JP2020517526A - METHOD AND APPARATUS FOR MANUFACTURING A Peeling Lid - Google Patents

Abstract

A peel lid having a rounded area surrounding the withdrawal opening (15) is achieved by applying a smaller thickness plastic strip (32) over the collar of the lid ring before forming the rounded area. It is formed. After forming the rolled area, the plastic strip is melted so that the plastic adheres well to the front and back of the release lid in the rolled area. In this way, a practically gas-tight seal of the cutting edge (31) of the peel lid results, with the possibility of being manufactured inexpensively and at high tempo. [Selection diagram] Fig. 9

Description

The invention relates to a method for the production of a peel lid according to the preamble of claim 1. Furthermore, the invention relates to a device for the production of a peel lid according to the preamble of claim 9 and a peel lid according to claim 15.

Peeling lids are known, for example, from US Pat. If the container closed with a peel lid contains a liquid corrosive content, such as salt water, the exposed cutting edges of the lid opening can corrode. In peel lids with so-called retort curls, rolling up the area with the cutting edge upwards and outwards and by covering with peel flakes provides some protection against the influence of the contents. Also, the exposed or possibly corroded cutting edges are not visible. However, depending on the aggressiveness of the contents and the shelf life of the filled container, traces of corrosion can become visible. Patent Document 3 proposes to seal the peeling flakes even in the rounded portion, thereby protecting the cutting edge from the contents of the can by sealing. However, the sealing at the sealing flange and additionally the rounded part has proved to be difficult to fully control in production at high production temps (Herstellkadenz). U.S. Pat. No. 6,096,037 additionally mentions that the gaps created during rounding can be filled with a hot-seal coating (Heisssiegelbeschichtung) of the peel flakes, which is indeed the case in the industrial production of peel flakes. It does not explain how it is feasible. Known release flakes only comprise a very thin hot seal layer and how this layer can be used for gap filling when hot sealing known to the person skilled in the art is carried out. It is not obvious to a person skilled in the art. The possibilities set out in WO 03/093750 are therefore practically almost impractical. It is known from WO 03/09311 to provide the mouth of the container with an outwardly rounded part so that the cutting edge does not come into contact with water. Therefore, it is proposed to protect the cutting edge with a modified hot melt material containing a thermoplastic elastomer. From US Pat. No. 6,037,697 a method and device is known according to the preamble of the independent claim, which enables effective protection of cutting edges. However, even with this known method, in rare cases, the protection of the cutting edge may be insufficient.

West German Utility Model Publication No. 29817592 West German Utility Model Publication No. 9203953 European Patent Application Publication No. 1153840 International Publication No. 02/790041 European Patent No. 20555736 International Publication No. 2015/164986

The problem underlying the present invention is that it is possible to manufacture peeling lids industrially at a very high tempo and at low cost, and the number of lids that are defective and do not adequately protect the cutting edge is substantially close to. It is to provide an improved method of zero.

This task was achieved in the first-mentioned method for the production of a peel lid by rolling the free end of the collar and then heating the rolled area so that the plastic material of the strip at least partially melts. Will be resolved.

The rolled area comprises at least the actual retort curl adjacent to the area of the lid ring forming the sealing surface, and in particular the entire area in which the strip of plastic material is present. Heating means that the rolled area is brought to a temperature which allows the melting of the plastics material, while it is not essential that the entire rolled area is brought to said temperature evenly. , Is advantageous. Melting of the plastic material does not mean that the entire plastic material of the strip has to be brought to the melting temperature. It may be sufficient for the material layer of plastic material adjacent to the lid material to melt in order to ensure that the plastic material adheres to the lid ring material. The heating is also not limited to the rolled area, the entire lid ring may be heated, but heating which is substantially limited or concentrated to the rolled area with the strip of plastic material is advantageous. .. To that end, any heat source can be used.

It has been found that by heating the rolled area and melting the plastic material of the strip it is possible to achieve optimum adhesion of the plastic material to both sides of the lid ring, both of which adjoin the plastic material of the strip in the rolled area. ing. An airtight seal to the contents of the container is achieved in the rounded area on which the peel lid rests. Therefore, in the peel lid manufactured according to the present invention, corrosion of the cutting edge can be reliably avoided.

