METHOD FOR PRODUCING A FLATABLE COMPLIANT COMPOSITE MATERIAL

Description

[0001] The invention relates to a method for producing a flat, flexible composite material, which comprises a carrier layer made of a flexible material, in particular in the form of a textile material, and a cover layer made of wood veneer connected thereto, which is more rigid, wherein a structure in the form of a plurality of grooves is engraved into the wood veneer of the cover layer by means of laser engraving in order to increase the flexibility of the wood veneer of the cover layer, comprising the following steps: Creating the structure to be engraved into the wood veneer of the cover layer and reading the structure into a control device of a program-controlled laser engraving device; arranging the composite material on a work table of the laser engraving device such that the wood veneer of the cover layer of the composite material is located on the side facing away from the work table; and activating at least one laser head of the laser engraving device connected to the control device and engraving the structure into the wood veneer of the cover layer of the composite material by means of the laser beam generated by the laser head (see US 2015 / 050454 A1).

[0002] Composite materials produced in this way are known and comprise, on the one hand, a carrier layer made of a flexible material, which is usually formed from a textile material, such as a woven fabric, knitted fabric, scrim, warp-knitted fabric, nonwoven fabric, or the like. The more rigid cover layer, in contrast, serves as a decorative layer and consists primarily of wood materials, in particular real wood veneer, which can, for example, have a thickness between approximately 0.1 mm and approximately 1 mm, in particular between approximately 0.25 mm and approximately 0.75 mm, and is generally glued to the carrier layer. The cover layer is laminated to the carrier layer, for example, with an intervening adhesive layer.The wood veneer of the cover layer is provided with a structure in the form of a plurality of grooves, which are engraved into the wood veneer by means of laser engraving and are intended, on the one hand, to give the cover layer an overall aesthetic impression, and, on the other hand, to increase the flexibility of the wood veneer of the cover layer, which is more rigid than the textile carrier layer.The fine laser engraving gives the wood veneer of the top layer and consequently the entire composite material an extraordinarily high degree of flexibility similar to leather or textile materials while still maintaining very high mechanical strength, so that such a composite material is suitable for a wide variety of applications, such as for clothing, as a decorative material for not necessarily flat visible surfaces of furniture, housings or vehicle interior trim parts, for covering seating furniture, for curtains, drapes, wall, ceiling and floor coverings and the like.

[0003] EP 2 776 240 B1 describes a generic method for producing a flat, flexible composite material with a carrier layer made of a textile fabric and a covering layer made of wood glued thereto, wherein the wood veneer of the covering layer of the prefabricated composite material is provided with the desired structure consisting of a uniform groove pattern by means of laser engraving.

[0004] In practice, however, it has been shown that the application of the structure of the wood veneer of the cover layer, which is formed in the form of a plurality of grooves, by means of laser engraving represents a considerable technical challenge, since the grooves of the structure engraved into the wood veneer must have a width as uniform as possible but very small, preferably z.B. in the range of approximately 10 µm to approximately 100 µm, and should have a depth as uniform as possible in order to at least partially or essentially completely cut through the wood veneer of the cover layer, while the carrier layer should remain essentially intact. Furthermore, the groove structure should extend with high precision and essentially evenly across the entire surface of the wood veneer of the cover layer, without any defects caused by the manufacturing process being visually detectable.

[0005] The aforementioned requirements cannot yet be satisfactorily met for several reasons, particularly with the increasing dimensions of the wood veneer of the cover layer. For example, attempts have been made to micromechanically shift the laser head across the width of the wood veneer of the cover layer in a program-controlled manner, which has proven to be very complex both in terms of construction and in terms of energy and time expenditure. Instead, attempts have also been made to engrave the groove structure into the wood veneer of the cover layer using a galvanometric laser. This laser is held stationary with respect to the composite material, but has a program-controlled movable mirror for deflecting the laser beam according to the desired structure. While such a galvanometric laser head is superior to a conventional,A laser head that can be moved along a plane has a significantly higher efficiency and is able to engrave the respective structure in particular up to approximately 10 to 65 times faster into the wood veneer of the cover layer, the problem in this case is that the galvanometric laser head cannot be positioned too close to the wood veneer of the cover layer, since, particularly in the case of a relatively large cover layer, a very oblique angle of incidence of the laser beam results at its edge areas, which consequently results in (too) wide and blurred grooves in the structure with only a small penetration depth into the cover layer, so that an aesthetically high-quality and uniform structure cannot be achieved over the entire surface of the cover layer, whereby there is also a risk that the laser head will become dirty due to local evaporation of the organic material of the cover layer and will require frequent cleaning,This leads to regular downtimes of the laser engraving devices. On the other hand, the galvanometric laser head cannot be positioned too far from the wood veneer, as this would require increased energy consumption to account for energy dissipation with increasing beam length. It would also be particularly difficult to precisely insert the structure in the form of very fine grooves into the wood veneer of the top layer, as the laser beam spreads out or widens with increasing beam length.

