EP4263161A1

EP4263161A1 - Method, manufacturing cell, and wood veneer

Info

Publication number: EP4263161A1
Application number: EP21840607.2A
Authority: EP
Inventors: Sebastian Stümpel; Philipp Dahlem
Original assignee: Sebastian Stuempel & Philipp Dahlem Rootpecker GbR
Current assignee: Sebastian Stuempel & Philipp Dahlem Rootpecker GbR
Priority date: 2020-12-21
Filing date: 2021-12-19
Publication date: 2023-10-25
Also published as: US20240051177A1; DE102020134525B4; DE102020134525A1; WO2022136203A1

Abstract

The invention relates to a manufacturing cell for producing a three-dimensionally deformable wood veneer, comprising - a receiving surface (4) for receiving a wood veneer (6) to be processed, and - a device (8) for partly or completely separating the wood veneer in order to form a plurality of veneer strands (10), wherein the invention is characterized by - a device (12) for pressing the wood veneer (6) to be processed and the veneer strands (10) against the receiving surface (4), and the device (12, 18) is designed to generate a pressure difference between a first side (14) and a second side (16) of the wood veneer (6) to be processed and the veneer strands (10).

Description

PROCESS, PRODUCTION CELL AND WOOD VENEER

The present invention relates to a method for producing a three-dimensionally deformable wood veneer, with the method steps: providing a wood veneer on a receiving surface, the wood veneer bearing against the receiving surface with a first side; Partially or completely separating the wood veneer into a plurality of veneer strands; Creation of connections between the veneer strands. The invention further relates to a manufacturing cell for producing a three-dimensionally deformable wood veneer and a three-dimensionally deformable wood veneer.

The document DE 101 24 913 C1 describes a method for producing a three-dimensionally deformable wood veneer according to the preamble of claim 1. According to DE 101 24 913 C1, narrow grooves are made in a wood veneer and the areas or veneer strands separated from one another by the grooves are formed by a shear-deformable Crosslink reconnected. During the making of the grooves and the application of the cross-connection, the veneer is held together by an undivided layer of the veneer, which is finally removed again by grinding, cutting or the like after the shear-deformable cross-connection has been applied.

According to the teaching of document DE 101 24 913 C1, a planar material is provided as a material for the method claimed there, the thickness of which is at least 5% greater than the thickness of the 3D planar element to be produced, narrow grooves being spaced apart from one another , where the groove depth is greater than or equal to the thickness of the 3D surface element and smaller than the thickness of the workpiece. Exactly this at least 5% of the thickness of the Material are therefore not or not completely divided when the grooves are made and form a bond between the separate areas as a full-surface layer until the actual shear-deformable cross-bond made of fleece or adhesive has been applied.

According to DE 101 24 913 C1, the final intended thickness of the three-dimensionally deformable wood veneer is produced by the final removal of this excess at least 5% of the thickness. The "excess 5% of the thickness" can, for example, be cardboard or the like, which is glued on before processing and then removed again by cutting and/or grinding after cutting and producing the shear-deformable cross-connection.

The disadvantage of the method described in DE 101 24 913 C1 is that at least the excess 5% of the thickness of each veneer produced is waste. Furthermore, the provision and removal of such an additional or carrier layer is time-consuming and costly due to the process steps required for this.

Against this background, the present invention is based on the technical problem of specifying an improved method and an improved production cell for producing a three-dimensionally deformable wood veneer, which in particular enable a more cost-effective, faster and resource-saving production of three-dimensionally deformable wood veneers. A three-dimensionally deformable wood veneer is also to be specified.

The technical problem described above is solved in each case by a method according to claim 1, a production cell according to claim 8 and a wood veneer according to claim 12. Further refinements of the invention result from the dependent claims and the following description.

According to a first aspect, the invention relates to a method for producing a three-dimensionally deformable wood veneer, with the method steps: providing a wood veneer on a receiving surface, the wood veneer bearing against the receiving surface with a first side; Partially or completely separating the wood veneer into a plurality of veneer strands; Making Connections between the veneer strands. The method is characterized in that the wood veneer and the veneer strands are pressed against the receiving surface by generating a pressure difference, with a first pressure on the first side of the wood veneer and the veneer strands being present, with a second pressure on a second side facing away from the first Side of the wood veneer and the veneer strands is present and wherein the first pressure is less than the second pressure. In other words, the wood veneer and the veneer strands are pressed against the receiving surface and held in position with a force that acts in particular over a large area.

It can be provided that the veneer strands are extended along a first direction and that the connections between the veneer strands are produced along a second direction, the second direction being different from the first direction.

Alternatively or additionally, connections between the veneer strands can be made along the first direction and/or inclined to the first and/or second direction.

The wood veneer and the veneer strands are held in position under pressure, so that an additional backing layer can be omitted. In this way, on the one hand, a flat surface can be achieved and, on the other hand, a faster and more resource-saving production of three-dimensionally deformable wood veneer can be made possible.

In particular, the wood veneer and the veneer strands are pressed against the receiving surface during the partial or complete separation and during the making of the connections between the veneer strands by creating the pressure difference.

Experiments have shown that both the wood veneer during partial or complete separation and the veneer strands can be reliably held in position by means of the pressure difference. In particular, tests have shown that even very narrow veneer strands that are completely separated from one another can be reliably held in position by means of the pressure difference, so that any shear-deformable cross-composite to be applied can be applied without an additional backing layer in order to provide a three-dimensionally deformable wood veneer.

