EP3967512A1 - Device for embossing films - Google Patents

Abstract

The invention relates to a device for embossing foils, with a base embossing plate (2) and a counter-embossing plate (3), the mutually facing surfaces of which are each at least partially flat and which, for embossing a foil lying between them, have their at least partially flat surfaces aligned parallel to one another on the one hand towards one another and on the other hand away from one another, the base embossing plate (2) being provided on its side facing the counter-embossing plate (3) with a plurality of embossing inserts (4) for embossing a plurality of blanks to be punched out of the foil (17) and wherein the embossing inserts (4) are designed and arranged in such a way that during the embossing of the film (17) they each interact with a corresponding embossing area (5) arranged on the side of the counter-embossing plate (3) facing the base embossing plate (2), characterized in that that each embossing insert (4) by means of its own embossing insert reverse age (6) is held on the base die plate (2) so that it can move in the normal direction to the at least partially planar surface of the base die plate (2) by a predetermined amount relative to the base support plate (2), by means of its own embossing insert spring (7) relative to the base die plate ( 2) is cushioned and is guided by means of its own embossing insert guide (8) in the cushioned movement made possible thereby relative to the base embossing plate (2). In this way, a device for embossing thin-walled foils is provided which comes closer to the goal of ensuring an embossing depth that is independent of the material thickness of the foil to be embossed.

Description

The invention relates to a device for embossing foils, with a basic embossing plate and a counter-embossing plate, the mutually facing surfaces of which are each at least partially flat and which, for embossing a foil lying between them, have their at least partially flat surfaces aligned parallel to one another on the one hand towards one another and on the other hand from one another are arranged such that they can be moved away, the base stamping plate being provided on its side facing the counter-stamping plate with a plurality of stamping inserts for stamping a plurality of blanks to be stamped out of the foil, and the stamping inserts being designed and arranged in such a way that when the foil is stamped they each have a interact with the corresponding embossing area arranged on the side of the counter-embossing plate facing the base embossing plate.

If embossing of a film is discussed here, then this also means, quite generally, a deformation of films. Smooth foils can be embossed or deformed, but also already pre-embossed or pre-deformed foils.

Films in the packaging sector, also known as blanks, typically have a thickness between 10 and 150 µm and can be provided with a wide variety of embossing. This embossing can be full-surface, partial or edge embossing. The reason for these embossings is typically to ensure the separation of the foils when they are presented in the form of a stack of foils for their attachment to, for example, a container, as explained below.

Such films, also known as sealing films, are used in the packaging industry for a large number of different products, for example as closures for corresponding packaging containers such as cups or boxes. The sealing foils are often obtained by punching out appropriate shapes from a strip-shaped material. The material used can be, for example, aluminum foil, plastic foil or composite materials made of plastic and aluminum. The material is often printed on at least one or both sides. To close packaging containers, the sealing foils are typically glued or welded onto the containers. For this purpose, the slides on the the side facing the packaging container can be provided, for example, with a layer of heat-sealing lacquer.

After a shape corresponding to the opening of the packaging container to be closed has been punched out of a band material, the shaped pieces obtained are usually stacked. To close the packaging container, the shaped pieces, e.g. provided as lids, are removed from the stack with suitable gripping systems, such as vacuum grippers, and placed on the opening of the packaging container to be closed. Depending on the attachment system used, e.g. by means of heat-sealing lacquer, the shaped pieces provided as lids are then connected to the packaging container under the action of pressure and/or heat. To prevent several shaped pieces from sticking together when the shaped pieces are lifted from the stack, it is known from the prior art to provide the shaped pieces with an embossing in the edge region, which prevents the individual shaped pieces from sticking together. In addition, it is also known that embossing is partially omitted in order to achieve better readability by barcode scanners. In order to carry out these different embossings, methods using engraved rollers or embossing plates are known. This embossing can also be carried out in a controlled manner using tactile marks for the printed image.

A problem that frequently occurs is that the foils used to be embossed can have differences in material thickness of up to 5 µm across the embossing width. As a rule, 2 to 18 blanks to be punched are arranged across the embossing width. Therefore, in many cases, there are different embossing depths for the different blanks that are punched out. This has negative effects on the ability to unstack and the stability of a stack of blanks manufactured in this way. If, for example, the embossing depth of the individual blanks varies greatly in the case of pure edge embossing, a stable stack of blanks cannot be formed, which can lead to considerable problems on the filling system - targeted removal is often not possible.