Preferably, the heating of the rolled area is carried out prior to the sealing of the release flakes onto the lid ring, so that this is a separate process step in the production of the lid. Thereby, the heating and melting of the plastic material can be carried out separately from the heat input during the sealing of the peeling flakes, and the influence of the heating of the rolled area on the sealing can also be prevented. In order not to affect the sealing or the sealing parameters for the sealing of the peeling flakes on the lid ring, between the heating of the rolled area and the sealing, e.g. Cooling can also be performed.

Advantageously, inductively actuated heating means are used for heating the rolled area. This produces eddy currents in the metallic lid material, which leads to heating of the lid material. The heating can act on the entire lid ring. Due to the arrangement of the electromagnetic induction heating means and, in some cases, the concentration of the magnetic field lines of the electromagnetic induction heating by the pole pieces, eddy currents can be generated mainly in the rounded areas. The electromagnetic induction heating of the metallic material of the lid ring allows a very rapid heating of the plastic material to a temperature at which melting of the plastic material occurs. Electromagnetic induction heating means have long been used in the industry for heating workpieces, are known to those skilled in the art and are commercially available. Alternatively, the heating can be done using infrared or hot air.

Furthermore, alternatively or additionally, the heating of the rolled area can be carried out during the sealing of the strip. In this case, it is advantageous to provide heating means in the sealing tool in contact with the rolled area so that direct heat transfer from the heating means to the rolled area takes place. Therefore, the heating of the rolled area can be carried out separately from the sealing of the peeling strip on the lid ring, so that the sealing is not disturbed by the heating of the rolled area. It is possible to carry out the heating outside the sealing tool, in particular electromagnetically, and additionally inside the sealing tool in two stages.

It is known to heat the sealing flakes on the lid ring twice, so that first the pre-sealing of the flakes on the lid ring, the second step A main sealing of the peeling flakes onto the ring is carried out, the temperature of the preliminary sealing being lower than the temperature of the main sealing. In this case, the heating of the plastic material in the strips or rolled-up areas is advantageously carried out in the second step during the main sealing of the peeling flakes. In this way, the pre-sealing at the lower temperature can be prevented from being affected by the additional heat input by heating the rolled area. Such heat input can be well controlled during main sealing at higher sealing temperatures.

The concept of the plastic material of the strip here includes that the strip comprises or consists of a polymer or a resin, and that the heating of the rolled area takes place at least up to the melting temperature of the plastic material of the strip. In particular, it comprises heating the rounded region to a temperature in the range 100°C to 200°C, in particular to a temperature in the range 140°C to 180°C. This means that the surface of the lid blank forming the heisssiegelfahig sealing surface for the release flakes is or comprises a polypropylene modified lacquer system or is a polypropylene laminated coating, or , Another coating comprising polypropylene and the back side of the lid blank is provided with a coating of an in-can coating comprising polyester, acrylic, epoxy or polyvinyl chloride. The above-mentioned material selection of the strips of plastic and the above-mentioned areas for heating lead to a particularly good connection between the above-mentioned coating of the lid blank or lid ring and the plastic strip.

A blowing agent can be added to the plastic material of the strip, resulting in foaming which can increase the sticking area or area when heating the rolled area.

The underlying problem of the present invention is also to provide a manufacturing device that enables the peel lid to be manufactured at a high tempo (Kadenz) and at low cost, and that substantially protects the cutting edge of the peel lid from corrosion. To do.

This problem is solved in the first-mentioned device with the salient features of claim 9.

Rolled by at least one further treatment station which is provided after the third treatment station in the transport direction and which is configured to heat at least the rolled region of the peel lid ring to at least the melting temperature of the plastic material. Optimal application of the plastic material to both sides of the lid ring, both adjacent to the plastic material of the strip in the area, is achieved by the above-mentioned device with heating of the rolled area and melting of the plastic material of the strip. By means of the device, in the peel lid produced thereby, an airtight seal of the rounded area on which the peel lid rests against the contents of the container is achieved. Corrosion of the cutting edges can thus be reliably avoided in the peel lid manufactured with the device according to the invention.

