Wood composite material with 3D embossment hot-pressed veneer

Abstract

The invention relates to the technical field of wood composite materials, in particular to a wood composite material with a 3D embossment hot-pressing veneer, which comprises a veneer layer and a base material which are bonded with each other, and is characterized in that a buffer material layer is further bonded between the veneer layer and the base material, and the thickness of the buffer material layer is 0.5-3.0 mm.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wood composites, in particular, relates to a kind of 3D embossing hot-pressed veneer wood composite. BACKGROUND

[0002] 3D embossing hot-pressed veneer wood composite belongs to a kind of veneer-based panel, according to the different base materials, including veneer-based fiberboard, veneer-based multi-layer composite board and veneer-based particle board, etc. When producing wood composite with general veneer, the veneer layer is stacked with the base material layer and sent into the press, and under the action of temperature and pressure, the adhesive in the veneer layer is hot-melted to bond the veneer layer and the base material. The difference of 3D embossing hot-pressed veneer wood composite lies in that the hot-pressed board is a concave-convex embossed surface, and the concave-convex embossed effect is pressed on the surface of the base material at the same time, of course, the veneer layer also deforms to be bonded on the surface of the base material.

[0003] However, there are some problems in pressing 3D embossing veneer on the surface of the base material. From the aspect of the base material, the base material used as veneer-based panel generally has considerable surface hardness, which makes it necessary to have larger hot-pressing pressure, longer hot-pressing time and larger hot-pressing pressure to press the concave-convex embossed effect on the surface of the base material, for example, 6-8 MPa, 210-220 ℃, 2-3 min; or make the surface of the base material have higher moisture content, for example, spray water on the surface. In actual operation, it is difficult to achieve the required values of the pressing time and pressure of the veneer layer, and the operation of spraying water on the surface of the base material is easy to cause uneven moisture content, white spots and other problems. Even after forced pressing, the concave part of the surface will rebound during use or storage.

[0004] From the aspect of the veneer layer, considering the cost, technical maturity and the surface hardness of the product (pencil hardness affected by the veneer layer), the veneer layer often uses impregnated paper of impregnated phenol formaldehyde resin adhesive or urea-formaldehyde resin adhesive, but the impregnated paper has greater brittleness, which (1) is contradictory to the longer hot-pressing time and pressure required for the base material to press the concave-convex embossed effect, (2) the transition between the concave part and the convex part of the concave-convex pattern pressed on the surface of the material with higher surface hardness is relatively harsh, which is more likely to cause the veneer layer to be damaged. SUMMARY

[0005] The purpose of the present application is to provide a kind of 3D embossing hot-pressed veneer wood composite to solve the problem of higher hot-pressing temperature and longer time of the product in the prior art, as well as the problems of uneven moisture content, white spots and veneer layer damage caused thereby. The following technical solutions are specifically adopted:

[0006] A 3D embossed hot-pressed veneer wood composite material comprises a veneer layer and a substrate which are bonded to each other, and a buffer material layer which is also bonded between the veneer layer and the substrate, and has a thickness of 0.5-3.0 mm.

[0007] As a preferred embodiment, the buffer material layer is a thermoplastic material, and has a thickness of 0.5-1.5 mm.

[0008] As a preferred embodiment, the 3D embossed hot-pressed veneer wood composite material is prepared by the following method:

[0009] Step one, sequentially stacking the veneer layer, the buffer material layer and the substrate from top to bottom;

[0010] Step two, preheating the stacked material at a temperature of 100-110℃, a pressure of 0-0.3 MPa and for a time of 15-25 s;

[0011] Step three, hot-pressing the preheated stacked material at a temperature of 140-160℃, a pressure of 6-8 MPa and for a time of 45-60 s;

[0012] Step four, maintaining the pressure and forcibly cooling to 50℃, and then naturally cooling to room temperature, and cold-pressing at room temperature for 3-5 min.

[0013] As a preferred embodiment, the buffer material layer comprises a bagasse layer obtained by bonding and pressing bagasse, and a bagasse fiber mixed layer connecting the bagasse layer and the substrate, and has an average density of 0.55-0.65 g / cm 3 .