Proceeding from this, it is the object of the invention to provide a device for embossing thin-walled foils that comes closer to the goal of ensuring an embossing depth that is independent of the material thickness of the foil.

This object is solved by the subject matter of patent claim 1. Preferred developments can be found in the dependent claims.

According to the invention, a device for embossing foils is therefore provided, with a base embossing plate and a counter-embossing plate, the mutually facing surfaces of which are each at least partially flat and which, for embossing a foil lying between them, have their at least partially flat surfaces aligned parallel to one another on the one hand towards one another and on the other hand are arranged to be movable away from one another, with the base stamping plate being provided on its side facing the counter-stamping plate with a plurality of stamping inserts for stamping a plurality of blanks to be stamped out of the film, and with the stamping inserts being designed and arranged in such a way that when the film is stamped they each a corresponding embossing area arranged on the side of the counter-embossing plate facing the base embossing plate, characterized in that each embossing insert can be held by means of its own embossing insert retainer in the direction normal to the w surface of the base die that is planar at least in sections is held on the base die so that it can move by a predetermined amount relative to the base support plate, being cushioned by means of its own die insert resilience in relation to the base die and being guided by means of its own die insert guide during the cushioned movement made possible by this relative to the base die.

It is therefore an essential aspect of the invention that an otherwise conventionally constructed device for embossing foils is provided with such embossing inserts on its base embossing plate, each of which has its own embossing insert retainer, its own embossing insert spring and its own embossing insert guide. The fact that each embossing insert is provided with its own embossing insert retainer, with its own embossing insert spring and with its own embossing insert guide means that such devices are provided separately for each embossing insert that interact only with this embossing insert and with no other. In this way, the invention allows the movement of each die when embossing the foil to be independent of the movements of the other dies. In particular, this enables the embossing inserts to behave in such a way that they are independent of one another "react" to different foil thicknesses, so that the embossing depth is essentially the same despite the different thicknesses. So if the foil to be embossed shows differences in its material thickness across its surface, this can be compensated for by the separate storage, springing and guidance of the individual embossing inserts. Fluctuations in the film thickness, which would otherwise have led to different embossing depths, can thus be compensated. In the best case, practically the same embossing depth can be achieved in this way with every embossing insert.

The embossing insert retainer ensures the basic attachment of the embossing insert to the base embossing plate. This fastening is such that the embossing insert can basically be moved relative to the base embossing plate, namely a movement in the normal direction to the at least partially planar surface of the base embossing plate is possible. This corresponds to movement of an embossing insert relative to the base die in a direction parallel or anti-parallel to the direction in which the base die and counter die are moved towards one another for embossing the foil. This means that each embossing insert during embossing, namely when the film is pressed between a respective embossing insert and a corresponding embossing area on the counter-embossing plate, allows the respective embossing insert to "pull back" to a certain extent towards the base support plate. This evasion or retreat of the respective embossing insert takes place in a controlled manner due to the embossing insert resilience assigned to the respective embossing insert in combination with the respective embossing insert guide, so that even with different material thicknesses over the surface of the foil to be embossed, there are differences in the embossing depths for the different Embossing inserts can be reduced or avoided entirely.

For this purpose, the embossing insert retainers can be designed in different ways. According to a preferred development of the invention, however, the embossing insert retainers each have a damping device for damping the possible movement of the respective embossing insert relative to the base embossing plate. Such a damping device therefore offers a certain resistance to the movement of the respective embossing insert, which makes the movement of the embossing insert relative to the base die plate more controllable.

Different damping devices can be provided for this purpose. According to a preferred development of the invention, however, the damping device comprises a spring bolt and/or a damping disk. It is particularly preferred that the embossing inserts are each held on the base embossing plate by means of a fastening device, the fastening device being guided through the damping device. If, for example, a spring bolt in combination with a damping disk is provided as the damping device in connection with this preferred embodiment of the invention, a screw is preferably passed through these components, with which the respective embossing insert is fastened to the base embossing plate.

