Field of the Invention

This invention pertains in general to the field of veneers. More particularly the invention relates a veneer suitable for bending in three dimensions around a point in the veneer, such as to be a part of furniture, and a system and method for manufacturing said veneer. Background of the Invention

Veneer is per definition a relatively thin sheet of wood material, which often is glued or by other means fixated on a panel to create an aesthetically attractive surface. Typically, the thickness of a veneer material lies in the range of 0 to 5 mm. However, in other applications veneer may be used to form a rigid construction of e.g. furniture, including a later covering by a surface coating. One such example is plywood, which is a planar construction of several layers of veneer being glued together.

In the field of woodwork, forming is a crucial process for allowing the creation of furniture or other objects not only including straight angles. Consequently, different methods for forming veneer are known.

GB840640 discloses a veneer, which is curved in more than one direction.

GB840640 further shows that a number of slots are provided in each of the veneer layers, which slots enable for bending of the veneer in order to form a seat back. A problem with GB840640 is that the slot provided veneer is only dimensioned, and thus suitable for only one single species of furniture, with regard to shape and size, which in this case is a specific seat back.

Hence, an improved veneer, suitable for several types of furniture would be advantageous.

Summary of the Invention

Accordingly, the present invention preferably seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solves at least the above-mentioned problems by providing a veneer, and a system and method for manufacturing such veneer according to the appended patent claims. An object of the invention is to overcome the disadvantages and problems of prior art. Another object is to provide a veneer that may be formed by three-dimensional bending.

An idea according to the present invention is to provide a veneer having a patterned surface that allows the veneer to be formed into an arbitrary shape.

According to a first aspect of the invention, a veneer is provided. The veneer comprises a sheet of wooden material, wherein said sheet of wooden material comprises a number of recesses which are aligned in at least one row, wherein each recess has an elongated shape which extends lengthwise the grain direction of the sheet of wooden material and having a width between 0, 1 and 3 mm. The distance between two successive recesses in a recess row is less than the length of each recess.

According to a second aspect a system for processing a veneer is provided. The system comprises a feeding line configured to transport a sheet of wooden material between an inlet and an outlet via a first roller having a plurality of protrusions which are aligned in rows wherein the distance between two successive protrusions in each row is less than the length of each protrusion, whereby the first roller by means of rotation is configured to imprint the veneer, thereby creating recesses, corresponding to the plurality of protrusions and having a width between 0, 1 and 3 mm, in the veneer.

According to a third aspect a system for processing a veneer is provided. The system comprises a feeding line configured to transport a sheet of wooden material between an inlet and an outlet via a pressing area, a master stamp having a plurality of protrusions which are aligned in rows wherein the distance between two successive protrusions in each row is less than the length of each protrusion, and pressing means configured to press said master stamp onto said sheet at said pressing area, such that the protrusions are transferred as recesses having a width between 0,1 and 3 mm in said sheet.

According to a fourth aspect a method for processing a veneer is provided. The method comprises providing a sheet of wooden material, aligning said sheet to a roller, said roller having a plurality of protrusions which are aligned in rows wherein the distance between two successive protrusions along a row is less than the length of each protrusion, and creating a plurality of recesses in the veneer by rotation of the roller comprising the plurality of protrusions against said veneer, said recesses having a width between 0,1 and 3 mm.

According to a fifth aspect a method a method for processing a veneer is provided. The method comprises providing a sheet of wooden material, aligning said sheet to a master stamp, said master stamp having a plurality of protrusions which are aligned in rows wherein the distance between two successive protrusions is less than the length of each protrusion, and pressing said master stamp onto said sheet such that the protrusions are transferred as recesses in said sheet, said recesses having a width between 0,1 and 3 mm.

According to a sixth aspect a holder for holding at least two veneers before and during three dimensional bending is provided.

According to a seventh aspect a rigid construction comprising the processed veneer is provided.

Brief Description of the Drawings

These and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of

embodiments of the present invention, reference being made to the accompanying drawings, in which

Fig. 1 is a schematic illustration showing the concept of arc height.