[0014] As a preferred embodiment, the bagasse layer is obtained by self-bonding of bagasse.

[0015] As a preferred embodiment, the method for preparing the 3D embossed hot-pressed veneer wood composite material comprises a composite substrate preparation process and a hot-pressing process; wherein the composite substrate preparation process comprises the following steps:

[0016] Step one, laying bagasse having a moisture content of 12-15% to obtain a bottom layer having a stacking thickness of 3-5 mm;

[0017] Step two, pre-pressing the bottom layer at a temperature of 185-190℃, a pressure of 0.3-0.8 MPa and for a time of 25-35 s;

[0018] Step three, laying a first wood fiber having glue thereon as a bottom wood fiber layer on the pre-pressed bottom layer, and the first wood fiber has a moisture content of 6-8%;

[0019] Step four, a second wood fiber after the facility glue is laid on the bottom wood fiber layer as a surface wood fiber layer, the moisture content of the second wood fiber is 12-14%;

[0020] Step five, hot pressing the group blank layer including the bottom layer, the bottom wood fiber layer and the surface wood fiber layer, the hot pressing temperature is 185-190℃, the pressure is not less than 6MPa, and the time is 60s.

[0021] As a preferred embodiment, the hot pressing process is used to hot press and bond the surface layer and the composite substrate, the hot pressing temperature is 170-180℃, and the time is 25-35s.

[0022] As a preferred embodiment, the surface layer includes a single layer of paper, the single layer of paper is an impregnated paper impregnated with a resin, the resin includes a main agent and an auxiliary agent, the main agent is a phenolic resin adhesive or a urea-formaldehyde resin adhesive, and the auxiliary agent includes a plasticizer and / or a softener.

[0023] As a preferred embodiment, the surface layer includes two single layers of paper and an elastic layer arranged between the two single layers of paper.

[0024] As a preferred embodiment, the auxiliary agent further includes a flexibility enhancing auxiliary agent selected from one or more of polyvinyl alcohol, polyurethane dispersion, and nano-silica sol.

[0025] The 3D embossed hot-pressed surface of the wood composite material of the technical solution of the present application can maintain a high surface hardness while reducing the hot pressing temperature and shortening the hot pressing time, and the concave part (compressed part) is not easy to rebound.

[0026] In particular, compared to forming a concave-convex pattern on the surface of a high-hardness substrate, when a concave-convex pattern is formed on the buffer material layer, the concave part and the convex part can form a more natural transition surface, thereby better avoiding damage to the fragile surface layer during pressing.

[0027] At the same time, compared to the prior art technology of spraying water on the surface of the substrate to increase the surface moisture content to soften the surface, the buffer material layer provided by the present application can avoid uneven moisture content and surface white spots. DETAILED DESCRIPTION

[0028] The technical solutions in the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The following description of at least one example embodiment is merely illustrative in nature, and is in no way limiting on the application or its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the present application.

[0029] Embodiment 1: A wood composite material with 3D embossed hot-pressed veneer, comprising a wear-resistant layer, a veneer layer, a cushion material layer, a substrate and a balancing layer, the cushion material layer is located between the veneer layer and the substrate.

[0030] The wear-resistant layer is a prior art aluminum oxide impregnated paper. The veneer layer is a prior art urea-formaldehyde resin adhesive impregnated paper with a thickness of 0.2 mm. The substrate is a medium density fiberboard with a thickness of 16 mm, a moisture content of 12%, a deviation of less than 0.5%, and a width of 4 feet by 8 feet. Of course, the substrate can also be other optional man-made boards with optional thicknesses, such as high-density boards, multi-layer plywood or integrated materials, etc. The cushion material layer has a certain flexibility and elasticity, with a thickness of 0.5-3.0 mm. In this embodiment, the cushion material layer is a hot-melt EVA film layer with a thickness of 0.5 mm. The balancing layer is a prior art colorless urea-formaldehyde resin adhesive impregnated paper.

