WO2006097005A1

WO2006097005A1 - Tear-off lid and method for production thereof

Info

Publication number: WO2006097005A1
Application number: PCT/CH2006/000146
Authority: WO
Inventors: Marcel Oberholzer
Original assignee: Soudronic Ag
Priority date: 2005-03-17
Filing date: 2006-03-13
Publication date: 2006-09-21
Also published as: EP1858767A1; PT1858767T; US20080223856A1; ES2670943T3; EP1858767B1

Abstract

The invention relates to a lid ring (20') for production of a tear-off lid, whereby a hot-sealing coating (62) is only applied to the edge (68) of the dispensing opening (25). A material saving is thus possible relative to conventional full-surface application. A coating different to the hot-sealing coating can form the lid ring surface outside the hot-sealing coating.

Description

Acronym lid and method for its manufacture

Reference to related applications

This application claims the benefit of Swiss Patent Application No. 453/05, filed on Mar. 17, 2005, the entire disclosure of which is hereby incorporated by reference.

background

The invention relates to a tear-open lid having a cover ring with a removal opening covered by a tear-open film, wherein the cover ring and tear-off film are detachably connected to one another in a connection area by means of heat-sealable plastic coating along the edge of the removal opening. Furthermore, the invention relates to a container with a tear-open lid. Furthermore, the invention relates to a method for producing a tear-open lid, in which a tear-open foil is fastened by means of heat sealing by means of a heat-sealable material to a lid 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. especially metal foil, is closed. Such covers can be referred to as a tear-open lid. An additional lid made of plastic arranged above the metal lid makes the packaging can be re-sealed during the period of use. The cover ring is known to be made from a fully coated starting material, wherein a hot-sealable polypropylene coating or polypropylene-containing coating is applied over the entire surface on the upper side of the starting material intended for heat-sealing the tearable film. This coating makes the work steps in the deformation of the cover ring with. From 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 improve a tear-open lid of the type mentioned.

This is achieved with a tear-open with the characterizing features of claim 1.

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 lid ring and the tear-open are connected, a significant amount of Heisssiegelmateri- can be saved as. 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 lie below the heat-sealable coating or be recessed there. The heat-sealable coating is preferably a polypropylene layer or a polypropylene-containing layer, but it is also possible to use other heat-sealable materials. The invention is further 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 9.

In particular embodiments of the method, the heat-sealable coating is applied to the edge or in the connection region either on the already preformed or finished molded lid ring prior to application and sealing of the film or applied to the later forming the edge or connecting region region of the undeformed starting material.

In another embodiment, the heat-sealable coating is applied in the case of a preformed cover ring in a targeted manner also via the special edge flanging (so-called "retort curl") of the removal opening. In either case, the heat-sealable coating can be applied to the metallically bright lid ring or the metallically bare starting material (which may be a metal-coated metal), or the heat-sealable coating can be applied to an already non-metallic coated lid ring or non-metallic coated starting material. be deposited material, wherein the non-metallic coating is not heat sealable and eg a PET coating is.

Brief description of the drawings

Further embodiments, advantages and applications of the invention are evident from the dependent claims. Proverbs and from the following description based on the figures. Showing:

Figure 1 is a schematic side view of an apparatus for conveying and producing lids; Figures 2 to 8 sectors of metal lids for explaining the production thereof;

FIG. 9 shows a further preferred embodiment of a conveying device;

FIG. 10 shows the coating of starting material for the cover ring or the tear-open foil with heat-sealable material;

FIG. 11 shows the coating of a cover ring with heat-sealable material;

FIG. 12 shows the coating of another embodiment of the cover ring with heat-sealable material;

FIG. 13 shows a coated cover ring before the application of the tear-off film;

FIG. 14 shows a tear-open film coated in the marginal area with heat-sealable material; and