The rolled area is typically the retort curl adjacent to the area of the lid ring that forms the sealing surface. The heating achievable by the treatment station means that the rolled area is brought to a temperature which allows the melting of the plastic material, with the entire rolled area being brought to said temperature uniformly. Is not essential, but advantageous. Melting of the plastic material does not mean that the entire plastic material of the strip has to be brought to the melting temperature. It may be sufficient for the material layer of plastic material adjacent to the lid material to melt in order to ensure that the plastic material adheres to the lid ring material. The heating is also not limited to rounded areas, the entire lid ring may be heated, but heating concentrated in substantially rounded areas is advantageous. To that end, any heat source can be used.

Advantageously, the further processing station is provided with electromagnetic induction heating means as a heat source. This allows the lid ring, in particular its rounded region, to be heated particularly quickly to the desired temperature required for melting the strip of plastic. In this way, the high production temp of the stripper can also be maintained by the additional processing station.

Additional processing stations may be provided along the transport path of the device, anywhere between the processing stations that produce the rolled area and the sealing station. It can be placed before or after the spinning station of the device. Placing in front of the rotating station is advantageous as it allows the lid ring to be cooled again to the sealing station. For cooling, it is possible in some cases to use additional cooling stations, which cool the lid ring, for example by means of a stream of air. Cooling in front of the sealing station has the advantage that the sealing parameters are not affected by prior heating of the lid ring.

However, it is also conceivable that a further processing station is integrated in the at least one sealing station and comprises heating means in contact with the rounded area in the sealing tool. In a device with two sealing stations in succession in the transport direction for carrying out the pre-sealing and the main sealing of the peeling strip, the further processing station is preferably integrated in the second sealing station. To be done.

The further processing station is configured to heat the rounded region, in particular in the temperature range 100° C. to 200° C., in particular in the temperature range 140° C. to 180° C. Furthermore, the application station for applying the strip-shaped plastic strip produces a strip having a substantially uniform thickness, in particular in the range from 0.05 mm to 0.5 mm, in particular about 0.1 mm. Is advantageously configured so that it can be done. The thin strip thickness is advantageous for achieving the melting temperature quickly.

Further, the present invention comprises a fixed portion surrounding the periphery, a sealing flange having a release lamina sealed thereto, and a rounded region laterally adjacent to the withdrawal opening and surrounding the sealing flange. The edge is made of plastic, which is a concept meaning polymer or resin, and the peeling lid is provided with a seal fixedly bonded to the front and back of the peeling lid by melting of the plastic in the rolled area. This lid has the advantages mentioned above.

Further configurations, advantages and applications of the invention will become apparent from the dependent claims and the following description with reference to the figures.

FIG. 6 is a vertical cross-sectional view through a lid blank, a lid ring and a peeling lid for explaining a processing step in forming the peeling lid. FIG. 6 is a vertical cross-sectional view through a lid blank, a lid ring and a peeling lid for explaining a processing step in forming the peeling lid. FIG. 6 is a vertical cross-sectional view through a lid blank, a lid ring and a peeling lid for explaining a processing step in forming the peeling lid. FIG. 6 is a vertical cross-sectional view through a lid blank, a lid ring and a peeling lid for explaining a processing step in forming the peeling lid. FIG. 6 is a vertical cross-sectional view through a lid blank, a lid ring and a peeling lid for explaining a processing step in forming the peeling lid. FIG. 6 is a vertical cross-sectional view of a lid ring in manufacturing a peel lid according to the present invention. FIG. 7 is an enlarged view of a part of the lid ring of FIG. 6. FIG. 8 shows the lid ring of FIG. 7 after rounding the edges of the extraction opening to form the rolled area of the lid ring. FIG. 9 is an enlarged view of a part of the lid ring of FIG. 8. It is a top view of the lid ring of a peeling lid. FIG. 6 is a schematic side view of an apparatus according to the invention for producing a peeling lid having a cutting edge sealed by the method of the invention. FIG. 6 is a vertical cross-sectional view of a portion of a sealing tool for heating a rolled area within the sealing tool. FIG. 13 is a schematic view of the sealing tool of FIG. 12 taken vertically.

