BE1030601B1 - Method for machining a surface of a pressing tool, and device for machining a surface of a pressing tool - Google Patents

Abstract

A method is shown for processing a surface (2) of a pressing tool (1), in particular a press plate, in which the application of a mask (5) takes place in at least two application processes, wherein in a first application process a first mask layer (6) is applied by a first print head (51) and in a second application process a second mask layer (7) is applied by a second print head (52), and wherein the first application process and the second application process differ from one another in at least one process parameter and/or wherein the material of the first mask layer (6) and the material of the second mask layer (7) differ from one another in at least one material property, and wherein the first print head (51) and the second print head (52) for applying the mask (5) are each positioned along two directions, in particular directions normal to one another, above a support (50) for the pressing tool (1). In addition, a device (100) for machining a surface (2) of a pressing tool (1) is shown.

Description

Method for machining a surface of a pressing tool, and device for machining a surface of a pressing tool

[0001] The present invention relates to a method for machining a surface of a pressing tool, in particular a press plate, in which in at least two application processes on the surface of the

A mask is applied to the pressing tool to create a surface structure on the pressing tool.

[0002] Furthermore, the present invention relates to a device for machining a surface of a pressing tool.

State of the art

[0003] Material boards, for example wood-based panels, are required for the furniture industry and for interior design, for example for laminate flooring. The material boards have a core made of MDF (medium density fiberboard) or HDF (high density fiberboard), on which

Different material layers are placed on the core on at least one side, for example an (optical) decorative layer and a protective layer (overlay layer).

[0004] In order to avoid distortion in the material panels produced, such material panels are generally provided with the same number of material layers on both sides; in order to connect the individual layers of the material panels (core, material layers, etc.) to one another, these are pressed together in a press using special pressing tools, in particular press plates or endless belts. The surface of the material panels is also embossed in the process. Hot presses are usually used to connect the various material layers made of thermosetting resins, for example melamine resin, to the surface of the core under the influence of heat by fusing the plastic materials.

[0005] The decorative layers determine the pattern and color design of the material panels; a desired surface structure, however, can be achieved by using suitable pressing tools. For example, a wood or tile decor can be printed on the decorative layer (decorative paper), or decorative layers with patterns and color designs are used that are artistically designed according to the respective intended use. Overlay layers that are printed on the top or bottom side can also be used.

[0006] To improve a lifelike reproduction, especially in the case of material panels with wood, tile or natural stone decor, the pressing tools are provided with a surface structure that is designed to conform to the decorative layer and forms a negative image of the desired surface structure. Therefore, the

Press tools create a 3D profile (depth structuring) which is, for example, modelled on the wood veins of a wooden surface in order to give the decorative layer of the material board the appearance of such a

wooden surface.

[0007] To further improve a lifelike reproduction, especially of wood, tile or natural stone surfaces, pressing tools are used which also have certain degrees of gloss.

By setting a certain degree of gloss in a selected surface area of the pressing tool, it is possible to create reflections or shades in the material plate, which for example give the viewer the impression of a natural wood, tile or natural stone surface of other materials.

[0008] To achieve the conformal embossing of the material plates — i.e. the required accuracy of fit of decorative layer(s) and

Surface structure of the material plate — is used for the production of

Press tools require a high quality standard. In particular, the press plates or endless belts are used as upper and lower tools in short-cycle presses, which are covered with press plates, or in double-belt presses with endless belts, whereby the embossing and heating of the material plates takes place at the same time, so that the

Duroplast resins of the decorative and/or overlay layers of the material plates are first melted, the surface structure corresponding to the surface structuring of the pressing tools is introduced into the external material layers, and the structured material layers are connected to the core of the material plate by subsequent hardening.

[0009] To achieve the desired surface structuring in or on the

To produce press tools, for example, digitized image data of a

A decorative template can be used to apply an etching resist for structuring the press plates or endless belts. For this purpose, an etching resist is applied to the press plates or endless belts, for example using a digital printer, in order to then carry out an etching process. After removing the etching resist, further processing of the press tool can be carried out, whereby several etching processes can be carried out in succession, preferably for surface structuring with particularly deep/high structures. For this purpose, an etching resist is again applied to the already etched press plate or endless belt and a new etching is carried out until the desired

In addition, the individual etching processes can be used to create a coarse or fine structuring of the surface structure, depending on which surface structure the material plate is to be given.

[0010] Alternatively or in addition to the described etching processes or other material-removing processing processes, material-applying processes can also be used to produce the surface structure (layer by layer) on the surface of the pressing tools. In most of these processes, masks (masking) are used to protect the surface of the pressing tool from subsequent material application or removal.

