JP2020100132A - Composite uneven plate material by high frequency - Google Patents

Abstract

To provide a composite uneven plate material by high frequency.SOLUTION: There is provided a composite uneven plate material by high frequency. The composite uneven plate material has uneven wood grain on at least one side, and it is made by a method including pretreatment, heat treatment, pressure treatment, hardening treatment, temperature lowering treatment and curing treatment. The uneven grain of the produced uneven plate material has randomness, thus it maintains the natural characteristics of the original wood, and does not require a troublesome processing step such as engraving or using a mold. The uneven wood grain may be provided on one side or both sides, if necessary, thus increasing the original beauty of wooden boards.SELECTED DRAWING: Figure 1

Description

The present invention belongs to the technical field of wood board processing, and particularly relates to a composite uneven board material by high frequency.

There are various methods for achieving the unevenness effect on the conventional plate material by using a mold or engraving, but in the conventional method, the unevenness effect is generally obtained by using a preset mold. It was realized that the original natural wood grain of wood could not be expressed, the drawings of each wooden board were similar, the traces of human processing were obvious, and the uneven wood grain appeared randomly on each wooden board. In addition, the manufacturing process of the mold and engraving is complicated, and the cost is high, and the conventional methods for realizing the uneven effect are limited to the density of the plate material and the density is insufficient. In other cases, it cannot be used for producing the uneven plate material.

In order to solve the above technical problems, the present invention provides a composite uneven plate material by high frequency.

The specific technical solution of the present invention is as follows.

The high-frequency composite uneven plate material according to the present invention has uneven wood grain on at least one side surface. It is mainly made in the following steps.

a. Pretreatment: A wooden board whose density does not exceed 0.5 kg/m ³ is treated to have a water content of 8%-18% and a thickness of 2 cm or less,
b. Heat treatment: N pretreated wood boards are selected and overlapped and brought into contact with each other, and N≧2, the pretreated wood boards are heated to a wood board temperature of 60° C. to 80° C. with high frequency and kept warm for 2-3 minutes,
c. Pressure treatment: The heat-treated wood board is compressed at a preset compression rate S, preferably the preset compression rate is set to 10%-70%, and the thickness at which N pieces of wood boards contact is U1, Assuming that the thickness after pressing is U2, P=U1/U1.
d. Curing treatment: The pressure-treated wooden board is heated to 200-240°C by high frequency under a condition that the preset compressibility does not change, and kept warm for 4-6 minutes.
e. Temperature drop treatment: The pressure-treated wooden board is inclined at the conventional compression rate to lower the temperature,
f. Curing treatment: Leave the temperature-decreased wood board at room temperature for 8-10 days to obtain high-frequency composite uneven board material.

Here, the grain direction of the wood board is perpendicular to the thickness direction. The uneven wood grain of the uneven plate material produced in the present invention has randomness, keeps the original natural characteristics of wood, engraving, and does not require a troublesome processing step such as using a mold, and at a time. When compressed, m uneven surfaces having different shapes are generated. Number of uneven surfaces m, m=2*(o-1) (o≧2, o represents the number of boards), of which there are two uneven boards with uneven wood grain on one side, and uneven wood texture on both sides There are m-2 uneven plates, and the uneven plate material produced by the method of the present invention can have uneven wood grain on one side or uneven wood grain on both sides as needed, which enhances the original beauty of the wood board. The manufacturing method provided by the present invention is simple, and by the above-mentioned several steps, it is possible to press a plurality of woods into an uneven plate material having uneven wood grain, and to reduce the content of formaldehyde and xylene to zero. be able to.

Preferably, the N wood boards selected before the heat treatment in step b can be cut in one board, the thickness of the N wood boards may be the same or different, the grain direction or the slope. It can be cut along (such as 5%). Preferably, it is incomplete sawing (shown in FIG. 3), leaving 0.5-1 cm on the edge of the wood board so as to connect the three wood boards, thereby preventing displacement of the upper and lower wood boards after compression. The uneven plate material produced by this method can secure the uneven wood grain more uniformly and is easy to transport.

Preferably, by installing a hot melt adhesive film on the edge of the adjacent wood boards 0.5-1 cm, it is possible to prevent the upper and lower wood boards from being displaced after compression, and the uneven board material produced by this method has uneven wood grain. Can be secured more uniformly and is easy to transport.