[0031] Through the above structure, the cushion material layer replaces the surface layer of the substrate as the material layer that actually forms the concave-convex embossed effect. In other words, during the hot-pressing process, the cushion material layer (hot-melt EVA film layer) softens under heat and can be pressed to form a concave-convex embossed pattern, while being able to bond with the veneer layer and the substrate respectively. Thus, the wood composite material with 3D embossed hot-pressed veneer of the present embodiment, by virtue of the setting of the cushion material layer, can press a concave-convex embossed pattern on the cushion material layer under the conditions of relatively low hot-pressing temperature and relatively short hot-pressing time. At the same time, through experiments, replacing the surface layer of the substrate with the cushion material layer as the material layer that actually forms the concave-convex embossed effect does not reduce the surface hardness of the final product.

[0032] In particular, in the present embodiment, the cushion material layer is a hot-melt EVA film layer, and the concave part (compressed part) after pressing does not easily rebound, and can better maintain the pattern in use.

[0033] At the same time, compared to forming a concave-convex pattern on the surface of a high-hardness substrate, when forming a concave-convex pattern on the cushion material layer, the concave part and the convex part can form a more natural transition surface, thereby better avoiding damage to the brittle veneer layer during the pressing process.

[0034] Example 2: The difference between this example and Example 1 is that the cushioning material layer is a hot-melt TPU film layer with a thickness of 1.0 mm.

[0035] Example 3: The difference between this example and Example 1 is that the facing layer includes a single layer of paper, which is an impregnated paper impregnated with a resin including a main agent and an auxiliary agent, the main agent being a phenolic resin adhesive, and the auxiliary agent including a plasticizer and a softener. Among them, the plasticizer is a prior art, for example, the epoxy plasticizer used in this example, and the addition amount is 1%. The softener is also a prior art, for example, the quaternary ammonium salt softener used in this example, and the addition amount is 1%. Through the use of the above-mentioned auxiliary agent, the facing layer has the advantages of high temperature resistance and good ductility to adapt to the tensile deformation in the hot pressing process and avoid damage. The impregnation means adopts any one of the prior art, for example, impregnation at room temperature (room temperature) and normal pressure (one standard atmosphere), followed by 70°C heating and pre-curing and drying.

[0036] Example 4: The difference between this example and Example 3 is that the facing layer includes two single layers of paper, and an elastic layer is bonded between the two single layers of paper.

[0037] The resin used to impregnate the single layer of paper also includes a flexibility-enhancing auxiliary agent selected from one or more of polyvinyl alcohol, polyurethane dispersion, and nano-silica sol. In this example, the addition amount of the flexibility-enhancing auxiliary agent is 1%, which includes polyvinyl alcohol, polyurethane dispersion, and nano-silica sol, and the ratio of each component is 1:1:1. The impregnation means adopts any one of the prior art, for example, impregnation at room temperature (room temperature) and normal pressure (one standard atmosphere), followed by 70°C heating and pre-curing and drying.

[0038] The elastic layer is a prior art, for example, a polyolefin thermoplastic elastomer (POE) treated by surface polarity modification, with a thickness of about 0.05 mm. The elastic layer and the two single layers of paper are pre-bonded by prior art means such as hot pressing or extrusion, and the total thickness of the facing layer obtained by hot pressing or extrusion is 0.2 mm.

[0039] Example 5: This example provides a method for preparing a wood-based composite material for a 3D relief hot-pressed facing according to Examples 1-4, including the following steps:

[0040] Step one, send the wear-resistant layer, the facing layer, the cushioning material layer, the substrate and the balancing layer placed in the order from top to bottom into the press and place them on the lower platen of the press. The press is a hydraulic oil hot press of the prior art, and at least the upper platen (corresponding to the decorative layer) of the press has a sunken 3D relief pattern, so that a sunken 3D relief pattern can be formed by hot pressing. Among them, the wear-resistant layer, the facing layer, the cushioning material layer and the balancing layer are pre-made finished products, which only need to be unwound (and cut); the substrate is also a pre-made finished product.

