DE102022203336A1 - Composite panel and process for its production - Google Patents

Abstract

The invention relates to a composite panel made of fibrous plant material, a process for its production and its use as a structural material, in particular for the production of furniture.

Description

The invention relates to a composite panel made of fibrous plant material, a process for its production and its use as a structural material, in particular for the production of furniture.

From the DE 10 2009 043017 A1 is a molded body, in particular a plate made of fibrous, leafy natural materials. Such a shaped body is intended for use as an insulating material or cushioning material for transport packaging and does not have the strength required for use as a structural material.

The WO 2014/107767 describes a composite panel made from plant material that is suitable as a structural material. However, a chemical-synthetic adhesive must be used to produce this composite panel.

The previously known composite materials made from plant material often do not have the required strength for use as a structural material. In addition, many of these materials have the disadvantage that synthetic chemical binders or adhesives are used to produce them, which make recycling these materials difficult or even impossible. On the other hand, the medium-density wood fiber boards (MDF boards) used in the furniture industry, particularly to produce inexpensive furniture, generally contain formaldehyde-containing adhesives as binders and are only partially recyclable.

The object of the invention is to provide a composite panel made of fibrous plant material that has a strength suitable for use as a structural material and can easily be almost completely recycled or disposed of in an environmentally friendly manner. A further object of the invention is to provide a method for producing a composite panel made of fibrous plant material.

According to the invention, this object is achieved by a composite panel with the features of independent claim 1. Advantageous further developments result from subclaims 2 to 8. The task is further solved by a method according to claim 9. Advantageous embodiments of the method result from subclaims 10 to 16. The invention furthermore relates to the use of the composite panel according to the invention according to claims 17 and 18.

The composite panel according to the invention has two outer layers made of veneer wood and at least a first inner layer made of fibrous plant material and contains an adhesive made from natural raw materials as a binder.

Suitable according to the invention is veneer wood with a smooth surface, as is also used, for example, for the production of MDF boards. This veneer is thin wood sheets whose thickness is at least 0.5 mm, preferably 0.5 to 8 mm and in particular 0.5 to 4 mm. The thicknesses of the two outer layers of veneer wood can be the same or different. The thicknesses of the two outer layers of veneer wood are preferably the same.

All plant materials that consist of fibers whose length is many times, in particular at least 10 times, their width are suitable as fibrous plant material. Preferably at least 50% of the fibers of the fibrous plant material have a fiber length of at least 5 cm, preferably 5 to 10 cm. Particularly suitable plant fiber materials are hay, straw or grass or mixtures of these materials. Grass is particularly preferred according to the invention. The fibrous plant material can contain small amounts, preferably up to 15% by volume, of admixtures of plant material that does not have fibers, such as leaves or green waste.

The adhesive made from natural raw materials is preferably a glue based on animal proteins or a vegetable paste. Particularly preferably, the adhesive made from natural raw materials is a starch adhesive or a flour adhesive, in particular a flour adhesive in which the weight ratio of water to flour before processing is between 30:70 and 70:30. The proportion of water to be selected in the specified range depends on the moisture of the fibrous plant material used in such a way that a higher proportion of water is advantageous for very dry fibrous plant material. A weight ratio of water to flour of 50:50 before processing has often proven to be particularly suitable.

According to the invention, the first inner layer has a thickness of at least 2 mm, preferably from 4 mm to 35 mm and in particular from 10 mm to 25 mm.

In one embodiment of the invention, the composite panel according to the invention can have one or more further inner layers in addition to the two outer layers made of veneer wood and the first inner layer, with inner layers made of veneer wood being arranged between the inner layers. The thickness of the inner layers of veneer wood is the same chen area such as the thickness of the outer layers of veneer wood. The thicknesses of the inner layers of veneer wood can be the same or different and the same thickness, thicker or thinner than the two outer layers of veneer wood. The thicknesses of the inner layers of veneer wood are preferably the same thickness or thinner than the two outer layers of veneer wood or, if the two outer layers of veneer wood have different thicknesses, the same thickness or thinner than the thinner of the two outer layers of veneer wood. Particularly preferably, the two outer layers of veneer wood and the inner layers of veneer wood have the same thickness.

