METHOD FOR PRODUCING A VENEERED WOODEN MATERIAL AND WOODEN MATERIAL COMPRISING A SUPPORTING PLATE AND AT LEAST TWO VENEERS

Abstract

The invention relates to a method for producing a wooden material having a supporting plate and at least one first, non-external veneer and a second veneer on a first surface of the supporting plate, wherein the supporting plate, the first and the at least second veneer are connected to one another by synthetic resin. In order to create a cost-effective wooden material board with a veneered surface, a liquid synthetic resin is applied, in excess, in relation to the quantity required for gluing purposes, to the supporting plate and/or to the first veneer and/or the at least second veneer, the synthetic resin applied in excess is dried but not cured, a stack of material to be pressed comprising the supporting plate, the first, non-external veneer and the at least second veneer is assembled, and the stack of material to be pressed is compressed in a high-pressure press to form a wooden material.

Claims

1. A method for producing a wooden material (1) with a supporting plate (2) and at least one first, non-external veneer (5a) and a second veneer (5b) on a first surface (3) of the supporting plate, wherein the supporting plate (2), the first and the at least second veneer (5a, 5b) are connected to one another by means of synthetic resin (7), wherein a liquid synthetic resin (7) is applied in an amount of at least 150 g/m.sup.2, given as 100% solid material, and thereby in excess in relation to the quantity required for gluing purposes, to the supporting plate (2) and/or the first veneer (5a) and/or the at least second veneer (5b), the synthetic resin (7) applied in excess is dried but not cured, the supporting plate (2), the first, non-external veneer (5a), and the at least second veneer (5b) are assembled to form a stack of material to be pressed, and the stack of material to be pressed is compressed in a high-pressure press at a press-forming pressure of 25 N/mm.sup.2 to 50 N/mm.sup.2, at a press-forming temperature of 160° C.-220° C. as well as a press-forming time of 20 seconds-60 seconds, to form a wooden material (1).

2. The method according to claim 1, wherein at least three veneers are applied to a first surface (3) of the supporting plate (2).

3. The method according to claim 1, wherein a first partial quantity of the synthetic resin (7) and at least one further partial quantity of the synthetic resin are applied to different surfaces of the supporting plate (2) and/or a veneer (5a, 5b).

4. The method according to claim 1, wherein the synthetic resin (7) is used in excess of at least 30% in relation to the quantity required for gluing purposes.

5. The method according to claim 1, wherein the synthetic resin (7), given each time as 100% solid material, is applied with a quantity of at least 200 g/m.sup.2 to the supporting plate (2) or the veneer (5a, 5b).

6. The method according to claim 1, wherein the veneer (5a, 5b) is compressed during compressing by at least 30% of the original veneer thickness.

7. The method according to claim 1, wherein an outer veneer surface of the wooden material (1) is subjected to a surface treatment or a print is applied to it.

8. The method according to claim 1, wherein an outer veneer surface of the wooden material (1) is embossed and a print is applied to it, wherein embossing and printing generate a synchronous decoration formed by embossing and print.

9. A wooden material according to claim 1, having a supporting plate (2) and a first as well as at least a second veneer (5a, 5b), which are connected to one another by means of a synthetic resin (7), wherein the at least first, non-external veneer (5a), and the at least second veneer (5b) are compressed in their veneer thickness, wherein the synthetic resin (7) penetrates at least 100% of the veneer thickness of the first veneer (5a) and penetrates at least 30% of the veneer thickness of the at least second veneer (5b), and wherein the veneer surface is embossed.

10. The wooden material according to claim 9, wherein, with a wooden material (1) on the first surface (3) of which three veneers have been applied, 100% of the veneer thickness of the first and the at least second veneer and at least 30% of the veneer thickness of the third veneer have been penetrated by synthetic resin.

11. The wooden material according to claim 9, wherein the veneer surface has a print applied to it.

12. The wooden material according to claim 9, wherein the first veneer (5a) and the second veneer (5b) have different colors.

