EP1858767B1 - Tear-off lid and method for production thereof - Google Patents

Description

background

The invention relates to a method for producing a tear-open lid according to the preamble of claim 1, in which a tear-open foil is fastened by means of heat-sealing by means of a heat-sealable material to a cover ring with removal opening.

State of the art

It is known to carry out covers for can or box-type packaging as cover rings permanently fastened on top of the packaging, in particular of metal, which form a removal opening which, until the first use of the contents of the package, is interrupted by a heat-sealable seal on the cover ring. in particular metal foil, is closed. Such covers can be referred to as a tear-open lid. An additional, arranged over the metal lid lid made of plastic makes the packaging during the period of consumption of their contents resealable. The cover ring is known to be made of fully coated starting material, wherein on the top of the starting material intended for heat-sealing the tearable film, a heat-sealable polypropylene coating or polypropylene-containing coating is applied over the entire surface. This coating makes the work steps in the deformation of the cover ring with. Such a cover ring is in EP 0 408 268 B and it is mentioned that instead of the tearing film can be provided over the entire surface with the heat-sealable polymer film. EP 0 090 957 A mentions that the sealing connection between lid ring and tear-open foil is effected by means of a hot-seal lacquer provided on the surfaces to be joined together. WO 2005/019047 A it shows that on the lid ring a sealing layer, in particular of an adhesive is applied. Out WO 01/07330 It is known to apply the heat-sealable, full-surface coating of the cover ring only after the deformation has been carried out.

Presentation of the invention

The invention is based on the object to provide a method for producing tear-open.

This is achieved in the method of the type mentioned above with the characterizing features of claim 1.

In the method, the heat-sealable coating is applied only to the edge or in the connection region on the later forming the edge or connecting region region of the undeformed starting material before applying and sealing the film.

Characterized in that the heat-sealable layer is limited to the edge of the removal opening or only on the connection area and thus is essentially limited to the actual sealing area, in which the cover ring and the tear-open are connected, a significant amount of the heat-sealing material can be saved. Furthermore, it has been found that the heat sealable coating material is unfavorable in the deformation of the lid outside the seal area and is often injured, for example, during flanging. Outside the sealing area, however, a different coating of the lid can be provided, for example a coating of PET (polyethylene terephthalate), which is already known in the art as underside coating (ie the filling in the container facing coating). In this case, the PET coating in the connection area or on the edge of the removal opening may be below the heat-sealable coating or be recessed there. Preferably, the heat sealable Coating a polypropylene layer or a polypropylene-containing layer, but other heat-sealable materials can be used.

Brief description of the drawings

• Figur 1 eine schematische Seitenansicht einer Vorrichtung zur Förderung und Herstellung von Deckeln;
• Figuren 2 bis 8 Sektoren von Metalldeckeln zur Erläuterung von deren Herstellung;
• Figur 9 eine weiter bevorzugte Ausführungsform einer Fördervorrichtung;
• Figur 10 die Beschichtung von Ausgangsmaterial für den Deckelring oder die Aufreissfolie mit heisssiegelfähigem Material;
• Figur 11 die Beschichtung eines Deckelringes mit heisssiegelfähigem Material;
• Figur 12 die Beschichtung einer anderen Ausführungsform des Deckelringes mit heisssiegelfähigem Material;
• Figur 13 einen beschichteten Deckelring vor dem Aufbringen der Abreissfolie;
• Figur 14 eine Aufreissfolie, die im Randbereich mit heisssiegelfähigem Material beschichtet ist; und
• Figur 15 eine Schnittansicht einer Ausführungsform des Aufreissdeckels.

Further embodiments, advantages and applications of the invention will become apparent from the dependent claims and from the following description with reference to FIGS. Showing:

• FIG. 1 a schematic side view of a device for the promotion and production of lids;
• FIGS. 2 to 8 Sectors of metal lids for explanation of their manufacture;
• FIG. 9 a further preferred embodiment of a conveying device;
• FIG. 10 the coating of starting material for the cover ring or the tear-open film with heat-sealable material;
• FIG. 11 the coating of a cover ring with heat-sealable material;
• FIG. 12 the coating of another embodiment of the cover ring with heat-sealable material;
• FIG. 13 a coated cover ring before applying the tear-off film;
• FIG. 14 a tear-off film which is coated with heat-sealable material in the edge region; and
• FIG. 15 a sectional view of an embodiment of the tear-open.