The manufacture of a peel lid according to the prior art, known to the person skilled in the art, can be briefly described with reference to FIGS. FIG. 1 shows a lid blank 1. At the beginning of the transport path of the manufacturing apparatus 20 (FIG. 11), a stack 12 is shown that includes a plurality of such lid blanks, which lid blanks are individually unloaded and can be varied along the transport path. It is processed by the processing station. From the lid blank, the lid ring is first formed and then further processed up to the finished peel lid. The lid blank is, for example, a round plate made of metal which is coated and thus protected against corrosion, for example coated tinplate. The backside coating on the upper side in FIG. 1 is usually different from the front side coating of the blank 1 in FIG. 1 on the lower side. These blanks have, for example, a diameter of 11 cm, the edges 6 of which have already been preformed by a processing machine (not shown), the formation of the edges 6 being later performed on the finished release lid container or can. It is used for mounting by folding connection (Falzverbindung). This is known to the person skilled in the art and will not be described further here. The lid blank 1 of FIG. 1 and the lid ring 2 of FIGS. 2 to 4 are shown with their back side facing up, as described above, while the finished peel lid is shown in FIG. The release lamina 8 is shown facing up. The treatment in the apparatus is first carried out in the state of FIGS. 1 to 4, followed by a rotation station 26, which is responsible for the sealing of the peeling strips 8 (Aufsiegeln) onto the respective lid ring. In order to do so, the lid ring is brought into the state shown in FIG.

The transport device 22 for transporting the lid blank, the lid ring and the peeling lid in the manufacturing device 20 along the transport path in the direction of the arrow A from one processing station to the next processing station has two teeth which extend in particular parallel. Formed by belts, which are provided with accommodating parts for lid blanks or lid rings, as known to the person skilled in the art from WO 2006/017953. Again, this will not be discussed further here. In the processing stations known to the person skilled in the art and shown here only schematically, the blanks to be processed are each picked up from the carrier 22 and processed by the respective processing station and again to the carrier 22. Will be returned. This is indicated by the upward and downward arrows at the processing station. In each processing station, a drive for the processing station is shown below the transport means. This is used for raising and lowering the blank and lid ring and for carrying out the respective process steps.

At the punching station 23, the lid blank 1 is formed into the lid ring 2 by first cutting out the central portion 30 of the blank and treating it as waste. In this way, a removal opening for the peeling lid is formed, which opening is closed by the peeling flakes in a subsequent manufacturing process. Adjacent to the extraction opening 15, the sealing flange 7 remains. The metal material is exposed at the cutting edge 31 or the metal plate of the lid ring 2 is no longer protected by the coating. At the processing station 24, the edge of the take-out opening is pulled up into a collar 4, which is rounded at the subsequent processing station 25, so that a so-called retort curl 5 is formed. The shape of the rolled portion or retort curl may be different. The rounded portion that forms the edge of the dispensing opening will protect the user of the can from the sharp cutting edge 31 when dispensing the contents of the can.

As shown, when the manufacturing process is carried out with the sealing flange 7 facing down, a rotation station 26 for rotating the lid ring follows, so that during further processing the sealing flange 7 is After the spinning station, it is located above in the transport device 22 and in the processing station.

After that, a peeling strip 8 is sealed on the sealing flange, which is a two-stage process with a first sealing station or pre-sealing station 27 and a second sealing station or main sealing station 28. It can be carried out. The sealing process is also known to those skilled in the art and will not be described further here. It may be followed by a further processing station in which the sealing flakes are embossed, the release tabs are positioned and the seals are hermetically tested. This is also known to the person skilled in the art and will not be described further here. At the end of the manufacturing apparatus 20, a completed peeling lid 10 (FIG. 5) is obtained, the take-out opening 15 of which is covered by a peeling strip 8 which is sealed in a sealing flange 7. The edge of the ejection opening 15 is formed by the retort curl 5 which is bent upwards and outwards (in the state of the lid according to FIG. 5). The finished peel lid 10 is secured to the can shell (shown only by the wall 11 in FIG. 5) by means of its folding edge 6 so that the can can be closed. This is done during the filling operation where the can is filled with the contents. The filled can can be opened later by peeling the peeling flakes from the lid ring with its peeling tab 18 and thereby opening the ejection opening 15.

In the following, the method known from WO 2015/164986 and the method according to the invention for applying strips of plastic material to rolled areas are described, to the extent necessary, known. And reference is made to the manufacturing process described above or to known manufacturing equipment.

