring during capping; Figure 7 is an enlarged view of a portion of the cap ring of Figure 6; Figure 8 is a rolled area of Figure 7 used to form the cap ring at the edge of the extraction opening The cover ring after the segment; FIG. 9 is an enlarged view of a portion of the cover ring of FIG. 8; FIG. 10 is a top view of the cover ring tearing off the cover; FIG. For manufacturing a tear-off cap having a sealed cutting edge according to the method of the present invention; FIG. 12 is an upright cross-sectional view of a portion of a sealing tool for performing heating of the rolled-in section in the sealing tool; 13 is an explanatory view of the upright cutting sealing tool of FIG.

With reference to FIGS. 1 to 11, it is known to those having ordinary knowledge in the technical field of the present invention that the manufacture of a tear-off lid according to this prior art can be immediately explained. Figure 1 shows cover blank 1. The stack storage 12 is shown at the beginning of the conveying path of the manufacturing device 20 (FIG. 11), which contains a plurality of the blanks, the blanks are individually separated and along the conveying path by different Processed by the processing station, where the cover ring is first formed from the cover blank and then further processed until the completed tear-open cover. The cover blank is, for example, a circular disk made of coated metal, which is thereby protected from corrosion, for example made of coated tinplate. The coating material on the bottom side of the top in FIG. 1 is usually different from the coating material on the upper side of the blank 1, and the blanks are located at the bottom in FIG. These blanks have a diameter of, for example, 11 cm, and have been pre-formed on the edge 6 by a not-shown processing machine, and the shape of the edge 6 has later torn apart the completed tearing by bending the joint The role of the lid attached to the container or tank. This is known to those with ordinary knowledge in the technical field of the present invention, and therefore will not be described in more detail here. The blank 1 of FIG. 1 and the cover ring 2 of FIGS. 2 to 4 are shown with their bottom sides facing upward, as mentioned, and the completed tearing of the cover of FIG. 5 is shown with its upper side, and therefore The tear foil 8 is displayed upward. The treatment in this device can be initially made in the position of FIGS. 1 to 4, followed by a conversion station 26, which brings the cover ring into the position of FIG. Individual cover ring.

In the manufacturing device 20, the transport device 22 that transports the cover blank, the cover ring, and the tear-off cover from one processing station to the next processing station along the transport path in the direction of arrow A is particularly provided by The two parallel toothed belts for the accommodating portion of the cover blank or the cover ring, respectively, are known from WO 2006/017953 by those having ordinary knowledge in the technical field of the present invention. This is also not described in more detail here. In a processing station known to those of ordinary skill in the technical field of the present invention and shown here only briefly, each of the blanks to be processed is lifted by the transport device 22 and by the The individual processing station processes and returns to the transport device 22. This is indicated by arrows pointing up and down at these processing stations. The drive for the processing station of each processing station is indicated below the transport device. It has the effect of lifting and lowering the blanks and the cover ring and performing the individual processing steps.

In the stamping processing station 23, the cover ring 2 is first formed by the cover blank 1 by cutting the middle section of the blank 30 and discharging it as waste. In this way, the removal opening of the tear-off cover is formed, which is sealed with the tear-off foil in a subsequent manufacturing step. Following this take-out opening 15, the sealing flange 7 is left. The metal material is exposed at the cutting edge 31, or the metal sheet of the cover ring 2 is no longer protected by the coating material or the coating materials, respectively. The edge of the take-out opening is pulled upwards in the processing station 24 as a collar 4, and this collar is rolled in another processing station, so that a so-called crimp 5 is formed. The shape of the rolled-in or curled flask can be different respectively. During the extraction of the contents of the can, the roll-in of the edge forming the extraction opening determines that the user of the can is protected from the sharp cutting edge 31.

If the processing steps are carried out by the sealing flange 7 which has been guided downwards, as shown, there is the conversion station 26 behind which rotates around the cover ring, so that during another processing, the sealing flange 7 is at the The conversion station is then located on top of the transport device 22 and in the processing station.