[0006] JP 2017-070978 A describes a method for laser engraving decorative, thread-like structures into an unspecified substrate using the laser beams of at least two adjacent laser heads. To achieve a smooth transition between the structures generated by each of the two laser heads, it is proposed to generate the structure generated by each laser head in an overlapping area of the laser's working areas using both laser heads. However, since the structures of both laser heads—i.e., twice as many line structures as in the adjacent discrete working areas of a respective laser head—are present in the overlapping area, the result leaves much to be desired, particularly from an aesthetic point of view.

[0007] Furthermore, laser engraving devices with multiple laser heads are known for other applications. For example, DE 196 34 190 A1 describes a laser engraving device with two galvanometric laser heads, whose laser beams can be focused simultaneously but independently of one another on different working areas of a workpiece by means of controlled, movable mirrors in order to mark the workpiece at different locations. However, applying a largely uniform structure to the wood veneer of the cover layer of a generic composite body is only possible to a limited extent in this way, since it has been shown that the transition between the structural sections generated by the laser beam of a respective laser head is visually discernible and therefore cannot meet aesthetic requirements.The same applies to a laser engraving method known from US 2010 / 0272961 A1 for producing a structure composed of multiple lines, which can involve the use of two lasers, each with a working area assigned to a respective laser. Finally, US 2009 / 0188543 A1 discloses a method for engraving linear structures on thin coatings of solar panels using multiple lasers, in which the starting point of each line generated by one laser is overlapped with the end point of another line generated by the other laser. d.h. The starting and end points of each line of the structure are engraved by both lasers.

[0008] The invention is based on the object of developing a method for producing a flat, flexible composite material of the type mentioned at the outset, while at least largely avoiding the aforementioned disadvantages, in a simple and cost-effective manner to the effect that both time- and energy-efficient engraving of a uniform and homogeneous structure over the entire surface of the wood veneer of the cover layer, even of large-format composite materials, is possible with very high precision.

[0009] According to the invention, this object is achieved in a method of the type mentioned at the outset in that at least two laser heads of the laser engraving device, which are connected to the control device, are activated in order to engrave the structure simultaneously into adjacent regions of the wood veneer of the cover layer of the composite material, which regions are assigned to a respective laser head, by means of the laser beam of a respective laser head, the laser heads being program-controlled in such a way that in a first overlapping section of the adjacent regions of the composite material, the structure is randomly engraved into the wood veneer of the cover layer partly by the laser beam of one laser head and partly by the laser beam of the other laser head, so that there is no sharp boundary between the working regions of the laser heads and consequently no visible transition between the regions of the cover layer processed by different laser heads.

[0010] In a flat, flexible composite material produced by means of such a method, which has a carrier layer made of a flexible material, in particular in the form of a textile material, and a cover layer made of wood veneer connected thereto, which is more rigid in comparison, the wood veneer of the cover layer accordingly comprises a structure in the form of a plurality of grooves, engraved by means of laser engraving.

[0011] The invention therefore provides that first - after the flat composite body has been joined by connecting, such as gluing, the textile carrier layer to the as yet unengraved wood veneer of the decorative cover layer - the desired structure is created, e.g. using a suitable CAD program, and read into the control device or into a memory unit assigned to it of the program-equipped laser engraving device, as is known as such from EP 2 776 240 B1 cited at the outset. As is also known from this, the composite material prefabricated in this way is then placed on the work table of the laser engraving device in such a way that the wood veneer of the cover layer of the composite material is on the side facing away from the work table and is thus exposed to the laser heads connected to the control device of the laser engraving device.The laser heads of the laser engraving device are then activated to engrave the respective structure in the form of grooves into the wood veneer of the top layer of the composite material using the laser beam generated by each laser head.

[0012] The invention provides that the at least two laser heads connected to the control device engrave the structure simultaneously into adjacent areas of the wood veneer of the cover layer of the composite material, which are assigned to a respective laser head, by means of the laser beam of a respective laser head, wherein in the case of two laser heads, for example, one laser head engraves the structure in a left-hand longitudinal area of the cover layer, while at the same time the other laser head engraves the structure in a right-hand longitudinal area of the cover layer, so that time-effective engraving of the structure is possible with high precision, since the laser heads can be arranged at an optimal distance from the wood veneer of the cover layer and both the beam length and the angle of incidence of the laser beams of both orof all laser heads can be selected to be very similar, so that a uniform and homogeneous structure is produced in a highly precise manner over the entire surface, even of large-format, flat composite bodies. In order to prevent the areas of the wood veneer of the cover layer engraved by different laser heads from being visible due to even slight discontinuities in the structure in the transition area between these areas, and in this way impairing the overall aesthetic impression and / or causing a regionally changed compliance of the composite body, the invention provides in particular that the laser heads are program-controlled in such a way that in a first overlap section of the adjacent areas of the composite material, the structure is randomly engraved into the wood veneer of the cover layer partly by the laser beam of one laser head and partly by the laser beam of the other laser head.Consequently, according to the invention, the regions of the composite body processed by a respective laser head of the laser engraving device are not each assigned to a fixed and unchangeable, adjacent working region of a respective laser head, but rather overlap the adjacent working regions of a respective laser head in the first overlap section, in which the structure is randomly engraved into the wood veneer of the cover layer partly by the laser beam of one laser head and partly by the laser beam of the other laser head. In this way and according to the invention, there is no sharp boundary between the working regions of the laser heads and consequently no visible transition between the regions of the cover layer processed by different laser heads, wherein the first overlap section can preferably have a width of, for example, between approximately 2 mm and approximately 50 cm, in particular between approximately 5 mm and approximately 25 cm.