By repeatedly applying appropriate masks and then applying or removing material, surface structures of various designs can be created.

[0011] Regardless of the method chosen, the

Press tool finally a surface structuring that the

Negative of the surface structure to be embossed into the material plate. In this case, elevations in the surface structuring correspond to the depressions to be embossed in the surface structure of the material plate, or depressions in the surface structuring correspond to the elevations that the surface structure of the material plate should have.

[0012] In particular, where material panels are to be produced which are to be used, for example, as floor or wall panels or in furniture production, large-format

Press tools are used which have at least one edge length of more than one meter. Furthermore, the press tools can also be used for

Pressing of plastic films, release films, PVC surfaces or LVT (Luxury Vinyl Tiles), whereby the size of the pressing tools is adapted to the end products. It is also possible to use the pressing tools to press check cards, passports, credit cards or

Plastic cards are pressed, whereby in this case the security-relevant features are usually important. If the security-relevant features are applied to the decorative layers, a

Pressing is usually done with a smooth or slightly structured

Press tool. Alternatively, it is also possible to emboss safety-relevant features into the surface of the decorative layer using the press tools.

[0013] EP 2 848 424 B1, for example, discloses such a material-applying process for producing the surface structuring on the

Surface of the pressing tool is known, in which a mask is applied to the surface of a pressing tool in order to cover partial areas of the surface. After the mask has been applied, a metal layer is applied to the uncovered areas of the surface, so that a surface structure consisting of elevations is created on the surface of the pressing tool. After the metal layer has been applied, the mask can be removed and/or another mask can be applied and another metal layer can be applied, so that the surface structure is built up layer by layer.

[0014] US 2010 / 0 260 969 A1 discloses a method for producing a

Press plate for applying a surface structure to a floor panel is known, wherein the press plate has a press plate surface, and the method comprises the following steps: First, fine projections are created on the press plate surface, then the resulting fine projections are covered with a surface treatment-resistant material, and then the press plate surface including the resistant material is subjected to a surface treatment.

[0015] However, such methods all suffer from the disadvantage that the application of the mask over larger areas of the surface of the

Press tool is very complex, especially if fine surface structures with high resolution are to be applied over a large area of the surface. Especially if surface structures of different sizes are to be created at the same time, the above-mentioned processes are limited in their efficiency and sometimes require very long production times, since the resolution of the printing processes or the application processes is based on the smallest to be produced.

Surface structuring, which in turn results in low efficiency and high production costs.

Description of the invention

[0016] The present invention therefore has the task of

Efficiency and economic viability of a process of the type mentioned above

Art to improve.

[0017] According to the invention, the stated object is achieved in that the application of the mask takes place in at least two application processes, wherein in a first application process a first mask layer is applied by a first print head and in a second application process a second mask layer is applied by a second print head, and wherein the first application process and the second

Application process differ from each other in at least one process parameter and/or wherein the material of the first mask layer and the material of the second mask layer differ in at least one

material properties, and the first

Print head and the second print head for applying the mask, each along two, in particular mutually normal, directions over a

Support for the pressing tool can be positioned.

[0018] If the mask is applied in at least two application processes, and a first mask layer is applied in a first application process and a second mask layer is applied in a second application process, the application process can be made more flexible in the method according to the invention. The mask on the

The surface of the pressing tool is composed of the mask layers applied in the first and second application processes.

[0019] This is particularly advantageous when coarse structures are applied in the first application process by the first mask layer and in the second application process by the second

Fine structures are applied to the mask layer, whereby the fine structures complement the coarse structures. The areas in which the first and second mask layers are applied can in particular overlap, so that the mask layers applied one after the other combine to form the mask.

[0020] In addition to the division of the application of the mask into coarse and

Fine structures, according to the invention, any other subdivision of the

Mask according to the type of structures in a first and second application process can be advantageous. In particular, if the mask has structures that require a special or particular application process that is not compatible with the application of other structures, the method according to the invention can be characterized by its high flexibility.

[0021] In the same way, optionally in addition to the first and second

Mask layer, further mask layers can be applied in further application processes, so that the mask consists of more than two

mask layers.

[0022] Due to the more flexible application process of the mask, the first application process and the second

Application process differ from each other in at least one process parameter. By using different process parameters, the type of application in the first application process can differ from that of the second application process, or the first mask layer can be applied in a different way than the second mask layer. For example, it is possible for the first application process to be carried out at a different speed or

accuracy than the second application process, making the entire mask application more efficient and economical.

[0023] Additionally or alternatively, the material of the first mask layer and the material of the second mask layer can differ from each other in at least one material property. This makes it possible to obtain a mask which is composed of different materials and can thus more flexibly cover a desired area of the surface of the pressing tool by selecting the appropriate material.