After that, the ripped foil 8 is sealed to the sealing flange in two steps, with a first sealing station or pre-sealing station 27, respectively, and a second sealing station or main sealing station 28, respectively. This sealing process is also known to those with ordinary knowledge in the technical field of the present invention, and will not be described in more detail here. There may be an additional processing station behind, where the stamping of the sealing foil is performed, the tear-off latch is positioned, and the tightness check is made. This is also known to those with ordinary knowledge in the technical field of the present invention, and will not be described in more detail here. At the end of the manufacturing device 20, the completed tear-open cover 10 (FIG. 5) is produced, in which the tear-off foil 8 spans over its take-out opening 15 and the tear-off foil is sealed at the sealing flange 7 on. The edge of the take-out opening 15 is formed by a crimp 5 that bends upwards and outwards (in the position of tearing off the cap according to FIG. 5). The completed tear-open lid 10 can be attached to the can shell by its folded edge 6 (which is indicated only by the wall member 11 in FIG. 5), and thereby seal the can body. This is made during the filling operation, during which the tank has been filled with filling contents. The filled can can be opened later by tearing the tear-off foil from the cover ring by tearing the latch 18, so that the take-out opening 15 is opened.

In the following, a process known from WO 2015/164986 A1 for applying strips made of plastic material in the rolled-in section and the process according to the invention are described, wherein if necessary, its Also refer to the above-mentioned conventional manufacturing steps or the conventional manufacturing apparatus, respectively.

6 and 7 show the cover ring, and the processing steps for drawing the edge of the extraction opening for forming the collar 4 have been carried out. This is done in the processing station 24. For the preferred example shown (or in a separate step), the curvature to the inner side is established at the upper end 34 of the collar 4, which simplifies the later used to form the curl of the neck roll. Furthermore, the plastic strip 32 is attached to the inner side 40 of the collar 4 in a working step. The application of this plastic layer is made in a separate processing station 29 arranged between the drawing station 24 and the rolling-in station 25.

The strip-shaped strip 32 made of the plastic material is formed during rolling into a seal for the cutting edge 31, which is shown below. The strip 32 is composed of plastic, where the term is also intended to include polymers or resins. These plastic materials are commercially available, and in particular are also available in quality, so that they can reliably withstand the sterilization temperature during the sterilization of the filled container, and therefore will not melt again at the sterilization temperature, making The seal formed by the strip is maintained during the sterilization period. The strip is preferably formed with a uniform thickness along the entire height of the strip, as shown. It is provided as a thin plastic strip, preferably with a thickness d in the range between 0.05 mm and 0.2 mm, preferably with a thickness of about 0.1 mm. The height H of the strip may for example be between 1 and 3 mm.

By injection of molten, liquid plastic material, this application is preferably made from WO 2015/164986 A1 in a manner known to those of ordinary skill in the technical field of the present invention, where the relative movement of the nozzle and the cover ring occurs . Preferably, the cover ring is moved in the direction of rotation in the processing station 29, and during this time, the inner side 40 of the collar 4 is moved through the outlet opening of the injection nozzle statically arranged during application, the Plastic appears from it. The cover ring system is thus lifted, rotated in the processing station 29, and the application system is activated when the cover ring has reached the correct position with respect to the outlet opening. After at least one complete rotation, if the belt running through the inner side without clearance or the one belt is separately formed, the cover ring is moved downward again towards the conveying device, wherein the rotation is terminated so that the cover ring It can be placed on the accommodating part of the conveying device. Thereafter, transportation to the rolling-in station 25 occurs. The plastic of the belt 32 has been cooled and solidified while being applied on the cover ring, so that no plastic flow occurs during the subsequent transportation, and the belt is stable in the displayed shape. If necessary, a cooling mechanism such as a fan may be provided in the application station or the processing station 29, respectively.

