Treatment method for preventing artificial forest castanopsis hystrix from cracking and deforming

Abstract

The invention discloses a treatment method for preventing artificial forest castanopsis hystrix from cracking and deforming. The treatment method comprises the following steps: (1) drying; (2) balancing; (3) dipping; (4) heat treatment; and carrying out ventilation balance on the heat-treated plate in a natural environment for 2 weeks to obtain the heat-treated plate. The modifier adopted in the method is good in thermal stability, a staged heat treatment mode is adopted, the drying efficiency of the modified material is improved, the modifier is fully cured, meanwhile, the plate is subjected to heat treatment, the size stability of the plate is further improved, and the cracking deformation preventing castanopsis hystrix plate is obtained; furthermore, the method is simple and convenient to operate, large-batch treatment can be achieved, and the obtained artificial forest castanopsis hystrix modified material capable of preventing deformation and cracking is resistant to water and moisture, stable and resistant to cracking.

Description

Technical Field

[0001] The invention relates to the technical field of artificial forest wood processing, and in particular to a processing method for preventing artificial forest red cones from cracking and deforming. Background Art

[0002] Artificial red cone (hereinafter referred to as: red cone) has a straight trunk, hard material, excellent mechanical properties, and strong corrosion resistance. It is the preferred wood for furniture, building materials, carving, shipbuilding and other industries. However, red cone has large internal stress and poor dimensional stability. Its wood is very easy to deform and crack during storage, drying and use, which limits its use to a certain extent. In the prior art, heat treatment and chemical agent treatment are more often used to improve the dimensional stability of wood and prevent cracking and deformation, but problems such as reduced mechanical properties and formaldehyde release have been criticized; in addition, long-term water immersion treatment can improve the cracking of red cone, but this method is only used to reduce the cracking of red cone logs during storage, and fails to improve the deformation and cracking of red cone caused by humidity changes in subsequent applications. It is not suitable for actual production and daily applications. Therefore, people need a green treatment method that fundamentally improves the dimensional stability of red cone wood and prevents red cone from deforming and cracking during use. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a treatment method for preventing artificial forest red cone from cracking and deformation, aiming to obtain an artificial forest red cone that is easy to operate, resistant to water and moisture, and stable in cracking and prevents deformation and cracking.

[0004] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0005] A method for preventing artificial forest red cones from cracking and deforming, comprising the following steps:

[0006] (1) Drying: Place the artificial forest red cone board in an environment with a certain initial temperature, and then soften it with superheated saturated steam. After softening, let the board cool naturally to the initial temperature, ventilate, reduce the moisture content in the drying kiln, make the air humidity in each area of ​​the drying kiln balanced, and continue to dry at the initial temperature environment for 20 days;

[0007] (2) Balance: The kiln is opened on the 21st day, and the dried boards are placed in the natural environment for 7 days to balance;

[0008] (3) Impregnation: The board after balancing in step (2) is allowed to stand in a vacuum environment (standing in a vacuum state can remove the air and other substances in the wood, and the inhalation of the modifier at this time is more conducive to the modifier entering the interior of the wood), and then the modifier is added for impregnation, the vacuum is released, and then the pressure is increased to 0.2MPa, 0.4MPa, 0.6MPa, and 0.8MPa in sequence;

[0009] (4) Heat treatment: the artificial forest red cone board obtained after the immersion in step (3) is placed in a ventilated place indoors, ventilated and air-dried in a natural environment, and then placed in a high-temperature heat treatment box, and a staged heating heat treatment is adopted, which is divided into a pre-drying stage, a drying stage, a heat treatment stage, and a cooling stage in sequence; the pre-drying stage: drying at 50°C, 70°C, and 90°C for 24 hours respectively; the drying stage, raising the temperature to 110°C and 130°C, drying for 4-6 hours each, and the oxygen content is 8%-10%; the heat treatment stage, raising the temperature to 180-200°C, heat treatment for 2-4 hours, and the oxygen content is 2%-3%; in the cooling stage, heating is stopped, and the board is taken out when the temperature in the heat treatment box drops to room temperature; the heat-treated board is ventilated and balanced in a natural environment for 2 weeks, and the moisture content after balance is 7%-9%.

[0010] Preferably, the plantation red cone board described in step (1) is obtained by sawing 25-40 year-old plantation red cone into 3-5 cm boards.

[0011] Preferably, the initial temperature in step (1) is 37-41° C.; the ventilation is performed by turning on the fan and adjusting the direction of the fan every 2 hours to reduce the moisture content in the drying kiln.

[0012] Preferably, the superheated saturated steam softening in step (1) is to pass superheated saturated steam for 30 minutes to soften the artificial forest red cone board; the superheated saturated steam has a steam pressure of 0.5 MPa and a steam temperature of 158°C.

[0013] Preferably, the modifier described in step (3) is a melamine-urea-glyoxal (MUG) resin for impregnation, that is, glyoxal is heated to 45-65°C, melamine is added to react for 10-20 minutes, urea is added and mixed thoroughly for reaction, and then the pH is adjusted to 5-7 with sodium hydroxide, and the material is cooled to obtain the modifier; wherein the molar ratio of melamine, urea and glyoxal is (0.05-0.2):(0.4-0.6):1; the solid content of the obtained modifier is 48%-50%, and it is adjusted to a solid content of 10-30% with deionized water before use.

[0014] Preferably, in step (3), the vacuum environment has a vacuum degree of >0.08, and after standing for 1 hour, a modifier with a solid content of 10%-30% is added and immersed for 2 hours; the pressure is sequentially increased to 0.2MPa, 0.4MPa, 0.6MPa, and 0.8MPa, and each pressure is maintained for 2 hours.