Fig. 2 is a schematic top view of a veneer having a recess pattern according to an embodiment;

Fig. 3a is a veneer comprising a symmetrical recess pattern according to an embodiment;

Fig. 3b is a veneer comprising an asymmetrical recess pattern according to an embodiment;

Fig. 4 is a schematic top view of a veneer having a recess pattern according to an embodiment;

Fig. 5 is a cross-sectional view of a veneer according to an embodiment;

Fig. 6 illustrates a system for processing a veneer according to an embodiment; Fig. 7 illustrates a cut out of a roller according to an embodiment;

Fig. 8 illustrates a roller according to an embodiment;

Fig. 9 illustrates a system for processing a veneer according to an embodiment; Fig. 10 illustrates a system for processing a veneer according to an

embodiment; and

Fig. 11 illustrates a holder for a stack of veneers according to an embodiment. Description of embodiments

Several embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in order for those skilled in the art to be able to carry out the invention. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The embodiments do not limit the invention, but the invention is only limited by the appended patent claims. Furthermore, the terminology used in the detailed description of the particular embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention.

The following description focuses on embodiments applicable to a veneer suitable for bending in three dimensions around a point in the veneer, a roller for processing the veneer, and a method of producing said veneer.

It is an object of the invention to provide a veneer and/or a stack of veneers which enables three dimensional bending around a point at the surface of the veneer or top/bottom surface of the stack of veneers.

Arc height is a parameter which may be used to define the magnitude of the three dimensional bending. In general terms, in three dimensional applications, the arc height defines how much a surface may be bent around a point without breaking.

One could also define the arc height as the perpendicular distance between a plane intersecting the boundaries of a round object, such as a sphere, and the object boundary, at the middle point of the area defined by the plane and the intersecting boundaries of the object. When the round object is a sphere, the arc height in relation to the diameter of the circle formed along the boundary at the intersection of the plane may define the magnitude of the three dimensional bending. Hence, the higher arc height value, while keeping the circle diameter constant, will render a higher magnitude of three dimensional bending. Throughout the description the terms arc height and bending curvature are used analogously and are both intended to define the magnitude of the three dimensional bending around a point at the veneer, or a point at the top or bottom of the stack of veneers.

Hence it is an object of the invention to provide a veneer and/or stack of veneers which allow for as large arc height as possible.

For illustrative purposes Fig. 1 illustrates the concept of arc height AH in three dimensions. In Fig. 1 the arc height AH is shown for a half, hollow ellipsoidal body having a first diameter dl and a second diameter d2. In the case the first diameter equals the second diameter the half ellipsoid is a half sphere. It should be appreciated that in reality the curvature of the veneer does not strictly have to follow the curvature of an ellipsoid or sphere, since this explanation is merely for explanatory purposes.

In an embodiment, according to Fig. 2, a wood veneer 10 is provided. The veneer comprises a number of recesses 11a, l ib, 12a, 12b which are aligned in rows 11 , 12, etc. Each recess has an elongated shape which extends lengthwise the grain of the wood veneer. Recess pattern - dimensions & sizes

The veneer comprises a recess pattern. According to an embodiment, the distance Lb between two successive recesses 11a and 1 lb, or 12a and 12b is less than the length of each recess 11a, l ib, 12a, 12b. Thereby, the major part of an area of each row, i.e. an area formed by the row length, i.e. physical length of the veneer along the grain direction, times the width of each recess, comprises recesses.

Furthermore, each of the two ends of each recess overlaps each transversally neighboring recess. Hence, a first end of each recess overlaps each neighboring recess, by a distance denoted Lol as is indicated in Fig. 2. The second end of each recess overlaps each neighboring recess by a distance denoted Lo2. The length L of each recess may thus be defined as:

L=Lol+Lo2+Lb

Hence, this means that the areas on every recess row having no recesses, which are denoted with a distance Lb, in Fig.1 are phase shifted with the corresponding areas of each neighboring recess row.

In an embodiment the overlapping is symmetrical, i.e. Lol=Lo2 rendering L = 2Lol + Lb = 2Lo2 + Lb.

The symmetrical overlapping is preferred in some applications since such a pattern provides the veneer with a symmetrical bending rigidity. Such a symmetrical recess pattern configuration is shown in Fig. 3a.

In a typical forming process, such as three-dimensional bending, both sides of the veneer will be subject to compression forces as well as strain forces. The recesses may thus absorb the compression forces, while the area of the veneer not covered by recesses may absorb the strain forces. In an embodiment the overlapping is asymmetrical, i.e. Lol≠Lo2, while both Lol and Lo2 is larger than 0. Such an asymmetrical recess pattern configuration is shown in Fig 2 and Fig. 3b. An asymmetrical recess pattern may be advantageous when an asymmetrical end shape of the veneer is desired.