The thickness of the further inner layers is also at least 2 mm, preferably from 4 mm to 35 mm and in particular from 10 mm to 25 mm. The thicknesses of the first inner layer and the further inner layers can be different or preferably the same. As the number of inner layers increases, it is preferred to reduce the thickness of the inner layers.

The composite panels according to the invention are characterized by strength, rigidity, wear resistance, high density and hardness and are therefore suitable as a structural material for applications in which they are exposed to mechanical stress or weight. They can be used in particular, like MDF panels, to build furniture.

Another advantage of the composite panels according to the invention is that they do not contain any environmentally harmful components. They are largely compostable when disposed of and can be easily recycled by being shredded and used again in the production of new composite panels.

1. a) Vermengen von faserigem Pflanzenmaterial mit einem aus natürlichen Rohstoffen hergestellten Klebstoff;
2. b) Aufbringen einer gleichmäßigen Schicht der unter a) erhaltenen Mischung aus Pflanzenmaterial und Klebstoff auf eine Seite einer Schicht aus Furnierholz;
3. c) Verpressen der unter a) erhaltenen Mischung mit der Schicht aus Furnierholz unter Erwärmen zu einem ersten Verbund;
4. d) Beschichten des unter c) erhaltenen ersten Verbunds mit dem aus natürlichen Rohstoffen hergestellten Klebstoff auf der nicht mit Furnierholz beschichtete Seite des unter c) erhaltenen ersten Verbunds.
5. e) Zuführen einer zweiten Schicht aus Furnierholz und Aufbringen auf die nicht mit Furnierholz beschichtete Seite des unter d) erhaltenen, mit dem aus natürlichen Rohstoffen hergestellten Klebstoff beschichteten ersten Verbunds und Verpressen der zweiten Schicht aus Furnierholz mit dem unter c) erhaltenen Verbund unter Erwärmen zu einer Verbundplatte mit zwei Außenschichten aus Furnierholz.

The invention also relates to a method for producing a composite panel from fibrous plant material, comprising the following steps

1. a) mixing fibrous plant material with an adhesive made from natural raw materials;
2. b) applying a uniform layer of the mixture of plant material and adhesive obtained under a) to one side of a layer of veneer wood;
3. c) pressing the mixture obtained under a) with the layer of veneer wood while heating to form a first composite;
4. d) Coating the first composite obtained under c) with the adhesive made from natural raw materials on the side of the first composite obtained under c) that is not coated with veneer wood.
5. e) supplying a second layer of veneer wood and applying it to the side not coated with veneer wood of the first composite obtained under d) and coated with the adhesive made from natural raw materials and pressing the second layer of veneer wood with the composite obtained under c) while heating a composite panel with two outer layers of veneer wood.

All plant materials that consist of fibers whose length is many times, in particular at least 10 times, their width are suitable as fibrous plant material. Preferably at least 50% of the fibers of the fibrous plant material have a fiber length of at least 5 cm, preferably 5 to 10 cm. Particularly suitable plant fiber materials are hay, straw or grass or mixtures of these materials. Grass is particularly preferred according to the invention. The fibrous plant material can contain small amounts, preferably up to 15% by volume, of admixtures of plant material that does not have fibers, such as leaves or green waste.

The adhesive made from natural raw materials is preferably a glue based on animal proteins or a vegetable paste. Particularly preferably, the adhesive made from natural raw materials is a starch adhesive or a flour adhesive, in particular a flour adhesive in which the weight ratio of water to flour before processing is between 30:70 and 70:30. The proportion of water to be selected in the specified range depends on the moisture of the fibrous plant material used in such a way that a higher proportion of water is advantageous for very dry fibrous plant material.

