DE202022102256U1 - Rotary die-cut elastomer element as an ejection element and/or fixing element - Google Patents

Abstract

Rotary punching elastomer element (10) as an ejection element and/or fixing element for attachment to a punching cylinder (3) or a punching half-shell (4) of a rotary punching device (1),
the rotary die-elastomer element (10) being provided with an adhesive layer on its contact surface intended for attachment to a die-cutting cylinder (3) or a die-cutting half-shell (4),
characterized,
that the adhesive layer is formed by a double-sided adhesive tape (13), that a carrier layer (14), a first adhesive layer (16) facing the rotary die-cast elastomer element (10) and arranged on a first carrier-layer side (15), and a first adhesive layer (16) on the rotary die-cast elastomer element (10) has a second adhesive layer (19) which faces away and is arranged on a second carrier layer side (18) opposite the first carrier layer side (15), and
that at least the second adhesive layer (19) facing away from the rotary die-casting elastomer element (10) is formed by a rubber-based adhesive.

Description

The invention relates to a rotary punching elastomer element as an ejection element and/or fixing element according to the preamble of claim 1 and a rotary punching device according to the preamble of claim 15.

Rotary punching devices are known in different embodiments ( DE 10 2009 033 576 A1 ; DE 602 02 629 T2 ; DE 10 2015 107 313 A1 ). This die-cutting technique is very widespread in the paper-processing industry for rotary processing of solid and corrugated cardboard, for example for the production of folding boxes, cut envelopes, etc. A rotary die-cutting device usually has a die-cutting cylinder or a die-cutting half-shell with surfaces usually made of a wooden material, on which die-cutting grooves or Cutting knives are arranged, and furthermore a counter-die cylinder, with both components rotating and between them the sheet or web-shaped material to be die-cut, in particular solid cardboard and corrugated cardboard, being fed through. In general, the problem with rotary die-cutting is that die-cut material, in particular die-cut waste, can become jammed between the scoring or cutting blades. This problem can be solved in a known way by ( DE 10 2009 033 576 A1 ) That between cutting blades rotary punching elastomer elements are attached as ejection elements and / or fixing elements on the punching cylinder or a half-shell punching, which have a material thickness, for example, approximately corresponding to the height of the cutting blade. During the rotary stamping process under pressure, the elastomer elements, which are formed by rubber plates, for example, are pressed together. After the pressure is released, the elastomeric material expands to its original thickness and the material to be processed is again raised above the height of the cutting blades, so that in particular a punching waste is ejected.

Such rotary die-cut elastomer elements have different dimensions depending on the die-cutting task and are usually cut out of a flat and often relatively hard elastomer plate, for example a rubber plate. The rotary die elastomeric elements are adhered to the die cylinder or die half-shell by gluing, for example with a liquid adhesive. The rotary die-elastomer elements have to be bent according to the diameter of the die-cutting cylinder or the half-shell of the die-cutting. Such diameters can vary greatly and are usually between 165 and 650 mm, so that there are correspondingly strong bends in the elastomer elements, particularly in the case of small diameters. Therefore, after attachment, due to the spring properties of the elastomeric material, the rotary die elastomeric elements are subject to a relatively large bending stress with a restoring force that tends to return the rotary die elastomeric elements to their planar, flat shape. As a result, there is a risk that the adhesive bond will not hold during the rotary die-cutting process, so that the rotary die-elastomer elements can at least partially detach, in particular from the wooden surfaces of the die-cutting cylinders or the die-cutting half-shells. This means that the punching result is negatively influenced and the punching process may have to be interrupted.

To counter this problem, in the DE 10 2017 008 094 A1 proposed to provide the rotary punching elastomer elements on their underside intended for attachment to a punching cylinder or a punching half-shell and/or on their upper side intended for contact with a material to be punched with a plurality of bending relief grooves, with which the bending stress or the restoring force can be reduced. However, the manufacture of such grooved rotary die elastomeric elements is relatively complicated and expensive.