Ways to carry out the invention

Based on FIGS. 1 to 9 briefly known processing equipment and manufacturing steps for the production of metal lids are explained with tear-off. FIG. 1 shows a schematic side view of a known device 1, which has a plurality of processing stations 3 to 8 and a further station 9 on a machine frame 2. A conveyor 10, 13, 14 conveys the lid parts or the finished lid with tear-off in the conveying direction, which is indicated by the arrow C, from the beginning of the device at the stack 11 to the end of the device where the lid slides over into the shelves 16 or 17 arrive. From the stack 11 lid parts are stacked in a known manner and get into the conveyor. This has two each individually laterally of the cover parts or cover arranged long rails 10, which are lying on shelves 10 'and in the stations 3 to 9 cover parts or cover when lifting the rods 10 by means of the drive 14 in the direction A upwards Lift and then by forward movement in the direction of arrow B (rectified as the arrow C) by the crank drive 13 by an amount forward. Thereafter, the rods are moved in the direction of arrow A downwards with the lid parts or lids are in turn stored on their filing points. The rods 10 are then moved below the storage positions in the direction of arrow B against the arrow C to the rear then perform the process described again. The cover parts or cover rest between the transport on their storage positions or are located in the processing stations and are processed there. After a processing step of all processing stations, the renewed promotion. FIG. 2 shows stacked metal lid blanks 20 as an example of lid parts as they are in the stack 11. These blanks 20 are for example round metal discs of eg 11 cm diameter. Of course, other basic shapes, such as square or rectangular discs and other diameters are readily possible. The blanks 20 are already in a processing machine, not shown, at its edge as in FIG. 2 shown preformed. According to one embodiment of the present invention, they may already be suitably heat-sealably coated in only one area or, according to another embodiment, they are only coated in one area in a subsequent step. Both will be explained in more detail later. In the FIG. 2 and the following figures, only one sector of the entire disk is shown to simplify the drawings. In the first processing station 3 of FIG. 1 is punched by punching with top and bottom tool an opening (removal opening of the lid) into the disc, which is in FIG. 3 it can be seen in which the edge of the opening is denoted by 21 and the punched round disc with 27. This disc arrives as waste in the container 12 of FIG. 1 , The punching processing station 3 is driven by a drive 15, as is the case with the other stations. At the processing station 4, a pulling of the edge 21 takes place downwards, whereby the in FIG. 3 shown course 22 of the edge is achieved. The now annular cover parts or cover rings 20 'now reach the processing station 5, in which the film 25 is placed over the opening of the cover ring 20' and fixed there by heat sealing, which in the FIGS. 5 and 6 is apparent. The metal foil 25 may also be provided on the underside thereof also over the entire surface with a heat-sealable plastic layer according to the prior art. The required film blank 25 is usually punched out in the station 5 from a wide film web and placed over the central recess of the cover ring and the film is pressed by the heat sealing station at the edge of the circular recess of the part 20 under heat, so that the film 25 with the metal cover ring 20 'is sealed by melting and subsequent cooling of the plastic layer. This process is basically known and will not be explained here. At most a cooling processing station can cool down 7 be provided. In the processing station 8, the film 25 is embossed 24 (FIG. FIG. 7 ), and it is further the edge 22 crimped to the finished edge 23. In a test station 9, the now finished lid are subjected to a test, which usually includes a density test for the peel-off film 25 applied to the lid. If the film is tightly mounted on the remaining metal lid, the lid enters the receptacle 16 for the finished lid. If a leak is detected, the lid passes over the other slide shown in the waste container 17th

