EP2529905A1 - Device and method for perforating films - Google Patents

Abstract

The device (1) has a cutting edge (3) and a stationary blade (5). The stationary blade has pattern which cooperates with the cutting edge along a line of action so that a film (2) in the areas of contact with the cutting edge and the stationary blade is perforated. An interlocking is provided to run vertical to direction of conveyance (2a) of the film. A mechanical, pneumatic or hydraulic suspension is provided for an elastic bearing of the stationary blade. An independent claim is included for method for perforating sheets.

Description

The invention relates to a device for perforating films and a corresponding method using the device according to the invention.

Films are known to be useful for labeling containers, such as bottles. For this purpose, for example, a film web, a film tube or another suitable web-shaped material is unwound from a roll and provided at predetermined separation points with a transverse perforation. Individual labels are then preferably made immediately prior to labeling by severing along the perforation.

A device for Querperforierung web-like material is for example from the DE 20 2006 015 561 U1 known. The web-like material is passed between two rotating rollers, wherein on one of the rollers two offset by 180 ° grooved perforating are provided which press the film against the other roller, thereby perforating the sheet-like material. The perforating knives are here resiliently mounted in the lateral surface of the roller to reduce the reject rate when starting and stopping the cutting device. The disadvantage, however, is that the perforation pattern is incorporated in the cutting edge of the perforation. For the perforation thus a comparatively expensive to produce and expensive wearing part is needed.

A cutting tool for cutting labels is further from the DE 10 2009 009 820 A1 1 known. The cutting tool comprises two offset by 180 ° and arranged parallel to a common axis of rotation cutting elements which are resiliently mounted. These cooperate with a rotating cutting roller, in which the cutting elements corresponding counter cutting strips are provided. Labels unrolled from a roll are inserted between the rotary cutter and the rotating cutter roll and severed by the cooperation of the cutter elements and the counter cutter bars. Although the cutting element can be comparatively easily replaced by resilient mounting in a groove, this is a comparatively expensive wearing part.

Thus, there is a need for a device for perforating films, in which the wear parts can be exchanged in a simple manner, inexpensive and flexible.

The stated object is achieved with a device according to claim 1. Accordingly, the device according to the invention comprises a cutting edge and a counter-cutting edge, wherein the counter-cutting edge has a pattern which cooperates with the cutting edge along a line of action such that a film perforates in contact areas with the cutting edge and the counter-cutting edge becomes. The perforation is in particular a transverse perforation. Any sheet material may be used, such as paper, plastic, metal or fabric foil, which can be punctured by the cooperation of a cutting edge and a counter-blade, such as foils, tubes and the like.

Thus, the course of the line of action can be given essentially by the pattern of the counter-blade. Accordingly, a substantially rectilinear cutting edge can be used. Since a straight edge is cheaper to produce than a cutting edge with perforation, the cost of replacing wear parts, especially the cutting edge can be reduced.

The pattern of the counter-blade is preferably three-dimensional. The pattern may consist of elevations and depressions, for example. Also conceivable is a counter-blade, are formed in the continuous recesses. The counter-blade could for example be in the form of a helix or the like.

The line of action can also be designed such that the material to be perforated is not perforated in non-contact areas with the cutting edge and the counter-cutting edge. However, it is possible that the material, particularly a film, in the non-contact areas may be damaged to a desired extent, for example, by further tearing a perforation from the contact area towards the non-contact area to a desired extent Way to create a perforation area that is greater than the contact area with the cutting edge and the counter-blade.

Preferably, the line of action is changeable to set a ratio of perforation to non-perforation of the film. An exchange of the cutting edge in a production-related change in the film perforation is therefore unnecessary. The ratio of perforation to non-perforation is given for example by an aspect ratio along the line of action. The line of action could, for example, be changed by replacing the counter-blade with a counter-blade of another type. The line of action can also be changed to set a uniform, predetermined ratio of perforation to non-perforation for films with different material properties and / or thicknesses.

In a particularly favorable embodiment, the line of action is adjustable by changing the position of the cutting edge and the counter-blade to each other. As a result, replacement of the counter-blade when setting the line of action is unnecessary. The line of action and / or the ratio of perforation to non-perforation can thus be flexible to different material properties and / or material thicknesses as well as to different processing speeds be adapted to the device according to the invention. In a transverse perforation of the film, the position of the cutting edge and the counter-blade relative to one another take place substantially in a longitudinal direction of the film.