[0041] Step two, the pre-softening step, in this step, the temperature of the upper and lower platens of the press is 100-110℃, and 100℃ is taken as an example in this embodiment; the upper and lower platens are in contact with the surface of the laminated material without pressure, that is, 0-0.3MPa can be regarded as no pressure contact, and the contact state is maintained for 20s.

[0042] Step three, the heating step, in this step, the temperature of the platens is raised to 140-160℃ at a heating rate of 8-12℃ / min, and 10℃ / min is taken as an example in this embodiment.

[0043] Step four, the hot pressing step, in this step, the pressure of the platens is raised to 6-8MPa at a pressure raising rate of 0.5-0.8MPa / s, and the pressure is maintained for 45-60s after reaching the set pressure, and 0.5MPa / s is taken as an example in this embodiment. The hot pressing pressure is 8MPa, and the pressure maintaining time is 50s; the staged hot pressing process can avoid the rupture of the decorative layer caused by rapid forming;

[0044] Step five, the cooling and pressure maintaining step, in this step, the temperature of the platens is lowered to 50℃ at a cooling rate of 8-12℃ / min by a cooling system (such as a circulating cold water system), and then it is naturally cooled without considering the cooling rate, and the pressure is maintained at 6-8MPa during the process;

[0045] Step six, the cold pressing step, in this step, the cold pressing is carried out at room temperature (i.e. the natural temperature without disturbance, such as 30℃) and a pressure of 6-8MPa for 3-5min, and 3min is taken as an example in this embodiment.

[0046] After the cold pressing step is completed, the 3D embossed hot-pressed veneer wood composite material can be directly unloaded and taken out, and naturally stored for 72h.

[0047] The 3D embossed hot-pressed veneer wood composite materials prepared by the embodiments 1-4 are respectively marked as samples 11, 12, 13 and 14.

[0048] Embodiment 6: A 3D embossed hot-pressed veneer wood composite material, comprising a wear-resistant layer, a decorative layer, a buffer material layer, a substrate and a balancing layer which are bonded to each other, and the buffer material layer is located between the decorative layer and the substrate.

[0049] The wear-resistant layer is an alumina trihydrate impregnated paper of the prior art. The facing layer is a urea-formaldehyde resin adhesive impregnated paper of the prior art, with a thickness of 0.2 mm. The substrate is a medium density fiberboard, with a thickness of 16 mm, a moisture content of 12%, and a deviation of less than 0.5%. The cushion material layer includes a bagasse layer formed by bagasse bonding and pressing, and a bagasse fiber mixed layer connecting the bagasse layer and the substrate, with a total thickness of 0.5-3.0 mm, and in this embodiment, 1 mm. The density of the cushion material layer is 0.55-0.65 g / cm 3 The balancing layer is a colorless urea-formaldehyde resin adhesive impregnated paper of the prior art.

[0050] Through the above structure, the cushion material layer replaces the surface layer of the substrate as the material layer that actually forms the concave-convex relief effect. In other words, during the hot-pressing process, the cushion material layer (the bagasse layer and the bagasse fiber mixed layer) softens under heat and can be pressed to form a concave-convex relief pattern. Thus, the wood composite material of the 3D relief hot-pressed veneer of this embodiment, by arranging the density-differentiated cushion material layer, can press a concave-convex relief pattern on the cushion material layer under the conditions of a relatively low hot-pressing temperature and a relatively short hot-pressing time. At the same time, through experiments, replacing the surface layer of the substrate with the cushion material layer as the material layer that actually forms the concave-convex relief effect does not reduce the surface hardness of the final product.

[0051] In particular, in this embodiment, compared to the surface of the substrate with a higher density, the cushion material layer includes the bagasse layer and the bagasse fiber mixed layer with a lower density, which can better maintain the pattern and is less likely to rebound in the recesses.

[0052] At the same time, compared to forming a concave-convex pattern on the surface of a high-hardness substrate, forming a concave-convex pattern on the cushion material layer can form a more natural transition surface between the recesses and the convexes, thereby better avoiding damage to the relatively brittle facing layer during pressing.