The object of the invention is therefore to propose a rotary punching elastomer element as an ejection element and/or fixing element which, despite an essentially planar initial shape, can be attached to a punching cylinder or a punching half-shell of a rotary punching device in a process-reliable and curved manner with little effort, in particular by gluing.

This object is achieved with the features of claim 1 with regard to the rotationally stamped elastomer element.

According to claim 1, a rotary punching elastomer element is provided as an ejection element and/or fixing element for attachment to a punching cylinder or a punching half-shell of a rotary punching device, with the rotary punching elastomeric element 10 being provided with an adhesive layer on its contact surface intended for attachment to a punching cylinder or a punching half-shell. According to the invention, it is provided that the adhesive layer is formed by a double-sided adhesive tape that has a carrier layer, a first adhesive layer facing the rotary die-cut elastomer element and arranged on a first carrier layer side, and a first adhesive layer facing away from the rotary die-cut elastomer element and on a second carrier layer side opposite the first carrier layer side arranged designated, second adhesive layer. At least the second adhesive layer facing away from the rotary die-cut elastomer element is formed by a rubber-based adhesive.

Such a second adhesive layer formed by a rubber adhesive has high temperature resistance and also very high adhesive strength, which ensures in a functionally safe and reliable manner that the rotary die-elastomer elements do not detach from the surface of a die cylinder or from a conventional rotary die-cutting process a punching half-shell replaces a rotary punching device. In addition, the rubber also harmonises perfectly with the regularly existing wooden surfaces of the punching cylinders or punching shells.

For almost the same reason, according to a particularly preferred embodiment, the first adhesive layer facing the rotary die-cut elastomer element is also formed by a rubber-based adhesive. Very good adhesion of the adhesive layer to the rotary die-cut elastomer element is also achieved here. Depending on the specific elastomer material used for the rotary die-cut elastomer element, the first adhesive layer may also be formed by an acrylic-based adhesive, for example if the elastomer material of the rotary die-cut elastomer element allows the adhesive to penetrate into the rotary die-cut elastomer element, instead of just wetting it on the outside.

In the context of the present invention, in connection with the term "elastomeric element", an elastomer or an elastomeric material is understood to mean any material (or any substance) that (or the) has elastic properties and thus has the property, after the action of a force to return to its original state or original shape, in particular possessing the property, after a force or pressure relief, from its deformed, for example bent, and/or compressed state, to its original unloaded state, in particular to its original shape and/or or thickness to return. The term elastomer or elastomer material is therefore to be interpreted here in a broad sense and in particular as “having elastic properties”. The specific materials will be discussed in more detail later.

At this point it should also be clarified again that the term “half” in connection with the term “punched half shell” here or in the present technical field does not mean that this punched half shell must necessarily or exactly extend over half the circumference viewed in the circumferential direction , but of course any shell arrangement that extends only over a partial area of the circumference is covered by the term “punched half shell”, i.e. explicitly also those that extend over more or less than half the circumference.

In principle, the rubber base can be formed by natural rubber, which is a renewable, natural raw material, but is preferably a synthetic rubber, which allows production with uniform quality. The use of a synthetic rubber made from butadiene, in particular in the form of polybutadiene copolymers, is particularly preferred here.

As the investigations carried out by the inventors have shown, there is particularly good adhesion of the second adhesive layer of the rotary die-cutting elastomer element to the surface of a die-cutting cylinder or a half-shell die-cutting if the weight per unit area of the adhesive of the second adhesive layer is 15 to 150 g/m ² , preferably 17 to 100 g /m ² , more preferably 25 to 60 g/m ² . This applies analogously to the first adhesion layer.

In principle, more layers than just the first or second adhesive layer can be applied to the different or opposite sides of the carrier layer, with the individual layers also being able to differ in terms of the material. In this case, however, the first adhesive layer and the second adhesive layer always form the outer layers. The additional layers can be used here, for example, to adjust the elastic properties of the rotary die-cast elastomer element. However, a structure that is easy to produce is particularly preferred, in which the first adhesive layer and/or the second adhesive layer is/are connected to the carrier layer immediately and directly and on opposite sides of the carrier layer.