With a further improvement, the surface roughness of the wooden board pre-treated with step a does not exceed 2.5 μm.

According to the present invention, by limiting the surface roughness of the wooden board, it is possible to prevent two adjacent wooden boards from being compressed, meshed with each other, and difficult to separate.

Further improving, in the heat treatment process, the middle region and the peripheral region of the wood are heated with high frequency, and the high frequency ratio of the middle region and the peripheral region is 1:0.88-0.94, Then, the middle region and the peripheral region of the heat-compressed wood are each heated with a high frequency, and the high frequency ratio of the middle region and the peripheral region is 1:0.93-0.96.

According to the present invention, due to the above limitation, it is possible to prevent the outer layer wood board from being scorched and the compression of the inner layer wood board failing to meet the requirement.

As a further improvement, in step b, the density difference between any two of the N wooden boards does not exceed 0.15 kg/m ³ .

INDUSTRIAL APPLICABILITY The present invention can improve the depth of the uneven grain of the compressed wood plate by specifically limiting the density difference between any two wood plates during the heat treatment.

With further improvement, the step d temperature reduction processing specifically includes the following steps.

The surface of the wooden board hardened by the water cooling technique is cooled to a wooden board average temperature of 70-90°C at a rate of 5-15°C/min, the water flow rate of the water cooling technique is 4.5-5m/s, and the wooden board surface temperature is 120°C. When cooling to −130° C., wind cooling is performed, the wind speed is 9.2 to 9.7 m/s, the temperature of the wind is 55 to 60° C., and the angle between the wind direction and the upper and lower surfaces of the wooden board is Is also 55-58°.

In the present invention, the deformation recovery rate of the concavo-convex plate material can be reduced to 0.5% by lowering the temperature by the above method.

Further improvement, the pretreatment of step a includes stacking and contacting the wooden boards in the lateral direction, arranging them in the vertical direction and contacting each other, and optionally combining the both, and preferably the wooden boards. There are three compression directions, and at least two wood boards are prepared in each compression direction.

The method provided by the present invention may be performed by compressing wooden boards that are arranged in a lateral direction in parallel, or by compressing wooden boards that are arranged in a vertical direction, or by arranging them in a lateral direction. And the arrangement in the vertical direction may be combined. The uneven wood grain pressed by the three patterns is different, and uneven wood grain is formed on either side of each wood board, and extra edging or a small wood board is contacted to press the uneven wood texture to save waste. You can

When further improving and making contact between the wooden boards in an overlapping manner, assuming that the compressibility of the high-pressure and high-temperature treated wooden boards is P and the densities of the respective wooden boards are ρ1, ρ2... ρn, the average density of each wooden board is ρ , And ρ~ and P satisfy the following conditions.
0.4 kg/m ³ ≦ρ˜<0.5 kg/m ³ , 10%<P≦40%,
0.3 kg/m ³ ≦ρ˜<0.4 kg/m ³ , 40%<P≦60%,
ρ~<0.3 kg/m ³ , 60%<P≦70%.

The present invention, by the above method, the compression rate can be adjusted according to the density of the wooden board, the compression rate is too small to press the uneven wood grain, or the compression rate is too large and the uneven wood grain is too deep. It is possible to avoid the appearance, the unattractive appearance, and the occurrence of cracks.

As a further improvement, when the thickness of the pressure-treated wood board in step c is 1 cm or less, the upper or lower surface of the pre-treated wood board is coated with an electrically insulating cloth.

According to the present invention, by covering the upper surface and the lower surface of the pretreated wood board with an electric insulating cloth, it is possible to prevent the equipment from being burned by a strong arc generated during high frequency heating.

After further improvement, the deformation recovery rate after leaving the composite concavo-convex plate material for 14 days is less than 0.5%, and the bending strength is 80-100 MPa.

With further improvement, the depth of the uneven grain of the composite uneven plate member is 400 to 10000 μm.

With further refinement, the raw material for making wood boards is selected from one or more of poplar, shinanoki and radiata pine.

The materials provided by the present invention can be used to manufacture aircraft carrier internal warehouses, warship internal warehouses, cruise ship internal warehouses, floors, doors or cabinets. The material produced by the method provided by the present invention is environmentally friendly, safe and does not cause any injury to human body.