FIG. 13 shows an embodiment of a cover ring for a tear-open. The cover ring 20 'may be shaped similar or identical to those in the FIGS. 2 to 8 illustrated cover rings or tear-open lid. In FIG. 13 the cover ring is now completely visible and also its removal opening 25 ', which is subsequently covered by the tear-open film 25 by being sealed onto the cover ring. The heat-sealable coating is provided only at the edge of the removal opening and in particular only in the actual connection region between the cover ring and tear-open, which in the FIG. 13 is shown by a strip 62 of heat-sealable plastic material. Outside the edge of the removal opening (or the inner edge of the cover ring) and in particular outside the actual connection area no heat-sealable plastic coating is provided. Thus, the remaining surface of the upper side of the cover ring 20 ', that is the outside of the edge and in particular outside the connection area lying surface, and in particular the deformed for connection to the container surface or the outer edge of the cover ring, not provided with a plastic coating or optionally only with a different plastic coating to the heat-sealable plastic coating. For the heat-sealable plastic coating, in particular a layer comprising polypropylene or polypropylene particles, for example a lacquer layer containing such particles, is suitable. Corresponding heat-sealable coating materials are known in the art and are used commercially for sealing the tear-open film. One of them different plastic coating, which thus forms the sole plastic coating of the top of the lid ring outside the edge of the removal opening or the connection area, for example, may be a coating of PET (polyethylene terephthalate). Such a non-heat-sealable layering can, of course, also be located in the edge or connection area, but then lies below the heat-sealable coating 62 FIG. 13 invisible underside of the cover ring may be provided with such a different to the heat-sealable coating coating and in particular also a PET coating.

FIG. 10 shows a production variant according to the invention, in which the heat-sealable coating material is applied to the starting material for the production of the cover rings. The starting material 60 is a metal sheet, which may be provided with a metallic coating, for example. On the metal sheet may further be provided a plastic coating of a not intended for heat sealing plastic material, which is, for example, the mentioned PET coating. This coating can be provided on both sides of the starting material 60 or the metal sheet 60, so in particular over the entire surface on the upper side visible in the figure and / or also over the entire surface on the underside which is not visible in the figure. The heat-sealable plastic coating, in particular polypropylene coating, is then applied to the starting material 60 in such a way that it is applied to the cover blank 20 formed from the starting material 60 or Cover ring 20 'comes to rest on the edge of the removal opening 25' or in the connection area. In FIG. 10 This is in turn represented by the band-shaped plastic layer 62, which can be sprayed, for example by means of movable nozzles 61, or which can also be placed as a finished tape. After applying the heat-sealable plastic coating of the lid blank 20 is formed and then the lid ring 20 'and the finished lid according to the FIGS. 2 to 8 , The attachment of the tear-open film 25 by heat sealing is then carried out in the manner known in principle.

The Figures 11 and 12 show non-inventive other embodiments for applying the heat-sealable coating or for the formation of the cover ring. Here, the heat-sealable coating 62 is applied to the already preformed cover ring 20 ', in which already the removal opening is formed and the edge of the removal opening has been flanged. In the variant of FIG. 11 This is a simple curl 66, where, however, in the variant of Figure 12, a special flanging has been selected, which is known under the technical term "retort-curl". In this bead 67, the resulting by the formation of the removal opening cut edge in which a possible sheet metal coating is no longer intact, flanged upwards and inwards, like this FIG. 12 is apparent. In both variants, the heat-sealable coating 62 is applied to the edge 68 of the removal opening, for example by a corresponding nozzle 63, which is stationarily arranged above the rotating cover ring, or which drivingly moves along the edge of the stationary cover ring. In the variant of FIG. 12 with retort curl 67, it is provided as a preferred feature that the coating 62 covers the flanging region, so that the cut edge is likewise enclosed by the coating.

As already mentioned, the coating can cover substantially the entire edge 68 of the removal opening, as with the coating 62 of FIG FIG. 12 is shown, or the coating may also be made less wide, so that it covers substantially only the connection area over which the tear-off is attached. As already explained above, an additional non-heat-sealable plastic coating may be provided on the cover ring, eg a PET coating which covers the cover ring at the areas not covered by the heat-sealable coating 62, but which may also be below the heat-sealable coating 62. In any case, it is relevant to the invention that the heat-sealable coating 62 does not extend over the entire upper side of the cover ring. Also, the underside of the respective cover ring may be provided with a non-heat-sealable coating, preferably in turn a PET coating. The shaped outer edge 64 for attaching the finished lid to a container in a known per se can be carried out according to various known manner and will not be described here.