The backing itself can be made of any suitable material, although paper or non-woven fabric are preferred materials for forming a backing and the backing, respectively. In contrast to the regularly used stable carriers made of PP or PET, for example, the use of a paper or fleece carrier creates less tension in the adhesive tape, so that the restoring forces of the elastomer put less strain on the adhesive bond.

Furthermore, the second adhesive layer can also be provided with a removable or removable cover liner.

As the investigations carried out by the inventors have also shown, the double-sided adhesive tapes can have different material thicknesses or strengths, depending on the application. The material thickness of the double-sided adhesive tape made up of at least the first adhesive layer, backing layer and second adhesive layer is therefore particularly preferably 0.05 to 0.5 mm, preferably 0.08 to 0.3 mm, most preferably 0.1 to 0.2 mm.

The elastomeric material of the rotary die elastomeric element has a Shore A hardness of 5 to 90, preferably a Shore A hardness of 10 to 60, for an excellent fixing and ejection function.

The rotary die-cut elastomer element can in principle be made up of two or more layers in the manner of a sandwich and/or of different elastomer materials, although a material-uniform and/or one-piece design of the rotary die-cut elastomer element is the preferred design.

In principle, the rotary die-cut elastomer element can have different shapes. Particularly preferably, however, the rotary die-cut elastomer element is in the form of a rotary die-cut elastomer plate or a rotary die-cut elastomer strip.

The rotary die-elastomer elements according to the invention are preferably arranged between scoring or cutting knives, for example for ejecting punch waste or as “transport rubber” for sheet transport through the die-cutting station. In this case, the element thickness can correspond approximately to the height of the creasing or cutting blade, or the element thickness is greater or smaller than the height of the creasing or cutting blade.

Furthermore, a rotary die-cut elastomer element according to the invention of specific dimensions can be cut from a flat elastomer plate. Such a cut can be made, for example, mechanically, for example by means of a plotter blade or a plotter blade of a cutting plotter, or alternatively by means of water jet cutting or laser beam cutting, to name just a few examples. Alternatively, a rotationally stamped elastomeric element of specific dimensions can also be produced by cutting to length from an elastomeric strip material.

As already mentioned, in the context of the present invention, an elastomer or an elastomeric material of the rotary-die elastomeric element is understood to mean any material that has elastic properties and has the property of returning to its original state or shape after the action of a force , that is, in particular, has the property of returning from its deformed, for example bent, and/or compressed state to its original unloaded state, in particular to its original shape and/or thickness, after a force or pressure relief. The term elastomer or elastomer material is therefore to be interpreted here in a broad sense and in particular as “having elastic properties” and includes not only elastomers in the classic sense, but any material having elastic properties. As the investigations carried out by the inventors have shown, particularly good adhesion results can be achieved for the rotary die-cast elastomer element if polyurethane is used as the material for the elastomer element, in particular aromatic polyurethanes which are preferably based on aromatic isocyanates and polyether polyols. Aromatic polyurethanes are cheaper than aliphatic polyurethanes, which are basically more UV-resistant and color-stable, but this is irrelevant for the use shown here. However, if better UV resistance and color stability are desired, aliphatic polyurethanes can of course also be used as the elastomer material. Good results have also been achieved with ethylene vinyl acetate copolymers (EVA). Both the solid material and the foamed version of the materials are suitable for the production of an elastomer element according to the invention.

Furthermore, according to the invention, a rotary punching device is claimed with a punching cylinder or a punching half-shell, on which at least one rotary punching elastomer element according to the above embodiments is attached. Here, too, the advantages achieved are again identical to the advantages mentioned above.

The invention is further explained by way of example with reference to a drawing.

• 1 eine schematische Darstellung einer Rotationsstanzvorrichtung, und
• 2 eine schematische Seitenansicht auf eine beispielhafte Ausführungsform eines erfindungsgemäßen Rotationsstanz-Elastomerelementes.

Show it:

• 1 a schematic representation of a rotary punching device, and
• 2 a schematic side view of an exemplary embodiment of a rotary die-elastomeric element according to the invention.