The uneven wood grain of the uneven plate material produced in the present invention has randomness, maintains the original natural characteristics of wood, engraving, there is no need for complicated processing steps such as using a mold, the present invention The concavo-convex plate material produced by the method can have concavo-convex wood grain on one side or concavo-convex wood grain on both sides, if necessary, to increase the original beauty of the wooden board.

It is two uneven plate materials having uneven wood grain on one surface, which is produced by compressing two wooden boards. Two uneven plate materials having uneven wood grain on one side and one uneven plate material having uneven wood grain on both sides, which are produced by compressing three wooden boards. It is an incomplete sawing in which one piece is cut into three wood boards, and two uneven board materials having uneven wood grain on one side and one uneven board material having uneven wood texture on both sides pressed by the three wood boards. Is. It is the uneven plate material 1 produced by the method of the present invention. It is the uneven plate member 2 manufactured by the method of the present invention. It is the uneven plate member 3 manufactured by the method of the present invention.

(Examples 1 to 7)
Each of the seven types of uneven plate materials according to Examples 1-7 of the present invention is manufactured by the following steps.

a. Pretreatment: A wooden board having a density not exceeding 0.5 kg/m ³ is treated to have a water content of 8%-18% and a thickness of 2 cm or less to prepare a pretreated wooden board.
b. Heat treatment: N pretreated wood boards are selected and brought into contact with each other, and N≧2, the pretreated wood boards are heated to a wood board temperature of 80° C. to 100° C. with high frequency, and kept warm for 2-3 minutes,
c. Pressure treatment: The heat-treated wood board is compressed at a preset compression rate S, preferably the preset compression rate is set to 10%-70%, and the thickness at which N pieces of wood boards contact is U1, Assuming that the thickness after pressing is U2, P=U2/U1.
d. Curing treatment: The pressure-treated wooden board is subjected to high-frequency heating at 200 to 240° C. under a condition that the preset compression rate does not change, and is kept warm for 4 to 6 minutes.
e. Temperature drop treatment: The pressure-treated wooden board is inclined at the conventional compression rate to lower the temperature,
f. Curing treatment: The temperature-decreased wooden board is left at room temperature for 8 to 10 days to obtain a high-frequency composite uneven board material.

The surface roughness of the plate pretreated in step a is 2.5 μm or less.

In the heat treatment, the middle region and the surrounding region of the wood are heated with high frequency, respectively, and the high frequency ratio of the middle region and the surrounding region is 1:0.88-0.94. In the hardening process, the middle region and the surrounding region of the heat-compressed wood are heated with high frequency, respectively, and the high frequency ratio of the middle region and the surrounding region is 1:0.93-0.96.

The density difference between any two of the N wooden boards in step b is 0.15 kg/m ³ or less.

The step d temperature reduction processing specifically includes the following steps.
The surface of the wooden board hardened by the water cooling technique is cooled to a wooden board average temperature of 70-90°C at a rate of 5-15°C/min, the water flow rate of the water cooling technique is 4.5-5m/s, and the wooden board surface temperature is 120°C. When cooling to −130° C., wind cooling is performed, the wind speed is 9.2 to 9.7 m/s, the temperature of the wind is 55 to 60° C., and the angle between the wind direction and the upper and lower surfaces of the wooden board is Is also 55-58°.

When the wooden boards are brought into contact with each other in an overlapping manner, assuming that the compressibility of the high-pressure and high-temperature treated wooden boards is P and the densities of the respective wooden boards are ρ1, ρ2... ρn, the average density of each wooden board is ρ~, ρ~ And P satisfy the following conditions.
0.4 kg/m ³ ≦ρ˜<0.5 kg/m ³ , 10%<P≦40%,
0.3 kg/m ³ ≦ρ˜<0.4 kg/m ³ , 40%<P≦60%,
ρ~<0.3 kg/m ³ , 60%<P≦70%.
Here, Table 1 shows specific parameters of Example 1-7.