FIG. 15 shows the embodiment of FIG. 12 with already attached tear-off film 25. The same reference numerals designate again the same elements, in particular the heat-sealable coating 62, which extends over the retort curl 67. Shown is in FIG. 15 also that the heat-sealable coating 62 at the edge of the removal opening can also extend over the actual connection region which is defined by the congruent region of tear-open film and edge 68, which is indicated by the part 62 'of the heat-sealable coating, which is slightly above the connection region protrudes and is located on the edge 68 outside the connection area. The surface 70 of the lid with the cover ring 20 'may, as already mentioned several times be provided with a coating, in particular a PET coating, which may also extend below the heat-sealable coating 62 on the edge 68. Also, the bottom 69 may be provided with such or another plastic coating, which are preferably already provided on the flat starting material. Also in the embodiments according to the Figures 11 . 12 and 15 For example, the heat-sealable coating 62 may be applied as a finished tape instead of being applied by means of the nozzles 63.

FIG. 14 further shows an embodiment in which on the tear-open film 25 on the underside a heat-sealable coating in the form of only a marginal coating 65, in particular the band-shaped coating 65 is applied. This coating may be provided instead of or in addition to the heat-sealable coating 62 of the cover ring and performs according to the finished connection FIG. 15 to substantially the same result, in which the heat-sealable coating 62 is only on the edge 68 or in the connection region between the cover ring and tear-open film. Also, the width of the coating 65 of the tear-open film can be selected so that a retort curl 67 is covered. It is also possible to provide both coatings 62 on the cover ring and 65 on the tear-open film. The application of the coating 65 on the underside of the tear-open film can according to FIG. 10 take place, in which case the starting material 60 is just the material of the tear-open, which is subsequently punched out of the starting material 60, including the tear tab 71.

FIG. 9 shows a schematic representation of a conveyor device 30 according to a preferred embodiment. This conveying device 30 is designed for conveying lid-shaped objects of the type described. The conveyor again serves to intermittently Conveying the lid parts or lid to the individual processing stations, which are preferably the previously described processing stations for lid production and the test station 9. These stations are in FIG. 9 not shown, but it is clear to the skilled person how he can arrange these along the conveyor to perform the respective processing. In FIG. 9 It is further shown that a further conveying device 30 'is arranged next to the conveying device 30. This can be driven by the same drive 33, 37 or have its own drive. Further conveying devices could be provided in order to increase the total number of conveyed lid parts or lids. With the illustrated conveying device 30, the cover parts or covers can be conveyed at high speeds of, for example, 200 objects per minute and with reproducible sub-steps between the stations. It also results in a flexible concept for a large format range of the items or lid, which can range from 50 to 200 mm in diameter with round lids and can also accommodate various rectangular formats, eg for the common fish cans. The conveyor is also designed as a compact module for single-track or multi-track as shown.

In the preferred embodiment shown, the conveying device has two toothed belts 31 and 32, which in particular lie with their surfaces in the same planes, that is coplanar, and which are guided at the beginning and at the end of the conveyor via pulleys 34, 36, so that an endless belt drive in the necessary for the number of processing stations length. The stepwise synchronized with the processing stations timing belt movement is effected by a stepper motor or servo motor which drives the timing belt by sprockets, as can be seen in the figure with the motor 33 and the drive shaft 38. If further conveying devices, as the conveyor device 30 'are provided, so the timing belt can be driven via the same engine via other drive axles or have its own motor drive. The motor 33 is controlled by a timing belt advancing control 37, which control 37 is either an entire control of the lid manufacturing apparatus which also controls the processing stations and the station 9, or which controller 37 is a conveyer only controller. which communicates with a parent controller for the lid manufacturing device. The motor 33 and the other drive components for the toothed belts are arranged on a machine frame 35, which is indicated in the figure only by the feet 35. On the timing belt drivers are attached, which in FIG. 9 are generally designated 40, wherein the opposing drivers of the toothed belts 31 and 32 form a receptacle for the respective object. By the toothed belt movement, this recording formed by the carriers 40 along the conveying path and in the direction of the arrow C is shown from the input side of the conveyor, which is located on the motor side, to the output side of the guide roller 36 moves. In the embodiment shown, a cover 50 is provided in each case above the toothed belt and over the drivers 40, which cover in each case the toothed belt and a part of the driver. In the field of processing stations, this cover 50 each has a recess 52 which allows removal of the objects from the drivers 40 so that the object can be lifted from the carriers and processed in the station and subsequently returned to the driver. As a rule, no recesses 52 are provided between the stations, so that there the lifting of the objects is blocked by the carriers through the cover 50. In addition to or instead of blocking the lift off through the cover 50, the drivers can also be designed magnetically, which can also prevent lifting of the objects during the conveying step, if the object consists at least partially of a magnetically firm material.