Figure 15 is a sectional view of an embodiment of the tear-open lid.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIGS. 1 to 9, briefly known processing devices and production steps for the production of metal lids with a tear-off foil are explained. 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 cover parts or the finished cover with tear-off foil 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 on slides in the shelves 16 or 17 pass. From the stack 11 lid parts are stacked in a known manner and get into the conveyor. The latter has two long rails 10, each of which is arranged individually on the side of the cover parts or cover, which cover parts or covers lying on shelves 10 'or in stations 3 to 9 when lifting the rods 10 by means of the drive 14 in direction A. lift it upwards and then move it forwards by a forward movement in the direction of the arrow B (rectified like the arrow C) by the crank drive 13. 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 covers rest between their 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 present in the stack 11. These blanks 20 are for example round metal discs of eg 11 cm diameter. Of course, other basic forms, such. B. ^■ square or rectangular discs and other diameters readily possible. The blanks 20 are already preformed in a processing machine, not shown, at its edge as shown in Figure 2. 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 figure 2 and the following figures, only one sector of the entire disc is shown in each case to simplify the drawings. In the first processing station 3 of Figure 1, an opening (removal opening of the lid) is punched into the disc by punching with top and bottom tool, which can be seen in Figure 3, in which the edge of the opening is designated 21 and the punched round Disc with 27. This disc arrives as waste into the container 12 of FIG. 1. The stamping processing station 3 is driven by a drive 15, as is also the case with the other stations. At the processing station 4, the edge 21 is pulled downwards, as a result of which the course 22 of the edge shown in FIG. 3 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 can be seen in Figures 5 and 6. According to the prior art, the metal foil 25 can also be provided on its underside with a heat-sealable plastic layer over its entire surface. The required film blank 25 is usually punched 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 round recess of the part 20 under heat, so that the film 25 with the metal cover ring 20 'is tightly connected by melting and subsequent cooling of the plastic layer. This process is basically known and will not be explained here. For cooling, at most a cooling processing station 7 may be provided. In the

Processing station 8, the film 25 is provided with an embossment 24 (Figure 7), and it is further the edge 22 crimped to the finished edge 23. In a PrüfStation 9 dre now finished lid are subjected to a test, which is usually a density test for on the

Cover applied release liner 25 includes. If the foil is fastened tightly to the rest of the metal lid, the lid reaches into the receptacle 16 for the finished lid. If a leak is detected, the lid passes over the other slide shown in the waste container 17. Figure 13 shows an embodiment of a

Cover ring for a tear-open lid according to the present invention. The cover ring 20 'may be shaped to be similar or identical to the cover rings or tear-open covers illustrated in FIGS. 2 to 8. In Figure 13, the cover ring is now completely visible and also the removal opening 25 ', which is subsequently covered by the tear-open film 25 by being sealed onto the cover ring. Contrary to the state of the art, according to the invention, the heat-sealable coating is now provided only at the edge of the removal opening and in particular only in the actual connection region between cover ring and tear-open film, which is shown in FIG. 13 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 KunstStoffbeschichtung is provided according to the invention. Thus, the remaining surface of the top of the cover ring 20 ', ie 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 ge - if necessary, only with a plastic coating that is different from 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 for sealing the Tear-off film used commercially. 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, additionally also be located in the edge or connection region, but then lies below the heat-sealable coating 62. The underside of the cover ring, which is not visible in FIG. 13, can also be provided with such a coating that is different from the heat-sealable coating and in particular also be provided with a PET coating. FIG. 10 shows a production variant 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 completely 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 lies at the edge of the removal opening 25 'or in the connection region in the case blank 20 or lid ring 20' formed from the starting material 60. In FIG. 10, this in turn is represented by the band-shaped plastic layer 62, which can be sprayed on, for example, by means of movable nozzles 61, or which can also be applied as a finished band. After applying the heat-sealable Kunststobff coating The cover blank 20 is then shaped and then the cover ring 20 'and the finished cover according to FIGS. 2 to 8. The fastening of the tear-open film 25 by heat sealing is then carried out in the manner known in principle. FIGS. 11 and 12 show other embodiments for applying the heat-sealable coating or for forming the cover ring. Here, the heat-sealable coating 62 is applied to the already preformed cover ring 20 ', in which the removal opening is already formed and the edge of the removal opening has been flanged. In the variant of FIG. 11, this is a simple flanging 66, whereas in the variant of FIG. 12, a special flanging has been selected, which is known under the term "retort-curl". In the case of this flanging 67, the cut edge formed by the formation of the removal opening, in which any sheet metal coating is no longer intact, is crimped upwards and inwards, as can be seen from FIG. 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 stated, the coating can cover substantially the entire edge 68 of the removal opening, as shown with the coating 62 of FIG. 12, or the coating can also be made less wide, so that it essentially covers only the connection area over which the tear-off foil is attached. As already explained in ^'advance, an additional non heisssiegelfä- on the lid ring be provided, for example, a PET coating, which covers the lid ring at the not covered by the heat-sealable coating 62 points, which may also be under the heat-sealable coating 62, however. 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, as has hitherto been the case in the prior art. The underside of the respective cover ring can also be provided with a non-heat-sealable coating, preferably again a PET coating. The shaped outer edge 64 for fastening the finished lid to a container in a manner known per se can accordingly be embodied in various known ways and will not be explained in any more detail here.