The fibrous plant material is mixed with the adhesive made from natural raw materials in step a) preferably in a volume ratio of 80:20 to 60:40. The amount of adhesive can be selected in the lower range if the fibrous plant material has a largely uniform structure. On the other hand, the amount of adhesive must be chosen so high that no cavities or air bubbles form in the layer of fibrous plant material during pressing in step c), as these reduce the stiffness and strength of the composite panels. When mixing, care must be taken to ensure that the fibrous plant material is not subjected to mechanical stress that would alter the structure of the fibrous plant material. Mixtures are therefore preferably suitable for mixing in step a). machinery. Such machines are known to those skilled in the art and are offered commercially, particularly for the baking and meat industries.

In particular if the fibrous plant material is particularly moist or is to be stored for a longer period of time before processing, it is advisable for the fibrous plant material to be dried in an air stream with circulation before process step a) in order to avoid rot. Drying is preferably carried out at temperatures below 100 ° C, in particular at 40 to 80 ° C, for a time of preferably at least 2 hours to a maximum of 24 hours.

In step b), a uniform layer of the mixture of fibrous plant material and adhesive obtained in step a) is applied to one side of a layer of veneer wood. According to the invention, a thin layer of adhesive made from natural raw materials can be applied to the veneer beforehand. The adhesive application can be as thin as desired, as long as it is applied to the entire surface of the veneer wood. In particular, a layer thickness of approximately 1mm has proven to be advantageous. For this purpose, the mixture of fibrous plant material and adhesive obtained in step a) is preferably transferred to a storage container with a metering device and applied in a defined layer thickness to a layer of veneer wood passed under the metering device. The layer thickness of the fibrous plant material is at least 25 mm, preferably from 50 mm to 400 mm and in particular from 125 mm to 300 mm. Suitable devices for this, e.g. doctor blades or rollers, are known to those skilled in the art.

The veneer wood obtained in step b) and coated with the mixture of fibrous plant material and adhesive is then placed in a press. The pressing is preferably carried out at a temperature of 60 to 80 ° C and preferably at a pressure of 1.0 to 5.0 bar (100 to 500 kPa), in particular 1.0 to 3.5 bar (100 to 350 kPa) , until the water is largely removed from the first composite.

Then, in step d), the first composite obtained in step c) is coated on the side not coated with veneer wood with a thin layer of the adhesive made from natural raw materials. Alternatively, according to the invention, instead of applying the adhesive in step c), in step e) a second layer of veneer wood, thinly coated on one side with the adhesive made from natural raw materials, can be supplied and with the adhesive-coated side on the side not coated with veneer wood of the first layer obtained under c). Composite will be applied. The adhesive coating of the first composite or the second layer of veneer wood is carried out, for example, using a doctor blade and/or rollers. Corresponding application systems are known to those skilled in the art and are commercially available.

In step e), a second layer of veneer wood is added to the first composite obtained in step d) and coated with the adhesive made from natural raw materials. Then in a press, preferably a plate press, in particular a veneer press, with heating, preferably at a temperature of 60 to 80 ° C, and preferably with a pressure of 1.0 to 5.0 bar (100 to 500 kPa), in particular pressed at 1.0 to 3.5 bar (100-350 kPa) to form a composite panel with two outer layers of veneer wood, the first inner layer of which has a thickness of at least 2 mm, preferably from 5 mm to 35 mm and in particular from 10 mm to 25 mm .