Table 1: Specific parameters of Examples 1-7

(Example 8)
The high-frequency composite uneven plate material according to Example 8 of the present invention is manufactured through the following steps.

a. Pretreatment: A wooden board whose density does not exceed 0.5 kg/m ³ is treated to have a water content of 8%-18% and a thickness of 2 cm or less,
b. Heat treatment: pretreated three contacting the wood board was placed, respectively the density of three wooden board ^{0.46kg / m 3, 0.39kg / m} 3, a 0.43 kg / ^{m 3,} wooden board Of water content of 9%, 11%, 13% and thickness of 0.6cm, 0.8cm, 0.4cm respectively, and preheated wood board is heated at high temperature of 100℃ and heated. The time is 3 min.
c. Pressure treatment: The heat-treated wooden board is compressed at a preset compression rate S, the preset compression rate is set to 10%, the thickness at which N wooden boards are brought into contact is U1, and the thickness after pressing is Let P be U2 and P=U1/U1.
d. Curing treatment: The pressure-treated wooden board is heated to 2240° C. at a high frequency under a condition that the preset compression rate does not change and is kept warm for 5 minutes.
e. Cooling treatment: The pressure-treated wooden board is forcibly cooled under a low temperature condition for a certain period of time.
f. Curing treatment: The temperature-decreased wooden board is left for 12 days at room temperature to obtain a high-frequency composite uneven board.

Here, the step e temperature lowering process specifically includes the following steps.
e1: The high temperature-treated wood board of step d is placed in an environment of 95° C. for 8 minutes to obtain a first temperature dropping board.
e2: The first temperature-decreasing wood board treated in step e1 is placed in an environment of 75° C. for 15 minutes to obtain a first temperature-decreasing board.
e3: The second temperature-decreasing wood board treated in step e2 is placed in an environment of 45° C. for 20 minutes to obtain a first temperature-decreasing board.

Here, the raw materials for producing the wood board are selected from poplar, Shinanoki and radiata pine.

Here, the total thickness of the pressure-treated three wooden boards in step c is 0.9 cm, and the upper surface of the pretreated wooden boards is covered with an electrically insulating cloth.

(Controls 1 to 14)
The 14 types of high-frequency composite concavo-convex plate materials according to Comparative Example 1-14 are different from Example 3 in parameters, and specific parameters are shown in Tables 2 and 3.

Table 2: Specific parameters of Comparative Example 1-7

Table 3: Specific parameters of Control Example 8-14

Table 4: Specific parameters of Comparative Examples 15-18

Here, the heating temperature 1 and the heat retention time 1 are the temperature and time at the time of heat and pressure treatment, the heating temperature 2 and the heat retention time 2 are the temperature and time at the time of curing, and the water content is the average of the wood boards. Moisture content. Five points were uniformly selected as measurement points on the wooden board, the water content of each point was measured, and the average water content is the value obtained by dividing the sum of the water content of the five points by 5. The two wood boards in Example 1 were made by selecting from poplar and non-wood, respectively, and the three wood boards of all test examples and control examples other than Example 1 were poplar, Shinanoki and radiata pine. Each is adopted and produced.

(Control example 19)
The concavo-convex plate material according to Comparative Example 19 is manufactured by the following steps.

a. Pretreatment: A wooden board whose density does not exceed 0.5 kg/m ³ is treated to have a water content of 8%-18% and a thickness of 2 cm or less,
b. Heat treatment: pretreated three contacting the wood board was placed, respectively the density of three wooden board ^{0.46kg / m 3, 0.39kg / m} 3, a 0.43 kg / ^{m 3,} wooden board Of water content of 9%, 11%, 13% and thickness of 0.6cm, 0.8cm, 0.4cm respectively, and preheated wood board is heated at high temperature of 100℃ and heated. The time is 3 min.
c. Pressure treatment: The heat-treated wooden board is compressed at a preset compression rate S, the preset compression rate is set to 10%, the thickness at which N wooden boards are brought into contact is U1, and the thickness after pressing is Suppose U2, then P=U2/U1.
d. Curing treatment: The pressure-treated wooden board is heated to 240° C. with high frequency under a condition that the preset compression rate does not change and is kept for 5 minutes.
e. Cooling treatment: The pressure-treated wooden board is forcibly cooled under a low temperature condition for a certain period of time.
f. Curing treatment: The temperature-decreased wooden board is left for 12 days at room temperature to obtain a high-frequency composite uneven board.

Here, the raw materials for producing the wood board are selected from poplar, Shinanoki and radiata pine.

Example 5 of the cooling process step is as follows.

Among them, the total thickness of the pressure-treated three wooden boards in step c is 0.9 dm, and the upper and lower surfaces of the pretreated wooden boards are covered with the electric insulating cloth.

(Example 1)
The press working effect test of the uneven plate material is as follows.