Preferably, the pattern, seen in a plan view of the film, extends in an adjustment range of the action line obliquely to the line of action and / or curved. As a result, the action line within the adjustment range can be adjusted particularly precisely and in particular continuously. The perforation of the film can thus be adapted to material properties and / or the thickness of the film and / or exposure times and / or reaction forces when perforating the film particularly accurately, and / or the respective production conditions. The line of action can run over any combination of straight and curved pattern sections.

Preferably, the pattern repeats periodically along the line of action. This makes it possible to achieve a uniform and flexibly adjustable perforation over the entire width of the film. Suitable patterns with periodicity include zig-zag patterns, sinusoidal waveforms, or any combination of such periodic waveforms. The line of action thus cuts the pattern several times in plan view.

Preferably, the film is a foil tape or a film tube, and the line of action extends transversely, wherein the ratio of perforation to non-perforation by adjusting the position of the counter-blade and the line of action is adjustable in the longitudinal direction. Such an arrangement can be realized particularly favorable with rotating cutting and counter cutting. It is thus possible to provide a transverse perforation of film strips or film tubes with particularly high machine performance.

In a particularly favorable embodiment, the cutting edge and the counter-blade lie on rollers which can be synchronized with one another. Further, a rotational position offset of the rotating rollers to one another, so a difference between the rotational positions of the cutting edge and the counter-blade during interaction, adjustable. In this way, an adjustability of the line of action in the longitudinal direction of the film can be provided in a particularly simple manner. Additional means for adjusting the position of the counter-blade and / or the cutting edge on the associated rollers in the longitudinal direction of the film, ie in the direction of rotation of the roller, are therefore unnecessary. The counter-blade can in particular be firmly connected to the roller in the direction of rotation or be formed integrally therewith.

Preferably, the counter-blade is a tool cutting edge incorporated into the roller surface. Such a counter-blade is particularly robust and reliable and eliminates the need for additional Mounts of the counter-blade to the roll surface. The tool cutting edge can be produced for example by laser engraving of the roll surface.

Preferably, the cutting edge is an exchangeable cutting tool or part of a replaceable blade. As a result, a wear-related change of the cutting edge can be carried out in a particularly simple and time-saving manner.

In a particularly favorable embodiment, the cutting edge is rectilinear. As a result, wear-related operating costs of the device according to the invention can be minimized. Furthermore, uniform cutters can be used as standard fittings for various counterblades. In particular, cutting knives, as used in conventional labeling, can also be used for the perforation of films. This further reduces the operating costs of labeling units.

In a particularly favorable embodiment, the line of action is automatically adjustable by means of a motor and a control unit as a function of at least one material parameter of the film, in particular from the parameter group of the thickness, the modulus of elasticity and the maximum tensile stress, and / or depending on at least one machine parameter for separating the Foil along the perforation, in particular a set for separation tensile stress. This allows the film perforation to be flexibly adapted to different production conditions. The motor is, for example, a drive motor of a cutting roller and / or a drive motor of a counter-cutting roller. By a change in the rotational speed of the cutting roller and / or the counter-cutting roller, a predetermined angular offset between the rollers can then be brought about. The motor may also be an actuator to adjust the position of the counter-blade or the blade on the respective roller. The material parameters of the film and / or the machine parameters can be determined continuously during the continuous perforation of a film web or a film tube and continuously evaluated by the control unit. This can provide a perforation with particularly consistent quality.

Preferably, a mechanical, pneumatic or hydraulic suspension is provided for the spring-elastic mounting of the cutter and / or the counter-blade. As a result, the wear of the cutting edge can be further reduced. In addition, short-term loads when starting, shutting down and / or changing machine parameters can be reduced.

The stated object is further achieved by a method according to claim 13 using the device according to the invention. Accordingly, the cutting edge cooperates with the pattern of the counter-blade in such a way that the course of the pattern along the line of action has a relationship defined by perforation to non-perforation of the slide. Here, the course of the action line essentially corresponds to the course of the perforation on the film.