• f) Aufbringen einer gleichmäßigen Schicht der in Schritt a) erhaltenen Mischung aus Pflanzenmaterial und Klebstoff auf eine der äußeren Schichten aus Furnierholz der in Schritt e) erhaltenen Verbundplatte;
• g) Verpressen der in Schritt f) aufgebrachten Mischung mit der äußeren Schicht aus Furnierholz unter Erwärmen zu einem Verbund;
• h) Beschichten des unter g) erhaltenen Verbunds mit dem aus natürlichen Rohstoffen hergestellten Klebstoff auf der nicht mit Furnierholz beschichteten Seite.
• i) Zuführen einer weiteren Schicht aus Furnierholz und Aufbringen auf die nicht mit Furnierholz beschichtete Seite des in Schritt g) erhaltenen Verbunds und verpressen der weiteren Schicht aus Furnierholz mit dem in Schritt h) erhaltenen, mit dem aus natürlichen Rohstoffen hergestellten Klebstoff beschichteten Verbund unter Erwärmen zu einer Verbundplatte mit zwei Außenschichten aus Furnierholz.

In a special embodiment of the invention, the following additional steps are carried out to produce a composite panel:

• f) applying a uniform layer of the mixture of plant material and adhesive obtained in step a) to one of the outer layers of veneer wood of the composite panel obtained in step e);
• g) pressing the mixture applied in step f) with the outer layer of veneer wood while heating to form a composite;
• h) Coating the composite obtained under g) with the adhesive made from natural raw materials on the side not coated with veneer wood.
• i) supplying a further layer of veneer wood and applying it to the side of the composite obtained in step g) that is not coated with veneer wood and pressing the further layer of veneer wood with the composite obtained in step h) and coated with the adhesive made from natural raw materials while heating into a composite panel with two outer layers of veneer wood.

In step f), a uniform layer of the mixture of fibrous plant material and adhesive obtained in step a) is applied to one of the outer layers of veneer wood of the composite panel obtained in step e) in a manner analogous to step b). According to the invention, a thin layer of the adhesive made from natural raw materials can be applied to the veneer beforehand.

Then, in step g), the mixture obtained in step f) is mixed with a further layer of the mixture Composite panel coated from fibrous plant material and adhesive, similar to step b), is fed to a press, preferably a panel press, in particular a veneer press, and pressed into a composite with heating. The pressing is preferably carried out at a temperature of 60 to 80 ° C and preferably at a pressure of 1.0 to 5.0 bar (100 to 500 kPa), in particular 1.0 to 3.5 bar (100 to 350 kPa) , until the water is largely removed from the further layer of the mixture of fibrous plant material and glue.

In step h), analogous to step d), the composite obtained under g) is coated with a thin layer of the adhesive made from natural raw materials.

Then in step i), analogous to step e), a further layer of veneer wood is applied to the side of the composite obtained under g) that is not coated with veneer wood as an outer layer. The composite provided with an outer layer of veneer wood is fed into a press, preferably a panel press, in particular a veneer press, and heated, preferably at a temperature of 60 to 80 ° C, and preferably at a pressure of 1.0 to 5.0 bar (100 to 500 kPa), in particular at 1.0 to 3.5 bar (100 to 350 kPa) to a composite panel with two outer layers made of veneer wood and a first and at least one further inner layer made of fibrous plant material and made from natural raw materials Adhesive pressed. The process steps f) to i) can also be carried out several times, preferably two to four times in succession, using the composite panel obtained in the previous step i) as the starting material instead of the composite panel obtained in step e), so that composite panels with two outer layers Veneer wood, a first inner layer made up of fibrous plant material and an adhesive made from natural raw materials and several, preferably one to four, further inner layers made up of fibrous plant material and made from an adhesive made from natural raw materials can be produced.

The invention also relates to the use of the composite panel according to the invention as a structural material for the production of objects that are exposed to mechanical stress or weight. The use of the composite panel according to the invention for producing furniture is particularly preferred.

Further advantages, special features and useful developments of the invention result from the following presentation of preferred exemplary embodiments based on the illustrations.