The wood veneer and the veneer strands refer to one and the same semi-finished product in different processing states. Before the partial or complete separation, the semi-finished product to be processed is referred to in the present text as "wood veneer". During and after the partial or complete separation, the semi-finished product is referred to as "veneer strands", regardless of whether the veneer strands are completely separated from one another or are still connected to one another in sections or locally.

The terms "wood layer" and "wood layer" and "wood sheet" are used synonymously in the present text. The terms “layer” and “layer” or “additional layer” and “additional layer” are used synonymously in the present text.

If a wood veneer is mentioned here, it can be a flat or plate-like material that has one or more layers of wood. For example, it can be provided that the wood veneer consists of a single layer of wood of one type of wood.

The wood veneer may comprise a layer or sheet of wood which has been separated from a trunk of a wood species or from a block of wood which has already been processed by sawing and/or cutting processes and/or peeling processes.

Alternatively it can be provided that the wood veneer has at least one wood layer of a wood species and has at least one additional layer which is connected to the wood layer over the entire surface.

The additional layer can have a further layer of wood of another or the same type of wood or, for example, have a fleece or cardboard. The wood veneer may have two or more additional layers. The wood veneer can in particular have up to ten additional layers or in particular have up to five additional layers. The wood layer can be glued to such an additional layer. If two or more additional layers are provided, the additional layers can be glued together, for example.

The wood veneer can therefore in particular be a mono-material, that is to say only have one type of wood, or it can be a sandwich material, that is to say have two or more layers of one or more types of wood and/or other materials layered flat on top of one another.

A thickness of the wood veneer measured perpendicularly to the first side of the wood veneer or to the supporting surface has, in particular, an amount selected from a range between 0.3 mm up to and including 20 mm.

In particular, the wood veneer has a thickness selected from a range between 0.3 mm up to and including 2 mm.

In particular, the wood veneer has a thickness selected from a range between 0.45 mm up to and including 1.2 mm.

In particular, the wood veneer has a thickness selected from a range between 1 mm and 5 mm inclusive.

In particular, the wood veneer has a thickness selected from a range between 5 mm up to and including 20 mm.

The wood veneer can be, for example, a sheet-like material with a thickness of, for example, 1.2 mm.

The wood veneer can have a length of up to 100 cm.

The wood veneer can have a length selected from a range of 10 cm - 100 cm. The wood veneer can have a length selected from a range of 100 cm - 1000 cm.

The wood veneer can have a width of up to 100 cm.

The wood veneer can have a width selected from a range of 10 cm - 100 cm.

The wood veneer can have a width selected from a range of 100 cm - 1000 cm.

The wood veneer may have a rectangular shape. For example, the wood veneer can have a length of about 80 cm and a width of 60 cm.

The wood veneer may have a square shape. For example, the wood veneer can have a length of about 40 cm and a width of 40 cm.

The individual veneer strands can each have a width selected from a range of 0.5 mm - 3 mm.

The individual veneer strands can each have a width selected from a range of 3 mm - 50 mm.

Provision can be made for the first pressure to have an amount selected from a range between 0.1 mbar and 800 mbar. Provision can be made for the first pressure to have an amount selected from a range between and including 0.1 mbar-500 mbar. Provision can be made for the first pressure to have an amount selected from a range between and including 0.1 mbar-200 mbar. Provision can be made for the first pressure to be negative relative to the ambient pressure.

Alternatively or additionally, it can be provided that the second pressure has an amount selected from a range between 1013.25 mbar and 3000 mbar inclusive. Provision can be made for the second pressure to have an amount selected from a range between 1013.25 mbar - 1500 mbar inclusive. Provision can be made for the second pressure to have an amount selected from a range between 1100 mbar and 1500 mbar inclusive. Provision can be made for the second pressure to be an overpressure relative to the ambient pressure. It can be provided that the second pressure corresponds to the ambient pressure.

It can be provided that the pressure difference between the first and the second pressure is 200 mbar or more. It can be provided that the pressure difference between the first and the second pressure is 500 mbar or more. It can be provided that the pressure difference between the first and the second pressure is 800 mbar or more. It can be provided that the pressure difference between the first and the second pressure is 1000 mbar or more.

It can be provided that the pressure difference between the first and the second pressure is 3000 mbar or less. It can be provided that the pressure difference between the first and the second pressure is 2000 mbar or less. It can be provided that the pressure difference between the first and the second pressure is 1100 mbar or less.

The pressure difference can be generated in particular as a static pressure difference and can be kept essentially constant over the period of time of the production steps, so that the pressure difference during the method steps fluctuates by less than 10%, in particular by less than 5%, more particularly by less than 2.5% varies.

When it is said here that the wood veneer is pressed against the receiving surface by generating a pressure difference, the first pressure and the second pressure are generated in a pressure medium that exerts the pressure on the wood veneer. The pressure medium is in particular a fluid, more particularly a gas or gas mixture, more particularly ambient air. As is known, ambient air consists of approx. 78% by volume of nitrogen, approx. 21% by volume of oxygen and 1% by volume of other gases. It can be provided that such a pressure medium, in particular ambient air, acts in particular directly on the wood veneer and the veneer strands or is in contact with the wood veneer and the veneer strands.