[0053] Example 7: The difference between this embodiment and Example 6 is that the facing layer includes a single layer of paper, which is an impregnated paper impregnated with a resin. The resin includes a main agent and an auxiliary agent. The main agent is a phenolic resin adhesive. The auxiliary agent includes a plasticizer and a softener. The plasticizer is of the prior art, such as the epoxy plasticizer used in this embodiment, with an addition amount of 1%. The softener is also of the prior art, such as the quaternary ammonium salt softener used in this embodiment, with an addition amount of 1%. Through the use of the above auxiliary agent, the facing layer can have the advantages of high temperature resistance and good ductility to adapt to the tensile deformation during hot pressing and avoid damage. The impregnation means adopts any one of the prior art, such as normal temperature (room temperature) and normal pressure (one standard atmosphere) impregnation, followed by 70°C heating, pre-curing and drying.

[0054] Example 8: The difference between this example and example 7 is that the facing layer comprises two single-layer papers, and an elastic layer is adhesively arranged between the two single-layer papers.

[0055] The resin used for impregnating the single-layer paper further comprises a flexibility enhancing aid selected from one or more of polyvinyl alcohol, polyurethane dispersion, and nano-silica sol. In this example, the flexibility enhancing aid is added in an amount of 1%, and comprises polyvinyl alcohol, polyurethane dispersion, and nano-silica sol in a ratio of 1:1:1. The impregnation means is any one of the prior art, such as room temperature (room temperature) and atmospheric pressure (one standard atmosphere) impregnation, followed by 70°C heating pre-curing and drying.

[0056] The elastic layer is of the prior art, such as polyolefin thermoplastic elastomer (POE) treated by surface polarity modification, with a thickness of about 0.05mm. The elastic layer is pre-bonded with the two single-layer papers by means of hot pressing or extrusion of the prior art, and the total thickness of the facing layer obtained by hot pressing or extrusion is 0.2mm.

[0057] Example 9: Example 9 provides a method for preparing the wood composite material of the 3D embossed hot-pressed facing of examples 6-8, comprising a composite substrate preparation process and a hot pressing process. The implementation of the composite substrate preparation process can utilize the continuous flat pressing production line of the prior art to realize continuous production, or utilize the hot press to realize laboratory small test or pilot test. In this example, the continuous flat pressing production line is used to obtain the sample.

[0058] According to the equipment characteristics of the continuous flat pressing production line, the composite substrate preparation process comprises the following steps:

[0059] Step one, the first layer laying step, in which a layer of bagasse with a thickness of about 3-5mm is laid on the laying section of the conveying line by means of a throwing machine or other prior art equipment, as the bottom layer; the bagasse is obtained by means of pressing or other prior art means, without sizing, with a moisture content of 12-15%, a fiber length of about 2mm, and an aspect ratio of 70-80.

[0060] Step two, the pre-pressing step, in which the bottom layer of bagasse is conveyed through the pre-pressing section of the continuous flat pressing production line, which provides a temperature of 185-190°C and a pressure of 0.3-0.8MPa to the bagasse layer through the hot roller and the tension belt, and the bagasse layer passes through this section for 25-35s. In this example, the set temperature is 185°C and the set pressure is 0.5MPa.

[0061] Step three, the second laying step, in which a first wood fiber layer is laid on the pre-pressed bottom layer by spraying or other means of the prior art, the first wood fiber being sized by the prior art with a phenol-formaldehyde resin adhesive having a solid content of 25%, the first wood fiber having a moisture content of 6-8% after sizing and drying.

[0062] Step four, the third laying step, in which a second wood fiber layer is laid on the first wood fiber layer as a surface wood fiber layer, the second wood fiber being sized by the prior art with a phenol-formaldehyde resin adhesive having a solid content of 25%, the second wood fiber having a moisture content of 12-14% after sizing and drying.

[0063] Step five, the pressing step, in which the assembly layer including the bottom layer, the first wood fiber layer and the second wood fiber layer is conveyed along the conveying line and passes through a hot pressing section of the continuous flat pressing production line, the section providing a temperature of 185-190°C and a pressure of no less than 6 MPa to the assembly layer by the hot roller through the tension belt, the assembly layer passing through the section for 60 s. In this embodiment, 190°C and 8 MPa are taken as examples.