The concavo-convex environmental protection type door plates made in Example 1-7, Control Example 1-11 and Chinese Patent CN107901178A were set as Test 1-7 sets, Control 1-11 sets and Positive 1 set, and the concavo-convex effect of the concavo-convex plate materials of each set Was evaluated, and five parallel samples were used for each set as an example, and the results were averaged. The results of consideration are shown in Table 5.

Table 5: Pressing effect of uneven plate materials of each group

As can be seen from Table 5, the water content, thickness, density, heating time, and heating temperature of the wooden board all significantly affect the press working effect of the uneven plate material, and the water content of the wood is 8-18%, and the thickness is As long as it is controlled within 2 cm, the density is 0.5 kg/m ³ or less, the heating time is 2-3 min, and the heating temperature is 80° C.-100° C., the uneven plate material has a clear wood grain, a uniform density, and cracks and expansion phenomena. It can be made so that it does not exist. When the heating temperature and time continue to rise, the input and the output are not proportional, the uneven plate material produced by the method of the present invention does not have any uneven wood grain, has peculiarity, and has uneven wood grain on one side An uneven plate material (shown in FIG. 1) and an uneven plate material (shown in FIG. 2) having uneven wood grain on both sides can be produced.

(Example 2)
The consideration of the deformation recovery rate is as follows.

Example 3-5, Comparative Example 12-15 and the uneven plate material produced by the method for producing the surface uneven type decorative plate material produced in Chinese Patent CN101195291B were set as Experiment 8-10 sets, Control 12-15 sets and two positive sets, The thickness of each set of concavo-convex plate materials before compression, after completion of production and after leaving for 30 days after completion of production were considered, and the deformation recovery rate R was calculated. The results are shown in Table 6.

R=Tr−Tc/T ₀ −Tc, where Tr is the thickness of the uneven plate material after standing for 30 days, Tc is the thickness of the uneven plate material after compression, and T ₀ is the _value before compression. The thickness of the uneven plate material.

Table 6: Results of consideration of deformation recovery rate

As can be seen from Table 6, the temperature lowering method significantly affects the deformation recovery rate of the uneven plate material, and the temperature lowering method and the curing time provided in the present invention significantly reduce the deformation recovery rate of the uneven plate material. When the parameters of the temperature lowering treatment are changed or the curing time is short, the deformation recovery rate of the uneven plate material is remarkably improved, and the deformation recovery rate of the uneven plate material produced in the present invention is 2 positive. Remarkably lower than uneven plate material.

(Test Example 3)
The consideration of the performance index is as follows.

The concavo-convex plate materials produced by the method for producing the surface irregularity type decorative plate material produced in Example 5-7 and Chinese Patent CN101195291B were tested 11-13 sets and positive 3 sets, and the performance index of the concavo-convex plate material of each set was considered, The results are shown in Table 7.

Table 7: Consideration of each parameter of high temperature decompression treatment

As can be seen from Table 7, the preset compression ratio is closely related to the density. The compressibility was set by the method provided by the present invention, each performance index of the uneven plate material produced was good, and the preset compressibility and the density did not match (set by the method provided by the present invention. If not), the respective performance indexes of the uneven plate material are remarkably lowered, and the uneven plate material manufactured according to the present invention has better specific gravity and other indexes as compared with the uneven plate material manufactured using the template.

(Test Example 4)
The charring test is as follows.

The concavo-convex plate materials produced by the methods of Example 8 and Comparative Examples 16-18 were used as a test 14 sets and a control 16-18 set, and the scorching degree of both the front and back surfaces of the concavo-convex plate materials of each set was considered, and the results are shown in Table 8. Show.

Burntness (%) = burnt area on both the front and back surfaces of the uneven plate material/surface area on both the front and back surfaces of the uneven plate material.

Table 8: Results of charring test

As can be seen from Table 8, when the thickness of the pressure-treated wood board is 1 cm or less, it is necessary to cover the upper surface or the lower surface of the pre-processed wood board with an electrically insulating cloth. In the process of, the high frequency ratio of the intermediate region to the high frequency of the peripheral region is 1:0.88-0.94, and in the curing process, the ratio of the high frequency of the intermediate region to the high frequency of the peripheral region is 1:0. It is 0.93-0.96, and if not, there is a risk that charring or equipment damage will occur.

(Test Example 5)
A concavo-convex plate material was produced by the method of Examples 4-5 and Comparative Example 16, and the tensile force used to separate two adjacent wooden boards was calculated. The results are shown in Table 9.