Completely severing the wood veneer into a plurality of veneer strands means severing across the entire thickness so that the veneer strands are completely separated from each other. After the complete separation and before the connections are made, the veneer strands can therefore be in the form of individually removable separate veneer strands, each of which is no longer connected to its adjacent veneer strands. Only when the connections are made are the completely separate strands of veneer combined to form the three-dimensionally deformable wood veneer.

A partial separation of the wood veneer to form a plurality of veneer strands means that the veneer strands remain connected to one another at least in sections after the separation and before or during the production of the connections. In other words, the veneer strands are not completely separated from one another by the cutting, but connections between the veneer strands remain. This can be achieved in that the veneer strands are not separated from one another at least in sections over the full thickness of the wood veneer and/or interrupted separation points are introduced.

The receiving surface can be a substantially continuous flat surface against which the wood veneer lies flat and flat. Alternatively, the receiving surface can be grid-like and have a plurality of intersecting webs, so that the wood veneer is only supported in a grid-like manner and rests against the intersecting webs. Alternatively, the receiving surface can have a plurality of segments spaced apart from one another. Alternatively or in addition, the receiving surface can have a surface structure that promotes an even distribution of a pressure, for example intersecting grooves. In this case, in particular, no porous or permeable material structure of the receiving surface is necessary. It can be provided that the first pressure is generated by means of a vacuum pump. In other words, the wood veneer can be "sucked" onto the receiving surface by means of a vacuum pump in order to generate the pressure difference and press the wood veneer onto the receiving surface.

It can be provided that the first pressure is a negative pressure generated in comparison to an atmospheric pressure of a working environment.

Provision can be made for the receiving surface to have a porous material. In particular, the receiving surface can be formed on a plate that has a porous material or consists of a porous material.

The vacuum pump can be connected to the porous material, so that during operation the vacuum pump also generates the first pressure as a negative pressure within the pores of the porous material and this negative pressure is thus present via the porous material on the first side of the wood veneer.

If a porous material is mentioned here, it is in particular an air-permeable material such as an open-pored, foamed material, an air-permeable wood material such as MDF or chipboard, a fabric, a sintered material or the like.

Alternatively or additionally, the receiving surface can have a material that is not permeable to air or consist of a material that is not permeable to air, such as a metal or the like. The non-air-permeable material can have a surface structure, bores, channels or the like, in the area of which a vacuum acting on the wood veneer or the veneer strands can be generated

For example, provision can be made for the receiving surface to have through-openings which have been made in the material of the receiving surface, for example by mechanical processing methods such as drilling or milling. However, it is preferably provided that the receiving surface is a flat surface made of a porous material, which is a flat surface of the wood veneer and the Veneer strands made possible by generating a negative pressure using a vacuum pump.

The following method step can take place: Laying the wood veneer and/or the veneer strands flat on the receiving surface, the receiving surface being in particular a flat surface and in particular having a porous material and the first pressure being applied in particular via pores of the porous material on the wood veneer and/or the veneer strands applied.

It can be provided that the second pressure is the atmospheric pressure (1 bar) of the working environment. If the first pressure is generated, for example, by means of a vacuum pump, i.e. it is, for example, a negative pressure that is reduced compared to atmospheric pressure, the second pressure can be applied as atmospheric pressure of the working environment on the second side of the wood veneer and the veneer strands and the wood veneer and the veneer strands in this way against the Press receiving surface.

Alternatively or additionally, it can be provided that the second pressure is generated by means of a pump, so that, for example, a pressure that is higher than the ambient pressure of a working atmosphere, i.e. an overpressure, can be generated in the area of the second side in order to press the wood veneer against the receiving surface . It can therefore be provided that the second pressure is an overpressure and the first pressure corresponds to the ambient pressure of a working atmosphere. It can therefore be provided that the second pressure is an overpressure and the first pressure is a negative pressure. The terms "overpressure" and "negative pressure" refer to an ambient pressure of the working atmosphere, which is approx. 1 bar.

However, the generation of a pressure difference preferably takes place exclusively by means of a vacuum pump, so that the first pressure is lower than an atmospheric pressure of a working environment, while the second pressure applied to the second side is the atmospheric pressure of the working environment. Provision can be made for the wood veneer and/or the veneer strands to be pressed against the receiving surface by means of at least one hold-down device. Such a hold-down device can, for example, be a terminal strip or the like. Provision can be made for such a hold-down device to be used for pre-positioning of the wood veneer before the pressure difference is generated. Alternatively, it can be provided that the wood veneer and/or the veneer strands are pressed against the receiving surface at least at times during the performance of the method steps both by the hold-down device and due to the pressure difference generated.

It can be provided that a hold-down device clamps the wood veneer before and/or during the partial or complete separation and in particular counteracts cutting or separating forces during partial or complete separation, so that the wood veneer is subjected to tensile stress during the partial or complete separation.

Provision can be made for two or more hold-down devices to be used in order to press the wood veneer and/or the veneer strands against the receiving surface. In particular, it can be provided that six hold-down devices or fewer, in particular four hold-down devices or fewer, are used in order to press the wood veneer and/or the veneer strands against the receiving surface. In particular, it can be provided that exactly two hold-down devices are used in order to press the wood veneer and/or the veneer strands into the receiving surface.