• 1 zeigt eine erfindungsgemäße Verbundplatte (1) mit zwei Außenschichten (2) aus Furnierholz und einer ersten Innenschicht (3) aus faserigem Pflanzenmaterial.
• 2 zeigt eine erfindungsgemäße Verbundplatte (7) mit zwei Außenschichten (2) aus Furnierholz, drei innen liegenden Schichten (4) aus Furnierholz, einer ersten Innenschicht (3) aus faserigem Pflanzenmaterial und drei zusätzlichen Innenschichten (5) aus faserigem Pflanzenmaterial.
• 3a zeigt eine schematische Darstellung der Verfahrensschritte a) bis c). Dabei wird auf einer Transportvorrichtung (300) eine Platte aus Furnierholz (31) zugeführt und aus einer Zuführung (35) das vorher durch Vermengen hergestellte Gemisch aus faserigem Pflanzenmaterial und aus natürlichen Rohstoffen hergestelltem Klebstoff (35a) aufgetragen und in einer Presse (36) zu einem ersten Verbund (37) aus Furnierholz und faserigem Pflanzenmaterial verpresst.
• 3b zeigt eine schematische Darstellung der Verfahrensschritte d) und e). Dabei wird in einer Klebstoff-Auftragsvorrichtung (38) der erste Verbund (37) mit dem aus natürlichen Rohstoffen hergestellten Klebstoff beschichtet. Dann wird über den Stempel der Presse (39a, 39b) eine weitere Platte aus Furnierholz (31 a) zugeführt, die mittels Unterdrucks an dem Stempel gehalten wird. Das Furnierholz (31 a) wird auf die mit dem aus natürlichen Rohstoffen hergestellten Klebstoff beschichtete, noch nicht mit Furnierholz beschichtete Seite des Verbunds (37) aufgelegt und mittels der Presse (39a,39b) zur fertigen Verbundplatte verpresst. Dabei zeigt (39a) die Presse vor dem Auflegen des Furnierholzes und (39b) die Presse nach dem Verpressen.
• 4a zeigt eine schematische Darstellung der Verfahrensschritte f) und g). Dabei wird auf einer Transportvorrichtung (400) eine Verbundplatte (40) zugeführt und aus einer Zuführung (45) das vorher durch Vermengen hergestellte Gemisch aus faserigem Pflanzenmaterial und aus natürlichen Rohstoffen hergestelltem Klebstoff (35a) aufgetragen und in einer Presse (46) zu einem Verbund aus Furnierholz und faserigem Pflanzenmaterial verpresst.
• 4b zeigt eine Schematische Darstellung der Verfahrensschritte h) und i). Dabei wird in einer Klebstoff-Auftragsvorrichtung (48) der in Schritt g) erhaltene Verbund mit dem aus natürlichen Rohstoffen hergestellten Klebstoff beschichtet. Dann wird über den Stempel der Presse (49a, 49b)) eine weitere Platte aus Furnierholz (41 a) zugeführt, die mittels Unterdrucks an dem Stempel gehalten wird. Das Furnierholz (41a) wird auf die mit dem aus natürlichen Rohstoffen hergestellten Klebstoff beschichtete, noch nicht mit Furnierholz beschichtete Seite des Verbunds aufgelegt und mit der Presse (49a,49b) zur fertigen Verbundplatte verpresst. Dabei zeigt (49a) die Presse vor dem Auflegen des Furnierholzes und (49b) die Presse nach dem Verpressen.

