Wood fibre based panel with a surface layer

Abstract

A building panel with a surface layer including a wood veneer, a wood fibre based core and a sub-layer between the surface layer and the core. The sub-layer includes wood fibres and a binder. The surface layer has surface portions including material from the sub-layer. The surface portions including material from the sub-layer extend into the wood veneer.

Claims

1. A method to produce a building panel, the method comprising: applying a wood fibre powder and a binder on a first side of a wood fibre based core, to obtain a first sub-layer; applying a first wood veneer, comprising holes through the first wood veneer, on the first sub-layer; and applying heat and pressure to bond the first wood veneer, the first sub-layer and the wood fibre based core together, thereby material from the first sub-layer is pressed into the holes of the first wood veneer, to form a first surface layer, wherein the building panel comprises a second surface layer, wherein the second surface layer is on a second side opposite the first side of the wood fibre based core, wherein the second surface layer comprises a second sub-layer of a wood fibre powder and a binder, and a second wood veneer on the second sub-layer, and the method further comprising, prior to applying heat and pressure to form the first surface layer, pre-pressing the first sublayer, wherein the binder of the first sub-layer is partially cured during the pre-pressing.

2. The method as claimed in claim 1, further comprising applying a foaming agent in the first sub-layer.

3. The method as claimed in claim 2, wherein the wood fibre powder comprises lignocellulosic particles or cellulose particles.

4. The method as claimed in claim 1, further comprising applying different colour pigments, wherein portions of the first sub-layer are visible in the holes of the first veneer, wherein the colour of the visible first sub-layer portion varies along the building panel, or such that the portion of the first sub-layer in the holes forms a pattern.

5. The method as claimed in claim 1, further comprising applying a protective overlay with wear resistant particles on the first wood veneer.

6. The method as claimed in claim 1, wherein the first sub-layer comprises colour pigments and/or a colorant.

7. The method as claimed in claim 1, wherein the first sub-layer comprises wear resistant particles.

8. The method as claimed in claim 1, further comprising applying a protective overlay with wear resistant particles on the first wood veneer prior to pressing.

9. The method as claimed in claim 1, further comprising pre-treating the first veneer, prior to applying heat and pressure.

10. The method as claimed in claim 9, further comprising pre-treating the first veneer, prior to applying heat and pressure, by brushing.

11. The method as claimed in claim 1, wherein after applying pressure, the first wood veneer comprises embossed portions, and wherein a part of the first sub-layer is more compressed under an embossed surface portion than under a non-embossed surface portion.

12. The method as claimed in claim 1, wherein the first surface layer comprises embossed portions and protrusions, wherein the binder of the first sub-layer bonds porous portions of the first wood veneer in a compressed position to form the embossed portions, and wherein the binder does not bond non-porous portions of the first wood veneer in the compressed position so that non-porous portions of the first wood veneer form the protrusions.

13. The method as claimed in claim 1, the method further comprising applying a protective overlay with wear resistant particles on the first wood veneer prior to pressing, wherein the first sub-layer comprises wear resistant particles, wherein the panel comprises, after pressing, the first surface layer with surface portions comprising material from the first sub-layer, wherein the surface portions comprising material from the first sub-layer are flush with a remainder of the first surface layer, to obtain an entire surface layer with wear resistant particles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure will by way of example be described in more detail with reference to the appended schematic drawing, which shows an embodiment of the disclosure.

(2) FIG. 1 illustrates a building panel according to an embodiment of the disclosure.

DETAILED DESCRIPTION

(3) FIG. 1 shows a building panel with a surface layer 1 comprising a wood veneer, a core 2, and a sub-layer 3 arranged between the surface layer 1 and the core 2. The core 2 may be wood fibre based board such as MDF, HDF, particle board, plywood, OSB etc. The core 2 may be a WPC (Wood Plastic Composite). The core 2 may in one embodiment be a mineral board. The building panel may be a floor panel, a wall panel, a ceiling panel, a furniture component, skirting boards, mouldings, edging profiles, etc.

