US20200346484A1

US20200346484A1 - Method and device for surface processing

Info

Publication number: US20200346484A1
Application number: US16/865,358
Authority: US
Inventors: René Pankoke
Original assignee: Hymmen GmbH Maschinen und Anlagenbau
Current assignee: Hymmen GmbH Maschinen und Anlagenbau
Priority date: 2019-05-03
Filing date: 2020-05-03
Publication date: 2020-11-05
Also published as: US20200346395A1; EP3733308A3; WO2020225215A2; CN112188936B; WO2020225214A1; EP3752296A2; EP3733308A2; EP4215282A1; WO2020225215A3; CN112399922B; CN112399922A; WO2020225210A2; CN114174076A; CN112188936A; EP3733308C0; WO2020225210A3; US11559824B2; PL3733308T3; US20230144445A1; EP3733308B1

Abstract

A method for processing a surface (2) of a workpiece (1) is disclosed. Besides, a device for performing the method is disclosed.

Description

RELATED APPLICATIONS

This application claims the benefit of priority of German Patent Application No. 10 2019 206 431.0 filed on May 3, 2019, and European Patent Application No. 19 208 741.9 filed on Nov. 12, 2019, the contents of which are incorporated herein by reference in their entirety.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to a method and a device for processing a surface of a workpiece, in6 particular, for producing a decorative surface.
For producing decorative surfaces in the industrial scale, the decorative surfaces having the aim of reproducing tiles or wood surfaces, except from a layer forming the later surface, further manipulation media are also applied temporarily in order to manipulate the surface of the layer so that, finally, the decorative surface can be produced.
For example, EP 3 109 056 A1 describes a method for producing a structure on a surface. Thereto, a liquid layer is applied onto a workpiece. Subsequently, a manipulation medium in the form of droplets is sprayed onto the liquid layer, whereby, a displacement of the liquid layer occurs by the droplets so that recesses together forming a structure in the liquid layer are formed therein. Subsequently, this layer is fixed. In this way, a surface having a wood or tile look can be produced on the layer.
EP 3 415 316 A1 discloses a method in which a manipulation medium is applied onto the liquid layer in the form of droplets or fine droplets, wherein the manipulation medium has the characteristic to at least partially absorb electromagnetic radiation. When the liquid layer is irradiated, for example, by an Excimer laser, a polymerization on the surface of the liquid layer causing a micro folding occurs there, wherein the micro folding has a matt surface as a result later. Thereby, the manipulation medium on the surface of the liquid layer at least partially absorbs the radiation so that, here, the polymerization occurs less strongly. As a result, these areas are glossier than the areas where no manipulation medium was located.
In the known methods, after the performing of the method, in particular, when the layer is at least partially cured, a part of the layer has to be removed once again in order to achieve the finally desired surface design. In particular, in the production in a production line, this has to take place quickly so that a high production throughput can be achieved. Also, the device and the method used when removing parts of the layer have to be industrially qualified, i.e., it must be possible to produce at a high availability without too much manual cleaning effort.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to achieve this problem.
This object is achieved by the subject-matters of the independent claims. Advantageous further developments are subject-matter of the subclaims.
Preferably, a method for removing parts of a layer on a surface of a workpiece is provided, the method comprising the following steps:

- establishing a mechanical contact between a contact element and the layer on the surface of the workpiece for removing parts of the layer;
- physical separating of removed parts of the layer from the parts of the layer remaining on the surface of the workpiece.

Alternatively or additionally, a method for removing parts of a layer on a surface of a workpiece is provided, the method comprising the following steps:

- generating a fluid flow for removing parts of the layer;
- physical separating of removed parts of the layer from the parts of the layer remaining on the surface of the workpiece.

Thereby, the fluid flow impinges on the layer, preferably, at an angle between 1° and 90°.
Preferably, a combination of the two preceding methods to one entire method is provided, wherein each of the steps of the methods is executed at least once.
Preferably, the layer on the surface of the workpiece has differences in hardness of at least a factor 1.5, preferably of at least a factor 2, between harder areas and the less hard areas.
As hardness of the layer, in particular, the scratch hardness or the stretch resistance of the layer shall be understood. As long as these cannot or can only hardly be measured in a possible embodiment due to a low viscosity of the layer or of parts of the layer, alternatively, the percentage ratio of chemical bonds transformed by polymerization can be understood as the hardness described here.
Alternatively or additionally, the layer on the surface of the workpiece has differences in viscosity of least a factor I.5, preferably of at least a factor 2, between the higher viscous areas and the less high viscous areas.
Preferably, the physical separating of the removed parts of layer from the parts of the layer remaining on the surface of the workpiece is performed by sucking away, wiping away, blowing away, or by a combination of these steps.
Preferably, the layer located on the surface of the workpiece and the contact element move relatively with respect to one another when removing the parts of the layer.
Preferably, the contact element comprises a stationary and/or a moved brush and/or a grinding element and/or a plane element, wherein, preferably, the brush, at least as a moved brush, comprises a disk brush and/or a roller brush and/or a brush band and/or, as stationary brush, a beam having a brush trimming, and/or wherein the contact element, particularly the brush, comprises textile and/or plastic fibers, in particular, nylon fibers, Anderton, and/or metal, particularly steel, brass, or copper as bristles.
Preferably, simultaneously with establishing the mechanical contact between the contact element and the layer on the surface, and/or simultaneously with the generating of the fluid flow onto the layer, an irradiation of the layer and/or of the contact element and/or of the surroundings of the contact element in which the separated parts of the layer are located is performed. The irradiation is preferably performed by electromagnetic radiation.
Preferably, the contact element is cleaned continuously during the physical separating, wherein the cleaning is preferably performed by the use of a combination of an electromagnetic beam source and/or a suction device and/or a mechanical chipping edge.
Preferably, a nozzle configured to generate a fluid flow is continuously cleaned during the physical separating, wherein the cleaning is preferably performed by a combination of an electromagnetic beam source and/or a suction device and/or one or several further drying devices or beam sources. Thereby, the one or several drying devices and/or beam sources can also be located within the one or several suction devices.
Preferably, before establishing the mechanical contact between the contact element and the layer, cleaning of the surface of the layer is performed. Alternatively or additionally, after the physical separating of parts of the layer, a cleaning of the residual layer remaining on the surface of the workpiece is performed.
Preferably, before the generating of the fluid flow onto the layer, cleaning of the surface is performed. Alternatively or additionally, after the physical separating of parts of the layer, cleaning of the residual layer remaining on the surface of the workpiece is performed.
Preferably, the continuous cleaning of the contact element, particularly of the brush, is performed by an irradiation with UV radiation, preferably at a wavelength between 180 and 400 nm, in combination with a stripping off of cured residual components of the separated parts of the layer on a chipping edge and a suctioning away of these residual components by means of a suction device.
Preferably, the continuous cleaning of the nozzle takes place by irradiation with UV radiation, preferably at a wavelength between 180 and 400 nm, in combination with a suctioning away of residual components of the separated parts of the layer by means of a suction device.
Preferably, for cleaning the surface of the layer, a cleaning agent being preferably subsequently removed, in particular, preferably by means of a stripper and/or a suction device, is applied onto the layer. The cleaning agent is preferably liquid until pasty. The cleaning agent is configured to enclose debris and dirt on the surface of the layer, wherein, subsequently, removing of the cleaning agent with the enclosed debris and dirt can be performed.
Except from the pure processing of the layer on the workpiece, a deployment of a manipulation medium can be provided.
Preferably, a method for producing a decorative surface on a workpiece is provided, the method having the following steps:

- applying a manipulation medium at least onto and/or into a part of a liquid layer located on the workpiece and/or at least on a part of the workpiece;
- removing parts of the layer, wherein the removing is performed mechanically and/or in a contactless, particularly fluidic, manner.