[0013] An algorithm suitable for the random assignment of one or the other laser head for engraving the structure into the wood veneer of the decorative layer in the first overlap section can expediently be stored in the control software of the control device of the laser engraving device, wherein the width of the first overlap section can preferably be adjustable, e.g. by means of a conventional input device such as a keyboard, a touchscreen or the like, in order to be able to adapt it to the respective design of the desired structure if necessary.

[0014] If the structure is engraved in the wood veneer of the cover layer in the form of grooves extending at least partially between two adjacent regions of the composite material assigned to a respective laser head, as is usually the case with flat composite bodies of this type, the starting and end points of the grooves generated by the laser beam of one laser head, as well as the end and starting points of the grooves generated by the laser beam of the other laser head, can be randomly determined in the first overlap section. Those grooves of the structure which extend from the region processed by one of the laser heads across the first overlap section into the adjacent region of the wood veneer of the cover layer processed by another laser head, consequently have randomly offset starting and ending points in the first overlap section.End points from which the laser beam of one laser head or up to which the laser beam of the other laser head has engraved the respective groove into the wood veneer of the top layer.

[0015] As already indicated, the method according to the invention, due to its high precision with respect to the laser beams of the laser heads acting at very similar angles on the wood veneer of the cover layer, makes it possible for the structure engraved in the form of a plurality of grooves into the wood veneer of the cover layer to be engraved in such a way that the carrier layer remains essentially intact, whereas the wood veneer of the cover layer is at least partially or essentially completely severed. The wood veneer of the cover layer should advantageously be severed at least largely, i.e. in particular to at least about 70% of its thickness, preferably to at least about 80% of its thickness, most preferably to at least about 90% of its thickness, or even essentially completely, so that the composite material can be imparted with very high flexibility while also having very high mechanical strength.

[0016] According to an advantageous embodiment, it can further be provided that the work table of the laser engraving device with the composite material is displaced past the laser heads, in particular substantially continuously or semi-continuously, in order to successively engrave the structure into adjacent areas of the wood veneer of the cover layer, wherein the direction of displacement of the work table is selected substantially parallel to the extension direction of the first overlap section between the laser heads. In this way, very large-format webs of the composite material can be processed practically continuously in a very time-efficient manner, and assembly or assembly processes are eliminated.Removal times are minimized, wherein the composite material is expediently displaced successively in such a way that it is successively fed to the work areas assigned to a respective laser head and then, after the structure has been engraved into the respective areas of the wood veneer of the cover layer, is displaced further in order to process the following work areas assigned to a respective laser head. Furthermore, it is conceivable in this way, for example, to provide the carrier layer made of textile material in the form of a continuous web, the latter being unwound from a roll, for example, after which the unwound continuous web is successively glued to wood veneers of the cover layer and the sheet-like composite material thus essentially continuously prefabricated is fed to the laser heads by means of the successively displaced work table in order to engrave the structure into the cover layer.After laser engraving, the highly flexible composite material can then be cut to the desired dimensions or wound onto rolls in the form of a continuous material.

[0017] The movement of the work table can be conveniently synchronized with the laser heads by means of a programmatically controlled drive of the work table, which is connected to the control device of the laser heads and moves the work table depending on the processing state of the structure.

[0018] For this purpose, the work table can, for example, have a carriage suitable for receiving the composite material, which is driven by the motor drive and guided past the laser heads along a guide, such as a linear guide. Instead, the work table can, for example, also comprise a belt conveyor suitable for receiving the composite material, e.g. in the form of a revolving carrier belt, which is driven by the motor drive. Alternatively, it is conceivable, for example, for the work table to comprise a roller conveyor suitable for receiving the composite material, having a plurality of parallel rollers or cylinders, at least some of which are rotationally driven by the motor drive.