FIG. 15 shows the embodiment of FIG. 12 with the tear-off film 25 already fastened. The same reference symbols designate the same elements again, in particular the heat-sealable coating 62, which extends over the retort curl 67. It is also shown in FIG. 15 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 cover-like region of tear-open film and edge 68, which is indicated by the part 62 'of the heat-sealable coating is slightly projecting over the connection area and is located on the edge 68 outside the connection area. The surface 70 of the cover with the cover ring 20 'can, as already mentioned several times, be provided with a coating, in particular a PET coating, which can 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 case of According to FIGS. 11, 12 and 15, the heat-sealable coating 62 can be applied as a finished tape, instead of being applied by means of the nozzles 63. FIG. 14 further shows an embodiment in which a heat-sealable coating in the form of a marginal egg on the tear-open film 25 on the underside - Tigen coating 65, in particular the band-shaped coating 65 is applied. This coating can be provided instead of or in addition to the heat-sealable coating 62 of the cover ring and results in the finished compound according to Figure 15 for substantially the same result, in which the heat sealable coating 62 only on the edge 68 or in the connection area between cover ring and Tear-open film is located. 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 for both coatings 62 to be provided on the cover ring and 65 on the tear-open film. The application of the coating 65 to the underside of the tear-open film can take place according to FIG. 10, in which case the starting material 60 is just the material of the tear-open film which is subsequently punched out of the starting material 60, including the tear-open tab 71.

FIG. 9 shows a perspective view of a conveying device 30 according to a preferred embodiment. This conveying device 30 is designed to convey ceiling-shaped objects of the kind described. The conveyor device in turn serves for cyclically conveying the lid parts or covers to the individual processing stations, which are preferably the previously described processing stations for lid production and the PrüfStation 9. These stations are not shown in Figure 9, but it is clear to the skilled person, like this can arrange 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 stepping motor or servomotor, which drives the toothed belt by sprockets, as can be seen in the figure with the motor 33 and the drive axle 38. If further conveying devices, such as the conveying device 30 ', are provided, their toothed belts can be driven by the same motor via further drive axes or have their own motor drive. The motor 33 is controlled by a control 37 for making the stepwise advancing movement of the toothed belts, which controller 37 controls either an entire control of the lid manufacturing process. Device is that controls the processing stations and the station 9, or which control 37 is a control only for the conveyor, which communicates with a parent control 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 toothed belt drivers are fixed, which are generally designated 40 in Figure 9, wherein the opposing drivers of the toothed belts 31 and 32 form a receptacle for the respective object. As a result of the toothed belt movement, this receptacle formed by the drivers 40 is moved along the conveying path and in the direction of the illustrated arrow C from the input side of the conveying device, which is located on the motor side, to the outlet side at the deflection roller 36. 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 lift-off by the cover 50, the drivers may also be magnetically configured, which may also prevent lifting of the articles during the conveying step when the article is at least partially made of a magnetically-durable material.