Description of the images:

• 1 shows a composite panel (1) according to the invention with two outer layers (2) made of veneer wood and a first inner layer (3) made of fibrous plant material.
• 2 shows a composite panel (7) according to the invention with two outer layers (2) made of veneer wood, three inner layers (4) made of veneer wood, a first inner layer (3) made of fibrous plant material and three additional inner layers (5) made of fibrous plant material.
• 3a shows a schematic representation of process steps a) to c). A plate made of veneer wood (31) is fed onto a transport device (300) and the mixture of fibrous plant material and adhesive (35a) made from natural raw materials, previously prepared by mixing, is applied from a feeder (35) and in a press (36). pressed into a first composite (37) made of veneer wood and fibrous plant material.
• 3b shows a schematic representation of process steps d) and e). The first composite (37) is coated with the adhesive made from natural raw materials in an adhesive application device (38). Then another panel made of veneer wood (31a) is fed via the stamp of the press (39a, 39b), which is held on the stamp by means of negative pressure. The veneer wood (31a) is placed on the side of the composite (37) that is coated with the adhesive made from natural raw materials and is not yet coated with veneer wood and pressed into the finished composite panel using the press (39a, 39b). (39a) shows the press before placing the veneer and (39b) the press after pressing.
• 4a shows a schematic representation of process steps f) and g). A composite plate (40) is fed on a transport device (400) and the mixture of fibrous plant material and adhesive (35a) made from natural raw materials, previously prepared by mixing, is applied from a feeder (45) and formed into a composite in a press (46). pressed from veneer wood and fibrous plant material.
• 4b shows a schematic representation of process steps h) and i). The composite obtained in step g) is coated with the adhesive made from natural raw materials in an adhesive application device (48). Then the stamp of the press (49a, 49b)) another plate made of veneer wood (41a) is fed, which is held on the stamp by means of negative pressure. The veneer wood (41a) is placed on the side of the composite that is coated with the adhesive made from natural raw materials and is not yet coated with veneer wood and pressed into the finished composite panel using the press (49a, 49b). (49a) shows the press before placing the veneer and (49b) the press after pressing.

Example:

A veneer wood panel 80x110mm with a thickness of 0.8 mm was thinly coated over the entire surface with a flour adhesive (weight ratio of water to flour before processing of 50:50). A carefully hand-mixed mixture of grass and the flour glue (volume ratio 70% grass / 30% flour glue) was applied to this veneer wood panel with a layer thickness of 30mm and at 70 ° C for 2 hours with a pressure of 2 bar (200 kPa). pressed to a thickness of 24mm. A second veneer wood panel 80x110mm with a thickness of 0.8mm was then placed on the layer of grass and flour glue, which had been coated with the flour glue described above in the same way as the first veneer panel. The resulting composite was then pressed into a 4 mm thick composite panel at 70 °C for 2 hours at a pressure of 2 bar (200 kPa).

The composite panel produced in this way broke in the middle of the composite panel under a load of 6.5 kg.

The embodiments shown here represent only examples of the present invention and should therefore not be construed as limiting.

List of reference symbols:

10, 20, 30, 40

composite panel

11, 11a, 21, 21a, 31, 31a, 41, 41a

Outer layer made of veneer wood

12, 22, 32

First inner layer

23, 43

Internal layer of veneer wood

24, 44

Additional inner layer

35, 45

Feed mixture of plant material/adhesive

35a, 45a

Mixture of fibrous plant material/glue

36, 39a, 39b, 46, 49a, 49b

Press

37

First composite of veneer wood and plant material

38, 48

Glue applicator

300, 400

Transport device

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009043017 A1 [0002]
• WO 2014107767 [0003]

Claims (18)