In 1 is a highly schematic representation of a rotary punching device 1 in a side view, with which a material to be punched, here merely as an example, for example, a sheet or web-shaped corrugated cardboard 2, is processed.

For this purpose, the rotary die-cutting device 1 has in the upper area a die-cutting cylinder 3 with a rotation axis 17 and with a die-cutting half-shell 4 as a tool, as well as a counter-die-cutting cylinder 5 below it. The corrugated cardboard 2 is moved between the die-cutting cylinder 3 and the counter-cutting cylinder 5 (arrows 6a, 6b, 6c ).

A processing operation is explained as an example using a punched opening 7 in the corrugated board 2 that has already been punched. With the aid of creasing or cutting knives 8, 9 delimiting the punching opening 7, the punching opening 7 was punched out as the corrugated cardboard 2 passed. Between the creasing or cutting blades 8, 9 is a rotary die-elastomer element 10 applied to the die half-shell 4, for example glued, for example in the form of a rotary die-elastomer plate or in the form of a rotary die-elastomer strip, as an ejection element. The rotary die-elastomer element 10 here has a thickness approximately corresponding to the height of the scoring or cutting knives 8, 9 (that means it can also have a greater or lesser height than the scoring or cutting knives 8, 9) and is merely an example pressed together during the punching process and thus builds up a restoring force.

In 1 the state is shown in which the rotary punch elastomer element 10 formed, for example, by a rotary punch elastomer plate or, for example, by a rotary punch elastomer strip, is again in its unloaded initial state with its original thickness and, due to its restoring force, the punch waste 11 between the creasing or cutting knives 8, 9 has ejected according to the punched opening 7.

In the 2 1 is now a schematic side view of an exemplary embodiment of a rotary punching elastomer element 10 according to the invention, as it is used as an ejection element and/or fixing element in the rotary punching device 1.

Specifically, the rotary die-cutting elastomer element 10 is provided with an adhesive layer on its contact surface 12 intended for attachment to a punching cylinder 3 or a punching half-shell 4, which is formed here according to the invention by a double-sided adhesive tape 13, which has a carrier layer 14, one facing the rotary-die-cutting elastomer element 10 and a first adhesive layer 16 arranged on a first carrier layer side 15 and a second adhesive layer 19 facing away from the rotary die-cut elastomer element 10 and arranged on a second carrier layer side 18 opposite the first carrier layer side 15 .

In the preferred exemplary embodiment shown here, both the second adhesive layer 19 facing away from the rotary die-cut elastomer element 10 and the first adhesive layer 16 facing the rotary die-cut elastomer element 10 are formed by a rubber-based adhesive, for example natural rubber or preferably a synthetic one Rubber is formed.

The weight per unit area (dry weight) of the adhesive of the first adhesive layer and the second adhesive layer is here 15 to 150 g/m ² , preferably 17 to 100 g/m ² , particularly preferably 25 to 60 g/m ² .

How from the 2 As can clearly be seen, in the exemplary embodiment shown, both the first adhesive layer 16 and the second adhesive layer 19 are connected directly and directly to the carrier layer 14 on opposite sides of the carrier layer. The backing layer 14 can be formed here, for example, by a backing made of paper or fleece.

In addition, the exemplary embodiment shown here also provides for the second adhesive layer 19 to be covered or provided with a removable cover liner 20, which can be formed, for example, from a film or paper.

The material thickness of the double-sided adhesive tape 13 made up of the first adhesive layer 16, carrier layer 14 and second adhesive layer 19 is, for example, 0.1 to 0.2 mm.

Furthermore, the elastomeric material of the rotary die-casting elastomeric element 10 can have a Shore A hardness of 5 to 90, preferably a Shore A hardness of 10 to 60.

Here, the rotary die-cut elastomer element 10 is preferably made of polyurethane, optionally also of ethylene-vinyl acetate copolymers (EVA), the polyurethane preferably being an aromatic polyurethane.

