Method for producing a wood veneer, veneer block, method for producing a molded part, and molded part

A method for producing a wood veneer, where the wood veneer is provided as a decorative layer for a trim piece for a vehicle interior, wherein the molded part has at least one line element on a visible side, can involve the steps of a) providing a wood blank, b) generating two-dimensional cutting data by developing a designated three-dimensional shape of the wood veneer c) forming wood slats by cutting out the two-dimensional developed form of the wood veneer from the wood blank and slicing the two-dimensional developed form along the developed line elements on the basis of the two-dimensional cutting data, d) layering and gluing the cut wood slats to form a veneer block, e) compressing the wood slats and curing the veneer block, f) separating the veneer block into wood veneers. Moreover, the invention relates to a veneer block, a molded part, and corresponding methods of production.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention claims the benefit of priority to German Patent Application No. 10 2017 113 764.5, filed Jun. 21, 2017, entitled “Method for producing a wood veneer, veneer block, method for producing a molded part, and molded part” the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

This invention relates to a method for producing a wood veneer and a veneer block for producing a wood veneer. Moreover, the invention relates to a method for producing a decorative and/or trim piece for a vehicle interior fashioned as a molded part, and a molded part.

2. Background and Relevant Art

The wood veneer is designed as a decorative layer for a decorative and/or trim piece for a vehicle interior fashioned as a molded part, wherein the molded part has at least one line element on its front side, designed as the visible side.

Molded parts with line elements are known in themselves. The line elements may be so-called “flowing lines” or “form-following lines” as a styling element on the visible side of the molded part, such as line-shaped grooves.

These line elements are milled out in known molded parts, in particular being milled out in the finished structural parts in a costly manner with CNC milling machines, especially 5-axis CNC milling machines. This results in long process times and high production costs.

A further drawback of milling is that the wood structure and the shape of the structural part do not match up. This has the result that wood fibers may stick out along the grooves and stained margins may be formed in the coloration. Due to deviations between wood structure and grooves, weak sites may also be created on the structural part, possibly resulting in breakage. The aforementioned drawbacks result in long processing times and increased rejects.

Furthermore, the minimal diameter of the grooves is dependent on the diameter of the milling cutter. Moreover, the milled grooves may result in light irritation in the case of backlit structural parts.

BRIEF SUMMARY OF THE INVENTION

The problem which the present invention proposes to solve is to indicate a new method for producing a wood veneer as well as a new veneer block for producing a wood veneer, wherein the wood veneer is provided as a decorative layer for a decorative and/or trim piece for a vehicle interior fashioned as a molded part, wherein the molded part has line elements on its front side, designed as the visible side, with which drawbacks of the aforementioned milled grooves are at least for the most part avoided. Moreover, the problem of the invention is to indicate a new method for producing a decorative and/or trim piece for a vehicle interior fashioned as a molded part and a new molded part in which the decorative layer is a wood veneer that has been produced from a veneer block according to the invention or produced with a method according to the invention.

This problem is solved in regard to the features of the claimed method for producing a wood veneer, and features of the claimed veneer block for producing a wood veneer The problem is further solved by the features of the method for producing a decorative and/or trim piece fashioned as a molded part, and by the features of the claimed molded. Advantageous embodiments and modifications are indicated in the respective independent and dependent claims.

The method according to the invention for producing a wood veneer involves the steps:

a) providing a wood blank,

b) generating two-dimensional cutting data by developing a designated three-dimensional shape of the wood veneer including line elements provided in the wood veneer into a two-dimensional developed form of the wood veneer with developed line elements,

c) forming wood slats by cutting out the two-dimensional developed form of the wood veneer from the wood blank and slicing the two-dimensional developed form along the developed line elements on the basis of the two-dimensional cutting data,

d) layering and gluing the cut wood slats to form a veneer block,

e) compressing the wood slats and curing the veneer block,

f) separating the veneer block into wood veneers.

Steps a) and b) may be provided in any given sequence, in particular, the generating of two-dimensional cutting data as per step b) may occur already distinctly prior to the providing of a wood blank as per step a).

The benefits of the method according to the invention lie especially in the fact that the line elements, such as “form-following lines” or “flowing lines”, are introduced already in the veneer block and this veneer block is then worked up into wood veneers. This means that the drawbacks of milled grooves are at least for the most part avoided.

The wood blank may be a massive piece of wood, especially a single piece of massive wood, not being composed of several partial pieces and thus also not having any glue bonding. However, it may also be a glue-bonded block composed of laminate layers or veneer layers or wooden boards.