Connection of the different materials can be covered. For example, the choice of material can result in a different accuracy or resolution between the first and second mask layers (for example, coarse pre-printing through the first mask layer and fine overprinting through the second mask layer), which allows for a more efficient application of the entire mask to the surface of the

pressing tool and can thus increase the economic efficiency of the process.

[0024] A surface structuring within the scope of the invention can consist of coarse structures (coarse structures) and/or fine structures (fine

Structures), whereby the distinction between coarse and fine structures is made on the basis of the characteristic size of the respective structures. The characteristic size (width) of the

The size of the coarse structures is at least one, preferably at least two, orders of magnitude larger than the characteristic size (width) of the fine structures. The coarse structures can be a macroscopic corrugation of the surface of the pressing tool or larger, connected or flat structures.

Fine structures, on the other hand, can be fine lines, such as those characteristic of wood fibers or wood veins or wood nerves.

[0025] In general, it is mentioned that a rough pre-print is understood to mean the application of a part of the mask which is limited to the rough structures of the mask. In this case, only those

Structures are applied for which high resolution is not required during application, such as closed surfaces/volumes with smooth, unstructured or weakly structured contours. The

The method of applying the pre-printed form is not limited to printing processes, but can be any method of applying a mask layer.

[0026] In general, it is further mentioned that fine overprinting is understood to mean the application of a part of the mask which is limited to the fine structures of the mask which were not applied or omitted by the coarse pre-printing. The fine overprinting can be applied to the contours or edges of the coarse pre-printing and/or on the coarse pre-printing itself, but can also be applied completely independently of the coarse pre-printing, i.e. in areas where there is no coarse pre-printing.

[0027] According to the invention, the at least one different process parameter is, for example, a droplet size, a speed or a mass throughput when applying the material of the first and/or the second mask layer.

[0028] If the first and second mask layers are applied in the first and second application process using different droplet sizes, then, for example, in the first application process, a first mask layer can be applied using larger

Drops can be applied to prefabricate a coarse portion of the surface structuring, while in the second application process a second mask layer can be applied using smaller drops to ensure the high resolution of the fine portions of the surface structuring. The first application process can then be carried out more quickly and efficiently and does not have to achieve the same resolution as the second application process. Production costs can thus be reduced and the economic efficiency of the process increased.

[0029] If the first and second mask layers are applied at different speeds in the first and second application processes, the efficiency of the

The first application process can be carried out more quickly and thus, for example, more

Volume or mass of masking material on the surface of the

pressing tool or apply the masking material to the surface of the pressing tool with less precision.

[0030] By applying the first and second mask layers under

Application of different process parameters can thus

Efficiency of the process can be further increased, whereby the cost efficiency and economic viability of the process according to the invention can be increased.

[0031] According to an embodiment of the invention, the at least one different material property of the material of the first

mask layer and/or the material of the second mask layer

Viscosity, expansion capacity or grain size.

[0032] If the materials of the first and second mask layers have a different viscosity, for example, the application amount or application speed of the masking material can be controlled in the first and/or second application process. A higher

For example, viscosity can enable a higher deposition speed with a higher mass throughput, but can also affect the resolution or accuracy when applying the first and/or second mask layer.

[0033] If the materials of the first and second mask layers have different expansion capacities, mask layers with different volumes can be produced in a simple and efficient manner, for example with a constant mass throughput and/or a constant application speed. For example, the first mask layer can be applied in the first application process as a rough pre-print with an expanding masking material, whereby large areas of the surface of the pressing tool can be filled quickly and efficiently with the expanding material. In the second application process, a material that does not expand or only expands slightly can then be applied as a second mask layer, thus forming the fine structures in addition to the rough pre-print of the first

This fine overprint can then be carried out particularly quickly and efficiently, since only the fine structures with high

resolution, but no longer need to fill large areas.

[0034] If the materials of the first and second mask layers have a different grain size, the amount or volume of the mask layer applied in the first and/or second application process can also be controlled in a simple manner. The use of a masking material with a large grain size can, for example, enable the application of a coarse mask layer with low resolution and high volume in a short time, so that a quick and efficient coarse pre-print can be carried out. By using a masking material with a smaller grain size in a further application process, a fine overprint can be applied in a simple manner in addition to the coarse pre-print to form the fine structures with high resolution.

[0035] According to the invention, this enables an efficient, rapid and cost-effective application of the mask to the surface of the pressing tool.

[0036] According to an embodiment of the invention, the mask can be applied using image data to which the structures of the surface of the pressing tool are assigned. The image data can, for example, contain a wooden surface to be reproduced, which is then linked to the structures of the surface of the pressing tool or to the structures of the mask for generating the surface of the pressing tool. A method for simple and efficient

Production of a pressing tool for replicating wooden surfaces can be created in this way.