Reference List

1

rotary die cutter

2

corrugated cardboard

3

punch cylinder

4

punching half shell

5

anvil cylinder

6a

Arrow

6b

Arrow

6c

Arrow

7

punch opening

8th

Creasing or cutting knives

9

Creasing or cutting knives

10

Rotary Die Cut Elastomeric Element

11

punch waste

12

contact surface

13

double-sided tape

14

backing layer

15

first backing layer side

16

first adhesive layer

17

axis of rotation

18

second backing layer side

19

second adhesive layer

20

cover liner

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102009033576 A1 [0002]
• DE 60202629 T2 [0002]
• DE 102015107313 A1 [0002]
• DE 102017008094 A1 [0004]

Claims (15)

Rotary punching elastomer element (10) as an ejection element and/or fixing element for attachment to a punching cylinder (3) or a punching half-shell (4) of a rotary punching device (1), the rotary punching elastomeric element (10) at its end for attachment to a punching cylinder (3) or a bearing surface intended for a punching half-shell (4) is provided with an adhesive layer, characterized in that the adhesive layer is formed by a double-sided adhesive tape (13), that a carrier layer (14), one facing the rotary punching elastomer element (10) and on a first carrier layer side (15) and a second adhesive layer (19) arranged on a second carrier layer side (18) opposite the first carrier layer side (15) and facing away from the rotary die-cut elastomer element (10), and that at least the the rotary die-elastomer element (10), facing away from the second adhesive layer (19) with an adhesive on K rubber base is formed. Rotary Stamping Elastomeric Element claim 1 , characterized in that the first adhesive layer (16) facing the rotary die-cut elastomer element (10) is formed by a rubber-based adhesive. Rotary Stamping Elastomeric Element claim 1 or 2 , characterized in that the rubber base is formed by natural rubber or by synthetic rubber. Rotary Stamping Elastomeric Element claim 1 , characterized in that the first adhesive layer (16) facing the rotary die-cut elastomer element (10) is formed by an acrylic-based adhesive. Rotary die-elastomer element according to one of the preceding claims, characterized in that the weight per unit area of the adhesive of the first adhesive layer (16) and/or the second adhesive layer (19) is 15 to 150 g/m ² , preferably 17 to 100 g/m ² 25 to 60 g/m ² . Rotary die-elastomer element according to one of the preceding claims, characterized in that the first adhesive layer (16) and/or the second adhesive layer (19) is connected to the carrier layer (14) immediately and directly and on opposite sides (15, 18) of the carrier layer. are. Rotary punching elastomer element according to one of the preceding claims, characterized in that the carrier layer (14) is formed by a paper or fleece carrier. Rotary die-cutting elastomeric element according to one of the preceding claims, characterized in that the second adhesive layer (19) is provided with a removable cover liner (20). Rotary punching elastomer element according to one of the preceding claims, characterized in that the material thickness of the double-sided adhesive tape (13) made up of at least the first adhesive layer (16), carrier layer (14) and second adhesive layer (19) is preferably 0.05 to 0.5 mm 0.08 to 0.3 mm, most preferably 0.1 to 0.2 mm. Rotary punch elastomer element according to one of the preceding claims, characterized in that the elastomer material of the rotary punch elastomer element (10) has a Shore A hardness of 5 to 90, preferably a Shore A hardness of 10 to 60. A rotary die-cut elastomeric element as claimed in any one of the preceding claims, characterized in that the rotary-pressed elastomeric element (10) is formed by a rotary-cut elastomeric plate or a rotary-cut elastomeric strip. A rotary die-cut elastomeric element according to any one of the preceding claims, characterized in that the rotary-cut elastomeric element (10) is made of polyurethane or ethylene vinyl acetate copolymers (EVA). Rotary Stamping Elastomeric Element claim 12 , characterized in that the rotary die-cast elastomer element (10) is foamed. Rotary Stamping Elastomeric Element claim 12 or 13 , characterized in that the rotary die-cut elastomeric element (19) is an aromatic polyurethane. Rotary punching device (1) with a punching cylinder (3) or a punching half-shell (4) on which at least one rotary punching elastomer element (10) according to one of the preceding claims is attached.

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