[0019] In conjunction with such a substantially continuous or semi-continuous supply of the composite material to the laser heads, it is furthermore advantageous if a respective laser head is programmed in such a way that, in a second overlapping section extending substantially perpendicular to the direction of displacement of the work table, of adjacent regions of the composite material each assigned to the same laser head, the structure is randomly engraved into the wood veneer of the cover layer by the laser beam of the respective laser head before or after a displacement step of the work table.that the areas of the wood veneer of the cover layer, which are arranged next to one another in the direction of displacement of the work table and engraved one after the other in chronological order by one and the same laser head, are visible due to even slight discontinuities in the structure in the transition area of these areas and in this way impair the overall aesthetic impression and / or cause a partially changed compliance of the composite body, the invention accordingly provides - similar to the first overlap section formed between the working areas of adjacent laser heads - that a respective laser head is controlled by programming in such a way that, in a respective,In the second overlapping section of the adjacent regions of the composite material, extending approximately perpendicular to the direction of displacement of the work table, the structure is randomly engraved into the wood veneer of the cover layer by the laser beam of the respective (same) laser head, partly before a displacement step of the work table and partly after a displacement step of the work table. In this way, there is no sharp boundary between the regions of the wood veneer of the cover layer successively fed to the laser heads by means of the displaceable work table, and consequently no visible transition between the regions of the cover layer successively processed by a respective laser head. The second overlapping section (as well as the first overlapping section; see above) can preferably have a width of between approximately 2 mm and approximately 50 cm, in particular between approximately 5 mm and approximately 25 cm.

[0020] If, as mentioned above, the structure is engraved in the wood veneer of the cover layer in the form of grooves extending at least partially between two adjacent regions of the composite material each assigned to the same laser head, as is usually the case with generic flat composite bodies, the starting and end points of the grooves generated by means of the laser beam of the respective laser head before a displacement step of the work table as well as the end and starting points of the grooves generated by means of the laser beam of the respective laser head after a displacement step of the work table can again be randomly determined in the second overlap section.Those grooves of the structure which extend from the area machined by a respective laser head before a displacement step of the work table across the second overlap section into the adjacent area of the wood veneer of the cover layer machined by the same laser head after the displacement step consequently also have randomly offset start and end points in the second overlap section, up to which the laser beam of the respective laser head or from which the laser beam of the same laser head has engraved the respective groove into the wood veneer of the cover layer before or after a respective displacement step of the work table.

[0021] To ensure a consistently precise, flat alignment of the composite material on the work table during processing using the laser heads, an advantageous development can provide for the composite material to be sucked onto the work table, at least during the engraving of the structure. This can be achieved using any vacuum generator known in the art, e.g., in the form of pumps, which press the composite material against the work table, e.g., against its surface, against its carrier belt, or against its roller conveyor, as a result of the vacuum.

[0022] As already indicated, for the reasons stated above, the laser engraving machine can advantageously comprise at least two stationary galvanometric laser heads, which have at least one mirror and / or lens connected to the control device, wherein the laser heads are programmed by means of the control device in such a way that their mirrors and / or lenses are displaced according to the structure to be engraved in the wood veneer of the covering layer.Such galvanometric laser heads are known as such from the prior art, for example from DE 196 34 190 A1 cited at the beginning, whereby their advantages primarily consist in the fact that they are very time and cost efficient due to the fact that only the mirrors and / or lenses used for the controlled deflection of the laser beams have to be movable, but the laser heads themselves can be arranged stationary, and in particular do not require any complex mechanics for the translational displacement of the laser head.

[0023] As already mentioned, due to the plurality of laser heads, the distance between the wood veneer of the cover layer and the laser heads can be adjusted to the optimal level even in the case of large-format composite bodies, in order, on the one hand, to ensure the creation of a structure with very narrow grooves as a result of highly focused "short" laser beams and, on the other hand, to prevent components of the organic material of the cover layer that have been converted into the vapor phase from being deposited on the laser heads, which would require frequent cleaning. The laser heads are preferably arranged, for example, at a distance of between approximately 10 cm and approximately 150 cm, in particular between approximately 30 cm and approximately 130 cm, preferably between approximately 50 cm and approximately 110 cm, from the surface of the wood veneer of the cover layer of the composite material.

[0024] If desired, the wood veneer of the top layer can also be coated with a layer of varnish after laser engraving in order to seal the usually porous surface of the wood veneer of the top layer while ensuring a very high-quality aesthetic overall impression of the flat composite material.

[0025] A flat, flexible composite material produced by the method according to the invention can therefore, especially if it has relatively large dimensions, have a structure created in the wood veneer of the cover layer by laser engraving, which extends uniformly over substantially the entire surface of the wood veneer of the cover layer. The plurality of grooves of the structure engraved into the wood veneer of the cover layer can preferably at least partially or substantially completely cut through the wood veneer of the cover layer, whereas the carrier layer, in particular, remains substantially intact, in which case reference is made to the above explanations.Furthermore, the plurality of grooves of the structure engraved into the wood veneer of the cover layer can advantageously have a substantially uniform width and / or a substantially uniform depth, resulting in a high aesthetic appeal and a uniform resilience across the entire surface of the composite material, which largely corresponds to that of conventional leather or textile materials. Furthermore, the wood veneer of the cover layer can, if required, be coated with a lacquer layer, for example.