Thus, a manipulation medium is applied onto and/or into an at least partially liquid layer located on a workpiece. The manipulation medium can alternatively or additionally also be applied onto the workpiece itself. The applying of the manipulation medium thereby is performed preferably on subareas or sections of the liquid layer and/or of the workpiece. In the further proceeding of the method, parts of the layer are removed. The removing is preferably performed mechanically and/or in a contactless, particularly fluidic, manner. If the manipulation medium is applied directly onto the workpiece, preferably subsequently, the liquid layer is applied as described below. Preferably, before the removing of parts of the layer is performed, the layer together with the manipulation medium is dried and/or at least partially cured so that the viscosity of the layer increases.
These method steps can be provided in a method for producing a decorative surface on a workpiece. Between the execution of the removing of parts of the layer and the method steps performed before, however, a timely brake can be so that, particularly the removing of parts of the layer, can be an autonomous method.
Preferably, the parts of the layer which are removed also comprise parts of the manipulation medium located on or in the layer. In a specific embodiment, it is purely about the manipulation medium. If the manipulation medium is removed from the layer, this can be performed partially so that a residual of the manipulation medium remains on or in the layer.
However, the removing can also be performed completely so that the manipulation medium is completely removed.
Thus, the removing of parts of the layer can involve that the material of the layer itself is removed. Alternatively, also only the manipulation medium can be removed from the layer. However, also both, therefore, the material of the layer itself and the material of the manipulation medium can be removed.
Preferably, the mechanical removing of parts of the layer is performed by a removal device comprising a contact element being in contact with the layer, wherein the surface of the layer and the contact element move relatively with respect to one another.
Besides an opposite motion, a unidirectional or a motion formed in another manner can occur.
Preferably, the contact element comprises a stationary and/or a moved brush and/or a grinding element and/or a plane element, wherein the contact element is provided in a moving or stationary manner with respect to the workpiece. Preferably, at least as moved brush, the brush comprises a disk brush and/or a roller brush and/or a brush band and/or, as stationary brush, a beam having a brush trimming.
The grinding element and/or plane element is preferably configured to skim parts of the layer once again in order to expose the manipulation medium enclosed therein. Subsequently, the manipulation medium can be removed by means of the grinding element and/or the plane element or by means of other methods described here. The grinding element can preferably include a belt sander.
Generally, the contact element can comprise a stationary and/or a moved element. The contact element is further preferably designed as a cyclically working contact element, for example, comprising an abrasive belt or a roller brush. Thereby, the contact element preferably comprises portions which are cyclically not in contact with the layer during the removing. As described below, these portions can be cleaned at this moment.
Preferably, the contact element, particularly the brush, comprises textile and/or plastic fibers, in particular, nylon fibers, and/or metal, in particular steel, brass, or copper.
Moreover, fibers including abrasives can be deployed. Hereby, preferably, it's about fibers with Anderton. These fibers or materials are preferably included in the bristles of the brush. Thus, in particular, configurations of the brush having metal or plastic bristles are possible.
The brush preferably comprises bristles having a diameter of 0.05 to 2 mm, preferably 0.1 to 1.2 mm, further preferably 0.2 to 0.7 mm, especially preferred 0.2 to 0.3 mm.
Preferably, the removing of parts of the layer includes suctioning away the parts by vacuum, preferably by means of a suction device, and/or heating of the layer and/or of the manipulation medium, preferably, by supplying heat, particularly preferred for at least partial liquidation of the parts of the layer, particularly of the manipulation medium. Preferably, the heat supply can be performed by a heater or an IR radiator.
Preferably, a controlled and/or regulated motion of the contact element is performed. This can be, for example, the positioning of the contact element relative to the layer or, also, an adjustment of the number of revolutions or of the velocity of circulation of the disc brushes or of the brush band.
While the contact element removes parts of the layer, clogging of the contact element by the removed material of the layer and/or of the manipulation medium can occur. In the case of a brush, this means that the removed material settles in the bristles. As the case may be, a grinding element and/or a plane element can also be affected by the clogging. Therefore, a further step in which cleaning of the contact element is performed can be provided. The entire method for cleaning the contact element which is described below can also be executed independently from the method described in this application.
The cleaning can preferably be performed by mechanically stripping away the material on a stripping edge and/or also by means of suctioning away by vacuum, e.g., by the above mentioned or a further suction device.
In order to reduce the viscosity of the material and/or of the manipulation medium and, thereby, to improve the detachability from the contact element, also here, a supply of heat to the contact element can be provided. The supply of heat can preferably be performed by a heater or by an IR radiator. For example, the heater can be provided in the contact element.
Alternatively or additionally, the cleaning of the contact element can include that the contact element is irradiated by radiation, in particular, electromagnetic radiation and/or electron radiation, during the removing of the manipulation medium and/or of parts of the layer applied before. Thereby, in particular, it is achieved, that the material settled on the contact element is at least partly or completely cured and, then, exists in a hard and brittle form. Preferably, by the hardening of the material, it is achieved that it easily breaks loose from the contact element, in particular, from the bristles if a brush is provided. By mechanically stripping away and/or sucking away, this material can be removed from the contact element once again.
For the mechanical stripping away, for example, a stripping edge at which the clogged contact element can be passed can be provided, whereby the manipulation medium and/or the removed part of the layer can be stripped away. If, for example, the contact element comprises a brush, therefore, for this purpose, the bristles of the brush can come in contact with the stripping edge.