It can be provided that two hold-down devices are used to introduce a tensile stress into the wood veneer and/or the veneer strands along the first direction. In this way, the wood veneer and/or the veneer strands can be kept under tension during the separation and/or while the connections are being made. This supports in particular a flat position and/or a positional accuracy of the wood veneer and/or the veneer strands during the separation and/or during the making of the connections.

Provision can be made for the wood veneer to be partially or completely separated by cutting. It can be provided that the partial or complete separation of the wood veneer takes place by means of a knife or by means of several knives. The wood veneer can therefore be divided into the veneer strands by cutting with a knife or with several knives. The veneer strands are therefore separated from one another by cuts, which cuts can partially or completely penetrate the thickness of the wood veneer.

It can be provided that at least one knife is a rotary knife. Alternatively or additionally, it can be provided that at least one knife is a perforation rotary knife. Alternatively or additionally, it can be provided that at least one knife is a scoring knife. A respective rotary knife is in particular held or mounted such that it can rotate on an axis or can be driven in rotation about an axis of rotation by means of a drive. A scoring blade is in particular firmly connected to a holder, so that its degrees of freedom of movement are only provided by the machine axes, such as CNC-controlled linear and/or pivoting axes or the like.

Depending on whether the veneer strands are to be partially or completely separated from one another, the optimal knife for the processing task can be selected.

For example, it can be provided that for the complete separation of the wood veneer into a plurality of essentially parallel veneer strands, a rotary knife with a circular, uninterrupted blade is used, which completely separates a veneer strand from the remaining wood veneer to be divided with a single cut, for example.

If, for example, a partial separation is to be produced by interrupted cuts, perforation rotary knives can be used, which have a segmented blade so that the respective blade, depending on the angle, does not cut the wood veneer or only cuts part of its thickness.

A scoring knife can be used for both partial and complete cutting. A rotary knife with a circular, uninterrupted blade can also be used for partially separating the wood veneer if a cutting depth of the rotary knife is set such that the entire thickness of the wood veneer is not cut. In this way, the rotary knife introduces a separating point in the manner of a groove between adjacent veneer strands.

In particular, it is provided that the cuts, which partially or completely separate the veneer strands from one another, are oriented parallel to one another. Provision can be made for the cuts to be segmented, viewed in a longitudinal direction, so that the cuts are interrupted and cross braces remain between the veneer strands, which continue to locally connect the veneer strands to one another after they have been separated.

Provision can be made for two or more knives to be arranged next to one another in order to simultaneously make parallel cuts in the wood veneer and thus simultaneously produce several adjacent veneer strands.

Provision can be made for two or more knives to be arranged next to one another, with the arrangement of the knives covering the entire width of the wood veneer. Provision can thus be made for all veneer strands to be cut simultaneously with a single knife overrun.

Provision can be made for two or more knives to be arranged next to one another, with the arrangement of the knives covering part of the width of the wood veneer. Provision can thus be made for the veneer strands to be cut sequentially in two or more knife overruns. The number of overflows results from the ratio of the width of the wood veneer to the width of the knife arrangement. For example, if the width of the knife arrangement corresponds to one third of the width of the wood veneer, three passes are required to produce the veneer strands.

For such a knife arrangement, the width of the veneer strands results in particular from the distance between the adjacent knives. However, it is also possible, for example, to produce half cutting widths in which, after a first overflow, a second overflow takes place, with the knives being offset by half a knife spacing for the second overflow. A respective strand of veneer that has been produced in the first overflow is therefore divided into two strands of veneer in the second overflow, these two strands of veneer from the second overflow having half the width of the veneer strand from the first overflow. It goes without saying that in this way cut widths divided into thirds or quarters etc. can also be set as the width for the veneer strands.

For example, it can be provided that two or more knives, in particular up to one hundred rotary knives, further in particular up to twenty rotary knives, further in particular up to ten rotary knives are arranged side by side on a shaft.

It can be provided that the knives are assigned leading and/or trailing hold-down devices, which additionally press and fix the wood veneer against the support surface during cutting.

According to alternative configurations of the method, the partial or complete separation of the wood veneer can be done by milling, laser cutting, water jet cutting, plasma cutting, embossing, punching, bumping, splitting or the like.

It can be provided that the connections between the veneer strands are produced by applying an adhesive, in particular a plurality of adhesive strands being applied. For example, it can be provided that a plurality of parallel strands of adhesive are applied. Alternatively or in addition, the adhesive can be applied selectively as adhesive dots spaced apart from one another.

It can be provided that the first direction, along which the veneer strands are elongated and have been separated, and the second direction, along which the adhesive strands run, enclose an angle greater than 0° and less than or equal to 90° to one another. It can be provided that the first direction, along which the veneer strands are elongated and have been separated, and the second direction, along which the adhesive strands run, are parallel to one another and the Adhesive is introduced as adhesive strands at least partially into a parting line between the veneer strands and/or is applied to the parting line of adjacent veneer strands.

In particular, it can be provided that a longitudinal extension of the adhesive strands runs along the second direction and the second direction is in particular oriented orthogonally to the first direction, along which the veneer strands are longitudinally extended and have been separated.

It can further be provided that the adhesive strands cross at least partially.

It can be provided that the adhesive is a hot-melt adhesive, wherein a plurality of parallel adhesive strands can be applied simultaneously as hot-melt adhesive threads by means of a thread applicator in order to produce a plurality of connection points between adjacent veneer strands in an overflow.