An asymmetrical recess pattern may e.g. be provided when utilizing two successive rollers, for providing the recess pattern on the veneer, where the first roller comprises protrusions corresponding to each recess for every second recess row, e.g. row 11 and row 13 in Fig. 2, and the second roller comprises protrusions corresponding to each recess for every second recess row, e.g. 12 and 14 in Fig. 2.

The recess pattern measures set out throughout the present specification are exemplary measures that may be used for veneers used in furniture, such as chairs, sofas, etc. However, it should be appreciated that other measures may be used depending on the application.

The length L of each recess may be selected based on the desired bending curvature of the veneer or stack of veneers. According to an embodiment, the recess length (L) may be approximately 30 mm.

The distance Lb between two successive recesses 11a, l ib, 12a, 12b, in a recess row 11 , 12, 13 is selected based on the desired bending curvature of the veneer or stack of veneers. For example, the distance Lb may be approximately 10 mm.

The width of each recess may be selected based on the desired bending curvature of the veneer, which is due to the fact that the larger width, the better ability to bend the veneer. However, a too large width may be result in unintentional breaking of the veneer during bending. The width of each recess at each recess row may vary between 0,1 mm and 3 mm, such as 0,5 mm and 1 mm. In case of recesses having a non-uniform width, the maximum width is in the range of 0, 1 and 3 mm.

The perpendicular distance between two recess rows, i.e. the centre to centre distance between each recess row, may be also be selected based on the desired bending curvature of the veneer. For example, the centre to centre distance may be

approximately 4 - 5 mm.

In an embodiment, each recess has the shape of a triangular prism, wherein the base of the prism is arranged at the surface of the veneer such that the apex is formed at the bottom of the recess.

Fig. 4 illustrates a veneer having a recess pattern, wherein each recess at the surface of the veneer, i.e. seen from a top view, has the shape of an ellipsoid. In an embodiment, each recess of the recess pattern has a cylindrical shape extending into the veneer. Hence, each recess at the surface of the veneer, i.e. seen from a top view, has a circular shape. In this way each recess extends equally in along the grain direction as in the direction perpendicular to the grain direction of the veneer.

In an embodiment, each recess of the recess pattern has a conical or frusto- conical shape extending into the veneer. Hence, each recess at the surface of the veneer, i.e. seen from a top view, has a circular shape. In this way each recess extends equally in along the grain direction as in the direction perpendicular to the grain direction of the veneer.

Fig. 5 illustrates a cross-sectional side view of a veneer according to an embodiment, wherein each recess has a triangular cross-sectional shape, whereby the entire shape of the veneer may be triangular prism shaped.

Providing the recess pattern onto the veneer

A veneer according to what has previously been described may be processed by a method, comprising the steps of providing a sheet of wooden material, aligning said sheet to a roller 51 , said roller having a plurality of protrusions which are aligned in rows wherein the distance between two successive protrusions along a recess row is less than the length of each protrusion, and creating recesses in the veneer by rotation of the roller 51 over said veneer.

The recess pattern may be provided onto the veneer, using various techniques.

In an embodiment, according to Fig. 6, the recess pattern may be provided onto the veneer by means of a roller 51 having a number of protrusions 11a', 1 lb' corresponding to the desired recesses 11a, 1 lb in the veneer 10. The roller 51 may be made of steel.

Optionally the roller 51 may be positioned above a conveyor belt 91 , as is shown in Fig. 10, at a distance from the conveyor belt suitable for introducing a veneer there between. A veneer traveling on the conveyor belt 91 may be provided with the recess pattern by rotation of the roller 51 having the conveyor belt 91 as counter force. Optionally, the rotation of the roller 51 is performed using a motor (not shown).

However in an embodiment, due to the driving of the conveyor belt 91 the roller 51 may rotate freely without any connection to a motor, and still provide the recess pattern into the veneer.

The system for providing a recess pattern onto the veneer 10 may further comprise a second roller 52 for supporting the veneer. The axis of the second roller is parallel with the first roller 51. The second roller 52 may be positioned such that the veneer is able to enter a space between the two rollers, whereby the first roller imprints the recess pattern into the veneer based on counterforce made by the second roller 52. The roller 51 , the second roller 52 or both may be driven by a motor (not shown) such as to rotate, e.g. in the directions indicated by arrows in Fig. 6. In an embodiment, only the roller 51 is driven by the motor.