Except from the radiation hardening, further hardening methods can also be deployed in order to cure the material which has clogged the contact element. In general, various methods can be deployed in order to influence particularly the viscosity and/or the rigidity of material clogging the contact element. With contact elements cyclically working, it is important that the removing of parts of the layer as well as the cleaning of the contact element, therefore, the removing of these parts of the layer from the contact element, are performed within one cycle. Consequently, the influence on the viscosity, if it is performed in the method, has to be performed within this cycle. Since the material clogging the contact element is, in particular, material of the layer and/or of the manipulation medium, therefore, each method causing a curing or a change of the viscosity of these materials can be deployed basically. Therefore, there is a hint to the possibilities described in this application.
In a preferred embodiment, the material and/or the manipulation medium comprises a ratio of more than 70% of acrylates cross-linking by irradiation by electromagnetic radiation via the generation of chemical bonds and, therefore, the acrylates reduce the viscosity and, therefore, also the adhesiveness of the material and/or of the manipulation medium and increase the brittleness. Therefore, the above-described embodiment of the cleaning of the contact element is well suited to ensure an enduring and less failure-prone operation of an industrial facility producing according to the method of the invention.
In other embodiments, the material and/or the manipulation medium can also comprise other components, as, e.g., an aqueous mixture with bonding agents, pigments, and other additives, or can be constituted thereof.
Preferably, the removing of parts of the layer comprises a streaming onto the surface of the layer and/or of the manipulation medium by a fluid flow, in particular, by an airflow. In this way, in particular, the manipulation medium can be removed in a contactless manner which is preferably gentle for the surface of the layer. Therefore, also workpieces comprising elements which can be damaged by non-contactless methods, e.g., by the contact with an above-described brush, can be processed. For clarification, in FIG. 6, an embodiment of such a workpiece is shown. Here, a workpiece 1 in the form of a pre-milled plank having a layer 2 applied onto the workpiece surface is shown. Leftwards, the workpiece 1 comprises a connection element 1 a which can engage in a slot of a further workpiece in the sense of a slot and key connection in order to join together several workpieces in this way, e.g., as a flooring material. According to the state of the art, instead of slot and key, today, so-called “click-profiles” which are, e.g., illustrated in EP 2 280 130 A2, are used for the installation of the floor planks. These areas or also the transition area from the connection element towards the layer 2, probably, should not needlessly be mechanically stressed during the production. Therefore, particularly here, a contactless removing of parts of the layer is preferable.
Furthermore, the method can preferably also be used for surfaces outside the floor covering, e.g., for furniture, wall, ceiling surfaces or also for external facade elements or further applications.
Preferably, the fluid flow impinges on the surface of the layer and/or of the manipulation medium in an accordingly formed manner so that it extends across the entire width of the layer. The length of the extension of the impingement area of the fluid flow in the direction of motion of the workpiece is preferably 1% to 20%, especially preferred 5% to 15%, particularly 10% to 12%, of the length of the extension of the fluid flow across the direction of motion. Thus, a fluid flow as thin as possible, in particular, in the sense of an “air blade” or an “air knife”, is preferably used. Alternatively, a liquid flow, particularly containing water, can also be used as fluid flow.
Preferably, the fluid flow impinges on the layer and/or the manipulation medium at an angle less than 45°, preferably less than 30°, especially preferred less than 15°. In case that, for example, only the manipulation medium shall be detached, in particular, in the case of application of merely a manipulation medium onto the surface of the layer, a flat inflow is useful to achieve detachment from the layer. Depending on the situation, however, a steeper adjustment of the fluid flow can also be useful in order to, e.g., blow away a manipulation medium which is contained in recesses of the layer. Preferably, the angle is particularly cyclically varied during the execution of the method. The variation can preferably also be depending on the currently detected amount of the removed manipulation medium. This amount is preferably detected by a detection device, for example, detecting the weight of the removed manipulation medium.
Alternatively or additionally, the fluid flow can impinge on the surface of the layer also by so-called rotation nozzles. Thereby, with an entire diameter of the rotating nozzles of preferably 2-120 mm, especially preferred 5 to 50 mm, the rotation nozzles guiding the fluid flow to the surface rotate about a central axis. Thereby, a timely variable fluid flow is directed to the surface.
Preferably, the fluid flow further contains solid bodies enhancing the removing of parts of the layer. For example, sand or a comparable substance for additionally acting on the surface of the layer and/or of the manipulation medium besides the fluid flow can be included here. The fluid flow can particularly also be used, besides the manipulation medium, to remove also material from the layer.
The solid bodies have a diameter of preferably 0.0001 to 1 mm, preferred 0.001 to 30.5 mm, especially preferred 0.005 to 0.3 mm.
Alternatively or additionally, the solid bodies are configured to liquefy or to evaporate after the impingement on the layer and/or the manipulation medium. This can, for example, be achieved thereby that the solid bodies have the property to evaporate in the ambient temperature to which the workpiece including the layer is exposed. For example, this can be achieved by solid bodies of dry ice. These solid bodies of dry ice can particularly be applied onto the surface of the layer and/or of the manipulation medium by a dry ice beamer. Thereby, it is preferably achieved that the solid bodies do not remain on and/or in the layer. Thus, a subsequent removing of the solid bodies from the layer can be omitted.
Alternatively or additionally, the solid bodies can be supposed to be supplied with a liquid, particularly with water, during the generating of the fluid flow. Thereby, an increase of the mass of the solid bodies is achieved so that the effect to the surface of the layer and/or the manipulation medium is increased. The supply can be performed, e.g., by moving the solid bodies with the fluid flow through a fog of the liquid. Thereby, the solid bodies act as cloud condensation nuclei at which the components of the fog inhere, whereby, the supply of the solid bodies by the liquid is performed finally.
Particularly, the solid bodies can comprise sand grains, dry ice (solid CO₂), water ice (frozen water), sodium bicarbonate, or mixtures of these cited solid bodies.
Preferably, the method further comprises at least one of the following steps:

- applying a liquid layer onto at least a part of a surface of the workpiece and/or onto a manipulation medium applied onto the surface of the workpiece;
- curing the layer and/or the manipulation medium at least until partial curing.

In a specific embodiment, a method comprising this procedure is provided:

- applying a liquid layer onto at least a part of a surface of the workpiece and/or onto a manipulation medium applied onto the surface of the workpiece;
- applying the manipulation medium at least onto a part of the liquid layer and/or into the liquid layer and/or at least onto a part of the workpiece;
- curing the layer and/or the manipulation medium at least until partial curing;
- removing the manipulation medium as described above.

The layer and/or the manipulation medium is preferably configured to be polymerizable by means of electromagnetic radiation.
In a further specific embodiment, a method comprising the following procedure is provided:

- applying a liquid layer onto at least a part of a surface of the workpiece;
- applying the manipulation medium onto at least a part of the liquid layer and/or into the liquid layer;
- curing the layer and/or the manipulation medium at least until the partial curing;
- removing parts of the layer as described above.

In this last-named embodiment, by the last step (removing parts of the layer), the applied manipulation medium can also be completely or partially co-removed commonly.
In each conceivable embodiment of the method, in particular, in the two just described specific embodiments, further method steps which can be provided before, between and also after the heretofore described method steps can be provided. Moreover, individual method steps can also be repeated.
Preferably, the manipulation medium comprises water. In a specific embodiment, the manipulation medium consists exclusively of water.
Preferably, the layer and/or the manipulation medium comprises acrylate containing material.
During the execution of the method, the workpiece is preferably moved in a direction of motion and, therefore, it is supplied successively to elements of a device, wherein the elements are designed to execute the individual method steps. Alternatively or additionally, the elements of the device can be configured to move with respect to the workpiece.
For example, the method can be performed such that the layer is applied in a liquid form onto the surface of the workpiece. Subsequently, the manipulation medium is applied onto and/or into the layer. However, the method can also be configured such that the manipulation medium is first applied onto the surface of the workpiece. Subsequently an application of the layer is performed. Here, the manipulation medium functions preferably as placeholder so that regions of the surface of the workpiece do not contact the layer. If the manipulation medium is removed after the layer has been cured, these places remain as indentions or recesses in the layer. Of course, embodiments in which an application of the manipulation medium before as well as after the application of the layer is performed are conceivable. Also, a repeated iteration of the application of the layer and/or the manipulation medium is possible. If the manipulation medium is used as placeholder, the manipulation medium is preferably cured before the application of the liquid layer.
Before the application of the manipulation medium, drying or curing of the liquid layer, preferably by electromagnetic radiation at a wavelength of 200 to 400 nm, is performed, particularly to influence the viscosity of the liquid layer.
Preferably, after the application of liquid layer, the manipulation medium is applied onto parts of the liquid layer.
Preferably, the manipulation medium and the at least partially liquid layer are irradiated by electromagnetic radiation, preferably at a wavelength of 180 to 400 nm.
Moreover, the curing can also be executed several times. For example, a first curing of the layer until the partial curing can be executed before the manipulation medium is applied. In this way, a desired viscosity of the layer can be pointedly adjusted so that, for example, a structure arising by the application of the manipulation medium endures for a certain time before the structure melts.
Preferably, the curing contains an irradiation of the layer and/or of the manipulation medium by electromagnetic radiation, preferably by UV radiation and/or by irradiation by electron radiation.
The curing can preferably be performed at the same time as the removing of parts of the layer. For example, the place of the layer which is just in contact with the contact element can simultaneously be irradiated with UV radiation causing the curing. The same is valid for all possibilities removing in a mechanical or contactless manner as described above.
The manipulation medium covering parts of the layer can cause that the covered part of the layer does not cure in the same extent as the exposed parts. Thereby, in particular, it can concern about the here described methods for curing. After the removing of parts of the layer, then, a final curing of the remaining layer and/or the remaining manipulation medium is executed.
Alternatively or additionally, the curing includes active and/or passive drying. By active drying, in the following, each kind of drying in which the liquid layer is dried by generating specific conditions is understood. Therefore, the liquid layer and/or the manipulation medium can particularly be dried by means of incident flow of a fluid, particularly of air, and/or by supplying heat, particularly by means of IR radiation or by use of a heater.
Whereas, passive drying is preferably characterized in that the liquid layer and/or the manipulation medium cures for itself and without any further processing. This can, e.g., take place by a transport of the workpiece on a free track section of a conveyor transport and/or by depositing the workpiece.
Preferably, the curing by means of reaction curing takes place by, e.g., a two-component system which cures by a chemical reaction between the components of the layer and/or the manipulation medium within less than 30 minutes, preferably less than 5 minutes.
Preferably, the layer is cured after the application of the manipulation medium in such a way that the viscosity of places of the layer where the manipulation medium has been applied differs from the viscosity of the places where the manipulation medium has not been applied. Preferably, the difference corresponds to a factor of at least 1.5, especially preferred to a factor of at least 2. Preferably, the viscosity at places where the manipulation medium has been applied is less than at places where the manipulation medium has not been applied. In the case of radiation curing, this is justified thereby that the layer underneath the manipulation medium has been, at least partially, shielded from the radiation, whereby the layer has been exposed to a lesser amount of radiation and, thus, cured less.
Preferably, the curing of the layer until the final curing of the layer is performed after the removing of parts of the layer.
Preferably, the layer is at least partially cured before the application of the manipulation medium. If the manipulation medium has been applied before the liquid layer, also the manipulation medium can be at least partially cured, whereby preferably electromagnetic radiation, in particular UV radiation, is respectively used thereto. The curing is thereby preferably executed as described above.
Preferably, the applying of the liquid layer onto the workpiece is performed by a digital and/or analog procedure. Particularly preferred, the application of the liquid layer onto the entire surface of the workpiece is performed. In an analog procedure, the application can take place by means of an application roller or of a casting machine generating a liquid carpet of the material of the layer, wherein the work piece is moved through the carpet. An application roller and a casting machine have the advantage that the layer can be applied onto an area as broad as possible at small efforts. In a digital procedure, the application is performed by means of a digital printing technique, e.g., by a digital printing head or a digital nozzle beam. Thereby, the layer can also be applied only onto sub-areas of the workpiece.
Preferably, the application of the manipulation medium onto the workpiece and/or onto the liquid layer is performed by a digital procedure. Thereto, a digital printing technique, for example, with a digital printing head or a digital nozzle beam is deployed. Thereby, the manipulation medium to be applied can be deployed especially economically and precisely. However, an analog technique, as, e.g., a casting device, is also conceivable.
Preferably, the application of the manipulation medium includes an application of the manipulation medium in the form of droplets and/or in the form of fine droplets. The application of the manipulation medium onto the layer in form of droplets is preferably performed such that the droplet speed and/or the droplet volume is controlled such that recesses are brought into the layer by the droplets, wherein the recesses preferably have a depth of preferably 2 μm to 100 μm, especially preferred from 3 μm to 50 μm.
The emission of the fine droplets is preferably controlled such that their momentum when impinging on the surface of the liquid layer is not sufficient for at least partially overcoming the surface tension and/or the viscosity forces of the liquid layer so that the fine droplets preferably come to lie on the surface of the liquid layer. Especially preferred, the manipulation medium is applied onto the surface of the layer in the form of fine droplets as fog so that this fog forms particularly closed areas covering the surface of the layer.
Thereby, the fine droplets particularly have a volume from 0.1 pl to 1 pl, preferably from 0.3 to 0.8 pl, especially preferred from 0.5 to 0.6 pl.
Thereby, the droplets particularly have a volume from 1 pl to 80 pl, preferably from 3 pl to 12 pl, especially preferred from 5 pl to 10 pl.
The speed of the droplets and/or of the fine droplets is particularly between 0.5 m/s and 12 m/s, preferably between 3 m/s and 7 m/s, especially preferred between 5 m/s and 6 m/s.
The speed and/or the volume of the droplets and/or of the fine droplets can be varied during the applying of the manipulation medium.
The emission of the droplets is preferably controlled such that their momentum when impinging on the surface of the liquid layer is sufficient for at least partially overcoming the surface tension and/or the viscosity forces of the liquid layer so that a displacement of the liquid layer ensues by the droplets, whereby recesses and, in particular, a structure of 10 to 15 μm difference in height can be brought in.
Preferably, the manipulation medium is configured to at least partially absorb incident electromagnetic radiation, whereby, preferably at least 10%, especially preferred at least 30%, particularly at least 50%, of the incident electromagnetic radiation are absorbed. In this way, it is possible to shield the surface of the layer at least partially from the electromagnetic radiation so that, in particular, during curing of the liquid layer, the electromagnetic radiation acts varyingly strong on the surface of the layer. Compared to the exposed spots, the electromagnetic radiation acts weaker at the places of the layer covered by the manipulation medium. Therefore, if, e.g., a wavelength of less than 300 nm, preferable less than 250 nm, especially preferred less than 200 nm, is used, a micro folding on the surface of the layer can be generated, wherein the micro folding turns out weaker at the places of the layer covered by the manipulation medium than at the exposed places. As a result, the places which, during this irradiation, have not been covered will appear more matt than the places which have been covered by the manipulation medium. Specifically, a wavelength of 185 nm is used here. The irradiation preferably takes place in a protective gas atmosphere, in particular, in a N₂atmosphere.
Preferably, the manipulation medium and the layer are configured not to coalesce to each other during the curing. Thereby, the particularly complete removing of the manipulation medium is considerably facilitated.
Preferably, a device for performing the above mentioned method is provided, the device comprising:

- a transport device configured to transport a workpiece to further elements of the device and/or to move at least a further element of the device to the workpiece; and
- as further element, a removal device configured to remove parts of the layer in a mechanical manner, preferably by a contact element, and/or a fluidic manner, preferably by a fluid flow from a nozzle, wherein
- the device further comprises a control means configured to control the transport device and the further elements of the device in order to perform the method described above.

Further, preferably, a device for performing the above mentioned methods is provided, the device comprising:

- a transport device configured to transport a workpiece to further elements of the device and/or to move at least one further element of the device to the workpiece; and
- as further element, an application device, in particular, comprising a digital printing device configured to apply a manipulation medium onto an at least partially liquid layer located on the workpiece and/or onto a surface on the workpiece;
- preferably as further element, a curing device configured to cure the liquid layer and/or the manipulation medium; and
- as further element, a removal device configured to remove parts of the layer in a mechanical and/or fluidic manner, wherein
- the device further comprises a control means configured to control the transport device and the further elements of the device in order to perform one of the methods as described above.

The device can particularly comprise device features or configurations described above in the elucidation of the method.
Preferably, the transport device comprises a conveyor transport device on which the workpiece can be transported to the further elements of the device. Alternatively or additionally, it can also be configured such that at least one of the elements of the device is moved to the workpiece.
Preferably, the curing device comprises a radiation source for electromagnetic radiation, wherein the wavelength of the emitted radiation is preferably variable. Especially preferable, the emitted radiation is UV radiation.
Preferably, the curing device comprises a blower configured to blow a fluid flow, particularly an airflow, onto the layer and/or onto the manipulation medium in order to perform drying of the layer and/or of the manipulation medium.
Preferably, the removal device comprises a contact element for mechanical removing the contact element being configured to contact the surface of the layer and/or of the manipulation medium in order to remove parts of the layer.
Preferably, the removal device comprises a nozzle configured to let flow a fluid flow, preferably, an airflow, onto the surface of the layer in order to remove parts of the layer, in particular, the manipulation medium. The fluid flow is preferably configured as described above. The nozzle is preferably designed as being movable in order to be able to vary the angle at which the fluid flow impinges on the surface of the layer.
Preferably, the removal device comprises a suction device designed such that the manipulation medium is sucked from the layer by means of vacuum and/or already loosened parts of the layer, in particular, the manipulation medium, are sucked away.
Preferably, the suction device comprises a suction nozzle which is especially particularly designed as being movable and which can be approached to the surface of the layer in order to suck away the manipulation medium.
Preferably, the device comprises a chamber in which at least the nozzle and/or the suction nozzle is provided in order to collect loosened parts of the manipulation medium.
Preferably, the removal device comprises a heating device configured to heat the surface of the layer and/or the manipulation medium. Alternatively or additionally, the heating device can be configured to transmit heat to the contact element in order to prevent or reduce clogging of the contact element as described above. It can also be provided that the contact element comprises the heating device. Preferably, the heating device comprises an IR radiator.
Preferably, the contact element comprises a stationary and/or a moved brush and/or a grinding element and/or a plane element. Preferably, the contact element, particularly the brush, comprises textile and/or plastic fibers, particularly nylon fibers, and/or fibers of metal, particularly steel, brass, or copper. Apart from that, the contact element can be configured as described above. Further, the contact element can comprise fibers including a grinding means.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Below, the invention is described in detail by means of preferred embodiments and by means of the attached drawings.

In particular,

FIG. 1 shows an embodiment of the invention in which the removing of parts of the layer is performed in a fluidic manner;

FIG. 2 shows an embodiment of the invention in which the removing of the parts of the layer is performed in a mechanical manner;

FIG. 3 shows an embodiment of brushes for mechanical removing of parts of the layer;

FIG. 4 shows a further embodiment of brushes for mechanical removing of parts of the layer;

FIG. 5 shows a further embodiment of brushes for mechanical removing of parts of the layer;

FIG. 6 shows a workpiece in the form of a pre-milled plank having an applied layer;

FIG. 7 shows a possibility for cleaning the contact element;

FIG. 8 shows a device in the form of a production line;

FIG. 9 shows a possibility for cleaning the surface of the layer;

FIG. 10 shows a cross-section of a workpiece having a layer comprising different hardness grades; and

FIG. 11 shows an exemplary flowchart of a method.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