It is preferred if the distance of the toothed belt 31 and 32 is adjustable to one another, whereby the Distance of the opposing driver 40 of the two toothed belt is adjustable in order to adapt the conveyor to different article sizes can. For this purpose, transverse connections 58 can be provided in the conveying device, which allow a simple adjustment of the spacing of the toothed belt from one another. 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 in such a way that the toothed belts are exchanged for a set of other toothed belts with carriers 40 fixed at a different distance from each other. In this way, the toothed belt can be adjusted to one another by adjusting the distance and, by exchanging the toothed belt with differently spaced drivers, the desired large receiving area for objects can be created. In this way, a conversion to different object sizes for all drivers can be done simultaneously in a simple and rapid manner. The described 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. This can, of course, also be carried out in the case of tear-off decals which have been produced deviating from the production explained.

In both illustrated embodiments of the manufacturing or conveyor for the embodiments of the invention in which the heat-sealable coating is applied to the cover ring, a corresponding processing station along the conveying path is provided, this of course before the heat-sealing station. In the embodiments in which the coating is applied to the starting material, the coating is then already on the lid blanks at the beginning of shown processing and conveying paths available 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

claims

1. tear-open lid with a cover ring (20 ') with a removal opening (25') covered by a tear-open film (25), wherein the cover ring and tear-open film are detachably connected together by means of heat-sealable plastic coating (62) along the edge (68) of the removal opening in a connection region , characterized in that the cover ring outside the edge or the connection area is uncoated or provided with a different from the heat-sealable plastic coating (62) plastic coating.

2. Aufreissdeckel according to claim 1, characterized in that the heat-sealable plastic coating is a polypropylene layer or a polypropylene-containing layer, in particular a polypropylene-containing lacquer layer.

3. A tear-open lid according to claim 1 or 2, characterized in that the plastic layer other than the heat-sealable plastic coating is a polyethylene terephthalate layer or a polyethylene terephthalate-containing layer.

4. tear-open lid according to one of claims 1 to 3, characterized in that the plastic coating other than the heat-sealable plastic coating extends on one side or on both sides over the entire lid ring and thus in the connecting region under the heat-sealable coating.

5. Aufreissdeckel according to one of claims 1 to 4, characterized in that the cover ring has a crimping edge flanged flared edge (67) of the removal opening (25 '), and that the flanged edge is covered by the heat-sealable plastic coating.

6. tear-open lid according to one of claims 1 to 5, characterized in that the cover ring consists of metal.

7. tear-open lid according to one of claims 1 to 6, characterized in that the cover ring or the removal opening is round or oval or rectangular or has another non-circular shape.

8. Container with a tear-open lid according to one of claims 1 to 7.

9. A method for producing a tear-open lid, in which a tear-open film (25) is fastened by heat sealing by means of a heat-sealable material to a cover ring (20 ') with removal opening (25'), characterized in that the heat-sealable material (62) is applied to the cover ring only at the edge (68) of the removal opening (25) or in the connection region with the tear-open film and / or that the heat-sealable material (65) is applied to the tear-open film only at the edge thereof.

10. The method according to claim 9, characterized in that the heat-sealable material (62, 65) is applied to the starting material (60) prior to molding or punching.

11. Method according to claim 9, characterized in that the heat-sealable material (62,

65) after forming a cover blank (20) or cover ring (20 ') is applied or after a punching of the tear film.

12. The method according to any one of claims 9 to 11, characterized in that the heat-sealable

Material is applied in liquid form or applied as a solid tape.

13. The method according to any one of claims 9 to 12, characterized in that on the cover ring (20 ') an upwardly and inwardly facing flanging (67; retort-curl) is provided and that the heat-sealable coating tion the crimp is applied at least partially overlapping.

14. The method according to any one of claims 9 to 13, characterized in that the cover ring or its starting material is provided at least on one side, preferably on both sides, with a non-heat-sealable plastic coating.

15. The method according to claim 14, characterized in that the non-heat-sealable coating extends under the heat sealable coating (62) by the latter being applied as a layer on the non-heat-sealable coating.

16. The method according to any one of claims 1 to 9, characterized in that the lids are conveyed on a linear conveying device by means of toothed belts or chains to the processing stations and in particular to the hot-sealing station, optionally with upstream of a workstation along the conveying path, in which the heat-sealable coating is applied to the successive cover rings.