[0026] Further features and advantages of the invention will become apparent from the following description of an embodiment with reference to the drawings. Fig. 1a is a schematic perspective view of a carrier layer and cover layer forming the components of a composite material during the prefabrication of a blank of the composite material; Fig. 1b is a schematic perspective view of an embodiment of a galvanometric laser head of a laser engraving device according to Fig. 2 bis 6 during the engraving of a structure formed from a plurality of grooves into the cover layer of the composite material according to Fig. 1a ; Fig. 1c a schematic perspective view of an embodiment of the flexible composite material after laser engraving according to Fig. 1b ; Fig. 2 is a schematic perspective view of an embodiment of a laser engraving device suitable for carrying out a method according to the invention; Fig. 3 is a schematic front view of the laser engraving device according to the Fig. 2 ; Fig. 4 a schematic side view of the laser engraving device according to the Fig. 2 and3 ; Fig. 5 a schematic top view of the laser engraving device according to the Fig. 2 bis 4 ; Fig. 6 a schematic perspective detailed view of two galvanometric laser heads of the laser engraving device according to the Fig. 2 bis 5 during the simultaneous engraving of a structure formed from a plurality of grooves into the cover layer of the composite material; Fig. 7 is a schematic plan view of the wood veneer of the cover layer of a composite material, which has been provided with a structure formed from a plurality of grooves by means of laser engraving, but without overlapping sections being provided between the different areas processed by the respective laser heads; and Fig. 8 is a schematic plan view of four exemplary grooves of the structure formed by means of laser engraving using the laser engraving device according to Fig. 2 bis 6 structure engraved in the wood veneer of the cover layer, which extends between two regions of the composite material generated by different laser heads of the laser engraving device over a first overlap section.

[0027] In the Fig. 1a A situation is depicted during the prefabrication of a blank of a flat composite material, which is designated overall by the reference numeral 10. The composite material 10 comprises a carrier layer 12 made of a flexible material, such as a textile material, and a comparatively more rigid cover layer 11 made of a decorative wood veneer. To prefabricate the blank of the composite material 10, the carrier layer 12 is bonded to the cover layer 11, which can be done, for example, by means of an adhesive layer 13 arranged between the carrier layer 12 and the cover layer 11.

[0028] In the Fig. 1b is an embodiment of one of the galvanometric laser heads 18 of a device described below with reference to Fig. 2 bis 6 schematically shown a laser engraving device explained in more detail, which is used to engrave a structure 26 formed from a plurality of grooves into the wood veneer of the cover layer 11 of the blank of the composite material 10 according to the Fig. 1a serves to increase the flexibility of the wood veneer of the cover layer 11 and to give it an aesthetically high-quality overall impression. In the present case, the laser head 18 is a stationary galvanometric laser head 18, which has a mirror 19 that is largely freely movable in three-dimensional space in order to deflect the generated laser beam in the desired direction. The laser head 18, including a drive for its mirror 19 (not shown in the drawing), is connected to a control device of the laser engraving device (cf. Fig. 2 bis 6 ) in operative connection in order to be able to programmatically control the laser head 18 equipped with the movable mirror 19 by means of the control device in such a way that the mirror 19 is displaced according to the structure 26 to be engraved into the wood veneer of the cover layer 11. The desired structure 26 is created in advance, e.g., using a suitable CAD program, and read into the control device.

[0029] The Fig. 1c shows the finished, now very flexible, flat composite material 10, similar to known leather or textile materials, after the structure 26, which in the present case extends essentially uniformly over practically the entire surface of the cover layer 11, has been engraved into the wood veneer of the cover layer 11 by means of laser engraving.