(4) A low quality wood veneer is used as a surface layer 1. The veneer comprises cracks and other similar defects. The veneer is pressed against the core 2 with a powder based sub-layer 3 comprising wood fibres 4 and a binder 5 such that the powder floats and fills the cracks. The panel comprises after pressing a surface layer 1 with surface portions 6 comprising material from the sub-layer 3. The surface portions 6 comprising material from the sub-layer 3 extend into the wood veneer. The surface portions comprising material from the sub-layer may be flush with a remainder of the surface layer. A “surface portion” is a portion of the surface layer that is visible on the exposed surface of the surface layer facing away from the core.

(5) In one embodiment, the sub-layer 3 comprises a binder applied in liquid form.

(6) The panel may be pressed against an embossed press plate such that a part of the sub-layer 3 is more compressed under an embossed portion 8 than under a non-embossed surface portion.

(7) Preferably the building panel is a floor panel that may have a powder based balancing layer 7. A powder based balancing layer 7 may also be applied on any other type of building panel. The powder based balancing layer 7 may comprise lignocellulosic particles or cellulose particles and a binder, preferably a thermosetting binder, more preferably an amino resin such as melamine formaldehyde resin. The binder may also be applied in powder form, the sub-layer 3 being a dry powder layer. In one embodiment, the sub-layer 3 is a pre-pressed layer, wherein the binder has not completely cured during the pre-pressing.

(8) The binder of the sub-layer 3 may be a thermosetting resin, such as, for, example a melamine formaldehyde resin. The sub-layer 3 may also comprise colour pigments and wear resistant particles such as aluminium oxide particles. The wood fibres of the sub-layer 3 may be lignocellulosic particles or cellulose particles. The wood fibres of the sub-layer 3 may be at least partially bleached. The sub-layer may comprise a foaming agent. The wood veneer may be replaced by a cork veneer or a stone veneer.

(9) The sub-layer 3 may be applied in an amount of 200-600 g/m2, preferably 300-500 g/m2 such as about 400 g/m2. The amount of binder applied for the sub-layer 3 may be 100-300 g/m2, preferably 150-250 g/m2 such as about 200 g/m2. The sub-layer 3 may comprise the binder in an amount of 30-80 wt %, preferably in an amount of 40-60 wt % such as about 50 wt %.

(10) In an embodiment, a produced building panel may be 6-25 mm thick, preferably 8-15 mm thick after pressing, while the core may be 5-22 mm thick, preferably 7-14 mm thick. The sub-layer may be 0.1-2 mm thick after pressing.

(11) Using a protective overlay with wear resistant particles applied on the veneer is not excluded and this could increase the wear resistance of a wood veneer. Dry and wet overlays, which are produced by production methods where for example thermosetting resins in dry or wet form are mixed with aluminium oxide, without any fibres could also be used. Aluminium oxide particles mixed with melamine powder could for example be applied on a wood veneer prior to pressing and a wear resistant surface could be obtained without any surface coating after pressing. Dry and wet overlays may be applied on the surface layer prior to pressing. Wax may be applied, for example, as a powder, prior to pressing on the veneer. A lacquer may also be applied on the surface layer after pressing. A protective foil may also be applied on the veneer prior to pressing or on the surface layer after pressing.

(12) It is also contemplated that the building panel is provided with a second surface layer (not shown) comprising a wood veneer of the above described type. A sub-layer of the above described type is arranged between the second surface layer and a second surface of the core of the above described type. The second surface layer has surface portions comprising material from the sub-layer extending into the wood veneer. The second surface of the core faces away from the surface layer described above with reference to FIG. 1. In this embodiment, the surface layer described above with reference to FIG. 1 is considered as first surface layer.

(13) The building panel may be produced by a method comprising the step of: applying a wood fibre powder and a binder on a wood fibre based core, to obtain a sub-layer; applying a wood veneer, comprising holes through the veneer, on the sub-layer, applying heat and pressure to bond the veneer, the sub-layer and the wood fibre based core together, wherein a portion of the wood fibre powder and the binder is pressed into the holes.

(14) The method preferably comprises the step of applying a foaming agent. The foaming agent may facilitate the displacement of the wood fibre powder and the agent into the holes.