[0037] According to a further embodiment, the image data or the structures of the surface associated with the image data can be used to

Mask can be divided into at least the first and the second mask layer, wherein the first mask layer has the coarse structures and the second mask layer has the fine structures.

[0038] According to an embodiment of the invention, the first

Application process and the second application process can be carried out at least partially in parallel. For example, the second application process can begin as soon as the first application process has begun. The application of the second mask layer can always follow or follow the application of the first mask layer. Alternatively or additionally, the areas in which the first and second mask layers are applied can also not overlap and can be located at different points/sides of the pressing tool, so that application processes can be carried out at several points on the pressing tool at the same time. The parallel application of the first and second mask layers can always be carried out in such a way that the application processes do not hinder one another. In this way, a high level of parallelism and efficiency can be achieved when applying the mask, resulting in a particularly efficient and economical process.

[0039] According to an embodiment of the invention, the first

The application process is carried out by spraying on the first mask layer. By spraying on the masking material, a particularly high material throughput can be achieved at high speed, whereby the first mask layer can be applied in a short time.

However, by spraying the masking material, only a low resolution or accuracy in the mask layer can be achieved, which makes this application method particularly suitable if a coarse structure is to be applied as the first mask layer in the first application process.

[0040] According to an embodiment of the invention, the first

Application process and/or the second application process by

Printing the first mask layer or the second mask layer. A digital printing technique can preferably be used to apply the first and/or second mask layer, whereby the respective mask layer can be applied in particular using a print head which can be positioned over a support in two directions. Printing the first and/or second mask layer enables a very flexible and cost-effective

Process because a wide variety of different motifs and structures can be used without additional investment in applying the masks.

[0041] According to a further embodiment of the invention, the mask can be in the first partial area by means of a, in particular digital,

printing process, the first application process being a first printing process and the second application process being a second printing process. The mask can advantageously be produced entirely by printing processes on the surface, which enables a particularly flexible and versatile process.

[0042] In particular, the application of the mask can be divided into several

Printing processes can be divided into two printing processes, whereby the first mask layer can be printed in the first printing process and the second mask layer in the second printing process. By dividing the application of the mask into several printing processes, the different requirements with regard to print quality, resolution or speed of the respective mask layer can be met particularly easily and reliably. For example, if a mask with both fine structures and coarse or large-area structures is to be applied to the surface, it can be advantageous to carry out a first printing process with less precision to apply the coarse structures and a second printing process with greater precision to apply the fine structures. The first printing process can be carried out quickly or at high speed, while the second

Printing can be done slowly or at low speed.

In this way, a large amount of

Material can be printed to form the first mask layer, for example to fill large, flat structures quickly with low accuracy. In the second printing process, over the first

The fine structures can be printed on the first mask layer or in addition to the first mask layer, so that the inaccuracies in the printing of the first mask layer are compensated by the second mask layer. An efficient method for applying a mask that contains fine structures and coarse structures in different sizes can thus be provided.

[0043] According to an embodiment of the invention, the first

The first application process and/or the second application process are carried out parallel to a preferred direction of the surface structure to be created. The preferred direction can be along the main direction or

The direction of spread of depressions (valleys) or elevations (mountains) of the coarse structure can be selected. By applying or

Printing the first and/or second mask layer parallel to the preferred direction can produce a particularly clean print image with reduced

error tendency can be achieved, since the application of the mask layer in the

Essentially along the contour of the surface structuring.

For certain structural forms, the application in a

Direction normal to the preferred direction in a jagged or unclean

print image result.

[0044] After applying the mask, the surface in at least the second partial area is provided with a metal layer in order to

to create surface structuring on the pressing tool. According to a further embodiment of the invention, the metal layer can be a chrome, copper or nickel layer. The provision of the

The surface can be coated with the metal layer galvanically, chemically or mechanically, for example in a chrome plating bath to apply a chrome layer, thus providing the surface with the metal layer in those places which are not covered by the mask.

[0045] According to a variant, the surface of the

The pressing tool must be pretreated before the mask is applied in order to increase the adhesion between the surface and the metal layer. Such a pretreatment can be, for example, a galvanic, chemical or mechanical treatment. The pretreatment can, for example, roughen the surface of the pressing tool in order to improve the adhesion to the subsequent layers.