Different configurations are also possible for the embossing insert guides. According to a preferred development of the invention, the embossing insert guides each have a column guided in a bushing. It is preferably also the case here that the column of a respective embossing insert guide is fastened in the respective embossing insert and the sleeve is fastened in the base die plate.

With regard to the embossing insert springs, it is essential that this ensures a certain cushioning of the embossing inserts in relation to the base embossing plate. For this purpose, a respective embossing insert spring is preferably designed in such a way that it has an elastic element fastened to the respective embossing insert. Moreover, according to a preferred development of the invention, it is provided that each embossing insert is provided with a plurality of embossing insert guides and/or with a plurality of embossing insert springs. In addition, according to a preferred development of the invention, the shape of the embossing inserts is essentially round, with the embossing insert retainer being arranged centrally in each embossing insert. In this way, a particularly stable mounting and guiding of the embossing inserts on the base embossing plate is ensured.

The device according to the invention for embossing foils can also be designed differently with regard to the transport of the foil to be embossed and the arrangement of the embossing inserts. According to a preferred development of the invention, however, it has a transport device with which the film to be embossed can be moved in a transport direction relative to the base embossing plate, with at least some of the plurality of embossing inserts next to one another in a direction perpendicular to the transport direction are arranged. In other words, this means that according to this preferred development of the invention, at least some of the embossing inserts are arranged widthwise perpendicular to the working direction given by the transport direction of the film. According to a preferred development of the invention, it also applies that the embossing inserts, which are arranged next to one another in a direction perpendicular to the transport direction, are at least partially offset from one another in the transport direction. Such a staggered arrangement makes it possible to arrange as large a number of embossing inserts as possible on the surface provided by the base embossing plate, for example in the case of essentially round embossing inserts in the form of a practically hexagonal arrangement of the embossing inserts relative to one another, which leads to practically optimal utilization of the available surface.

As far as the embossing areas in the counter-plate that correspond to the embossing inserts provided in the base embossing plate are concerned, these can basically be configured in a conventional manner. According to a preferred development of the invention, in this context it applies that the embossing areas corresponding to the embossing inserts provided in the base embossing plate are configured as inserts that are detachably fastened in the counter-plate. In particular, the embossed areas designed as such inserts can be screwed into the counter-plate. According to a preferred development of the invention, it is also the case that the inserts are mounted in the counter-plate in an unsprung manner, preferably screwed in an unsprung manner in the counter-plate.

The invention is explained in more detail below using a preferred exemplary embodiment with reference to the drawings.

Fig. 1

schematisch ein System zum Prägen von Folien und Ausstanzen von Platinen mit einer Vorrichtung zum Prägen von Folien gemäß einem bevorzugten Ausführungsbeispiel der Erfindung,

Fig. 2 a-d

die Vorrichtung zum Prägen von Folien aus Fig. 1 in unterschiedlichen Ansichten,

Fig. 3

einen Prägeeinsatzrückhalter der Vorrichtung zum Prägen von Folien gemäß dem vorliegend beschriebenen bevorzugten Ausführungsbeispiel der Erfindung in einer Schnittdarstellung,

Fig. 4

eine Prägeeinsatzführung der Vorrichtung zum Prägen von Folien gemäß dem vorliegend beschriebenen bevorzugten Ausführungsbeispiel der Erfindung in einer Schnittdarstellung und

Fig. 5

eine Prägeeinsatzfederung der Vorrichtung zum Prägen von Folien gemäß dem vorliegend beschriebenen bevorzugten Ausführungsbeispiel der Erfindung in einer Schnittdarstellung,

Show in the drawings

1

schematically a system for embossing foils and punching out blanks with a device for embossing foils according to a preferred embodiment of the invention,

Fig. 2 ad

the device for embossing foils 1 in different views,

3

a sectional view of an embossing insert retainer of the device for embossing foils according to the presently described preferred embodiment of the invention,

4

an embossing insert guide of the device for embossing foils according to the presently described preferred embodiment of the invention in a sectional view and

figure 5

an embossing insert spring of the device for embossing foils according to the presently described preferred embodiment of the invention in a sectional view,

the end 1 An embossing and punching system 100 can be seen schematically, with which sealing lids can be embossed and punched out of a sheet-like foil 17, such as an aluminum foil or an aluminum/plastic composite foil. For this purpose, the system 100 has a transport device 16 which firstly feeds the sheet-like film 17 to an embossing device 1 . The embossing device 1 is explained in detail below. The foil 17 embossed by means of the embossing device 1 is then fed to a punching device 19, by means of which embossed foil elements, also referred to as blanks, are punched out. The embossed and punched film elements are finally stacked in a stack 20 and are thus available for further processing.