[0030] In the Fig. 2 bis 6 is an embodiment of a method for automated execution of the inventive method for producing the sheet-like flexible composite material 10 according to the Fig. 1c A program-engineered laser engraving device, which is provided overall with the reference numeral 200, is shown schematically. The laser engraving device 200 comprises a work table 202 which is displaceable in the direction of the arrow V in a controlled manner, in particular approximately horizontally, along a guide 201, in particular in the form of a linear guide, and in the present case is designed essentially in the manner of a carriage, which is designed to receive a composite material to be processed, in particular a relatively large-format and, for example, essentially web-shaped composite material according to the Fig. 1a and is able to successively supply the composite material 10 to a laser processing area 203 on the one hand, and on the other hand, after the removal of a finished processed composite material according to the Fig. 1c can be shifted back in the opposite direction to engrave a variety of composite materials in a largely continuous or semi-continuous manner, thereby enabling efficient mass production. The surface of the work table 202 serving to receive the composite material 10 can preferably be connected to a vacuum generator (not shown in the drawing) to press the composite material 10 against the work table during laser engraving and thus ensure precise, consistent, and reproducible alignment of the composite material in the laser processing area 203.A drive of the work table 202 is connected to a control device of the laser engraving device 200, also not shown in the drawing, which control device comprises a central data processing unit in a manner known per se, which in the present case is equipped with an input device 204 for entering and / or selecting a desired structure to be engraved into the cover layer 11 of the composite material 10, a desired processing program, etc. In addition, the laser engraving device comprises a plurality of - here two - galvanometric laser heads 183a, 183b which are also connected to the control device and are arranged stationary above the laser processing area 203, but are optionally height-adjustable, which are arranged at a distance from one another perpendicular to the direction of displacement V of the work table 202 and whose structure corresponds to that according to. Fig. 1 For the sake of completeness, however, it should be noted that the laser heads 183a, 183b do not necessarily have to be arranged perpendicular to the direction of displacement V of the work table 202, but can also be arranged offset therefrom, for example.

[0031] As in particular the Fig. 6 As can be seen, the laser heads 183a, 183b are arranged, for example, at a distance of approximately 75 cm from the work table 202 or the composite material 10 positioned thereon and serve the purpose of, by means of a respective, program-controlled displacement of their mirror 19 (cf. the Fig. 1b ) deflectable laser beam 181a, 181b the structure 26 (cf. the Fig. 1c ) simultaneously into adjacent areas B1, B2 of the wood veneer of the cover layer 11 of the composite material 10, which areas are assigned to the respective working area 182a, 182b of a respective laser head 183a, 183b, wherein the laser heads 183a, 183b are program-controlled according to the invention in such a way that in a first overlap section U1 of the adjacent areas B1, B2 of the composite material 10, the structure 26 is randomly engraved into the wood veneer of the cover layer 11 partly by the laser beam 181a, 181b of one laser head 183a, 183b and partly by the laser beam 181b, 181a of the other laser head 183b, 183a. The working areas 182a, 182b of the laser heads 183a, 183b orThe regions B1, B2 in which the structure 26 is engraved into the cover layer 11 are therefore not stationary according to the invention, but rather overlap in the first overlap region U1, in which parts of the structure 26 are randomly engraved into the cover layer by the laser beam 181a, 181b of one or the other laser head 183a, 183b, in order to ensure that, in particular in the case of a groove in the structure 26 extending from the working region 182a of one laser head 183a or from one region B1 of the cover layer 11 into the working region 182b of the other laser head 183b or into the other region B2 of the cover layer 11 of the composite material 10, a flowing, invisible transition is created which does not locally impair the material properties of the finished laser-engraved composite body 10, such as in particular its compliance.

[0032] In a similar way, the laser heads 183a, 183b are preferably programmatically controllable in such a way that in a second overlap section U2 (cf. the Fig. 7 ) adjacent regions of the composite material 10, each assigned to the same laser head 183a, 183b, the structure 26 is randomly engraved into the wood veneer of the cover layer 11 by the laser beam 181a, 181b of the respective laser head 183a, 183b, partly before a displacement step of the work table 202 and partly after a displacement step of the work table 202. The work areas 182a, 182b of a respective laser head orThe regions B1, B2 which are adjacent to one another in the direction of displacement V of the work table 202 and in which the structure 26 is engraved into the cover layer 11 are therefore also preferably not stationary, but rather overlap in the second overlap region U2, in which parts of the structure 26 are randomly engraved into the cover layer by the laser beam 181a, 181b of the respective laser head 183a, 183b before or after a respective displacement step of the work table 202, in order to ensure that, in particular in the case of a groove in the structure 26 which extends over at least two displacement steps of the work table 202, a flowing, invisible transition is produced which does not locally impair the material properties of the finished laser-engraved composite body 10, such as in particular its compliance.

[0033] In the Fig. 7 is a schematic plan view of a structure 250 of the wood veneer of a cover layer 11 of the composite material 10, which has been produced by laser engraving using two laser heads with stepwise displacement V of a work table, but ohne that overlapping sections U1, U2 have been provided between the different areas 251a, 251b, 251c, 251d processed by the respective laser heads. As can be seen from the Fig. 7 As can be seen, in the case of such discrete working areas of a respective laser head, visible transitions or irregularities 252a, 252b, 252c, 252d of the engraved structure 250 can arise both between the adjacent areas 251a, 251c and 251b, 251d, which have been processed by different laser heads, and between the adjacent areas 251a, 251b and 251c, 251d, which have each been processed by the same laser head but in different displacement positions of the work table, which are to be prevented according to the invention.