It is preferred if the spacing of the toothed belts 31 and 32 is adjustable relative to one another, whereby the distance of the mutually opposite drivers 40 of the two toothed belts is adjustable in order to be able to adapt the conveyor to different object sizes. For this purpose, transverse connections 58 can be provided in the conveying device, which allow a simple adjustment of the distance of the toothed belt from each other. Accordingly, the drive shaft 38 is configured to allow this distance adjustment. The distances between the drivers 40 on the respective toothed belt are given by the pitch of the toothed belt and the Mitnehmerbefestigung. This distance can be changed to adapt to the object size preferably such that the timing belt are exchanged for a set of other timing belt with spaced apart from each other drivers 40. In this way, by adjusting the distance of the timing belt to each other and can be created by replacing the timing belt with differently spaced drivers of the desired large receiving area for objects. In this way, a conversion to different object sizes for all drivers can be done simultaneously in a simple and rapid manner. The illustrated manufacturing steps for the tear-open lids and the corresponding conveyors and workstations are only to be understood as preferred examples and serve as an aid to understanding the invention. Of course, this can also be carried out with tear-open lids, which have been produced deviating from the explained production.

In both illustrated embodiments of the manufacturing or conveying device is for non-inventive Embodiments in which the heat-sealable coating is applied to the cover ring, a corresponding processing station provided along the conveying path, this of course before the heat-sealing station. In the inventive embodiments in which the coating is applied to the starting material, the coating is then already present on the lid blanks at the beginning of the illustrated processing and conveying paths and also on the material of the tear-open, which, as known, only needs to be punched ,

While preferred embodiments of the invention are described in the present application, it is to be understood that the invention is not limited thereto and may be embodied otherwise within the scope of the following claims.

Claims (6)

1. Method for manufacturing a peel-off lid, for which a peel-off foil (25) is attached to a lid ring (20') with extraction opening (25') by heat sealing by means of a heat-sealable material, wherein the heat-sealable material (62) is applied on the lid ring only at the edge (68) of the extraction opening (25) or in the connection area with the peel-off foil, characterized in that the heat-sealable material (62) is applied onto the initial material (60) for manufacturing the lid ring before its deformation or punching, and/or in that heat-sealable material (65) is applied onto the material of the peel-off foil only at the edge of the peel-off foil before punching it.
2. Method according to claim 1, characterized in that the heat-sealable material is applied as a liquid or is laid as solid tape.
3. Method according to one of the claims 1 or 2, characterized in that a flanging (67) oriented upward and inward is provided at the lid ring (20') and in that the heat-sealable coating is applied in such a way that it covers the flanging at least partly.
4. Method according to one of the claims 1 to 3, characterized in that the lid ring or its initial material, respectively, is provided with a non-heat-sealable plastic coating at least on one side, preferably on both sides.
5. Method according to claim 4, characterized in that the non-heat-sealable coating extends below the heat-sealable coating (62) by applying the latter as a layer onto the non-heat-sealable coating.
6. Method according to one of the claims 1 to 5, characterized in that the lids are transported on a linear transport device by means of toothed belts or chains to the processing stations and therefore to the heat-sealing station.

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