For a detailed description of the embossing device 1 according to the present preferred exemplary embodiment of the invention, reference is made to FIG Figure 2a , which shows the embossing device 1 in a section, Figure 2b , which shows the embossing device 1 in a plan view, partly in section Figure 2c , which shows the embossing device 1 in a side view along its long side and Fig. 2d 12 showing the embossing device 1 in a side setup along its short side. How eg from Figure 2a As can be seen, the embossing device has a base embossing plate 2 and a counter embossing plate 3 . The largest part of the surfaces of the base die 2 and the counter die 3 are formed by planar sections that are parallel to each other, in which in Figure 2a sectional view shown, namely run horizontally. The base die plate 2 is connected to the counter die plate 3 by means of die guides 21 in such a way that the base die plate 2 and the counter-stamping plate 3 can be moved towards one another on the one hand and away from one another on the other hand in a parallel orientation to one another. By moving the base embossing plate 2 away from the counter embossing plate 3 , the embossing device 1 is practically opened so that the foil 17 to be embossed can be guided between the base embossing plate 2 and the counter embossing plate 3 . For the actual embossing, the base embossing plate 2 and the counter embossing plate 3 are moved towards one another, so that finally the actual embossing process of the film 17 between the base embossing plate 2 and the counter embossing plate 3 occurs.

For this embossing process, the base embossing plate 2 is provided with a plurality of embossing inserts 4, in this case eight, which correspond to eight embossing areas 5 in the counter-embossing plate. These embossing areas 5 in the counter-embossing plate 3 are in the present case in the form of inserts which are unsprung screwed into the counter-embossing plate 3 with the aid of screws 18. The mutually facing surfaces of the embossing areas 5 and the embossing inserts 4 are the same as in conventional embossing devices known, designed in such a way that the desired embossing occurs during the actual embossing process on the film lying between the embossing inserts 4 and the embossing areas 5 .

How in particular Figure 2b removable, the embossing inserts 4 and thus also the embossing areas 5 are perpendicular to the in Figure 2b Transport direction T marked with an arrow arranged side by side. In addition, the embossing inserts 4 and thus also the embossing areas are also offset from one another in the transport direction. This leads to a practically optimal utilization of the available space.

It is now essential that the embossing device 1 according to the preferred exemplary embodiment of the invention described here has such embossing inserts 4, each of which can be held by its own embossing insert retainer 6 in the normal direction, in Figure 2b i.e. perpendicular to the plane of the drawing, are held on the base die 2 so that they can be moved by a predetermined amount relative to the planar surfaces of the base die 2, being cushioned in relation to the base die 2 by means of their own die insert spring system 7 and by means of their own die insert guide 8 in the cushioned movement thus made possible are led to the base stamping plate 2.

The embossing insert retainer 6 ensures the basic attachment of the embossing insert 4 to the base die plate 2 in such a way that a certain movement of the embossing insert 4 remains possible. This corresponds to a movement of the embossing insert 4 relative to the base embossing plate 2 in a direction parallel or anti-parallel to the direction in which the base embossing plate 2 and the counter embossing plate 3 are moved towards one another for embossing the foil 17 . This means that each embossing insert 4 during embossing, namely when the film 17 is pressed between a respective embossing insert 4 and a corresponding embossing area 5 on the counter-embossing plate 3, allows the respective embossing insert 4 to "pull back" to a certain extent towards the base support plate 2 will.

In this way, differences in the embossing depths in the various embossing inserts 4 can be reduced or avoided entirely, even with different material thicknesses across the surface of the foil 17 to be embossed. Specifically, each of the eight embossing inserts 4 has a centrally arranged embossing insert retainer, three embossing insert guides 8 and six embossing insert springs 7 . In the present case, these are configured as described below.