Provision can be made for the adhesive to be provided as a thread impregnated with hot-melt adhesive. The thread can be made of a natural or synthetic fiber. The thread can be a textile thread. The thread can have a plastic. If an adhesive is mentioned here, it can therefore be a thread coated with adhesive or impregnated with adhesive.

Provision can be made for the adhesive to be a liquid adhesive which is applied over the surface or in strands or threads.

Provision can be made for the adhesive to be provided as an adhesive tape or as a strip or thread material, so that individual strips or threads can be glued on in order to connect the veneer strands to one another. Provision can be made for the strip or thread material to be provided on a roll or spool and to be unwound from the roll or spool. Establishing the connections can also be referred to as applying a shear-deformable cross-connection. In particular, the cross-connection or connections are produced in such a way that the connections produced are shear-deformable and that the individual veneer strands can move in the longitudinal direction relative to one another in order to ensure improved three-dimensional deformability.

The adhesive can already be applied while the partial or complete separation is taking place. The adhesive can be applied after the partial or complete separation is complete. An application device for applying adhesive can be arranged together with a cutting or separating device for partially or completely separating the wood veneer on a common portal of a production cell and can be moved together with the cutting or separating device. The application device can be arranged on a portal of a production cell that is separate from the cutting or separating device.

In particular, a shear-deformable transverse composite can be produced by gluing the veneer strands by means of an applied adhesive, the adhesive being applied, for example, transversely to the veneer strands, for example being applied in a meandering pattern.

The adhesive can be, for example, a glue, a hot-melt adhesive, a multi-component adhesive or a rubber adhesive. The wood veneer and the three-dimensionally deformable wood veneer produced from it have the same layer structure and the same thickness, with any applied adhesive not being added to the layer structure and the material thickness.

According to a further embodiment of the method it can be provided that the wood veneer has at least one wood ply or a wood layer and has at least one textile ply or a textile layer. In this case it can be provided that the production of connections between the veneer strands, in particular in the second direction, takes place in that the textile layer in the partial or complete separation of the wood veneer is not divided or is not divided at least in sections. Thus, the production of connections between the veneer strands and the partial separation of the veneer strands take place simultaneously, with the textile layer forming part of the wood veneer, in particular a cross-connection. In this case, the textile layer forms a shear-deformable transverse composite.

If a textile layer or a textile layer is mentioned here, it consists in particular of a flat textile material such as a woven fabric, a knitted fabric, a knitted fabric, a mesh, a stitched fabric, a fleece, a felt or the like. The textile layer can consist of a natural or synthetic fiber.

In particular, the textile layer in the present case can be a fleece layer or fleece layer.

In particular, the fleece layer can have a unidirectional fleece, wherein the unidirectional fleece can have an anisotropic fiber direction.

It can be provided that, in addition to the textile layer, a wood layer of the wood veneer has only been partially separated, so that the veneer strands also have connections in addition to the textile layer that were part of the original wood layer of the wood veneer before the separation. In contrast to the shear-deformable transverse composite of the textile layer, these connections resulting from the wood layer are not shear-deformable and break or tear open during further processing or shaping of the three-dimensionally deformable wood veneer, while the shear-deformable transverse composite of the textile layer remains intact.

Thus, a partial separation of the wood veneer having the wood layer and the textile layer can take place, for example, by means of a perforation rotary knife that produces perforated or segmented cuts.

It is therefore possible to produce a three-dimensionally deformable wood veneer whose shear-deformable transverse composite consists of a textile layer and no additional adhesive is applied to produce the shear-deformable transverse composite. Alternatively, a three-dimensionally deformable wood veneer can be produced, the shear-deformable transverse composite of which has both a textile layer and an adhesive, in particular an adhesive applied in the manner described above.

According to a second aspect, the invention relates to a production cell for producing a three-dimensionally deformable wood veneer, with a receiving surface for receiving a wood veneer to be processed, with a device for partially or completely separating the wood veneer into a plurality of veneer strands. The production cell is characterized by a device for pressing the wood veneer to be processed and the veneer strands onto the receiving surface, the device being set up to generate a pressure difference between a first side and a second side of the wood veneer to be processed and the veneer strands.

The production cell is set up to carry out the method according to the invention described above. All structural features described with reference to the method according to the invention can be part of the device according to the invention, with individual features being discussed in more detail below.

The receiving surface can be a substantially continuous planar surface. Alternatively, the receiving surface can be grid-like and have a plurality of intersecting webs, so that the wood veneer is only supported in a grid-like manner and rests against the intersecting webs. Alternatively, the receiving surface can have a plurality of segments spaced apart from one another.

Alternatively or in addition, it can be provided that the receiving surface has through-openings and/or surface structures, such as grooves, intersecting grooves or the like, which are provided, for example, by mechanical Processing methods such as drilling or milling have been introduced into the material of the receiving surface.

The device for pressing the wood veneer to be processed onto the receiving surface can have a vacuum pump. For example, the vacuum pump can be an electric vacuum pump.

Provision is preferably made for the receiving surface to be a flat surface made of a porous material, with the vacuum pump being coupled to the porous material. In this way, the wood veneer and the veneer strands can lie flat over the entire surface by generating a negative pressure using the vacuum pump.

The vacuum pump can in particular be connected to the porous material in such a way that during operation the vacuum pump generates a first pressure as a negative pressure within the pores of the porous material and this negative pressure is thus applied via the porous material to a first side of the wood veneer to be processed.