Table 9: Test results of separation tensile force after pressing the uneven plate material of each group

As can be seen from Table 9, by limiting the surface friction force of the wooden board, the tensile force used to separate the two pressed wooden boards can be significantly reduced, and the surface friction force of the wooden board exceeds 2.5 μm. Therefore, a relatively large tensile force is required to separate the two wooden boards.

Claims (10)

a. Pretreatment: Select a wood board with a density of 0.5 kg/m ³ or less, and control the water content of the wood board to 8-18% and the thickness within 2 cm,
b. Heat treatment: N pretreated wood boards are selected and overlapped and brought into contact with each other, and N≧2, the pretreated wood boards are heated to a wood board temperature of 60° C. to 80° C. with high frequency and kept warm for 2-3 minutes,
c. Pressure treatment: The heat-treated wood board is compressed at a preset compression rate S, preferably the preset compression rate is set to 10%-70%, and the thickness at which N pieces of wood boards contact is U1, Assuming the thickness after pressing is U2, P=U1/U1,
d. Curing treatment: The pressure-treated wood board is heated to 200-240° C. with high frequency under a condition that the preset compression rate does not change, and is kept warm for 4-6 minutes,
e. Temperature drop treatment: The pressure-treated wooden board is inclined at the conventional compression rate to lower the temperature,
f. Curing treatment: leaving the temperature-decreased wood board at room temperature for 8-10 days to obtain a high-frequency composite uneven board material, which is produced by the step of having high-frequency composite uneven board material having at least one side surface .. The high-frequency composite concavo-convex plate material according to claim 1, wherein the surface roughness of the wooden board pretreated in step a does not exceed 2.5 µm. In the heat treatment process, the middle region and the peripheral region of the wood are heated with a high frequency, and the high frequency of the middle region and the high frequency of the peripheral region are 1:0.88-0.94. The intermediate region and the peripheral region of the cut wood are heated with high frequency, respectively, and the high frequency ratio of the intermediate region and the peripheral region is 1:0.93 to 0.96. High-frequency composite uneven plate material. In step b, the composite uneven sheet by high frequency according to claim 1, the density difference between any two wooden boards of the N pieces of wood board is characterized in that it does not exceed 0.15 kg / m ^3. In the step d temperature decreasing process, specifically,
a. The surface of the wooden board hardened by the water cooling technique is cooled to a wooden board average temperature of 70-90°C at a rate of 5-15°C/min, the water flow rate of the water cooling technique is 4.5-5m/s, and the wooden board surface temperature is 120°C. When cooling to −130° C., wind cooling is performed, the wind speed is 9.2 to 9.7 m/s, the temperature of the wind is 55 to 60° C., and the angle between the wind direction and the upper and lower surfaces of the wooden board is The high-frequency composite uneven plate material according to claim 1, further comprising a step of 55° to 58°. The pretreatment of step a includes stacking and contacting the wooden boards in the horizontal direction, arranging them in the vertical direction and making contact with each other, and optionally combining them, and preferably, the compression direction of the wooden boards is set to 3 At least two wood boards are prepared in each compression direction, The composite high-frequency concavo-convex board material according to claim 1, characterized in that it is prepared. When the wooden boards are brought into contact with each other in an overlapping manner, assuming that the compressibility of the high-pressure and high-temperature treated wooden boards is P and the densities of the respective wooden boards are ρ1, ρ2... ρn, the average density of each wooden board is ρ~, ρ~ And P are
0.4 kg/m ³ ≦ρ˜<0.5 kg/m ³ , 10%<P≦40%,
0.3 kg/m ³ ≦ρ˜<0.4 kg/m ³ , 40%<P≦60%,
ρ~<0.3 kg/m ³ , 60%<P≦70%
The composite concavo-convex plate material by high frequency according to claim 6, which satisfies the following condition. The high-frequency composite unevenness according to claim 1, wherein when the pressure-treated wood board in step c has a thickness of 1 cm or less, an upper surface or a lower surface of the pre-processed wood board is coated with an electrically insulating cloth. Plate material. The high-frequency composite uneven plate material according to claim 1, wherein the deformation recovery rate after leaving the composite uneven plate material for 14 days is less than 0.5%, and the bending strength is 80-100 MPa. The high-frequency composite uneven plate material according to claim 1, wherein the depth of the uneven grain of the composite uneven plate material is 400-10000 m.

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