[0046] According to an embodiment of the invention, after the

Applying the metal layer, the mask is removed from the surface. The mask in the first area of the surface can only serve to prevent the surface from being provided with the metal layer in the first area of the surface. This is particularly the case if the surface is provided with the metal layer galvanically, since in this process all exposed conductive areas of the

Surface is coated with the metal layer. Removing the

The mask can be removed chemically, for example by dissolving the mask, or mechanically, for example by polishing, grinding, etc. After the mask is removed, a surface structure corresponding to a negative of the mask is formed by the partial metal layer.

[0047] According to an embodiment of the invention, the material (masking material) of the first and/or second mask layer can be

The mask can be a lacquer, for example a UV lacquer, a resin, a plastic or the like, which can be removed from the surface of the pressing tool at a later point in time, particularly without leaving any residue. After the surface has been covered with the metal layer, the mask can then be removed again using a simple process - as described above.

[0048] In an alternative embodiment, the mask can remain on the surface after the surface has been provided with the metal layer.

[0049] In a further embodiment, the surface can be provided with a second metal layer after the metal layer has been applied. The second metal layer can, for example, cover the entire

Cover the surface, including the surface structure formed by the first metal layer. The second metal layer can also be a chrome, copper or nickel layer and can be applied galvanically, chemically or mechanically.

[0050] According to a further embodiment, the surface can be mechanically treated after the application of the metal layer, for example by

Polishing, using laser radiation, etc. and/or chemically, for example by etching. By subsequently processing the surface, the gloss level of the metal layer can preferably be adjusted so that areas of the surface structure or the surface with different gloss levels are created.

[0051] According to a further embodiment, the method according to the invention can be repeated after the above-mentioned steps.

A mask can be applied again to the (optionally processed) applied metal layer and then again covered with a

In this way, a layered construction of the surface structure is created, whereby, according to one design variant, the layers of the metal layer are stacked on top of each other in a pyramid shape.

[0052] The present invention also has the object of providing a device for machining a surface of a pressing tool, in particular a press plate, which enables machining of the surface to produce a surface structuring with high

Efficiency and speed possible.

[0053] The invention solves the problem by a device having a support for the pressing tool and at least a first print head and a second print head, wherein the first and second

Print head along two, particularly mutually normal,

directions above the support, and the first

Print head is designed to apply a first mask layer to the pressing tool and the second print head is designed to apply a second mask layer to the pressing tool, wherein the first and second print heads are also designed to apply the first and second

Apply a mask layer using different process parameters and/or using materials that differ from each other in at least one material property.

[0054] If the device has at least a first print head and a second print head, wherein the first and second print heads can each be positioned along two directions, in particular directions normal to each other, above the support, a high degree of flexibility in the application of the

Mask layers are achieved through the two print heads.

[0055] If the first print head is also designed to apply a first mask layer to the pressing tool and the second

Print head for applying a second mask layer to the press tool, a dedicated print head can be used for the

Application of a mask layer can be selected, which on the one hand enables parallel application of the mask layers and on the other hand enables special adjustment of the print heads to the respective material of the mask layer.

[0056] Finally, if the first and second print heads are designed according to the invention to apply the first and second mask layers using different process parameters, the flexibility in the application of the mask layers can be further increased.

[0057] According to one embodiment, the first print head and the second print head can be moved at different speeds over the support. For example, the first print head can be designed to be moved at a higher speed over the support than the second print head. Likewise, according to another embodiment, it is conceivable that the first print head is designed to deliver a higher mass throughput to the surface than the second print head. Also, according to another embodiment, it is conceivable that the first print head is designed to generate larger droplets when applied to the surface than the second print head.

[0058] Alternatively or additionally, the first and second print heads are designed according to the invention to print the first and second mask layers under

Using materials that differ from each other in at least one material property can also further increase the flexibility in applying the mask layers.

[0059] According to a further embodiment, the first

Print head and the second print head independently and/or simultaneously above the support for applying the first or second

The efficiency of the device in the mask layer can be

Processing can be further increased because it enables parallel application of the mask layers, whereby the application of the first mask layer can take place independently of the application of the second mask layer.

[0060] According to a variant embodiment, the device may comprise a

Controller connected to the first and second print heads and programmed to control the first and second print heads based on image data with associated height data.

[0061] According to a further embodiment variant, the controller can be programmed to break down the image data into first and second partial image data, each with associated height data, and to control the first print head based on the first partial image data to apply the first mask layer and to control the second print head based on the second partial image data to apply the second mask layer.

[0062] According to an embodiment of the invention, a first

A positioning device may be provided for positioning the first print head along a first direction above the support, a second positioning device may be provided for positioning the second print head along the first direction above the support, and a third positioning device may be provided for positioning the first and second positioning devices along a second direction above the support.