It is also possible to at first carry out steps a) to e), and then to provide the veneer block cured in step e) as a wood blank in a further step a) and once again to carry out steps b) to e) and only then to carry out step f). It is also possible to perform steps a) to e) several times in each case with the veneer block last cured as per step e) as a wood blank in step a), before step f) is carried out.

Preferably when providing the wood blank a single wood blank is provided for the entire veneer block to be produced and consequently for the wood veneer to be produced.

The line elements may be “form-following lines” or “flowing lines” as a styling element on the visible side of the molded part. Preferably, it is provided that the line elements run at least partly in a curve. For example, line elements may at least substantially follow an outer shape of the molded part. However, the line elements may also run entirely as straight lines.

Moreover, it is preferably provided that the line elements run parallel to the front side of the molded part. In particular, the line elements extend between two opposite edges of the wood veneer.

When speaking above or in the following of line elements, this means both a plurality of line elements, i.e., two or three or four or five line elements, etc., and also only a single line element. The use of the plural form “line elements” was chosen merely for reasons of better comprehension of the text. When a plurality of line elements are provided, these may run at least substantially parallel to each other, but also differing forms are possible.

The generating of the two-dimensional cutting data as per step b) may be done for example by calculating the two-dimensional development from three-dimensional CAD data. The cutting out and slicing on the basis of the two-dimensional cutting data as per step c) may be done by generating from the two-dimensional cutting data NC codes (NC is the abbreviation for Numerical Control) for a CNC cutting machine (CNC is the abbreviation for Computerized Numerical Control).

The cutting out of the developed two-dimensional form of the wood veneer from the wood blank as per step c) is advisedly done by cutting along the edges (margins) of the developed two-dimensional form.

An especially preferred modification of the invention proposes that the two-dimensional developed form of the wood veneer and the developed line elements are cut out from the wood blank such that the two-dimensional developed form of the wood veneer and/or the developed line elements follow a principal direction of a wood structure in the wood blank.

“Follow the principal direction of a wood structure” can mean that the two-dimensional developed form of the wood veneer and/or the developed line elements coincide at least in part with at least one section of a structure dictated by the grain of the wood or run at least substantially parallel to this structure or are at least similar to it.

If expedient, the two-dimensional developed form of the wood veneer and the developed line elements may also be marked out on or at the wood blank prior to the cutting, for example, to control the orientation of the form and/or line elements in relation to a principal direction of a wood structure in the wood blank.

Preferably, during the cutting out and slicing as per step c), the cutting is done along an outer contour of the developed form of the wood veneer and along the developed line elements, the sequence of the cuts usually not being important, that is, the cutting sequence may be optimized in terms of the cutting installation used.

Preferably, the cutting and slicing are done by means of high-pressure water jet cutting. Advisedly in this case a protective film is glued onto the side of the wood blank where the water jet impinges. Alternatively, the cutting and slicing may also be done by means of laser beam cutting or chip removing methods, such as CNC milling or band sawing, or punching.

An especially preferred variant embodiment of the invention proposes that during the layering and gluing of the cut wood slats the wood slats are layered in the same arrangement with respect to each other as they were arranged in the wood blank with respect to each other.

In step d), also only some of the cut wood slats may be layered and glued in order to form the veneer block. To form the veneer block it is also possible to provide in addition to the wood slats cut in the preceding step of the method further woods slats, which have been cut out from one or more other wood blanks, especially from wood blanks of a different kind of wood. In this way, wood slats of different woods can be blended to form the veneer block.

Between two wood slats there can be provided only one glue layer, by which the wood slats are glued together. This glue layer then forms a line element in the finished wood veneer.

Alternatively, according to one modification of the invention, during the layering and gluing of the cut wood slats at least one intermediate layer is inserted between every two wood slats. This intermediate layer then forms a line element in the finished wood veneer. Preferably, the intermediate layer is glued between the two wood slats.

The intermediate layer may be transparent and/or translucent.

The intermediate layer may be a lightguide or a light fabric.

According to one variant embodiment of the invention, the intermediate layer is or comprises a contrast veneer and/or a metal layer, especially an aluminum sheet and/or a copper sheet and/or a brass sheet, and/or a metal weave and/or metal strands and/or metal wires and/or a film, especially a plastic film, preferably a polycarbonate film, and/or textiles and/or leather and/or fleece and/or paper and/or cardboard and/or mineral materials (such as the mineral material known under the brand Corean®) and/or natural rubber and/or rubbers such as ethylene-propylene-diene rubbers (EPDM).