It can be provided that at least one knife is a rotary knife. Alternatively or additionally, it can be provided that at least one knife is a perforation rotary knife. Alternatively or additionally, it can be provided that at least one knife is a scoring knife.

Provision can be made for two or more knives to be arranged at a distance from one another in order to simultaneously make parallel cuts in the wood veneer and thus simultaneously produce a plurality of veneer strands adjacent to one another. Provision can be made for two or more knives to be arranged next to one another at equidistant intervals in order to simultaneously make parallel cuts in the wood veneer and thus simultaneously produce several adjacent veneer strands.

Provision can be made for two or more knives to be arranged next to one another, with the arrangement of the knives covering a width of 0.01 m or more and 10 m or less. It can be provided that two or more knives are arranged side by side, the arrangement of knives covering a width of 0.001 m or more and 1 m or less.

Provision can be made for two or more knives to be arranged next to one another, with the arrangement of the knives covering a width of 0.02 m or more and 1 m or less. Provision can be made for two or more knives to be arranged next to one another, with the arrangement of the knives covering a width of 0.03 m or more and 5 m or less. For example, it can be provided that two or more knives, in particular up to 500 rotary knives, more particularly up to 20 rotary knives are arranged side by side on a shaft.

Provision can be made for a distance between two adjacent knives to be 0.2 mm or more and 50 mm or less. It can be provided that a distance between two adjacent knives is 0.3 mm or more and 20 mm or less. Provision can be made for a distance between two adjacent knives to be 0.5 mm or more and 10 mm or less. Provision can be made for a distance between two adjacent knives to be 0.5 mm or more and 5 mm or less. Provision can be made for a distance between two adjacent knives to be 0.5 mm or more and 2 mm or less, in particular 1 mm.

It can be provided that the knives are assigned leading and/or trailing hold-down devices, which additionally press and fix the wood veneer against the support surface during cutting. Provision can be made for the leading and/or trailing hold-down devices to consist of a spring plate or, in particular, of a rolling roller.

The device for partially or completely separating the wood veneer can be infinitely adjustable in two or more coordinate directions and/or have a stop to limit the depth of the separating. The device for partially or completely separating the wood veneer can be steplessly adjustable in exactly three coordinate directions, for example, and/or have a stop to limit the depth of the separating. The device for partially or completely separating the wood veneer can be associated with revolving hold-down devices for fixing the veneer strands during cutting and/or gluing. The hold-down devices of the device for partially or completely separating the wood veneer can be cylinders, rollers or skids.

The wood veneer can be held on a movable table, e.g. movable relative to knives, so that the wood veneer can be moved by a linear movement of the table, e.g. in the direction of rotating or stationary knives, with a cutting feed being effected by the movement of the table. The production cell can have a CNC-controlled machine kinematics, which has up to three translatory and up to three rotational, controlled degrees of freedom of movement.

The production cell can have an application device for applying adhesive for connecting the veneer strands, wherein the application device for applying adhesive can have a heating device, wherein the heating device can be set up in particular for steplessly adjusting the adhesive temperature. Running hold-down devices can be assigned to the application device for fixing the veneer strands during the gluing. The hold-down devices of the application device can be cylinders, rollers or skids. The hold-down devices of the application device can simultaneously be the hold-down devices of the device for partial or complete separation. Alternatively, the hold-down device of the application device and the hold-down device of the device for partial or complete separation can be provided separately from one another.

The application device for applying adhesive can have a thread applicator with one or more heating nozzles, via which one thread or several threads are glued to the veneer strands with hot-melt adhesive in order to produce a transverse bond, in particular to produce a shear-deformable transverse bond.

The application device for applying the adhesive can be a thread applicator and can have a heating device in which heating nozzles are spring-mounted be able. The heating device can be set up to heat up the heating nozzles and to continuously adjust the temperature of the adhesive.

Each of the heating nozzles can be pressed elastically against the veneer strands during the application of the adhesive, it being possible for the heating nozzles to be mounted in an elastically elastic manner by means of respectively assigned springs.

According to alternative configurations, more than two heating nozzles can be held on the heating device. In particular, up to 50 heating nozzles can be held on the heating device, in particular up to 20 heating nozzles can be held on the heating device, more particularly 8 heating nozzles can be held on the heating device.

The cross-connection can be created with a thread that is coated with hot-melt adhesive.

In particular, the thread is drawn through the heating nozzles, whereby the hot-melt adhesive melts and is bonded to the veneer strands.

The production cell can have one, two or more hold-down devices for clamping the wood veneer against the receiving surface. The production cell can have one, two or more hold-down devices for applying tensile stress to the wood veneer. Alternatively or additionally, the tensile stress can be introduced as a process force as a result of a cutting or separating process.

According to a third aspect, the invention relates to a three-dimensionally deformable wood veneer, the wood veneer having veneer strands connected to one another, the wood veneer having at least one wood layer and at least one textile layer, the veneer strands being connected to one another by the textile layer and the textile layer not being divided or at least in sections is not divided. The three-dimensionally deformable wood veneer can have been produced using a method according to the invention. According to a fourth aspect, the invention relates to a three-dimensionally deformable wood veneer produced using a method according to the invention. In particular, the three-dimensionally deformable wood veneer shows no traces of processing resulting from the removal of a base layer.