6 and 7 show the lid ring which has already been subjected to the processing step of pulling the edges of the take-out opening to form the collar 4. This is done at processing station 24. In the illustrated advantageous example, then (or in a separate step) an inward curvature occurs at the upper end 34 of the collar 4, which facilitates subsequent rounding to form a retort curl. In addition, the plastic strip 32 is applied to the inner surface 40 of the collar 4 in one process step. Application of this plastic layer takes place in a separate processing station 29 located between the pulling station 24 and the rolling station 25.

A strip 32 of plastic material forms a seal for the cutting edge 31 during rolling, as will be shown below. The strip 32 is made of plastic, a concept here intended to be a polymer or resin. Such plastics are commercially available, in particular in a quality that reliably withstands the sterilization temperature during the sterilization of filled containers and therefore does not melt again at the sterilization temperature, so that it is formed by strips. The seal is retained during sterilization. The strips are preferably formed with a uniform thickness across the height of the strip, as shown. It is contemplated that it is a thin plastic strip having a thickness d, preferably in the range of 0.05 mm to 0.2 mm, preferably about 0.1 mm. The height H of the strip can be, for example, 1-3 mm.

Application is preferably carried out by spraying a molten liquid plastic material in a manner known to the person skilled in the art from WO 2015/164986, with relative movement of the nozzle and the lid ring. .. Advantageously, the lid ring is rotated in the processing station 29, during which the inner surface 40 of the collar 4 moves through the ejection openings of the stationary jet nozzles which are arranged during the application. Plastic is ejected from. Therefore, the lid ring is lifted and rotated at the processing station 29 and application begins when the cover ring reaches the correct position with respect to the jet opening. If, after at least one complete rotation, a band or such strip is formed which circumscribes the inner surface without clearance, the lid ring is again moved downwards towards the transport device and the rotation is stopped. As a result, the lid ring can again be lowered into the housing of the carrier. Then, transportation to the rounding station 25 is performed. The plastic of the band 32 has already cooled and solidified during application on the lid ring, so that during further transport, no plastic flow takes place and the band is stable in the form shown. If necessary, the coating or processing station 29 can be provided with cooling means, for example in the form of a blower.

During application, the distance of the ejection opening or the ejection nozzle to the inner surface 40 of the collar 4 during ejection of the liquid plastic is intended to be kept substantially constant, whereby the thickness of the strip 32 is increased. Is substantially constant and its small thickness is possible. This can be done in the manner known from WO 2015/164986. The process according to WO 2015/164986 is advantageous for the production of strip 32. However, within the scope of the invention, the strip 32 can also be applied to the lid ring in other ways. Thus, it is possible to insert a strip of prefabricated plastic material into the collar of the lid ring. This can be done at a separate processing station, or when pulling the collar at station 24, or when rolling the collar at station 25. In these cases, the illustrated station 29 is omitted.

It can be seen that the strip 32 is located on the inner surface 40 of the collar 4 so that it lies closer to the plane of the sealing flange 7 than the cutting edge 31. The positioning and sizing of the strip is such that strip 32 covers the lower 1/3 of collar 4 to approximately the lower half of collar 4. A higher height H of the strip is possible, but this increases the material cost of the plastic used, which is not necessary for further processing or for protection of the cutting edge. The height H is practically about 1 mm to 3 mm.

The lid ring according to FIGS. 6 and 7 with a plastic strip is provided with a retort curl 5 in a known manner at the processing station 25. This station 25 works with rounding tools known for this purpose, which are known to the person skilled in the art and need not be described in detail here. Modifications which are obvious to the person skilled in the art may possibly occur in the tool if the collar 4 has already been pre-curved at its upper edge 34 for rounding, which is advantageous. According to FIGS. 8 and 9 showing the lid ring after the rotation station 26, it can be seen that during the formation of the retort curl 5, the strip 32 forms a seal which prevents liquid from entering the interior of the retort curl. This protects the exposed cutting edge 31 from the effects of liquid in the can. It does not matter here whether the rounding is such that the cutting edge 31 is partially embedded in the strip 32, as shown, or simply in contact with the strip 32. Conversely, if the cutting edge 31 cuts the strip 32 and contacts the metal of the inner surface 40, the function of the strip 32 is not impaired. Therefore, normal manufacturing tolerances do not pose a problem when forming the retort curl 5. The plan view of FIG. 10 shows the lid ring as it is conveyed into the sealing station 27, in which the peeling strip is sealed over the take-out opening 15.