Preferably, the ratio of perforation to non-perforation is adjusted by shifting the line of action with respect to the pattern. The pattern thus defines a two-dimensional effective range on which the action line can be shifted. The effective area comprises contact surfaces for creating the perforation and non-contact areas in which the material to be perforated is not perforated. The pattern can thus be understood as a binary rastered effective range, which intersects the line of action. Depending on the pattern of the counter cutting edge, different ratios of perforation to non-perforation can be realized by shifting the action line.

In a particularly favorable development of the method according to the invention, the ratio of perforation to nonperforation during production operation is adjusted to a desired value. As a result, film sections for subsequent labeling with particularly high reliability and reproducibility can be separated with the required quality.

• Fig. 1 eine schematische Seitenansicht einer ersten Ausführungsform der erfindungsgemäßen Vorrichtung;
• Fig. 2 eine schematische Draufsicht auf eine Gegenschneide der ersten Ausführungsform mit einer schematisch angedeuteten Wirklinie;
• Fig. 3 einen schematischen Querschnitt durch eine Schneide und eine Gegenschneide der ersten Ausführungsform; und
• Fig. 4 eine schematische Ansicht einer Gegenschneide einer zweiten Ausführungsform der erfindungsgemäßen Vorrichtung.

Preferred embodiments of the invention are shown in the drawing. Show it:

• Fig. 1 a schematic side view of a first embodiment of the device according to the invention;
• Fig. 2 a schematic plan view of a counter-blade of the first embodiment with a schematically indicated line of action;
• Fig. 3 a schematic cross section through a cutting edge and a counter-blade of the first embodiment; and
• Fig. 4 a schematic view of a counter-blade of a second embodiment of the device according to the invention.

As the Fig. 1 1, a first embodiment 1 of the device according to the invention for the perforation of foils 2 comprises at least one cutting edge 3 and at least one counterknife 5, the contact of which with the foil 2 produces a perforation in the foil 2. The cutting edge 3 is preferably provided on a cutting roller 7 or another rotatable support with the direction of rotation 7a, the counter-blade 5 on a counter-cutting roller 9 or other rotatable support with the direction of rotation 9a, wherein the axes of rotation 7b and 9b are aligned parallel to each other. As the Fig. 1 further indicates, in particular at least two cutting edges 3 are circumferentially evenly distributed on the cutting roller 7, on the counter-cutting roller 9 a corresponding number circumferentially uniformly distributed counter blades 5. Particularly advantageous are four circumferentially distributed cutting edges 3 and counter cutting edges. 5

At the cutting roller 7 and the counter-cutting roller 9, a drive motor 11, 13 is provided in each case. The drive motors 11, 13 are synchronized by a control unit 15 such that upon rotation of the cutting roller 7 and the counter-cutting roller 9 in each case a blade 3 comes to rest against a counter-blade 5. Suitable rotational positions of the rollers 7, 9 are defined, for example, by the indicated rotational angles α, β. The film 2 is moved continuously in the direction of arrow 2a between the cutting roller 7 and the counter-cutting roller 9.

The cutting edges 3 are preferably resiliently mounted on a mechanical, pneumatic or hydraulic suspension 17 in the radial direction and guided in the circumferential direction. Guidance means of this kind are not shown for the sake of clarity. A spring-elastic bearing could alternatively or additionally be provided on the counter-cutting roller 9 for the counter-cutting edges 5. However, this is also not shown in favor of a clearer representation.

The counter-cutting edges 5 are preferably adjustable in the direction of the double arrow 5a by means of adjusting devices 19. These could, for example, be mechanically actuated or by means of an actuator (not shown) which can be actuated in particular by the control device 15. With the adjusting device 19, the position of the counter-blade 5 in cooperation with the corresponding cutting edge 3 in the longitudinal direction of the film 2, so in the direction of the arrow 2a, set.

As will become apparent from the following figures, the adjusting device 19 serves to set a contact area with the film 2, in which the cutting edge 3 and the counter-blade 5 cooperate in such a way that the film 2 lying therebetween is perforated. In general, it would also be conceivable to provide such adjusting devices on the cutting roller 7 in order to adjust the blades 3 accordingly.