The invention is described in more detail below with reference to a drawing showing exemplary embodiments. They each show schematically:

1A shows a production cell according to the invention in a plan view;

1B shows the production cell according to the invention in a side view;

2A shows a first process step of a method according to the invention;

2B shows a second process step of a method according to the invention;

2C veneer strands;

2D veneer strands;

2E shows a third process step of a method according to the invention;

2F shows a three-dimensionally deformable wood veneer;

2G shows a three-dimensionally deformable wood veneer;

3A shows a three-dimensionally deformable wood veneer;

3B shows a three-dimensionally deformable wood veneer;

4A shows a three-dimensionally deformable wood veneer;

4B shows a three-dimensionally deformable wood veneer;

5A shows a rotary knife; 5B shows a rotary perforating knife;

6A shows a thread applicator in a plan view;

FIG. 6B shows the thread applicator from FIG. 6A in a side view; FIG.

FIG. 6C shows the thread applicator from FIG. 6A in a further side view

7A another production cell according to the invention in a plan view;

FIG. 7B shows the production cell according to the invention from FIG. 7A in a side view.

Fig. 1A shows a production cell 2 for producing a three-dimensionally deformable wood veneer, with a receiving surface 4 for receiving a wood veneer to be processed 6. The receiving surface 4 is a flat surface which is oriented parallel to a plane x-y of the Cartesian coordinate system x-y-z according to FIG. 1A. The receiving surface has a porous material.

The production cell 2 has a device 8 for partially or completely separating the wood veneer 6 into a plurality of parallel veneer strands 10. The veneer strands 10 extend parallel to a z-axis of the Cartesian coordinate system x-y-z according to FIG. 1A.

The production cell 2 has a device 12 for pressing the wood veneer 6 to be processed and the veneer strands 10 onto the receiving surface 4, the device 12 for generating a pressure difference between a first side 14 and a second side 16 of the wood veneer 6 to be processed and the veneer strands 10 is set up (Fig. 1B).

The device 12 has a vacuum pump 18 which is connected via hose connections 19 to a plate 21, the receiving surface 4 is formed on the plate 21 and the plate 21 at least in the region of the receiving surface 4 from the porous material exists. The plate 21 can be sealed on a side remote from the receiving surface.

The vacuum pump 18 is set up to generate a negative pressure as the first pressure in the area of the side 14, the negative pressure being lower than an atmospheric pressure of a working environment U present on the second side 16 (FIG. 1B).

An application device 20 for applying adhesive 22 for connecting the veneer strands 10 is also provided. In the present case, the adhesive 22 is an adhesive thread 22. The application device 20 for applying the adhesive 22 is a thread applicator 20 and has a heating device 24 in which the heating nozzles 25 are spring-mounted, and the heating device 24 for heating the heating nozzles 25 and for continuous adjustment of the adhesive temperature (Fig. 6B).

During the application of the adhesive, each of the heating nozzles 25 is pressed in a resiliently elastic manner against the veneer strands, the resiliently elastic mounting of the heating nozzles 25 taking place by means of springs 27 assigned in each case.

The device 8 for partially or completely separating the wood veneer 6 has a cutting device 26 with a plurality of rotary cutters 28 which, viewed in the y-direction, are arranged at equidistant distances from one another.

The cutting device 26 is continuously adjustable in each coordinate direction x, y and z.

The application device 20 can be steplessly adjusted in each coordinate direction x, y and z.

According to alternative configurations, the cutting device 26 and the application device 20 can be held on a common tool holder.

Stops 30 may be provided to limit the depth of the severing. Production cell 2 has two hold-down devices 32 in order to fix the wood veneer 6 in place. For better clarity, the hold-down device 32 is shown transparently in FIG. 1B. According to alternative configurations, a single hold-down device 32 can be provided.

In addition, the device 20 can have further hold-down devices 33, which press the veneer 6 against the receiving surface 4, as the example according to FIGS. 7A and 7B shows. FIGS. 7A and 7B show a further embodiment of a device 20 which has additional hold-down devices 33 . The hold-down devices 33 are revolving hold-down devices 33, one hold-down device 33 being arranged in front of the rotary cutters 28 and one hold-down device 33 being arranged behind the rotary cutters 28. The hold-down devices 33 ensure that the veneer strands are not lifted off the receiving surface 4 by the rotary knife 28 . The hold-down devices 33 are elastically braced against the wood veneer or the veneer strands.

In a first method step, the wood veneer 6 is provided on the receiving surface 4 , the wood veneer 6 bearing against the receiving surface 4 with a first side 14 .

The wood veneer 6 is pressed against the receiving surface 4 by generating a pressure difference using the vacuum pump 18 . This also causes the wood veneer 6 to lie flat on the receiving surface 4, so that the wood veneer 6 rests against the receiving surface 4 over its entire surface and essentially without a gap.

The vacuum pump 18 generates a negative pressure as the first pressure in the area of the first side 14, which is lower than an atmospheric pressure of the working environment U in the area of the second side 16. The first pressure is generated as a static pressure and during the entire subsequent processing in the essentially kept constant.

Next, the wood veneer 6 is fixed with the hold-down devices 32, with additional hold-down device 33 can be provided for fixing. Then, in a second method step, the wood veneer 6 is completely separated into a plurality of veneer strands 10, the veneer strands 10 extending along a first direction, here parallel to the z-axis.

As can be seen from FIGS. 2C and 2D, the veneer strands 10 have been completely separated from one another, but according to FIG. 2B are still held in position by the pressure difference.