(15) The wood fibre powder may comprise lignocellulosic particles or cellulose particles.

(16) The method may comprise the step of applying different colour pigments, such that the colour of the visible sub-layer portion varies along the building panel, or such that the portion of the sub-layer in the holes forms a pattern.

EMBODIMENTS

(17) 1. A building panel comprising: a surface layer comprising a wood veneer, a wood fibre based core, and a sub-layer arranged between the surface layer and the wood fibre based core, wherein the sub-layer comprises wood fibres and a binder, wherein the surface layer has surface portions comprising material from the sub-layer extending into the wood veneer.

(18) 2. The building panel as in embodiment 1, wherein the surface portions comprising material from the sub-layer are flush with a remainder of the surface layer.

(19) 3. The building panel as in embodiment 1, wherein the surface layer comprises embossed portions and wherein a part of the sub-layer is more compressed under an embossed portion than under a non-embossed surface portion.

(20) 4. The building panel as in embodiment 1, wherein the sub-layer comprises colour pigments and/or a colorant.

(21) 5. The building panel as in embodiment 1, wherein the sub-layer comprises wear resistant particles.

(22) 6. The building panel as in embodiment 1, further comprising a powder-based balancing layer.

(23) 7. The building panel as in embodiment 1, wherein the wood veneer comprises holes and/or cracks, wherein the sub-layer fills the holes and/or cracks of the wood veneer.

(24) 8. The building panel as in embodiment 1, further comprising a protective overlay comprising wear resistant particles arranged on the surface layer.

(25) 9. The building panel as in embodiment 1, wherein the binder in the sub-layer is a thermosetting resin.

(26) 10. The building panel as in embodiment 1, wherein the binder in the sub-layer is a melamine formaldehyde resin.

(27) 11. The building panel as in embodiment 1, wherein the sub-layer comprises a foaming agent.

(28) 12. The building panel as in embodiment 1, wherein the surface layer is a cork layer.

(29) 13. A building panel comprising: a surface layer comprising a wood veneer, a wood fibre based core, and a sub-layer arranged between the surface layer and the wood fibre based core, wherein the sub-layer comprises wood fibres, a binder and wear resistant particles, wherein the surface layer has surface portions comprising material from the sub-layer extending into the wood veneer.

(30) 14. A building panel comprising: a surface layer comprising a wood veneer, a wood fibre based core, and a sub-layer arranged between the surface layer and the wood fibre based core, wherein the sub-layer comprises wood fibres, a binder and colour pigments and/or a colorant, wherein the surface layer has surface portions comprising material from the sub-layer extending into the wood veneer.

(31) 15. A building panel comprising: a surface layer comprising a veneer, a core, and a sub-layer arranged between the surface layer and core, wherein the surface layer has surface portions comprising material from the sub-layer extending into the veneer.

(32) 16. A method to produce a building panel, the method comprising: applying a wood fibre powder and a binder on a wood fibre based core, to obtain a sub-layer; applying a wood veneer, comprising holes through the veneer, on the sub-layer, applying heat and pressure to bond the veneer, the sub-layer and the wood fibre based core together, wherein a portion of the wood fibre powder and the binder is pressed into the holes.

(33) 17. The method as in embodiment 16, further comprising applying a foaming agent in the sub-layer.

(34) 18. The method as in embodiment 16, wherein the wood fibre powder comprises lignocellulosic particles or cellulose particles.

(35) 19. The method as in embodiment 16, further comprising applying different colour pigments, such that the colour of the visible sub-layer portion varies along the building panel, or such that the portion of the sub-layer in the holes forms a pattern.

(36) 20. The method as in embodiment 16, wherein after applying pressure, the wood veneer comprises embossed portions, and wherein a part of the sub-layer is more compressed under an embossed surface portion than under a non-embossed surface portion.

(37) 21. The method as in embodiment 16, further comprising applying a protective overlay with wear resistant particles on the wood veneer, preferably prior to pressing.

(38) 22. The method as in embodiment 16, wherein the sub-layer comprises colour pigments and/or a colorant.

(39) 23. The method as in embodiment 16, wherein the sub-layer comprises wear resistant particles.