13. The wooden material according to claim 9, wherein a second surface (4) of the supporting plate (2) is provided with a first and at least a second veneer (5a, 5b), which are connected to the supporting plate (2) by means of a synthetic resin (7).

14. The method according to claim 4, wherein the synthetic resin (7) is used in excess of at least 50% in relation to the quantity required for gluing purposes.

15. The method according to claim 4, wherein the synthetic resin (7) is used in excess of at least 100% in relation to the quantity required for gluing purposes.

16. The method according to claim 4, wherein the synthetic resin (7) is used in excess of at least 200% in relation to the quantity required for gluing purposes.

17. The method according to claim 5, wherein the quantity is at least 300 g/m.sup.2.

18. The method according to claim 5, wherein the quantity is up to 400 g/m.sup.2.

19. The method according to claim 6, wherein the veneer (5a, 5b) is compressed during compressing by at least 50% of the original veneer thickness.

20. The method according to claim 7, wherein the outer veneer surface of the wooden material is embossed, oiled or varnished.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Details of the invention are explained in greater detail using exemplary embodiments. In the drawings:

[0030] FIG. 1 shows a schematic representation of the wooden material according to the invention,

[0031] FIG. 2 shows a schematic representation of the first and second veneers that are fully penetrated by synthetic resin,

[0032] FIG. 3 shows a schematic representation of the first veneer, which is fully penetrated by the synthetic resin, and of the second veneer, which is partially penetrated by synthetic resin.

DETAILED DESCRIPTION

[0033] FIG. 1 shows a schematic representation of the veneered wooden material 1 according to the invention, here a supporting plate 2 with two veneers on a first surface, the top face 3. The supporting plate 2 has a top face 3 and an underside 4. On the top face 3, a first veneer 5a and, above it, a second veneer 5b are arranged, on the underside 4, a backing 6 is arranged. Between supporting plate 2 and first veneer 5a, a synthetic resin layer 7 is arranged, wherein the synthetic resin 7 has fully penetrated the first veneer 5a and has penetrated about 50% of the second veneer 5b (see FIG. 2). FIG. 3 shows a supporting plate 2 with a first and a second veneer 5a, 5b, which are fully penetrated by synthetic resin.

[0034] With the embodiment according to FIG. 1-3, the entire synthetic resin applied in excess was arranged as a layer 7 on the top face 3 of the supporting plate 2. Alternatively, however, it is also possible to arrange the synthetic resin on a veneer surface of the first or second veneer. In this context, it is particularly preferred if the synthetic resin is not applied to the external surface of the outer-most veneer, here the second veneer 5b. The synthetic resin can additionally be applied in several layers, both to the supporting plate and to a veneer, e. g. to the top face 3 of the supporting plate 2 and between the first and the second veneer 5a, 5b. The application in several layers to supporting plate and/or veneer results in a particularly uniform distribution of the synthetic resin.

[0035] As a supporting plate, any of the boards described above made from wood or wooden material can be used. The HDF boards chosen in the following can without any problems be replaced with other board types. As a veneer, any of the veneers mentioned above can be used, the veneers used as an example in the following can be replaced with other types of veneer at any time. Both for the supporting plates and for the veneer, board or veneer thicknesses or the density of the veneer can vary.

[0036] In the following, specific press-forming conditions are stated for producing the wooden material according to the invention. It must be stated that these are merely selected press-forming conditions, the pressure, temperature, and time intervals stated above allow for a variation in press-forming conditions, for example a shortening of the press-forming time with increased pressure or increased temperature, or an increase in both parameters. The same applies to a reduction of pressure and/or temperature with a concomitant lengthening of the press-forming duration.