In a third method step, connections 22 are produced between the veneer strands 10 along a second direction, the second direction being different from the first direction and being oriented parallel to the y-axis in the present case. The first and the second direction are thus oriented perpendicularly to one another.

The connections 22 are adhesive threads 22. The adhesive threads 22 or adhesive strands 22 form a shear-deformable transverse composite.

2F and 2G show a finished, three-dimensionally deformable wood veneer 34 which consists of the veneer strands 10 and the shear-deformable transverse composite formed from the adhesive threads 22. FIG.

3A and 3B show a finished, three-dimensionally deformable wood veneer 36 which consists of the veneer strands 10 and the shear-deformable transverse composite formed from the adhesive threads 22 . The wood veneer 36 differs from the wood veneer 34 in that the veneer strands 10 have been separated in the x-direction, i.e. in the direction of thickness, not completely but only partially.

4A and 4B show a finished three-dimensionally deformable wood veneer 38 consisting of the veneer strands 10. FIG. The veneer strands 10 have a fleece layer 40 and a wood layer 42, which have been partially separated by perforation knives with interrupted cuts. There are no adhesive threads, but instead the fleece layer 40 forms the shear-deformable transverse composite. When the three-dimensionally deformable wood veneer 38 is deformed, the existing cross-connections of the wood layer 42 break up, while the shear-deformable cross-connection of the fleece layer remains intact. Fig. 5A shows a rotary knife 44 with a circular, uninterrupted cutting edge 46.

Fig. 5B shows a rotary perforation knife 48 with a segmented cutting edge 50.

FIGS. 6A, 6B and 6C show the thread applicator 20 in three views. The thread applicator 20 has two heating nozzles 25 so that the thread applicator 20 can apply two adhesive threads simultaneously.

The thread applicator 20 has the heating device 24 in which the heating nozzles 25 are resiliently mounted. The heating device 24 is set up to heat up the heating nozzles 25 and to continuously adjust the temperature of the adhesive.

Each heating nozzle 25 is assigned a thread spool 48 from which the respective thread 22 coated with adhesive is unwound.

Claims

29

patent claims

1 . Method for producing a three-dimensionally deformable wood veneer, with the method steps:

providing a wood veneer on a receiving surface, the wood veneer abutting the receiving surface with a first side;

Partially or completely separating the wood veneer into a plurality of veneer strands;

Creating connections between the veneer strands; characterized in that the wood veneer and the veneer strands are pressed against the receiving surface by generating a pressure difference,

- wherein there is a first pressure on the first side of the wood veneer and the veneer strands,

- wherein a second pressure is present on a second side of the wood veneer and the veneer strands facing away from the first side and

- wherein the first pressure is smaller than the second pressure.

2. The method according to claim 1, characterized in that the veneer strands are extended along a first direction and the production of connections between the veneer strands takes place along a second direction, wherein the second direction is different from the first direction.

3. The method according to claim 1 or claim 2, characterized in that the first pressure is generated by means of a vacuum pump 30 and/or that the second pressure is the atmospheric pressure of a working environment. and/or that the second pressure is generated by means of a pump. Method according to one of the preceding claims, characterized in that the wood veneer and/or the veneer strands are pressed against the receiving surface by means of at least one hold-down device. Method according to one of the preceding claims, characterized in that the partial or complete separation of the wood veneer takes place by means of a knife or by means of several knives, in particular at least one knife being a rotary knife, a perforating rotary knife or a scoring knife. Method according to one of the preceding claims, characterized in that the connections between the veneer strands are produced by applying an adhesive, in particular a plurality of adhesive strands being applied, in particular that the adhesive is applied while the partial or complete separation takes place. Method according to one of the preceding claims, characterized in that the wood veneer has at least one wood layer and at least one textile layer and that the production of connections between the veneer strands takes place in that the textile layer is not divided when the wood veneer is partially or completely separated, or at least not in sections is divided. Production cell for producing a three-dimensionally deformable wood veneer, with a receiving surface (4) for receiving a wood veneer (6) to be processed, with a device (8) for partially or completely separating the wood veneer into a plurality of veneer strands (10), characterized by a Device (12) for pressing the wood veneer (6) to be processed and the veneer strands (10) onto the receiving surface (4), the device (12, 18) for generating a pressure difference between a first side (14) and a second side ( 16) of the wood veneer (6) to be processed and the veneer strands (10) is set up. Production cell according to Claim 8, characterized by a vacuum pump (18) and/or an application device (20) for applying adhesive (22) for connecting the veneer strands, in particular that the application device for applying adhesive (22) has a heating device (24) for particularly stepless adjustment of the adhesive temperature.

10. Production cell according to claim 8 or claim 9, characterized by at least one hold-down device for bracing the wood veneer against the receiving surface.

11 . Production cell according to one of Claims 8 to 10, characterized in that the device (8) for partially or completely separating the wood veneer (6) has a cutting device (26) with at least one knife (28) and/or in two, three or more Coordinate directions is continuously adjustable and / or has a stop (30) for limiting the depth of the separation.

12. Three-dimensionally deformable wood veneer, the wood veneer having veneer strands connected to one another, the wood veneer having at least one wood layer and at least one textile layer, the veneer strands being connected to one another by the textile layer and the textile layer not being divided or at least not being divided in sections, and/ or prepared according to a process according to any one of claims 1-7.