During application, it is determined that the distance from the outlet opening or the injection nozzle to the inner side 40 of the collar 4 is substantially constant during the spraying of the liquid plastic, so that the thickness of the strip 32 remains substantially constant , And its small thickness becomes possible. This can be made in a manner known from WO 2015/164986 A1. The procedure for generating the strip 32 according to WO 2015/164986 A1 is preferred. However, within the scope of the present invention, the strip 32 can also be applied to the cover ring in other ways. Therefore, it is possible to place a prefabricated strip made of plastic material into the collar of the cover ring. This can be done in a separate processing station, or during pulling of the collar in the station 24, or during rolling of the collar in the station 25. In these cases, the station 29 shown will be abolished.

It can be seen that the strip 32 is positioned on the inner side 40 of the collar 4 in such a way that the cutting edge 31 lies closer to the plane of the sealing flange 7. The positioning and dimensional design of the strap is approximately such that the strap 32 covers the lower third of the collar 4 up to approximately the lower half of the collar 4. The greater height H of the strip is possible, however, the amount of material used for the plastic used is increased without the need for separate further processing or protection of the cutting edge. The height H is actually about 1 mm to 3 mm.

The cover ring provided with plastic strips according to FIGS. 6 and 7 is provided with a crimp 5 in a conventional manner in the processing station 25. This station 25 works with a known roll-in tool for this purpose, so that this need not be described in detail here, since it is known to those of ordinary knowledge in the technical field of the present invention. For those of ordinary skill in the art of the present invention, one of the obvious modifications is potentially the result of selecting the tool, if the collar 4 has already been bent at its upper edge 34 for the roll-in, it is preferable. It can be seen according to FIGS. 8 and 9 that the strip 32 forms a seal during the formation of the crimp 5, which shows the cover ring after the conversion station 26, which prevents liquid from entering the crimp internal. In this way, the exposed cutting edge 31 is protected from the liquid located inside the tank. For this purpose, as explained, it is inappropriate if the roll-in is made so that the cutting edge 31 is partially embedded in the strip 32, or if it is only located in the strip 32. Even on the contrary, the cutting edge 31 cuts the strip 32 and the metal located on the inner side 40 without hindering the function of the strip 32. As such, the normal manufacturing tolerances during the formation of the crimp 5 are not effective. The top view of FIG. 10 shows that when the cover ring is transported in the sealing station 27, the tear foil is sealed to the take-out opening 15 here.

In the example of FIG. 11, the manufacturing device 20 for the tear-off cover includes a processing station 29 for applying the tape 32 on the cover ring and a processing station 25 for rolling into the collar 4.

According to the invention, the rolled-in edge section is heated in order to melt the strip 32 at least in the contact area of the metal to the cover or to the cladding located above it. The rolled-in edge section contains at least the crimp 5 as shown, for example, in FIG. 9, and in particular the entire part of the tear-off cap, which is covered by the strip 32. For the first exemplary embodiment, the processing station 35 is provided before the conversion station 26, where the rolled-in section is heated. This can be done in such a way that the processing station 35 is also lifted by the transport mechanism 22 with the lid and then heated in the processing station, and then placed on the transport mechanism. However, the cover ring or its rolled-in section can be heated in the processing station respectively when it is on the transport mechanism 22, so that it cannot be lifted by the transport mechanism. Before the conversion station in the processing station 35, the cover ring is still curled up or rolled into the section of the flask, showing upwards, as shown in FIG. 4, respectively. This makes it possible for the rolled-in section to be heated from above and preferably provided by the induction heating device in the processing station 35 for this, which is shown schematically as the unit 43. This embodiment of the heating device is known to those having ordinary knowledge in the technical field of the present invention and need not be described in more detail here. Instead of induction heating devices, it would also be possible to provide infrared radiation sources or hot gas sources.

In another exemplary embodiment, the processing station may be provided to heat the rolled-in section after the conversion station, and it is shown as a processing station 35 'in a broken line in the illustrated example. In this processing station, the rolled-in section is located at the bottom, and it is accordingly preferred that the heating source acts from below, so that it can be more advantageous to allow the cover ring to be passed therethrough The transport mechanism 22 lifts up the processing station 35 'to design the processing station 35' so as to perform the processing with the heating source. Also in this case, induction heating or another heating type can be provided, which is only shown schematically as unit 43.