The Fig. 2 shows a schematic plan view of the counter-blade 5 of the first embodiment 1. Substantially perpendicular to the conveying direction 2a of the film 2 extends a line of action 21, which by an overlap of the cutting edge 3 (in Fig. 2 not shown) and the counter-blade 5 is defined. In this case, the illustrated line of action 21 corresponds to a first overlap of the cutting edge 3 and the counter-blade 5 in a first relative position of the counter-blade 5 to the blade 3 and the line of action 21 'of a second overlap indicated by dashed lines the cutting edge 3 with the counter-blade 5 in a second relative position of the counter-blade 5 to the cutting edge 3. The adjustment and the adjustment between the first and second relative position are indicated by the double arrow 21 a.

It does not matter for the principle of action, whether the position of the cutting edge 3 is changed with respect to the counter-blade 5 or vice versa, or whether the counter-blade 5 is replaced by a counter-blade of another type. It is crucial that the counter-blade 5 has a three-dimensional pattern 23, which in the example of the Fig. 2 consists of raised contact surfaces 23a and on the other hand lowered non-contact regions 23b. Again Fig. 2 Further, the pattern 23 preferably includes a periodic juxtaposition of contact surfaces 23a and non-contact regions 23b.

The pattern 23 of the counter-blade 5 cooperates with the cutting edge 3 along the line of action 21 in such a way that the film 2 is perforated in perforation regions 25 and is substantially not perforated in non-perforation regions 27. The Fig. 2 further illustrates that the aspect ratio of the contact surface 23a and the non-contact regions 23b along the line of action 21 determines the relationship between the length of the perforation regions 25 and the length of the non-perforation regions 27. It can also be seen that a displacement of the line of action 21 in or against the transport direction 2a of the film 2 acts to change the perforation ratio. This is through in the Fig. 2 upwardly shifted line of action 21 'indicated with shorter perforation 25' and longer non-perforation 27 '.

The Fig. 3 shows the cutting edge 3 and in the Fig. 2 By virtue of the fact that raised regions 5b and perforation grooves 5c are provided on the counter cutting strip 5, a three-dimensional pattern 23 with corresponding contact surfaces 23a and non-contact regions 23b can be realized in a simple manner on the counter cutting strip 5. Such a counter-blade 5 can be produced for example by engraving, in particular by laser engraving, on the counter-cutting roller 9 or on an exchangeable counter cutting strip.

Like in the Fig. 3 is indicated, the cutting edge 3 can consequently be formed continuously, in particular straight. This is advantageous for a replacement of the cutting edge 3 caused by wear or damage. The cutting edge 3 can be a standardized clothing part for cutting and / or perforating labels and the like. The cutting edge 3 can be provided, for example, as a replaceable cutting tool or blade.

The line of action 21 can be compared with the pattern 23 by adjusting the in the Fig. 1 indicated rotational angle α, β of the cutting edge 3 and the counter-blade 5 move. Additionally or alternatively, the circumferential relative position 5a of the counter-blade 5 on the counter-cutting roller 9 can be adjusted. The latter would be advantageous, for example, if a synchronized rotational movement of the cutting roller 7 and the counter-cutting roller 9 should be maintained unchanged, regardless of the position of the line of action 21.

To set the rotational positions α, β of the cutting edge 3 and the counter-blade 5 to each other, the rotational speed of the cutting roller 7 or the rotational speed of the counter-cutting roller 9 could be temporarily changed until the line of action 21 is adjusted by the desired amount. Thereafter, the cutting roller 7 and the counter-cutting roller 9 with respect to the rotational positions α and β run synchronously again.

The Fig. 4 shows a grid-shaped counter-blade 31 of an alternative embodiment of the invention with a three-dimensional pattern 33, the contact surfaces 33a for cooperation with the cutting edge 3 includes and non-contact areas 33b, which are defined by the spaces between the contact surfaces 33a. Such counter-blade 31 could be formed by any three-dimensional structures comprising struts, arches or the like. Conceivable z. B. also helical structures. In this case, the contact surfaces 33a are advantageously arranged in a periodically recurring pattern and have a width which varies in the transport direction 2a of the film 2 and / or in the adjustment direction 21a of the line of action 21. As a result, in principle, the same advantages, in particular adjustment, can be achieved, as with the first embodiment 1. The counter-blade 5, 31 could of course be curved in accordance with the circumference of the counter-cutting roller 9.