[0064] After cutting, a composite substrate having a width of 4 feet and a length of 8 feet is obtained.

[0065] By the preparation method of this embodiment, (1) the low-density bagasse layer replaces the surface layer of the substrate as the material layer actually forming the concave-convex relief effect, which can reduce the process pressure and avoid the thickness rebound of the compressed part; (2) the bagasse as the surface layer (the surface layer bonded with the decorative layer) is laid on the bottom layer, which is conducive to the bonding strength between the bagasse layer and the wood layer; (3) the bagasse is glue-free, so that the amount of adhesive can be reduced or the environmental protection can be improved while overcoming the compression rebound; (3) the bagasse is subjected to pressureless pre-pressing, in which a certain degree of steam pressure is formed in the bagasse without a pressing plate, a pressing roller or other contact pressure, which is conducive to self-bonding, and the residual sucrose is decomposed to produce acetic acid under low oxygen conditions, which is conducive to the bonding strength between the bagasse layer and the wood layer; (4) the moisture content of the wood fiber laid adjacent to the bagasse layer is low, so that the steam in the bagasse has a migration path during hot pressing, avoiding staying in the bagasse and affecting the internal bonding strength.

[0066] The hot pressing process includes the following steps:

[0067] Step one, turn over the composite substrate, take the bottom bagasse layer as the surface layer, take the surface of the bagasse layer as the upper surface of the composite substrate, cover the wear-resistant layer and the decorative layer on the upper surface, cover the balancing layer on the lower surface, and send the stacked material into the press. The upper press plate of the press (corresponding to the decorative layer) has a 3D relief pattern, and the temperature of the press plate is 170-180℃. Among them, the wear-resistant layer, the decorative layer, the buffer material layer and the balancing layer are pre-made finished products, which only need to be uncoiled (and cut).

[0068] Step two, increase the pressure of the press plate to 4-5MPa at a pressure increasing speed of 0.5-0.8MPa / s, and keep it for 25-35s after reaching the set pressure. In this embodiment, the pressure increasing speed is 0.5MPa / s, the hot pressing pressure is 4.5MPa, and the pressure keeping time is 30s.

[0069] Step three, release the pressure, open the upper and lower press plates, and take out the 3D relief hot-pressed decorative wood composite material.

[0070] The composite substrate preparation process and the hot pressing process can be implemented in a short time interval, or the composite substrate can be stored for a period of time before being hot-pressed with the decorative layer. In this embodiment, the composite substrate preparation process and the hot pressing process can be implemented in a short time interval, and the obtained 3D relief hot-pressed decorative wood composite material is naturally aged for 72h.

[0071] The 3D relief hot-pressed decorative wood composite materials of Examples 6-8 prepared by this embodiment are marked as sample boards 21, 22 and 23 respectively.

[0072] Control example: a large piece of antique reinforced floor board prepared by the prior art without cutting, with a width of 4ft x 8ft. The same pattern of steel plate as used in Examples 5 and 9 is used as the upper press plate, the hot pressing temperature is 220℃, the hot pressing pressure is 8MPa, the preheating time is 60s, the hot pressing time is 120s, and water is sprayed on the surface of the medium density fiberboard before hot pressing.

[0073] The performance test results of sample boards 11-14 and 21-23 are shown in Table 1. The detection contents include:

[0074] (1) Surface white spots and decorative layer damage, the detection method is visual detection, and 100 pieces are detected by sampling;

[0075] (2) Moisture content deviation, the detection method is to take 6 samples of 20mm x 20mm size from the sample board, measure the moisture content of the 6 samples according to the drying method in GB / T17657-2013 "Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels", and calculate the percentage deviation between the maximum and minimum values;

[0076] (3) Surface hardness, the test method shall be carried out in accordance with GB / T 17657-2013 "Test methods for physical and chemical properties of wood-based panels and decorative wood-based panels".