After the heating of the rolled-in section, it may provide cooling, for example by a fan. It is particularly advantageous if the processing station 35 ′ is located behind the conversion station 26 and, furthermore, a pre-sealing station 27 for pre-sealing the ripped foil 8 is provided on the sealing flange 7. In addition to this, it is possible to generate undesirable effects for the pre-sealing temperature by heating the rolled-in section.

As an alternative to or in addition to the heating in the processing stations 35 and 35 ', the heating of the rolled-in section may be performed in the sealing tool of the sealing processing station. In case the processing station 27 is pre-sealed and the processing station 28 is used to mainly seal the ripped foil, it is preferable that the heating of the rolled section is made in the main sealing station 28. 12 and 13 show as an example the structure of the sealing tool for sealing the ripped foil and for heating the rolled section. FIG. 12 shows a detailed view of the bottom 36 of the sealing tool with the cover ring 2 on it, which is lifted by the transport mechanism 22 by the sealing tool. FIG. 13 shows the bottom sealing tool in the explanatory view, and after the sealing step of tearing the foil 8 with the cover ring 2. In the conventional sealing step not described in more detail here, a suitable sealing foil is placed on the cover ring and is attached by the sealing process and by the upper-not-shown sealing tool To the cover ring on the sealing flange 7 and then the tear-open cover is placed on the transport mechanism 22. In the drawing, the sealing tool has a special heating mechanism 38 visible, which directly contacts the rolled-in section and in particular the crimp 5 to facilitate the introduction of heat from the heating mechanism 38 into the It is rolled into sections for heating it and for melting the strip 32. In this example, the heating energy for the heating mechanism 38 is provided by the heating element 39, which also has the function of heating the lower sealing tool under the sealing flange 7. These electrically heated heating elements 39 are directly connected to the sealing tool and are in thermal flow contact with the heating mechanism 38 via the heat transfer layer 42. However, this is a preferred example, and it is obvious to those having ordinary knowledge in the technical field of the present invention that the heat generation for the heating mechanism 38 for the rolled-in section can also be provided in other ways. After leaving the sealing station 28, not only the ripped foil 8 is sealed to the ripped cover, but also the adhesion of the strip 32 to the two surfaces of the ripped cover has also been melted by melting the strip 32 improve.

According to the invention, the tear-off cover 10 of the rolled-in section with the take-out opening 15 is in such a way that the plastic strip 32 is applied to the collar of the cover ring before forming the rolled-in section To form. After the rolled-in section is formed, the plastic strip is melted to produce good adhesion of the plastic in the rolled-in section on the upper and bottom sides of the tear-off cap. In this way, the actual hermetic seal of the cutting edge 31 of the tear-off cap is achieved in an inexpensive manner and has the possibility of being manufactured at a high pace.

Although the preferred embodiments of the present invention are described in this application, it is clearly noted that the present invention is not limited thereto and can be implemented in other ways within the scope of the following patent applications.

Claims (15)