It may be provided that the gluing of the wood slats makes use of an adhesive which is or comprises polyurethane (PUR) and/or epoxy resin (EP). PVAC (polyvinylacetate) glues or resins such as urea resins or melamine resins or phenolic resins or acrylates may also be considered as the adhesive.

The adhesive may be applied to one or both of the surfaces being joined together. In the event that at least one intermediate layer is provided between two wood slats, adhesive may be applied to both of the surfaces of the wood slats to be joined together and enclose the intermediate layer between them. Likewise, adhesive may be applied to one or both of the surfaces of the intermediate layer to be glued.

According to another variant embodiment of the invention, during the compressing of the wood slats at least one cutting residue of the wood blank produced during the cutting and slicing as per step c) is used at least partly as a die and/or punch and/or support for the wood slats. Preferably, two cutting residues produced on opposite outer wood slats are used as dies and punches for the compressing of the wood slats.

In particular, it may be provided here that cutting residues produced during the cutting and slicing as per step c) are used at least partly as a die and/or punch and/or support for the wood slats during the compressing of the wood slats, wherein the wood slats are arranged between the cutting residues in the way in which the cutting residues and the wood slats were arranged in the original wood blank. The wood slats may then be glued together by compression between the cutting residues. This affords the advantage that no separate punch and die is required, so that even small lot numbers can be produced economically.

Of course, it is also alternatively possible to use a specially made die and/or punch and/or support.

It may be provided that the veneer block is sliced for separating into wood veneers, preferably with a vertical and/or horizontal and/or longitudinal razor machine. Alternatively, it may be provided that the veneer block is sawed for separating into wood veneers, preferably with a band saw, such as a horizontal band saw.

According to one development of the invention, the separating of the veneer block is done with an angle between 0° and 180° to cut surfaces of the wood slats, especially with an angle between 45° and 135° to cut surfaces of the wood slats. Preferably, the separating of the veneer block is done perpendicular to the cutting of the wood slats.

The veneer block according to the invention is intended for producing a wood veneer, which is provided as a decorative layer for a decorative and/or trim piece for a vehicle interior fashioned as a molded part. This molded part has at least one line element on its front side, designed as the visible side. The veneer block according to the invention comprises wood slats cut from a single wood blank. Preferably, the wood slats are layered in the same arrangement with respect to each other in the veneer block as they were arranged with respect to each other in the wood blank.

As regards the line elements, the foregoing remarks apply to the explanation of the method according to the invention for producing a wood veneer. In particular, only one glue layer between two wood slats may form a line element in the finished wood veneer, which may also be transparent or translucent or colored, for example.

Preferably the wood slats are glued together, wherein the adhesive is or comprises polyurethane (PUR) and/or epoxy resin (EP). PVAC (polyvinylacetate) glues or resins such as urea resins or melamine resins or phenolic resins or acrylates may also be considered as the adhesive.

According to one modification of the invention, it is provided that the veneer block has at least one intermediate layer between at least two wood slats. This intermediate layer then forms in the finished wood veneer a line element. Optionally, the intermediate layer may also be only a glue layer.

Preferably, the intermediate layer is glued between the two wood slats.

Preferably, the intermediate layer is transparent and/or translucent.

The intermediate layer may also be a contrast veneer and/or a metal layer, especially an aluminum sheet and/or a copper sheet and/or a brass sheet, and/or a metal weave and/or metal strands and/or metal wires and/or a film, especially a plastic film, preferably a polycarbonate film, and/or a textile and/or leather and/or fleece and/or paper and/or cardboard and/or mineral materials (such as the mineral material known under the brand Corean®) and/or natural rubber and/or rubbers such as ethylene-propylene-diene rubbers (EPDM).

The method according to the invention for producing a decorative and/or trim piece for a vehicle interior fashioned as a molded part, wherein the molded part comprises a decorative layer and has at least one line element on its front side, designed as the visible side, is characterized in that the decorative layer is a wood veneer produced from a veneer block according to the invention, and preferably with a method according to the invention.

The molded part according to the invention, which is a decorative and/or trim piece for a vehicle interior fashioned as a molded part, comprises a decorative layer and has at least one line element on its front side, designed as the visible side. The molded part is characterized in that the decorative layer is a wood veneer produced from a veneer block according to the invention, and preferably produced with a method according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Corresponding parts and components are designated with the same references in the figures, even among the different sample embodiments. Moreover, it should be noted that the dimensional relations, especially the layer thicknesses, are purely schematic to illustrate the invention and need not conform to the actual dimensional relations.