Composite panel, characterized in that it has two outer layers made of veneer wood (11, 11a, 21, 21a, 31, 31a, 41, 41a) and at least a first inner layer (12, 22, 32) made of fibrous plant material and one made of natural raw materials manufactured adhesive includes. Composite panel according to Claim 1 , characterized in that the first inner layer (12, 22, 32) has a thickness of at least 2 mm, preferably from 4 mm to 35 mm and in particular from 10 mm to 25 mm. Composite panel according to Claim 1 or 2 , characterized in that at least 50% of the fibers of the fibrous plant material have a fiber length of at least 5 cm. Composite panel according to one of the preceding claims, characterized in that the fibrous plant material is selected from the group of hay, straw or grass or mixtures of these materials. Composite panel according to one of the preceding claims, characterized in that the adhesive made from natural raw materials is a glue based on animal proteins or a vegetable paste. Composite panel according to one of the preceding claims, characterized in that the adhesive made from natural raw materials is a starch adhesive or a flour adhesive. Composite panel according to one of the preceding claims, characterized in that the adhesive made from natural raw materials is a flour adhesive in which the weight ratio of water to flour before processing is between 30:70 and 70:30. Composite panel according to one of the preceding claims, characterized in that, in addition to the two outer layers of veneer wood (11, 11a, 21, 21a, 31, 31a, 41, 41a) and the at least one first inner layer (12, 22, 32), it has one or has several additional inner layers (24, 44), with inner layers of veneer wood (23, 43) being arranged between the inner layers (12, 22, 32, 24, 44). Method for producing a composite panel (30, 40) comprising the steps a) mixing fibrous plant material with an adhesive made from natural raw materials; b) applying a uniform layer of the mixture of plant material and adhesive (35a) obtained under a) to one side of a layer of veneer wood (31); c) pressing the mixture (35a) obtained under a) with the layer of veneer wood (31) while heating to form a first composite (37); d) coating the first composite (37) obtained under c) with the adhesive made from natural raw materials on the side of the first composite obtained under c) that is not coated with veneer wood. e) supplying a second layer of veneer wood (31a) and applying it to the side not coated with veneer wood of the first composite (37) obtained under d) and coated with the adhesive made from natural raw materials and pressing the second layer of veneer wood (31a). the composite (37) obtained under c) with heating to form a composite panel (30) with two outer layers made of veneer wood. Method for producing a composite panel (30,40) according to Claim 9 , characterized in that the fibrous plant material is dried in an air stream with circulation before process step a). Method for producing a composite panel (30, 40) according to one of Claims 9 or 10 , characterized in that the fibrous plant material in step a) is mixed with the adhesive made from natural raw materials in a volume ratio of 80:20 to 60:40. Method for producing a composite panel (30,40) according to one of Claims 9 until 11 , characterized in that the pressing in step c) takes place at a temperature of 60 ° C to 80 ° C. Method for producing a composite panel (30, 40) according to one of Claims 9 until 12 , characterized in that the pressing in step c) takes place at a pressure of 1.0 bar to 5.0 bar (100 to 500 kPa), preferably 1.0 bar to 3.5 bar (100 to 350 kPa). Method for producing a composite panel (30,40) according to one of Claims 9 until 13 , characterized in that the pressing in step f) takes place at a temperature of 60 ° C to 80 ° C. Method for producing a composite panel (40) according to one of Claims 9 until 14 , comprising the additional steps f) applying a uniform layer of the mixture of plant material and adhesive obtained in step a) to one of the outer layers Veneer wood of the composite panel (40) obtained in step e); g) pressing the mixture applied in step f) with the outer layer of veneer wood while heating to form a composite; h) Coating the composite obtained under g) with the adhesive made from natural raw materials on the side not coated with veneer wood. i) supplying a further layer of veneer wood (41a) and applying it to the side of the composite obtained in step g) that is not coated with veneer wood and pressing the further layer of veneer wood (41a) with that obtained in step h) with that made from natural raw materials produced adhesive-coated composite with heating to form a composite panel (30) with two outer layers of veneer wood, the additional steps f) to i) using the composite panel obtained in the previous step i) as the starting material instead of the composite panel obtained in step e). can be carried out several times in a row. Method for producing a composite panel according to one of Claims 9 until 14 , characterized in that the pressing in step f) is carried out at a pressure of 1.0 bar to 5.0 bar (100 to 500 kPa), preferably 1.0 bar to 3.5 bar (100 to 350 kPa) he follows. Use of composite panels according to one of Claims 1 until 8th as a structural material. Use of composite panels according to one of Claims 1 until 8th for making furniture.

Images