Fig. 7 illustrates a cut out of a roller 51 according to an embodiment, wherein the roller 51 is threaded, and wherein each thread represents a recess row 11, 12. It may be observed from Fig. 7 that the protrusions on the roller 51 are triangular prism shaped, and that the surfaces with no protrusions along each recess/protrusion row, which are indicated by the distance Lb, are essentially flat. The essentially flat surface may be provided e.g. by milling away portions of the thread in a suitable manner. This is advantageous in that the roller 51 may be manufactured in a very cost efficient way, hence resulting in a very cost efficient veneer. In Fig. 7 the width of the base of each protrusion is approximately 4 mm, and the height of each protrusion with reference to the surface with no protrusions along each recess/protrusion row is 2,5 mm - 4 mm.

Fig. 8 illustrates the roller 51 seen from an angle. In an embodiment the roller 51 is not threaded, whereby each recess/protrusion row of the roller defines a closed loop.

A second alternative way of providing the recess pattern into the veneer is by milling.

According to an embodiment, the depth of each recess of the recess pattern in the veneer is less than the depth of the veneer.

According to an embodiment, each or at least one recess of the recess pattern in the veneer may be provided as a through-hole.

According to a yet further embodiment, the recesses may be provided by a flat master stamp 81, as is shown in Fig. 9. In such an embodiment, the method of processing the veneer may comprise providing a sheet of wooden material, aligning said sheet to a master stamp, said master stamp having a plurality of protrusions which are aligned in rows wherein the distance between two successive protrusions in one recess row is less than the length of each protrusion, and pressing said master stamp onto said sheet such that the protrusions are transferred as recesses in said sheet. The veneer may thus be manufactured according to said method by means of a system comprising a feeding line configured to transport a sheet of wooden material between an inlet and an outlet via a pressing area, a master stamp having a plurality of protrusions which are aligned in rows wherein the distance between two successive protrusions is less than the length of each protrusion, and a pressing means configured to press said master stamp onto said sheet at said pressing area, such that the protrusions are transferred as recesses in said sheet.

In such method, the width of each recess may be determined by controlling the pressure at which the master stamp is pressed onto the sheet. Consequently, a greater pressure will cause deeper recesses.

Applicability of the recess patterned veneer

The recess patterned veneer may be used to form a rigid construction of e.g. furniture, including a later covering by a surface coating, and particularly an at least partly three dimensionally bent rigid construction. In order to create a rigid construction several layers, i.e. a stack, of recess patterned veneers may be glued together.

Depending of the application the grain direction, and thus recess direction, between two neighboring veneers may differ.

For example, in some applications each veneer may have a grain direction essentially perpendicular to the grain direction of its neighbors. In other applications, a majority of the veneers in the stack may have a grain direction essentially in the same direction.

During compression molding of the stack, especially when the mold comprises three dimensional bends around a point therein, there is a risk that the crosscut end of each veneer may crack due to the intrinsic forces.

In order to alleviate this risk, the crosscut end of each veneer may be provided with an adhesive tape which encompasses the crosscut end edge.

To secure the stack of veneers before and during the three dimensional bending, a tape may be applied around the stack edges. By applying a tape around the edges of the stack before three dimensional bending the veneers of the stack are better prevented from folding during the three dimensional bending.

In an embodiment, according to Fig. 1 1 , a holder 101 for keeping the stack edges together is provided. The holder may be made of a flexible material. The holder may be C-shaped, whereby it acts as an elongated clamp around the stack edge. The usage of such a holder may be preferred since no tape around the stack ends is needed.

For example, such a holder may consist of a cylindrical tube, which has been cut lengthwise such as to create a C-shaped cross-section. Magnitude of 3D bending

The present inventors have been able to provide a durable stack of veneers allowing for an arc height of 15 mm for a diameter of 200 mm. This arc height value was achieved using a symmetrical recess pattern having the following parameter values: L = 30 mm, recess width = 1 ,5 mm, recess depth = 1 ,5 mm, Lb = 10 mm, c-t-c recess row = 5 mm.

Even though certain example measures of the recess pattern has been specified in the description above, it should be appreciated that also other measures could apply, depending on the type and shape of rigid construction. However, it should be appreciated that the distance Lb should always be less than the length L of each recess along the grain direction. Moreover, it should be appreciated that Lol and Lo2 is larger than 0 mm.

Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and, other embodiments than the specific above are equally possible within the scope of these appended claims.

In the claims, the term "comprises/comprising" does not exclude the presence of other elements or steps. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. The terms "a", "an", "first", "second" etc do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.