For example, the first direction can be an x-direction and the second

The first and second positioning devices are provided for positioning the first and second print heads in the x-direction, while the third positioning device serves to position the first and second positioning devices along the y-direction. A compact design of the device can be created in this way, since a separate positioning device along the y-direction is not required.

direction can be dispensed with. The shared use of the third positioning device for positioning the first and second print heads, however, leads to a limitation in that the application processes of the first and second print heads must be carried out sequentially one after the other.

[0063] The controller can be further programmed such that the second print head is sequentially positioned behind the first print head when applying the second mask layer during application of the first mask layer in such a way that the movement profiles of the first and second print heads do not overlap.

[0064] The controller can be further programmed to determine movement profiles of the first and/or second print head for applying the first or second mask layer from the image data with associated

to calculate elevation data.

Short description of the characters

[0065] The invention is described below using the embodiments shown in the figures as examples. The following

The following statements are therefore exemplary and are intended to illustrate the inventive concept, but in no way restrict it or even represent it conclusively. They show:

Fig. 1 is a schematic representation of a press plate with a surface structure in an axonometric view;

Fig. 2 is a schematic representation of the press plate from Fig. 1 in a

sectional view;

Fig. 3 is a schematic representation of the press plate during the process according to the invention in a sectional view, and

Fig. 4 is a schematic representation of the device according to the invention.

Ways to implement the invention

[0066] Fig. 1 shows a pressing tool 1 designed as a press plate with a surface 2. If the pressing tool 1 is used as intended for

Production or pressing of workpieces, a surface structuring 10 (Fig. 2) arranged on the surface 2 serves to give a workpiece, in particular a material plate, a certain surface structure in order to provide a viewer of the

workpiece, for example, to enhance or create the impression of a natural wood, tile or natural stone surface.

The purpose is the surface structuring 10 of the pressing tool 1 according to a specific template, for example according to a natural

Wood surface, selected. In the course of the manufacturing process of the pressing tool 1 or the processing of its surface 2, the surface structuring 10 must therefore be in or on the surface 2 of the

Press tool 1 can be inserted or applied so that by molding the surface structuring 10 into the workpiece the template-accurate

Surface structure is created.

[0067] Fig. 2 shows a schematic detailed view of the pressing tool 1 in a highly simplified sectional view, wherein the surface structuring 10 is formed from several individual layers 15, which

Individual layers 15 are applied to a core 14 of the pressing tool 1 by means of a material application process. Overall, this results in several structures, each of which has at least one elevation 4 and at least one depression 3 that is deeper in relation to the elevation 4. In other words, the elevation 4 of a structure is further away from the core 14 of the pressing tool 1 than the depression 3 of the structure. These structures of the surface structuring 10 represent, in a sense, the negative of those forms of the surface structure that are to be created in the workpieces to be processed with the pressing tool 1. The entire surface structuring 10 can additionally be coated with a cover layer 19, as shown in Fig. 2.

[0068] The individual layers 15 are metal layers, preferably

Chrome, nickel or copper layers. The top layer 19 is preferably a full-surface chrome layer, which can subsequently be processed mechanically, chemically or galvanically in order to achieve different degrees of gloss.

[0069] As can be seen from Fig. 1 and Fig. 2, the surface structuring 10 has coarse structures 16 and fine structures 17, wherein the coarse structures 16 and fine structures 17 are distinguished by a characteristic

Size of their structures differ from each other. In the embodiment shown in Fig. 1, the flat structures extended along a preferred direction 18 (which represent, for example, a wood grain) represent the coarse structures 16 and the fine lines (which represent, for example,

wood fibers or tracheae) represent fine structures 17. This

The image is reflected in Fig. 2, where the central coarse structure 16 can be assigned to the end of a flat wood grain from Fig. 1, while the fine structures 17 can be assigned to cross sections of wood fibers.

[0070] For the layer structure of the pressing tool 1, firstly - as shown in Fig. 3 - a mask 5 is applied, which partially covers the pressing tool 1. The mask 5 completely covers a first partial area 8 of the surface 2 with a first mask layer 6, while in a second partial area 9 by a second mask layer 7

Areas of the surface remain free of the mask 5. The second partial area 9, which is not completely covered with the mask 5, is then provided with a metal layer 15 as a single layer 15, and the mask 5 is then removed from the first partial area 8 if necessary. After the removal of the mask 5, the first partial area 8 of the surface is thus free of mask 5 and forms a gap in the applied metal layer 15. The step is then repeated by applying a mask 5 again and providing the pressing tool with another metal layer 15. This results in the pyramid-shaped

Layer structure of the elevations 4 of the surface structuring 10 shown in Fig. 2.