Exemplary Embodiment 1

[0037] A melamine resin (75% solid material, applied quantity: 300 g/m.sup.2) is rolled onto a first surface of a large-format supporting plate, here e. g. an HDF board (medium-density fiber board with increased raw density, format: 2800×2070×8 mm). This resin is produced e.g. by adding powdered melamine resin to liquid melamine resin (65 percent by weight). The melamine resin applied to the first surface of the supporting plate is dried in a circulating air dryer to a residual moisture content of approx. 10%. Subsequently, four veneers are placed on the dried melamine resin. Such veneers are oak and birch veneers in alternating order with a thickness of 0.6 mm each. The set-up was compressed in a short-cycle press at 200° C., 400 N/cm.sup.2 press-forming pressure, and a press-forming time of 25 seconds. After press-forming, the thickness of the veneers was 1.8 mm in total. By means of a cross-cut test, the adhesion of the veneer layers to one another was checked after cooling. This adhesion was good, i.e., even the outer-most veneer was firmly connected to the supporting plate or respectively the veneer arranged underneath the outer-most veneer. Afterwards, partial boards with a format of 2800×205 mm were saw-cut from the large-format board. A profile for laying without glue and a circumferential chamfer were milled into these partial boards. After laying, a multiplexed visual effect was discernable in the visible connect area (the chamfer).

Exemplary Embodiment 2

[0038] A melamine resin (75% solid material, applied quantity: 300 g/m.sup.2) is rolled onto a large-format supporting plate, here an HDF board (medium-density fiber board with increased raw density, format: 2800×2070×8 mm). This resin is produced by adding powdered melamine resin to liquid melamine resin (65 percent by weight). The melamine resin is dried in a circulating air dryer to a residual moisture content of approx. 10%. Subsequently, a first veneer, a birch veneer, is placed on the melamine resin, and a second veneer, a mahogany veneer, is placed on the first veneer or respectively birch veneer. The mahogany veneer has a thickness of 0.5 mm and the birch veneer has a thickness of 1.5 mm. The set-up was compressed in a short-cycle press at 200° C., 400 N/cm.sup.2 press-forming pressure, and a press-forming time of 25 seconds. By means of a cross-cut test, the adhesion of the veneer layers to one another was checked after cooling. The adhesion was good. Afterwards, partial boards with a format of 2800×205 mm were saw-cut from the large-format board. A profile for laying without glue was milled into these partial boards.

[0039] The thus produced board shows a perfect mahogany surface. Contrary to a 2 mm mahogany veneer as an alternative, the board according to the invention is significantly more cost effective due to the use of the cost-effective birch veneer.

Exemplary Embodiment 3

[0040] A melamine resin (75% solid material, applied quantity: 300 g/m.sup.2) is rolled onto a large-format supporting plate made from HDF (medium-density fiber board with increased raw density, format: 2800×2070×8 mm). This resin is produced e.g. by adding powdered melamine resin to liquid melamine resin (65 percent by weight). The melamine resin is dried in a circulating air dryer to a residual moisture content of approx. 10%. Subsequently, three veneers are placed on the melamine resin. Each of these veneers were oak veneers with a thickness of 0.7 mm. A non-woven fabric made from cellulose fibers with a grammage of 100 g/m.sup.2, which is equipped with conductive additives such as 2 percent by weight to 5 percent by weight carbon fibers or conductive carbon black, in relation to the non-woven fabric, is placed on top of the first, lowest-level veneer. The second and the third oak veneers are placed on top of this. The set-up was compressed in a short-cycle press at 200° C., 400 N/cm.sup.2 press-forming pressure, and a press-forming time of 25 seconds. The synthetic resin liquefies in the press, it penetrates the non-external veneers at least in portions completely and penetrates the outer-most veneer at least partially. By means of a cross-cut test, the adhesion of the veneer layers to one another was checked after cooling. The adhesion was good.

[0041] Afterwards, partial boards with a format of 2800×205 mm were saw-cut from the large-format board. On these partial boards, a profile for laying without glue was milled, and thereby a flooring element was produced. In the lower regions of the profile, in which the layer with the conductive non-woven fabric is located, a strip of conductive silver varnish is sprayed with regular spacing (every 5 cm), which increases the electric conductivity. After applying a voltage of 12 V, the flooring element output approx. 80 W/m.sup.2.

[0042] The thus produced partial boards have a significantly improved conductivity compared to similar partial boards without a conductive non-woven fabric.