FIG. 1 shows an embodiment of the invention in which the removing of parts of the layer, here, in particular, the manipulation medium, is performed in a fluidic manner.
A flat workpiece 1 moving from the right to the left in the drawing is shown. The workpiece 1 is covered by a liquid layer 2 forming the surface of the workpiece 1 after the complete curing. Into the liquid layer 2, a manipulation medium 3 has been brought in at some places in order to displace the liquid layer 2. The workpiece 1 is moved into a chamber 4, for example, by a transport device of a device according to the invention. The chamber 4 comprises, in the direction of motion, first, a curing device 5 comprising an UV radiation source emitting UV radiation onto the liquid layer 2 in order to cure it so that the viscosity of the layer 2 is changed. The UV radiation has thereby a wavelength of 200 to 400 nm. Subsequently, the workpiece 1 is fed to a nozzle 6 emitting a fluid flow against the direction of motion at an angle with respect to the surface of the layer 2. Thereby, the angle is maximum 45° or less. Preferably, an adaption of the angle between 0° and 45° is performed. This adaption can be done, for example, depending on the removed manipulation medium.
By the nozzle 6, the fluid flow is formed such that it exerts a flow pressure onto the manipulation medium 3, wherein the flow pressure is as high as the manipulation medium 3 breaks loose as part 13 of the layer 2 from the layer 2.
By the pressure of the fluid flow, subsequently, the loosened parts 13 of the manipulation medium 3 (framed in a dotted manner) are urged to the right where they are collected by a suction device 7 by vacuum and removed from the chamber 4.
In one embodiment, the fluid flow is configured such that it extends across the entire width of the workpiece 1, i.e., in a direction of extension of the workpiece 1 perpendicular to the drawing plane. In this way, it is ensured that all of the parts of the manipulation medium 3 are covered by the fluid flow which, in particular, upon a chaotically or irregularly inserted manipulation medium 3, obviates the need of a targeted streaming to individual regions of the surface of the layer 2.
As fluid, a liquid or a gaseous substance is deployed. Specifically, also, water and/or air can be deployed as the fluid.
FIG. 2 shows an embodiment of the invention, in which the removing of parts of the layer is performed in a mechanical manner.
A flat workpiece 1 moving from the left to the right in the drawing is shown. The workpiece 1 is covered by a liquid layer 2 forming the surface of the workpiece 1 after the complete curing. Into the liquid layer 2, a manipulation medium 3 has been brought in at some places in order to displace the liquid layer 2. The workpiece 1 is, for example, moved by a transport device of a device according to the invention.
In the direction of motion, first, a suction device 7 configured to suck away loosened parts 13 of the layer 2, in particular, the loosed manipulation medium 3, by means of vacuum is arranged. Thereto, the suction nozzle of the suction device 7 is aligned close to the surface of the layer 2. After the suction device 7, a brush 8 designed as roller brush is arranged. This brush 8 extends perpendicular to the drawing plane across the direction of motion of the workpiece 1. In this embodiment, the roller brush is rotated opposite to the direction of motion of the workpiece 1. The suction device 7 further comprises a radiation source 12. This radiation source 12 is configured to emit electromagnetic radiation, such as UV radiation, for curing the sucked-up parts 13 of the layer 2, whereby, curing of the parts 13 takes place within the suction device 7 so that there is no risk for adhering in and clogging the suction device 7.
By the contact of the bristles of the brush 8, parts 13 of the layer 2, in particular, the manipulation medium 3, are brushed away from the layer 2 and conveyed in direction of the suction device 7. This suction device 7 collects the loosened parts 13 (framed in a dotted manner).
Finally, a further radiation source 12 a configured to emit electromagnetic radiation, particularly UV radiation, to the brush 8 in order to cure and/or embrittle the material of parts of the layer 2 adhering there in order to clean the brush 8 is shown.
FIG. 3 shows an embodiment of brushes for mechanical removing of parts of the layer.
A workpiece 1 as well as several brushes 8 are shown in plan view. The workpiece 1 is moved through under the brushes 8 from the left to the right. The brushes 8 are here designed as disc brushes rotating in the shown directions of rotation 9 around a respective axis. When the workpiece 1 on which a layer with or without a manipulation medium (both is not shown) is located is moved through under the brushes 8, thus, parts of the layer, in particular, the manipulation medium, are mechanically removed by a contact with the brushes 8 relatively moving with respect to the workpiece 1.
By the rotating motion of the brushes 8, additionally to the relative motion between the workpiece 1 and the brushes 8, a further relative motion component is added so that the force by which the bristles of the brushes 8 act onto the layer or the manipulation medium is enlarged.
FIG. 4 shows a further embodiment of brushes for mechanical removing parts of the layer, in particular of the manipulation medium.
A workpiece 1 having a layer with or without a manipulation medium (both is not shown) as well as a brush band are shown in the side view. The workpiece 1 is moved from the left to the right. The brush band is trimmed with several brushes 8.
The brush band cyclicality circulates in the shown circulation direction so that the brushes 8 which are located at the underside of the brush band at the moment move from the right to the left opposite to the motion of the workpiece 1. In this way, additionally to the relative motion between the workpiece 1 and the brushes 8, a further relative motion component is added due to the motion of the workpiece 1 from the left to the right so that the force by which the bristles of the brushes 8 act onto the layer or the manipulation medium is enlarged.
FIG. 5 shows a further embodiment of brushes for mechanical removing of parts of the layer, in particular, of the manipulation medium.
A workpiece 1 which is moved through from the left to the right under a beam 11 comprising, on its side facing the workpiece 1, brushes which can contact the workpiece 1 or the layer and/or the manipulation medium thereon (both is not shown) is shown in the plan view. Thereby, the beam 11 extends across the entire extension of the workpiece 1, therefore, from above to below in the drawing.
FIG. 7 shows a possibility for cleaning the contact element.
A flat workpiece 1 which is moved from the left to the right in the drawing is shown. The workpiece 1 is covered with a liquid layer 2 which forms the surface of the workpiece 1 after the complete curing. Into the liquid layer 2, a manipulation medium 3 has been inserted at some places in order to displace the liquid layer 2. The workpiece 1 is moved, for example, by a transport device of a device according to the invention.
In the direction of motion, first, a suction device 7 configured to suck away parts 13 of the layer 2, particularly the loosed manipulation medium 3, by means of vacuum is arranged. Thereto, the suction nozzle of the suction device 7 is aligned close to the surface of the layer 2. After the suction device 7, a brush 8 designed as a roller brush is arranged. This brush 8 extends perpendicular to the drawing plane across the direction of motion of the workpiece 1. In this embodiment, the roller brush is rotated opposite to the direction of motion of the workpiece 1. Further, the suction device 7 comprises a radiation source 12. This radiation source 12 is configured to emit electromagnetic radiation, such as UV radiation, for curing the sucked-up parts 13 of the layer 2, whereby curing of the parts 13 takes place within the suction device 7 so that there is no risk that they adhere within the suction device 7 and clog it.
Apart from that, the functionality of the brush 8 as well as of the suction device 7 for removing the parts 13 of the layer 2, particularly the manipulation medium 3, is identical to the functionality of the embodiment in FIG. 2.
For cleaning the contact element or the brush 8, a radiation source 12 a emitting the UV radiation to the brush 8 and, thus, to the parts 13 of the layer 2 adhering on the bristles of the brush 8 is provided here, wherein the parts 13 can comprise the material of the layer 2 and material of the manipulation medium 3. In their rotary motion, the bristles of the brush 8 hit onto a stripper edge 14 after they have been irradiated by the radiation source 12 a. The stripper edge 14 extends downright in the drawing and comprises a surface being formed such that parts 13 of the layer 2 which has been loosed from the bristles, are guided into direction of a suction device 7 a located at this surface. The suction device 7 a is configured to receive the loosened parts 13 of the layer 2 and to the suck them away by means of vacuum.
The functionality of the cleaning of the brush 8 presents as follows:
Within a cycle, i.e., within one rotation of the brush 8, the bristles of the brush 8 first hit onto the surface of the layer 2, whereby, here, parts 13 of the layer 2 are removed. Parts 13 which are loosed and which do not adhere in the bristles of the brush 8 are conveyed by the brush in direction of the suction device 7 which sucks them away by means of vacuum. In the further course of the rotation of the brush 8, parts 13 adhered in the bristles of the brush 8 are irradiated by the radiation source 12 a, whereby they cure. The irradiation of the radiation source 12 a can be as strong as the parts 13 adhered in the bristles of the brush 8 embrittle. Subsequently, the bristles hit onto the stripper edge 14, whereby a mechanical effect to these parts 13 is achieved. Due to that, the cured and/or embrittled parts 13 loose from the bristles of the brush 8, whereby they are conveyed by their removal speed and the formed surface of the stripper edge 14 to the suction device 7 a. The suction device 7 a finally sucks away these parts 13. The bristles of the brush 8 cleaned in such manner are now available again for removing parts 13 of the layer 2 in a new cycle.
FIG. 8 shows a device in the form of a production line.
Two workpieces 1 which are moved one after another in the direction of motion from the left to the right are shown. Thereto, a transport device (not shown) is provided. The workpiece 1 comprises a liquid layer 2 on its surface. In and/or on the layer 2, a manipulation medium 3 is included. In the direction of motion, following elements are arranged one after another from the left to the right. First, a stationary contact element in the form of a brush 15 which is configured to contact the surface of the layer 2 in order to mechanically remove parts of the layer 2 is arranged. Thereby, it is here achieved that the manipulation medium 3 enclosed in the layer 2 is uncovered. After the brush 15, a radiation source 12 configured to emit UV radiation in the direction of the workpiece 1 or the layer 2 is arranged in order to at least partially cure the layer 2.
Subsequently in the direction of motion, an element comprising a chamber 4 through which the workpiece 1 is moved is provided. In the direction of motion, the chamber 4 first comprises a nozzle 6 emitting a fluid flow against the direction of motion of the workpiece 1 at an angle with respect to the surface of the layer 2. Thereby, the angle is maximum 90° or less. Preferably, an adaption of the angle between 0° and 30° is performed. This adaption can be performed, for example, depending on the removed material of the manipulation medium 3 and/or depending on the removed material of the layer 2. The fluid flow comprises solid bodies as described above in order to remove parts 13 of the layer 2. Further, the chamber 4 comprises a suction device 7 configured to suck away loosened parts 13 of the layer 2. Within the chamber 4, in the motion direction behind the nozzle 6, a radiation source 12 configured to irradiate the layer 2 with radiation in order to partially cure it so that the viscosity of the layer 2 changes is located. The radiation can, for example, be UV radiation having a wavelength of 200 to 400 nm.
In one embodiment, the fluid flow is configured such that it extends across the entire width of the workpiece 1, i.e., in a direction of extension of the workpiece 1 perpendicular to the drawing plane. In this way, it is ensured that all areas of the layer 2 are covered by the fluid flow.
A liquid or a gaseous substance is deployed as fluid. Specifically, also water and/or air can be deployed as fluid.
After the chamber 4, a contact element having a brush 8 in the form of a roller brush is arranged. The brush 8 is configured to mechanically remove parts of the layer 2. A radiation source 12 a, for example, emitting UV radiation to the brush 8, is arranged above the brush 8 in order to cure the material of the parts of the layer 2 adhering to the bristles in order to remove it out of the bristles, for example, at a stripper edge (not shown) for cleaning the brush 8.
The cleaning of the brush 8 can basically be performed according to the description to FIG. 7.
After the brush 8 in the direction of motion, a further radiation source 12 b is arranged. This radiation source 12 b emits, for example, UV radiation to the layer 2 and to an as possibly requested included manipulation medium 3 in order to perform a final curing.
FIG. 9 shows the removing of parts of the layer 2 with preceded and subsequent cleaning of the layer 2 by a device in the form of a production line.
Two workpieces 1 moved from the left to the right by a transport device having a conveyor transport 20 are shown. On the workpieces 1, a layer 2 is applied.
Thereby, before the removing of parts of layer 2, first, a cleaning agent 16 is applied onto the layer 2 by means of an application device 17, here comprising an application roller. Subsequently, this cleaning agent 16 is at least partially removed once again by a stripper 18. Subsequently, the removing of parts of the layer 2 by a stationary contact element 15 and a brush 8 is performed, wherein a UV beam source 12 is provided in order to irradiate the brush 8 and the contact element 15 in order to cure or brittle the thereat adhering material of removed parts of the layer 2. By means of a suction device 7, these parts 13 are continuously sucked away as described above. Moreover, as described in FIG. 7, a stripper edge (not shown) can be provided.
Subsequently, a further cleaning of the residual surface 2 remaining on the workpiece 1 is performed by means of a cleaning agent 16 a, an application device 17 a, and a device for removing the cleaning agent 16 a once again. Thereto, the device for removing once again the cleaning agent 16 a comprises a stripper 18 a being in contact with the surface of the layer 2 and a suction device 19 a. The suction device 19 a is configured to suck away and discharge the cleaning agent 16 a held back on the stripper 18 a.
Such a suction device for removing the cleaning agent 16 can also be provided at the first stripper 18.
FIG. 10 shows a workpiece 1 having a layer 2 on the surface of the workpiece 1, wherein the layer 2 has at least partially been cured and now comprises areas 2 a having a higher hardness grade and areas 2 b having a lower hardness grade, wherein these areas differ in the hardness grade about a factor of at least 1.5, preferably of at least 2. The here illustrated workpiece 1 having the layer 2 is, for example, further processed in one above-described method for surface processing.
FIG. 11 shows an exemplary flowchart of a method.
In a step S10, a layer is generated on a work piece as, e.g., shown in FIG. 10, wherein the layer has different hardness grades.
In step S12, the workpiece having the layer is moved to a removal device. Here, according to step S14, a contact between the surface of the layer and a contact element of the removal device is established.
Alternatively or additionally, according to step S15, a fluid flow having an optional solid body ratio is generated, wherein the fluid flow acts onto the surface of the layer, whereby parts of the layer are removed or loosed.
According to S16, after the establishing of the contact between the surface of the layer and a contact element according to step S14, a relative motion between the contact element and the surface is performed, wherein parts of the layer are removed or loosened.
According to step S18, separating of the loosened parts of the surface of the layer from the residual layer is performed. This can be performed, e.g., by sucking away, wiping away, or blowing away, or by another suitable measure.
In step S20, cleaning of the surface of the layer by means of contact or, also, in a contactless manner and/or by deploying a cleaning agent is performed.
The method can be further developed by exchanging, omitting and/or repeating several steps as well as by supplementing several steps.
The invention is not restricted to the here shown embodiments. Moreover, further devices and/or methods also corresponding to the invention can be achieved by combining, exchanging, or omitting individual features.
For example, the configuration of FIG. 7 can be supplementary integrated into the production line of FIG. 8 or provided instead of the chamber 4 and/or the here-shown brush 8.
Also, when in the FIGS. 2, 7, and 8, brushes 8 in the form of roller brushes are provided, supplementary or alternatively, the implementations of the brushes 8 of the FIGS. 3, 4, and 5 can be provided.
All of the nozzles 6 shown in the FIGS. 1 and 8 can be configured to emit a fluid flow with or without solid bodies, as described above. The fluid flow can include a gas and/or a liquid, wherein it especially includes air and/or water.
The radiation sources shown in all of the figures can be configured to, alternatively or additionally to the electromagnetic radiation, particularly UV radiation, also emit another radiation, as, e.g., electron radiation. The kind of radiation and/or the respective wavelength is thereby selected depending on the composition of the material of the layer 2 and/or of the manipulation medium 3 and/or depending on the desired effect of the radiation to the layer 2 and/or to the manipulation medium 3. Thus, for a complete curing, another wavelength and/or radiation can be deployed than if merely the viscosity of the layer 2 shall be changed in a previous step in order to, for example, prevent blurring of the recesses inserted by the manipulation medium 3.
All of the here-shown embodiments of the invention which at least comprise a brush 8 can further be configured such that the at least one brush 8 is provided movably. Thereby, it is to be understood that the at least one brush 8 can be moved actively in a predefined motion pattern. Therefore, for example, a disc brush can be provided at a pivotable suspension.