With the aid of the following drawings, a sample embodiment of the method according to the invention shall be explained more closely.

The method according to the invention is intended for producing a wood veneer10. The wood veneer10is intended as a decorative layer11for a decorative and/or trim piece for a vehicle interior fashioned as a molded part12. The molded part12should have line elements14on its front side13designed as the visible side.

In a step a) of the method according to the invention, a wood blank15is provided as represented inFIG. 1. A single wood blank15is provided for the entire veneer block19to be produced and consequently for the wood veneer10to be produced.

In a step b) of the method according to the invention, which may be performed after, but also before step a), two-dimensional cutting data is generated by developing an intended three-dimensional form of the wood veneer10including line elements14provided in the wood veneer10into a two-dimensional developed form16of the wood veneer10with developed line elements14. InFIG. 1, the two-dimensional developed form16of the wood veneer10and the developed line elements14are marked out on the wood blank15for clarity.

The two-dimensional developed form16of the intended wood veneer10and the developed line elements14are oriented in relation to the wood blank15such that the two-dimensional developed form16of the intended wood veneer10and the developed line elements14follow a principal direction of a wood structure of the wood blank15. “Follow the principal direction of a wood structure” means in this case that the two-dimensional developed form16of the intended wood veneer10and the developed line elements14at least partly coincide with at least one section of the wood structure dictated by the grain of the wood or match up with this wood structure.

Next, in a step c) of the method according to the invention, the two-dimensional developed form16is cut out from the wood blank15along the edges17of the two-dimensional developed form16. Moreover, cutting is done along the developed line elements14. In this way, wood slats18are formed.

During the cutting and slicing as per step c), cutting is done along several cutting edges23which may also extend beyond the actual edges17of the two-dimensional developed form16, depending on the cutting method used. For example, the cutting and slicing may be done by means of high-pressure water jet cutting. In this case, the cutting edges23shown inFIG. 1and extending beyond the two-dimensional developed form16may optionally be omitted.

The cut wood slats18are then layered and glued together in a step d) of the method according to the invention to form a veneer block19, as shown inFIG. 2.

During the layering and gluing together of the cut wood slats18, the wood slats18are layered in the same arrangement with respect to each other as they were arranged with respect to each other in the wood blank15.

Furthermore, during the layering and gluing together of the cut wood slats18an intermediate layer20is inserted between every two wood slats18. The intermediate layer may be a contrast veneer and/or a metal layer, especially an aluminum sheet and/or a copper sheet and/or a brass sheet, and/or a film, especially a polycarbonate film, and/or a textile and/or leather and/or fleece.

For the gluing together of the wood slats18an adhesive21is used which comprises PUR and/or epoxy resin, the adhesive21being applied to both surfaces of the wood slats18to be glued together.

After this, in a step e) of the method according to the invention, the wood slats18are compressed and the resulting veneer block19is cured.

During the compression of the wood slats18, as shown inFIG. 2, two cutting residues22of the wood blank produced during the cutting and slicing as per step c) are used as die and/or punch and/or support for the wood slats18. These may be clamped for example in a vise25.

In a final step f) of the method, the veneer block19as shown inFIG. 3is separated into wood veneers10, the veneer block19being sliced for the separation into wood veneers10, preferably with a vertical and/or horizontal and/or longitudinal razor machine. One example of a wood veneer10formed in such a way is shown inFIG. 4.

For the slicing, the slicing is done along the parting edges24on the veneer block19as shown inFIG. 3. The separating of the veneer block19occurs along the parting edges24and thus preferably perpendicular to the former cutting edges23of the wood slats18.

FIG. 5shows a molded part12according to the invention. The molded part12is a decorative and/or trim piece for a vehicle interior fashioned as a molded part12. It comprises a decorative layer11and has line elements14(not shown) on its front side13, designed as the visible side, which extend parallel to this front side13.

The decorative layer11is a wood veneer10, as shown inFIG. 4, which was produced from a veneer block19, shown inFIG. 3. The veneer block19comes from a single wood blank15, shown inFIG. 1.

The wood veneer may, as shown inFIG. 5, be back-injected with a carrier and thereby be pressed into a form intended for the molded part12.

LIST OF REFERENCE NUMBERS