Decisive for the device according to the invention and the method according to the invention is that the counter-blade 5, 31 has a three-dimensional pattern 23, 33 with contact surfaces 23a, 33a, which cooperates with the film 2 and with the blade 3, so that in contact areas of the film 2 with the cutting edge 3 and the counter-blade 5 a perforation in the film 2 is generated. Here, the counter-blade 5, which has only a slight wear compared to the blade 3, can be formed in a variety of ways. Accordingly, the cutting edge 3 can be structurally simplified in comparison to the prior art, so that the wear-related replacement of the cutting edge 3 can be carried out simply and inexpensively.

The ratio of perforation to non-perforation of the film 2 can then be effected by a simple displacement of the line of action 21 with respect to the counter-blade 5, 31. This leaves In particular, when using mutually corresponding cutting rollers 7 and counter-cutting rollers 9 by driving the drive motors 11, 13 realize in a simple manner.

In addition, the perforation can be constantly adapted to changing production conditions, such as a tensile stress in the subsequent separation of individual perforated sections of the film 2. For example, both the perforation and the tensile stress to the material properties and / or the thickness of the film 2 can be adjusted.

During operation of the device according to the invention, a film 2 or a film tube is preferably continuously fed and passed between the rotating cutting roller 7 and the counter-cutting roller 9. Their rotational positions α and β are constantly synchronized and adjusted if necessary by temporarily adjusting the rotational speed. Likewise, the circumferential position of the cutting edge 3 or the counter-blade 5 on the respective roller 7, 9 can be readjusted. By moving the line of action 21, the transverse perforation of the film 2 can be set in the ongoing production operation and adapted to current production conditions if necessary.

The described embodiments and variants can be arbitrarily combined in a technically meaningful way.

Claims (15)

Device (1) for perforating foils (2) with: - a cutting edge (3); and a counter-blade (5),
wherein the counter-blade has a pattern (23) which cooperates with the cutting edge along a line of action (21) such that a film is perforated in contact areas with the cutting edge and the counter-cutting edge. An apparatus according to claim 1, wherein the action line (21) is changeable to set a ratio of perforation (25) to non-perforation (27) of the film (2). Apparatus according to claim 1 or 2, wherein the line of action (21) is adjustable by changing the position of the cutting edge (3) and the counter-blade (5) to each other. Apparatus according to claim 2 or 3, wherein the pattern (23), seen in a plan view of the film, in an adjustment region (21a) of the line of action (21) oblique to the line of action and / or curved. Apparatus according to claim 4, wherein the pattern (23) is repeated periodically along the line of action. The device according to at least one of the preceding claims, wherein the film (2) is a film strip or a film tube and the line of action (21) is transverse thereto, and wherein the ratio of perforation (25) to nonperforation (27) is changed by changing the position of the counter cutting edge (5) and the line of action (21) is mutually adjustable in the longitudinal direction. Device according to at least one of the preceding claims, wherein the cutting edge (3) and the counter-blade (5) lie on rollers (7, 9) which can be synchronized with one another and a rotational position offset of the rotating rollers can be set to one another. Apparatus according to claim 7, wherein the counter-blade (5) is a tool cutting edge machined into the roller surface. Device according to at least one of the preceding claims, wherein the cutting edge (3) is a replaceable cutting tool or a component of a replaceable blade. Device according to at least one of the preceding claims, wherein the cutting edge (3) is continuous, in particular rectilinear. Device according to at least one of the claims, wherein the line of action (21) is automatically adjustable by means of a motor (11, 13) and a control unit (15) as a function of at least one material parameter of the foil, in particular from the parameter group of the thickness, the modulus of elasticity and Maximum tensile stress, and / or as a function of at least one machine parameter for separating the film along the perforation, in particular a tensile stress set for separation. Device according to at least one of the preceding claims, characterized in that a mechanical, pneumatic or hydraulic suspension (17) are provided for resilient mounting of the cutting edge and / or the counter-blade. A method of perforating foils with a device according to at least one of the preceding claims, wherein the cutting edge cooperates with the pattern of the counterknife such that the course of the pattern along the line of action defines a ratio of perforation to nonperforation of the foil. The method of claim 13, wherein the ratio of perforation to nonperforation is adjusted by shifting the line of action with respect to the pattern. A method according to claim 13 or 14, wherein the ratio of perforation to non-perforation during production is adjusted to a desired value.

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