[0071] From the differences in the characteristic size between

Coarse structures 16 and fine structures 17 of the surface structuring 10, challenges arise in the production of the surface structuring 10. If both coarse structures 16 and fine structures 17 are to be created on the surface 2 by applying a mask 5, the mask 5 must, on the one hand, partially have large

Cover surfaces without any structure and on the other hand fine

Structures with high resolution. These two requirements regarding the application of mask 5 (a lot of material / large area and high resolution of the structures) lead to the application of the

The mask as a whole must be made with high resolution and therefore takes a very long time due to the large amount of material that has to be applied.

[0072] For this reason, the method according to the invention provides for the mask 5 to be applied to the surface 2 of the pressing tool 1 in two application processes. In a first application process, a first mask layer 6 is applied and in a second application process, a second mask layer 7 is applied, as outlined in Fig. 3.

[0073] In order to accelerate the application of the mask 5, the first application process for applying the first mask layer

6 using a different material throughput than the second application process for applying the second mask layer 7. The use of a different material throughput is also accompanied by a different application speed, since with a higher material throughput and with a constant layer thickness, the application of a larger area of mask 5 per unit time is possible.

[0074] As in the embodiment shown in Fig. 3, coarse structures of the mask 5 are applied as the first mask layer 6 in the first application process, since the application of coarse structures does not require high precision or resolution and can be carried out in a shorter time. In the second application process, fine

Structures of the mask 5 are applied as a second mask layer 7. These can then be done slowly with high resolution, since no high material application is required. In addition, the first application process and the second application process can be done at least partially in parallel.

[0075] The first and second application processes are carried out as

Printing processes, whereby for the first application process a first

Print head 51 is used for the first application process and a second print head 52 is used for the second application process. The device 100 for carrying out the method according to the invention is described further below with reference to Fig. 4.

[0076] The application processes are advantageously carried out essentially parallel to the preferred direction 18 of the surface structuring 10 - as shown in Fig. 1. This can prevent fraying or jaggedness caused by small positioning inaccuracies of the print heads 51, 52 due to movements of the print heads 51, 52 normal to the contours of the structures (in particular the elevations 4). The structures thus obtained then have continuous contours along the

Preferred direction 18.

[0077] According to an alternative embodiment of the invention, which is not shown in detail in the figures, the first

The application process can also involve spraying on the first mask layer 6, whereby the material of the mask layer 6 can be, for example, a material that expands in volume (such as an expanding foam). This makes it possible to achieve a high surface area or

Volume application of the first mask layer 6 to cover the coarse

structures of the mask 5. The second application process can then be carried out by printing as described above and thus the fine

Create structures of the mask 5 as a second mask layer 7.

[0078] Finally, Fig. 4 shows a device 100 according to the invention for

Processing of the surface 2 of a pressing tool 1 is shown. The device 100 has a support 50 on which the pressing tool 1 is positioned.

[0079] A first print head 51 and a second print head 52 can be positioned above the support 50, whereby both print heads 51, 52 can be positioned independently of one another along the x and y axes. The print heads 51, 52 can also be positioned simultaneously above the support 50. The first print head 51 is designed to apply the first mask layer 6 to the surface 2 of the pressing tool 1 and the second print head 52 is designed to apply the second mask layer 7 to the surface 2 of the pressing tool 1.

[0080] The first and second print heads 51, 52 are also configured and designed in such a way that they can be moved at different speeds over the support 50, or can deliver different material throughputs to the surface 2 of the pressing tool 1. The first print head 51, as indicated in Fig. 4, can use a larger droplet size when applying the first mask layer 6 and thus provide a large area of the surface 2 with a coarse structure of the mask 5 as a coarse pre-print in a short time. The second print head 52, in turn, can deliver a lower material throughput (for example using a small

droplet size) and thus print fine structures of the mask 5 with high resolution on the surface 2 of the pressing tool 1 as a fine overprint.

[0081] For positioning the print heads 51, 52, the device 100 has a first positioning device 53 for positioning the first

print head 51 along the x-axis, a second positioning device 54 for positioning the second print head 52 along the x-axis and a third positioning device 55 for positioning the first and second positioning devices along the y-axis.

[0082] In a further embodiment of the invention, which is not shown in detail in the figures, the first and second print heads 51, 52 can also be designed to apply different materials for the first and second mask layers 6, 7 to the surface 2.

The materials can differ in several material properties, such as viscosity, expansion capacity or grain size.