LIST OF REFERENCE SIGNS

1 workpiece
1 a connection element
2 layer
3 manipulation medium
4 chamber
5 curing device
6 nozzle
7 suction device
7 a suction device
8 brush
9 direction of rotation
10 circulation direction
11 beam
12 radiation source
12 a radiation source
12 b radiation source
13 loosened parts of the layer
14 stripper edge
15 brush
16 cleaning agent
16 a cleaning agent
17 application device
17 a application device
18 stripper
18 a stripper
19 a suction device
20 conveyor transport
S10 method step
S12 method step
S14 method step
S15 method step
S16 method step
S18 method step
S20 method step

Claims

What is claimed is:

1. Method for removing parts of a layer (2) on a surface of a workpiece (1), the method comprising the steps:

establishing a mechanical contact between a contact element and the layer (2) on the surface for removing parts (13) of the layer (2);

physical separating of removed parts (13) of the layer (2) from the parts of the layer (2) remaining on the surface of the workpiece (1).

2. Method for removing parts of a layer (2) on a surface of a workpiece (1), the method comprising the steps:

generating a fluid flow, preferred at an angle between 1° and 90° with respect to the layer (2), for removing parts (13) of the layer (2);

3. Method according to claim 1, wherein

the layer (2) on the surface of the workpiece (1) has differences in hardness of at least a factor 1.5, preferably at least a factor 2, between harder areas (2 a) and less hard areas (2 b).

4. Method according to claim 1, wherein

the physical separating of the loosened parts (13) of the layer (2) from the parts of the layer (2) remaining on the surface of the workpiece (1) is performed by sucking away, wiping away, blowing away, or by a combination of these steps.

5. Method according to claim 1, wherein

the layer (2) located on the surface of the workpiece (1) and the contact element move relative to one another during removing of parts of the layer (2).

6. Method according to claim 1, wherein

the contact element comprises a stationary and/or moved brush (8, 15) and/or a grinding element and/or a plane element, wherein, the brush (8) preferably comprises, at least as moved brush (8), a disc brush and/or a roller brush and/or a brush band, and/or, as stationary brush (8), a beam (11) with brush trimming, and/or wherein

the contact element, particularly the brush (8, 15), comprises textile and/or plastic fibers, particularly nylon fibers, Anderton, and/or metal, particularly steel, brass or copper as bristles.

7. Method according to claim 1, wherein

simultaneously to the establishing of the mechanical contact between the contact element and the layer (2) on the surface, and/or, simultaneously to the generating of the fluid flow onto the layer (2), an irradiation of the layer (2) and/or of the contact element and/or of the surroundings of the contact element in which separated parts of the layer (2) are located is performed preferably by electromagnetic radiation.

8. Method according to claim 1, wherein

the contact element (8, 15) is continuously cleaned during the physical separating, wherein the cleaning is preferably performed by use of a combination of an electromagnetic beam source (5, 12) and/or a suction device (7, 7 a) and/or a mechanical chipping edge (14).

9. Method according to claim 2, wherein

a nozzle (6) configured to generate a fluid flow is continuously cleaned during the physical separating, wherein the cleaning is performed preferably by a combination of an electromagnetic beam source (5, 12) and/or a suction device (7, 7 a) and/or one or several further drying devices or beam sources (5, 12).

10. Method according to claim 1, wherein

before the establishing of the mechanical contact between the contact element and the layer (2), cleaning of the surface of the layer (2) is performed, and/or wherein, after the physical separating of parts of the layer (2), cleaning of the residual layer (2) remaining on the surface of the workpiece (1) is performed.

11. Method according to claim 2, wherein

before the generating of the fluid flow onto the layer (2), cleaning of the surface is performed, and/or, after the physical separating of parts of the layer (2), cleaning of the residual layer (2) remaining on the surface of the workpiece (1) is performed.

12. Method according to claim 8, wherein

the continuous cleaning of the contact element, particularly of the brush (8), is performed by irradiation with UV radiation, preferably with a wavelength between 180 and 400 nm, in combination with stripping off cured residual components (13) from the separated parts of the layer (2) on a chipping edge (14) and a sucking away these residual components (13) by means of a suction device (7, 7 a).

13. Method according to claim 9, wherein

the continuous cleaning of the nozzle (6) is performed by irradiation with UV radiation, preferably with a wavelength between 180 and 400 nm, in combination with sucking away residual components (13) of the separated parts of the layer (2) by means of a suction device (7, 7 a).

14. Method according to claim 10, wherein

for cleaning the surface of the layer (2), a cleaning agent (16) which is removed once again subsequently, particularly preferred by means of a stripper (18) and/or a suction device (19), is applied onto the layer.

15. Device for performing the method according to claim 1, the device comprising:

a transport device configured to transport a workpiece (1) to further elements of the device, and/or at least one further element of the device to the workpiece (1);

as further element, a removal device configured to remove parts (13) of the layer (2) mechanically, preferred by a contact element, and/or in a fluidic manner, preferred by a fluid flow out of a nozzle (6), wherein

the device further comprises a control means configured to control the transport device and the further elements of the device in order to perform the method according to claim 1.

16. Method according to claim 2, wherein

17. Method according to claim 2, wherein

18. Method according to claim 2, wherein

19. Device for performing the method according to claim 2, the device comprising:

the device further comprises a control means configured to control the transport device and the further elements of the device in order to perform the method according to claim 2.