[0077] Table 1

[0078] Mold Surface white / flakes Finishing layer damage / flakes Moisture content deviation / % Surface hardness 11 0 0 0.2 6H 12 0 0 0.2 6H 13 0 0 0.2 6H 14 0 0 0.2 6H 21 0 0 0.3 6H 22 0 0 0.3 6H 23 0 0 0.3 6H Comparative example 2 1 0.6 6H

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wood composite material with a 3D relief hot-pressed finish, comprising a surface layer and a substrate bonded together, characterized in that, A buffer material layer, with a thickness of 0.5-3.0 mm, is also adhesively disposed between the finishing layer and the substrate.

2. The wood composite material with 3D relief hot-pressed finish according to claim 1, characterized in that, The cushioning material layer is a thermoplastic material with a thickness of 0.5-1.5 mm.

3. The wood composite material with 3D relief hot-pressed finish according to claim 2, characterized in that, The 3D relief hot-pressed wood composite material is prepared by the following method: Step 1: The finishing layer, the cushioning material layer, and the substrate are stacked sequentially from top to bottom; Step 2: Preheat the laminated material at a temperature of 100-110℃, a pressure of 0-0.3MPa, and a time of 15-25s. Step 3: Hot-press the preheated laminated material at a temperature of 140-160℃, a pressure of 6-8MPa, and a time of 45-60s. Step 4: Maintain pressure and force cooling to 50°C, then allow it to cool naturally to room temperature. Cold press at room temperature for 3-5 minutes.

4. The wood composite material with 3D relief hot-pressed finish according to claim 1, characterized in that, The buffer material layer comprises a bagasse layer formed by binding and pressing bagasse together, and a bagasse fiber mixture layer connecting the bagasse layer and the substrate. The average density of the buffer material layer is 0.55-0.65 g / cm³. 3 .

5. The wood composite material with 3D relief hot-pressed finish according to claim 4, characterized in that, The bagasse layer is formed by the self-bonding of bagasse.

6. The wood composite material with 3D relief hot-pressed finish according to claim 4 or 5, characterized in that, The preparation method of the 3D relief hot-pressed wood composite material includes a composite substrate preparation process and a hot-pressing process; wherein, the composite substrate preparation process includes the following steps: Step 1: Lay a layer of bagasse with a moisture content of 12-15% to obtain a bottom layer with a thickness of 3-5mm; Step 2: Pre-compress the bottom layer at a temperature of 185-190℃, a pressure of 0.3-0.8MPa, and a time of 25-35s. Step 3: Lay the first wood fiber layer after applying adhesive on the pre-pressed bottom layer as the bottom wood fiber layer. The moisture content of the first wood fiber layer is 6-8%. Step four: A second layer of wood fiber, coated with adhesive, is laid on top of the bottom wood fiber layer as a top wood fiber layer. The moisture content of the second wood fiber is 12-14%. Step 5: Hot-press the preform layer comprising the bottom layer, the bottom wood fiber layer, and the surface wood fiber layer. The hot-pressing temperature is 185-190℃, the pressure is not less than 6MPa, and the time is 60s.

7. The wood composite material with 3D relief hot-pressed finish according to claim 6, characterized in that, The hot pressing process is used to hot press and bond the decorative layer and the composite substrate. The hot pressing temperature is 170-180℃ and the time is 25-35s.

8. The wood composite material with 3D relief hot-pressed finish according to claim 1, characterized in that, The finishing layer comprises a single-layer paper, which is resin-impregnated paper. The resin includes a main agent and auxiliary agents. The main agent is a phenolic resin adhesive or a urea-formaldehyde resin adhesive, and the auxiliary agents include plasticizers and / or softeners.

9. The wood composite material with 3D relief hot-pressed finish according to claim 8, characterized in that, The finishing layer comprises two single-layer paper sheets and an elastic layer adhesively disposed between the two single-layer paper sheets.

10. The wood composite material with 3D relief hot-pressed finish according to claim 8, characterized in that, The additives also include flexibility-enhancing additives, which are selected from one or more of polyvinyl alcohol, polyurethane dispersions, and nano-silica sols.