    A method for manufacturing a tear-open cap (10), wherein: a cap ring (2) having a central take-out opening (15) surrounded by a sealing flange (7) is formed by a stamping process Cover blank (1) is formed; the edge of the take-out opening is formed by pulling towards a collar (4), the collar protruding away from the sealing flange (7); a strip made of plastic (32) applied to one of the inner sides (40) of the collar; the collar (4) is rolled at its free end (34) and reaches to be located in a strip made of plastic; and a tear The foil (8) is sealed to the sealing flange (7); it is characterized in that after being rolled into the free end of the collar (4), the rolled-in section is used to make the strip ( 32) The plastic material is heated in such a way that at least partial melting occurs.         The method as described in item 1 of the patent application range, wherein the heating is performed before the tear foil is sealed onto the sealing flange.         The method as described in item 1 or 2 of the patent application scope, wherein one of the heating mechanisms working inductively is provided for heating.         The method according to any one of items 1 to 3 of the patent application scope, wherein the heating of the rolled-in section is borrowed during the sealing of the tear foil (8) on the sealing flange (7) It is made by a heating mechanism (38) in the sealing tool (36) contacting the rolled-in section.         The method as described in item 4 of the patent application scope, wherein the sealing of the ripped foil is a two-stage process (first two-stage process), which first includes a pre-seal and mainly seals the ripped foil in a second step Material onto the cover ring, and the heating of the plastic material of the strip is made during the main sealing of the ripped foil.         The method according to any one of claims 1 to 5, wherein the plastic material of the strip includes or consists of a polymer or a resin, and the heating is made at least to the strip The flow temperature of the plastic material, especially where the heating is made in the range from 100 ° Celsius to 200 ° Celsius, and in particular in the range from 140 ° Celsius to 180 ° Celsius.         The method according to any one of the items 1 to 6 of the patent application range, wherein the upper side of the blank forming the sealing surface for the tear-off foil has a covering material suitable for heat sealing, which is composed of The polypropylene (polypropylene) is composed or contains polypropylene, and the bottom side of the blank material has a coating material composed of or contains an internal varnish for the tank body.         The method as described in any one of claims 1 to 6, wherein a blowing agent is added to the plastic material of the strip.         A device (20) for manufacturing a tear-open cover (10), including a transport device (22) for a plurality of blanks (1), a plurality of cover rings (2), and a plurality of tear-open covers (10) ), And a plurality of processing stations (23-28) that are continuously provided in the transport direction (A) for processing the plurality of blanks, the plurality of cover rings, and the plurality of tear-open covers, one of which is the first processing A station (23) is provided as a stamping station for forming a cover ring (2) from a cover blank (1), and a second processing station (24) is provided for forming the cover ring protruding away from the bottom side (2) A collar (4), and a third processing station (25), wherein the third processing station is designed to be adapted to form a rolled-in section from the collar, and at least one of which is additionally provided A sealing station (27, 28), which is designed to be suitable for sealing a ripped foil (8) to a sealing surface (7) of the individual cover ring, one of which is an application station ( 29) Provided in the transport direction between the second processing station (24) and the third processing station (25), it is designed to be suitable for applying a surrounding plastic strip (32) to both ends to The inner side (40) of the collar (4), and the first The processing station (25) is designed to bring the rolled-in section (5) into contact with the plastic strip (32), characterized in that at least another processing station (35; 35 '; 28) is attached to the A third processing station (25) is then provided in the transport direction (A), which is designed to be suitable for heating at least the rolled-in section to at least the melting temperature of the plastic strip (32).         The device as described in item 9 of the patent application scope, wherein the other processing station has an induction heating mechanism (43).         The device according to any one of claims 9 or 10, wherein the other processing station is integrated in the at least one sealing station and has contact with the rolled-in section in the sealing tool A heating mechanism (38).         The device as described in item 11 of the scope of the patent application, wherein two sealing stations are provided one behind the other in the transport direction, and wherein the other processing station is integrated in the second sealing station.         The device according to any one of claims 9 to 10, wherein the other processing station is designed to be suitable in the temperature range from 100 ° C to 200 ° C, and in particular from The rolled-in section is heated in the range of 140 ° to 180 ° C.         The device according to any one of claims 9 to 13, wherein the application station (29) is designed to apply a strip-shaped plastic layer (32), which has a substantially uniform thickness, in particular It has a thickness in the range from 0.05 mm to 0.2 mm, and in particular has a thickness of about 0.1 mm.         A tear-off cover comprising a surrounding attachment section (6), a sealing flange (7) having a tear-off foil sealed to it, and one extending circumferentially around the sealing flange (7) The rolled-in section (5), which laterally limits the take-out opening, is characterized in that the rolled-in edge has a seal made of plastic, in particular polymer or resin ( 32), which is adhesively connected to the upper and lower sides of the tear-open cover by melting the plastic rolled into the section.