In the example of FIG. 11, the manufacturing apparatus 20 for the peel lid comprises a processing station 29 for applying the strip 32 on the lid ring and a processing station 25 for rolling the collar 4.

According to the invention, the rounded peripheral area is heated in order to melt the strip 32 or the coating on it, at least in the area of the lid in contact with the metal. The rolled-up peripheral region comprises at least the retort curl 5 and, in particular, the entire part of the peel lid covered by the strip 32, as can be seen in FIG. 9, for example. In the first exemplary embodiment, a processing station 35 is provided in front of the rotation station 26, in which the rolled area is heated. This is also done in this processing station 35 in such a manner that the lid is picked up from the transfer means 22, then the heating in the processing station is carried out, and then the mounting on the transfer means is performed. However, the lid ring or its rounded area can be heated in the processing station, on the transport means 22, ie without being picked up by the transport means. In the processing station 35 before the spinning station, the lid ring is still with the retort curl or rolled area facing up, as shown in FIG. This makes it possible to heat the rounded area from above, preferably for this purpose an electromagnetic induction heating device, shown diagrammatically as block 43, is provided in the processing station 35. The construction of such heating devices is known to those skilled in the art and need not be discussed at length here. An infrared source or a hot air source can be provided instead of the electromagnetic induction heating device.

In another exemplary embodiment, the processing station for heating the rolled area may be provided after the spinning station, which in the illustrated example is shown as dashed processing station 35'. In this processing station, the rounded area is at the bottom, so that it is advantageous for the heating source to act from below, so that the processing station 35' has a lid ring inside it for carrying out the processing by the heating source. It may be more advantageous to configure the so that it is picked up from the transport means 22. Again, an electromagnetic induction heater or other type of heater, shown only schematically as block 43, may be provided.

After heating the rolled area, cooling, for example by means of a blower, can take place. This is the case if a processing station 35 ′ is provided after the rotation station 26 and additionally a pre-sealing station 27 for the pre-sealing of the strip 8 on the sealing flange 7. It is particularly advantageous. Otherwise, heating of the rolled area can have an undesirable effect on the temperature of the pre-seal.

Instead of or in addition to heating in the processing station 35 or 35', heating of the rolled area may be performed in the sealing tool of the sealing processing station. In the case of pre-sealing by means of the processing station 27 and main sealing of the flakes by means of the processing station 28, it is advantageous if the heating of the rolled area takes place at the main sealing station 28. 12 and 13 exemplarily show the construction of a sealing tool for sealing the strip and heating the rolled area. FIG. 12 shows a detailed view of the lower part 36 of the sealing tool, on which the lid ring 2 has been picked up by the sealing tool from the transport means 22. FIG. 13 shows in a schematic view the lower sealing tool after the sealing step in which the peeling strip 8 is on the lid ring 2. Although not described further here, in the known sealing process, a suitable sealing foil is placed on the lid ring and fixed on the sealing flange 7 through the sealing process using an upper sealing tool (not shown). After that, the peeling lid is placed on the conveying means 22. In the figure, the sealing tool is provided with a special heating means 38, which is used to introduce its heat into the rolled area for heating the rolled area and for melting the strip 32. It can be seen that it is in direct contact with the enclosed area and in particular with the retort curl 5. The thermal energy for the heating means 38 is provided in this example by a heating element 39 which is also used for heating the lower sealing tool under the sealing flange 7. These heating elements 39 are electrically heated, are directly connected to the sealing tool and are in thermal flow connection with the heating means 38 via the heat conducting layer 42. Although this is an advantageous example, it is obvious to a person skilled in the art that the heat generation for the heating means 38 in the rounded area can also be done in other ways. After leaving the sealing station 28, not only is the peeling strip 8 sealed on the peeling lid, but the adhesion of the strip 32 to both surfaces of the peeling lid is improved by the melting of the strip 32.

In accordance with the present invention, the peel lid 10 having the rounded area of the dispensing opening 15 is formed such that the plastic strip 32 is applied onto the collar of the lid ring prior to forming the rounded area. After forming the rolled area, the plastic strip is melted so that the plastic adheres well to the front and back of the release lid in the rolled area. In this way, a substantially gas-tight sealing of the cutting edge 31 of the peeling lid is provided, with the possibility of being manufactured cheaply and at high tempo.