[0034] In the Fig. 8 is a plan view of four exemplary grooves 265a, 265b, 265c, 265d of the structure 260 engraved into the wood veneer of the cover layer 11 of the composite material 10, which are located, for example, between two different laser heads 183a, 183b of the laser engraving device 200 according to the Fig. 2 bis 6 generated regions B1, B2 of the composite material 10 extend over a first overlap section U1. At least parts of the structure 260 have been engraved into the wood veneer of the cover layer 11 in the form of grooves 265a, 265b, 265c, 265d extending at least partially between two adjacent regions B1, B2 of the composite material 10 assigned to a respective laser head 183a, 183b, wherein the starting and end points 261, 262, 263, 264 of the grooves 265a, 265b, 265c, 265d generated by means of the laser beam 181a, 181b of one laser head 183a, 183b and the end and starting points 261, 262, 263, 264 of the grooves 265a, 265b, 265c, 265d generated by means of the laser beam 181b, 181a of the other laser head 183b, 183a generated grooves 265a, 265b, 265c, 265d in the first overlap section U1 have been randomly determined, ie the grooves 265a, 265b, 265c, 265d begin ordo not end at the boundary of a respective discrete working area of a respective laser head 183a, 183b, as is the case with the . Fig. 7 is the case, but the starting and end points 261, 262, 263, 264 of the grooves 265a, 265b, 265c, 265d have been randomly determined within the first overlapping area U1 and consequently offset from one another in order to ensure the transition between the working areas 182a, 182b of the laser heads 183a, 183b (see also the Fig. 6 ) to "blur".

[0035] In a corresponding manner, it can be expediently provided that the structure 260 is engraved in the wood veneer of the cover layer 11 in the form of grooves 265a, 265b, 265c, 265d extending at least partially between two adjacent regions B1, B2 of the composite material 10, each associated with the same laser head 183a, 183b, wherein the starting and end points 261, 262, 263, 264 of the grooves 265a, 265b, 265c, 265d generated by means of the laser beam 181a, 181b of the respective laser head 183a, 183b before a displacement step of the work table 202 as well as the end and starting points 261, 262, 263, 264 of the grooves 265a, 265b, 265c, 265d generated by means of the laser beam 181a, 181b of the respective laser head 183a, 183b after a displacement step of the work table 202 are randomly determined in the second overlap section U2.

[0036] Finally, if desired, it can also be provided that the wood veneer of the cover layer 11 of the composite material 10 is provided with a layer of lacquer (not shown) after the laser engraving process described above, which can be done either manually or, in particular, also in an automated manner by feeding the completely engraved composite bodies 10, for example by means of the work table 202, piece by piece or in sections to a lacquering device (also not shown in the drawing) arranged downstream of the laser processing area 203 of the laser engraving device 200.

Claims

1. Method for producing a planar resilient composite material (10) which has a carrier layer (12) of a resilient material, in particular in the form of a textile material, and a cover layer (11) of wood veneer which is connected to said carrier layer (12) and is more rigid in comparison to the latter, wherein a structure (26, 260) configured in the form of a plurality of grooves (265a, 265b, 265c, 265d) is engraved in the wood veneer of the cover layer (11) by means of laser engraving, so as to increase the resilience of the wood veneer of the cover layer (11), comprising the following method steps: - establishing the structure (26, 260) to be engraved in the wood veneer of the cover layer (11), and importing the structure (26, 260) into a control apparatus of a laser engraving device (200) specified in programming terms; - arranging the composite material (10) on a worktable (202) of the laser engraving device (200) in such a manner that the wood veneer of the cover layer (11) of the composite material is located on the side facing away from the worktable (202); and - activating at least one laser head (18, 183a, 183b) of the laser engraving device (200) that is connected to the control apparatus, and engraving the structure (26, 260) in the wood veneer of the cover layer (11) of the composite material (10) by means of the laser beam (181a, 181b) generated by the laser head (18, 183a, 183b), characterized in that at least two laser heads (183a, 183b) of the laser engraving device (200) that are connected to the control apparatus are activated so as to, by means of the laser beam (181a, 181b) of a respective laser head (183a, 183b), engrave the structure (26, 260) simultaneously in adjacent regions (B1, B2) of the wood veneer of the cover layer (11) of the composite material (10) that are assigned to a respective laser head (183a, 183b), wherein the laser heads (18, 183a, 183b) in programming terms are controlled in such a manner that in a fist overlapping portion (U1) of the adjacent regions (B1, B2) of the composite material (10) the structure (26, 260) is engraved in the wood veneer of the cover layer (11) randomly in part by the laser beam (181a, 181b) of the one laser head (183a, 183b) and in part by the laser beam (181a, 181b) of the other laser head (183a, 183b).