3 shows such an embossing insert retainer 6 in section. It can be seen here that the embossing insert retainer 6 has a damping device 9 for dampening the possible movement of the embossing insert 4 on which it is provided relative to the base embossing plate 2 . The damping device 9 includes a spring bolt 10 and a damping disk 11 . The fact that this holder allows a certain movement of the embossing insert 4 relative to the base embossing plate 2 is due to the spring bolt 10 and the damping disk 11 .

4 now shows an embossing insert guide 8, also in section. It can be seen here that the embossing insert guide 8 has a column 14 guided in a bushing 13 . The column 14 is fastened in the respective embossing insert 4 while the bush 13 is held in the base embossing plate 2 .

the end figure 5 Finally, a sectional view of the embossing insert spring 7 used here can be seen. It can be seen that the embossing insert spring mechanism 7 has an elastic element 15 fastened to the respective embossing insert 4 . This elastic element is preferably made of a rubber material.

Reference List

1

embossing device

2

base embossing plate

3

die plate,

4

embossing inserts

5

embossing areas

6

embossing insert retainer

7

embossing insert suspension

8th

embossing insert guide

9

damping device

10

spring bolt

11

damping washer

12

Fastening device for holding an embossing insert

13

rifle

14

pillar

15

elastic element

16

transport device

17

foil

18

screws

19

punching device

20

stack

21

embossing guides

100

Embossing and punching system

T

transport direction

Claims (12)

Device for embossing foils, with a base embossing plate (2) and a counter-embossing plate (3), the mutually facing surfaces of which are each at least partially flat and which, for embossing a foil lying between them, have their at least partially flat surfaces aligned parallel to one another on the one hand towards one another and on the other hand, are arranged to be movable away from one another, the base embossing plate (2) being provided on its side facing the counter-embossing plate (3) with a plurality of embossing inserts (4) for embossing a plurality of circuit boards to be punched out of the foil (17), and the embossing inserts ( 4) are designed and arranged in such a way that during embossing of the film (17) they each interact with a corresponding embossing area (5) arranged on the side of the counter-embossing plate (3) facing the base embossing plate (2), characterized in that each embossing insert ( 4) by means of its own embossing insert retainer (6) in the normal direction ng to the at least partially flat surface of the base die (2) is held on the base die (2) so that it can move by a predetermined amount relative to the base support plate (2), being cushioned by means of its own die insert spring system (7) relative to the base die (2) and is guided by means of its own embossing insert guide (8) in the cushioned movement made possible thereby relative to the base embossing plate (2). Device according to Claim 1, characterized in that the die retainers (6) each have a damping device (9) for damping the possible movement of the respective die (4) relative to the base die (2). Device according to Claim 2, characterized in that the damping devices (9) each comprise a spring bolt (10) and/or a damping disc (11). Device according to one of the preceding claims, characterized in that the embossing inserts (4) are each held on the base embossing plate (2) by means of a fastening device (12), the fastening devices (12) each being guided through the respective damping device (9). Device according to one of the preceding claims, characterized in that the embossing insert guides (8) each have a column (14) guided in a bushing (13). Device according to Claim 5, characterized in that the column (14) is fastened in the respective embossing insert (2) and the bush (13) in the base embossing plate (2). Device according to one of the preceding claims, characterized in that the embossing insert springs (7) each have an elastic element (15) fastened to the respective embossing insert (4). Device according to one of the preceding claims, characterized in that each embossing insert (4) is provided with a plurality of embossing insert guides (8) and/or with a plurality of embossing insert springs (7). Device according to one of the preceding claims, characterized by a transport device (16) with which the film (17) to be embossed can be moved in a transport direction relative to the base embossing plate (2), at least some of the plurality of embossing inserts (4) being in are arranged next to one another in a direction perpendicular to the transport direction. Device according to Claim 9, characterized in that the part of the plurality of embossing inserts (4) which are arranged next to one another in a direction perpendicular to the transport direction are arranged at least partially offset from one another in the transport direction. Device according to one of the preceding claims, characterized in that the embossing areas (5) corresponding to the embossing inserts (4) provided in the base embossing plate (2) are designed as inserts releasably fastened in the counter-embossing plate (3). Device according to Claim 11, characterized in that the inserts in the counter-embossing plate (3) are mounted without springs.

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