It should be noted that although the present application describes advantageous embodiments of the invention, it is not limited thereto and can be practiced in other ways within the scope of the following claims.

Claims (15)

A method of manufacturing a peeling lid (10), comprising:
-From the lid blank (1) by stamping a lid ring (2) having a central withdrawal opening (15) surrounded by a sealing flange (7),
-By pulling the edge of the take-out opening, a collar (4) protruding in a direction away from the sealing flange (7) is formed,
-A strip (32) of plastic is applied to the inner surface (40) of the collar,
-The collar (4) is rolled at its free end (34) to lie inside the strip of plastic,
A peeling strip (8) is sealed on the sealing flange (7),
-After the free end of the collar (4) is rolled, the rolled area is heated so that at least partial melting of the plastic material of the strip (32) occurs.
A method characterized by the following. The method of claim 1, wherein the heating is performed prior to sealing the release flakes onto the sealing flange. 3. The method according to claim 1 or 2, wherein heating means for inductively operating is provided for the heating. The heating of the rolled area comes into contact with the rolled area within a sealing tool (36) during the sealing of the strip (8) onto the sealing flange (7). A method according to any one of claims 1 to 3, carried out by heating means (38). The sealing of the release flakes is a two-step process including an initial pre-sealing of the release flakes onto the lid ring and a main sealing in a second step, of the plastic material of the strip. The method of claim 4, wherein the heating is performed during the main encapsulation of the strip. The plastic material of the strip comprises or consists of a polymer or resin, and the heating is at least up to the flow temperature of the plastic material of the strip, in particular the heating is between 100°C and 200°C. 6. The method according to any one of claims 1-5, which is carried out in the range, in particular in the range 140<0>C to 180<0>C. The surface of the lid blank forming the sealing surface for the release flakes comprises a hot-sealable coating of polypropylene or comprising polypropylene, the back side of the lid blank consisting of or in-can coating 7. A method according to any one of claims 1 to 6, characterized in that it comprises a coating comprising. 7. A method according to any one of claims 1 to 6, characterized in that a foaming agent is added to the plastic material of the strip. An apparatus (20) for producing a peel lid (10), comprising a lid blank (1), a lid ring (2) and a transport device (22) for the peel lid (10), and a processing station (23). -28), the processing station is provided for the treatment of the lid blank, the lid ring and the peeling lid in succession in the transport direction (A), from the lid blank (1) to the lid ring (2). ) And a second processing station (24) for forming a collar (4) projecting away from the back side of the lid ring (2). ) And a third processing station (25) configured to form a rounded area from the collar, and further comprising a peeling strip on the sealing surface (7) of each of the lid rings. There is provided at least one sealing station (27, 28) for sealing (8), which in the transport direction comprises the second processing station (24) and the third processing station (25). In between there is provided a coating station (29) for coating the inner surface (40) of the collar (4) with a circumferential seamless plastic strip (32), said third processing station (25). Is configured to bring the rolled area (5) into contact with the plastic strip (32), at least after the third processing station (25) in the transport direction (A). Device, characterized in that at least one further processing station (35; 35'; 28) is provided for heating the area to at least the melting temperature of said plastic strip (32). Apparatus according to claim 9, wherein the further processing station comprises electromagnetic induction heating means (43). 11. The method according to claim 9 or 10, wherein the further processing station is integrated with the at least one sealing station and comprises heating means (38) in contact with the rounded area in the sealing tool. The described device. Device according to claim 11, wherein two sealing stations are provided in succession in the transport direction, the further processing station being integrated with the second sealing station. 10. The further processing station is configured to heat the rounded region in a temperature range of 100-200°C, in particular in a temperature range of 140-180°C. 10. The device according to 10. Said application station (29) is adapted to apply a strip of plastic strip (32), said strip having a substantially uniform thickness, in particular in the range 0.05 mm to 0.2 mm. Device according to any one of claims 9 to 13, characterized in that it has a thickness of, in particular, about 0.1 mm. A sealing flange having a fixed part (6) surrounding it, a peeling strip sealed on it, and a rounded region (5) surrounding it and laterally adjoining the removal opening (15). (7) and a rolled lid comprising a seal (32) made of plastic, in particular a polymer or a resin, the seal having a melting of the plastic in the rolled region. A peeling lid, which is fixedly bonded to the front and back surfaces of the peeling lid by means of.

Images