[0083] As shown in Fig. 4, the device 100 has a controller 60 which is connected to the first and second print heads 51, 52 and to the positioning devices 53, 54, 55 and can control them. The

The control unit 60 is programmed to control the print heads 51, 52 by means of the positioning devices 53, 54, 55 for applying the first and second mask layers 6, 7 using data 61. The data 61 can be image data of the images to be produced with the pressing tool 1.

surface structure (e.g. a wooden surface), which are correlated with height data of the surface structuring 10 of the pressing tool 1. In addition, the data 61 can be broken down into a first printing process and a second printing process, wherein in the first printing process the first mask layer 6 is used to produce the coarse structures of the

Mask 5 and in the second printing process the second mask layer 7 for

Generation of the fine structures of the mask 5 are printed.

[0084] The controller 60 is further programmed to carry out the method according to the invention as described above using the device 100.

Claims (16)

Patent claims 1. Method for processing a surface (2) of a pressing tool (1), in particular a press sheet, comprising applying a mask (5) to the pressing tool (1) in at least two application processes, wherein in a first application process a first mask layer (6) is applied by a first print head (51) and in a second application process a second mask layer (7) is applied by a second print head (52), wherein the first application process and the second application process differ from one another in at least one process parameter and/or wherein the material of the first mask layer (6) and the material of the second mask layer (7) differ from one another in at least one material property, and wherein the first print head (51) and the second print head (52) for applying the mask (5) are each positioned along two, in particular mutually normal, directions over a support (50) for the pressing tool (1), characterized in that the at least one different process parameter a droplet size, a speed or a mass flow rate during the application of the material of the first mask layer (6) and/or second mask layer (7). 2. Method according to claim 1, wherein the first mask layer (6) is applied in the first application process in at least a first partial area (8) of the surface (2) of the pressing tool (1), wherein the second mask layer (7) is partially applied in the second application process in at least a second partial area (9) of the surface areas, and the method further comprises Providing the surface (2) of the pressing tool (1) after the application of the mask layers (6, 7) in at least the second partial region (9) with a metal layer (15) in order to produce a surface structuring (10) on the pressing tool (1). 3. Method according to one of claims 1 to 2, that the at least one different material property of the material of the first mask layer (6) and/or the material of the second mask layer (7) is a viscosity, an expansion capacity or a grain size. 4. Method according to one of claims 1 to 3, characterized in that the first application process and the second application process are carried out at least partially in parallel. 5. Method according to one of claims 1 to 4, characterized in that the first application process is carried out by spraying the first mask layer (6). 6. Method according to one of claims 1 to 5, characterized in that the first application process and/or the second application process is carried out by printing the first mask layer (6) or the second mask layer (7). 7. Method according to claim 6, characterized in that the mask (5) is applied in the first partial area (8) by means of a, in particular digital, printing process, and that the first application process is a first printing process and the second application process is a second printing process. 8. Method according to one of claims 1 to 7, characterized in that the first application process and/or the second application process takes place parallel to a preferred direction (18) of the surface structuring (10) to be produced. 9. Method according to one of claims 1 to 8, characterized in that the metal layer (15) is a chromium, copper or nickel layer. 10. Method according to one of claims 1 to 9, characterized in that after the application of the metal layer (15) in at least the second partial region (9), the mask (5) is removed from the surface (2). 11. Method according to one of claims 1 to 10, characterized in that the surface (2) is provided with a second metal layer (15) after the application of the metal layer (15). 12. Method according to one of claims 1 to 11, characterized in that the surface (2) is processed mechanically, in particular by laser radiation, and/or chemically after the application of the metal layer (15). 13. Device (100) for processing a surface (2) of a pressing tool (1), in particular a press plate, comprising a support (50) for the pressing tool (1) and at least a first print head (51) and a second print head (52), wherein the first and second print heads (51, 52) can each be positioned along two directions, in particular directions normal to one another, above the support (50), and wherein the first print head (51) is designed to apply a first mask layer (6) to the pressing tool (1) and the second print head (52) is designed to Application of a second mask layer (7) to the pressing tool (1), wherein the first and second print heads (51, 52) are additionally designed to apply the first and second mask layers (6, 7) using different process parameters and/or to apply them using materials which differ from one another in at least one material property, characterized in that the at least one different process parameter is a droplet size, a speed or a mass throughput when applying the material of the first mask layer (6) and/or second mask layer (7). 14. Device according to claim 13, characterized in that the first print head (51) and the second print head (52) can be positioned independently of one another and/or simultaneously above the support (50) for applying the first or the second mask layer (6, 7). 15. Device according to claim 13 or 14, characterized in that the first print head (51) and the second print head (52) are movable at different speeds over the support (50). 16. Device according to one of claims 13 to 15, characterized in that a first positioning device (53) is provided for positioning the first print head (51) along a first direction above the support (50), that a second positioning device (54) is provided for positioning the second print head (52) along the first direction above the support (50), and that a third positioning device (55) is provided for positioning the first and second positioning devices (53, 54) along a second direction above the support (50).