2. Method according to Claim 1, characterized in that the structure (26, 260) is engraved in the wood veneer of the cover layer (11) in the form of grooves (265a, 265b, 265c, 265d) which at least in part extend between two adjacent regions (B1, B2) of the composite material (10) that are assigned to a respective laser head (183a, 183b), wherein the initial points and / or final points (261, 262, 263, 264) of the grooves (265a, 265b, 265c, 265d) generated by means of the laser beam (181a, 181b) of the one laser head (183a, 183b) and the final points and / or initial points of the grooves (265a, 265b, 265c, 265d) generated by means of the laser beam (181a, 181b) of the other laser head (183a, 183b) in the first overlapping portion (U1) are randomly established.

3. Method according to Claim 1 or 2, characterized in that the structure (26, 260) engraved in the wood veneer of the cover layer (11) in the form of a plurality of grooves (265a, 265b, 265c, 265d) is engraved in such a manner that the carrier layer (12) remains substantially intact, whereas the wood veneer of the cover layer (11) is at least in part or substantially completely cut through.

4. Method according to one of Claims 1 to 3, characterized in that the worktable (202) of the laser engraving device (200) with the composite material (10), is displaced past the laser heads (183a, 183b) in particular in a substantially continuous or semi-continuous manner, so as to engrave the structure (26, 260) successively in adjacent regions (B1, B2) of the wood veneer of the cover layer (11), wherein the displacement direction (V) of the worktable (202) is chosen so as to be substantially parallel to the direction of extent of the first overlapping portion (U1) between the laser heads (183a, 183b).

5. Method according to Claim 4, characterized in that the displacement of the worktable (202) in programming terms is synchronized with the laser heads (18, 183a, 183b) in that a drive of the worktable (202) that is connected to the control apparatus of the laser heads (183a, 183b) displaces the worktable (202) as a function of the processing state of the structure (26, 260).

6. Method according to Claim 4 or 5, characterized in that the worktable (202) - has a slide which is suitable for receiving the composite material (10) and is driven by a motorized drive and is guided past the laser heads (183a, 183b) along a guide (201); or - comprises a belt conveyor, in particular in the form of a revolving carrier belt, which is suitable for receiving the composite material (10) and is driven by a motorized drive and is guided past the laser heads (183a, 183b); or - comprises a roller track which has a plurality of rolls or rollers disposed in parallel and is suitable for receiving the composite material (10), at least some of the rolls or rollers being rotationally driven by means of a motorized drive so as to guide the composite material (10) past the laser heads (183a, 183b).

7. Method according to one of Claims 4 to 6, characterized in that a respective laser head (183a, 183b) in programming terms is controlled in such a manner that, in a second overlapping portion (U2), extending substantially perpendicularly to the displacement direction (V) of the worktable (202), of adjacent regions (B1, B2) of the composite material (10) that are in each case assigned to the same laser head (183a, 183b), the structure (26, 260) is engraved in the wood veneer of the cover layer (11) by the laser beam of the respective laser head (183a, 183b) randomly in part before a displacement step of the worktable (202), and in part after a displacement step of the worktable (202).

8. Method according to Claim 7, characterized in that the structure (26, 260) is engraved in the wood veneer of the cover layer (11) in the form of grooves (265a, 265b, 265c, 265d) which at least in part extend between two adjacent regions (B1, B2) of the composite material (10) that are in each case assigned to the same laser head (18, 183a, 183b), wherein the initial points and / or final points (261, 262, 263, 264) of the grooves (265a, 265b, 265c, 265d) generated by means of the laser beam (181a, 181b) of the respective laser head (183a, 183b) before a displacement step of the worktable (202), and the final points and / or initial points (261, 262, 263, 264) of the grooves (265a, 265b, 265c, 265d) generated by means of the laser beam (181a, 181b) of the respective laser head (183a, 183b) after a displacement step of the worktable (202) in the second overlapping portion (U2) are randomly established.

9. Method according to one of Claims 1 to 8, characterized in that the composite material (10), at least while the structure (26, 260) is being engraved in the wood veneer of the cover layer (11), is suctioned to the worktable (202).

10. Method according to one of Claims 1 to 9, characterized in that the laser engraving machine (200) has at least two stationary galvanometric laser heads (18, 183a, 183b) which have at least one mirror (19) and / or lens connected to the control apparatus, wherein the laser heads (18, 183a, 183b) by means of the control apparatus are controlled in programming terms in such a manner that their mirrors (19) and / or lenses are displaced in a manner corresponding to the structure (26, 260) to be engraved in the wood veneer of the cover layer (11).

11. Method according to one of Claims 1 to 10, characterized in that the laser heads (18, 183a, 183b) are disposed at a spacing of between 10 cm and 150 cm, in particular between 30 cm and 130 cm, preferably between 50 cm and 110 cm, from the surface of the wood veneer of the cover layer (11) of the composite material (10).

12. Method according to one of Claims 1 to 11, characterized in that the wood veneer of the cover layer (11) after laser engraving is provided with a lacquer layer.