[0015] Preferably, in step (4), the mixture is dried under ventilation in a natural environment for 7 days.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The modifier used in the method of the present invention has good thermal stability, and a staged heat treatment method is adopted to improve the drying efficiency of the modified material, so that the modifier is fully solidified, and the board is heat-treated at the same time, so that the dimensional stability of the board is further improved, and the anti-cracking and deformation red cone board is obtained; further, the method of the present invention is simple and easy to operate, and can achieve large-scale processing, so that the obtained anti-deformation and cracking artificial forest red cone modified material is water-resistant and moisture-resistant, and stable and anti-cracking; compared with untreated red cone wood, the water absorption rate is reduced by 15%-30%, the tangential shrinkage and swelling rate is reduced by 30%-50%, the radial shrinkage and swelling rate is reduced by 20%-40%, the volume shrinkage and swelling rate is reduced by 25%-45%, the number of cracks is 1 or 0, and the bending elastic modulus is increased by 13%-29%, the bending strength is increased by 16%-37%, the overall performance of the artificial forest red cone is improved, the application range thereof is expanded, the material is more suitable for environments with different humidity, and the economic value of the artificial forest red cone wood is increased. DETAILED DESCRIPTION

[0018] The specific implementation is described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific implementation. Unless otherwise specified, the raw materials and reagents used in the examples are all commercially available. The drying kiln is an axial flow drying kiln without a guide plate. The impregnation tank model used in the examples is SBK-450B.

[0019] Example 1

[0020] A method for preventing artificial forest red cone from cracking and deformation, the operation steps are as follows:

[0021] (1) Drying: Saw 25-year-old plantation red cone into 3 cm boards to obtain plantation red cone boards; heat the drying kiln to 37-41°C (initial temperature), put the sawn plantation red cone boards, and pass superheated saturated steam for 30 minutes (superheated saturated steam is steam with a pressure of 0.5 MPa and a temperature of 158°C) to soften the boards and release the internal stress of the wood. After the wood is naturally cooled to the initial temperature (initial temperature is 37-41°C), turn on the fan in the drying kiln, adjust the direction of the fan every 2 hours, reduce the moisture content in the drying kiln, balance the air humidity in each area of ​​the drying kiln, and continue drying at the initial temperature for 20 days;

[0022] (2) Balance: The kiln is opened on the 21st day, and the dried boards are placed in the natural environment for 7 days to balance;

[0023] (3) Impregnation: Take the raw materials according to the molar ratio of melamine, urea and glyoxal of 0.05:0.4:1, heat glyoxal to 45°C, add melamine to react for 10 minutes, then add urea to mix and react, then adjust the pH to 5 with sodium hydroxide, cool and discharge to obtain a modifier, the solid content of the obtained modifier is 48%-50%, and adjust the solid content to 10% with deionized water before use, and set aside; put the board after balancing in step (2) into an impregnation pot, evacuate, and let stand for 1 hour with a vacuum degree of >0.08, then allow the impregnation pot to absorb the above-mentioned modifier with a solid content of 10%, release the vacuum, and then pressurize to 0.2MPa, 0.4MPa, 0.6MPa, and 0.8MPa in sequence, and release the pressure to discharge the modifier after each pressure is maintained for 2 hours, and then take out the artificial forest red cone board obtained after impregnation;

[0024] (4) Heat treatment: the artificial forest red cone board obtained after the immersion in step (3) is placed in a ventilated place indoors, ventilated and air-dried in a natural environment for 7 days, and then placed in a high-temperature heat treatment box, and subjected to a staged heating heat treatment, which is divided into a pre-drying stage, a drying stage, a heat treatment stage, and a cooling stage in sequence; the pre-drying stage: drying at 50° C., 70° C., and 90° C. for 24 hours each;

[0025] Drying stage: raise the temperature to 110℃ and 130℃, dry for 4 hours each, and the oxygen content is 8%-10%;

[0026] Heat treatment stage: the temperature is raised to 180°C, heat treatment is performed for 2 hours, and the oxygen content is 2%-3%;

[0027] Cooling stage: stop heating, wait until the temperature in the heat treatment box drops to room temperature, and take out the board; ventilate and balance the heat-treated board in a natural environment for 2 weeks. After balance, the moisture content is 7%-9%, and the anti-cracking and deformation red cone board is obtained.

[0028] Example 2

[0029] A method for preventing artificial forest red cone from cracking and deformation, the operation steps are as follows:

[0030] (1) Drying: Saw 25-year-old plantation red cone into 3 cm boards to obtain plantation red cone boards; heat the drying kiln to 37-41°C (initial temperature), put the sawn plantation red cone boards, pass superheated saturated steam for 30 minutes (superheated saturated steam is steam with a pressure of 0.5 MPa and a temperature of 158°C) to soften the boards and release the internal stress of the wood; turn on the fan in the drying kiln, adjust the direction of the fan every 2 hours, reduce the moisture content in the drying kiln, balance the air humidity in each area of ​​the drying kiln, and continue drying at the initial temperature for 20 days;

[0031] (2) Balance: The kiln is opened on the 21st day, and the dried boards are placed in the natural environment for 7 days to balance;

[0032] (3) Impregnation: Take the raw materials according to the molar ratio of melamine, urea and glyoxal of 0.1:0.5:1, heat glyoxal to 55°C, add melamine to react for 15 minutes, then add urea to mix and react, then adjust the pH to 6 with sodium hydroxide, cool and discharge to obtain a modifier; the obtained modifier has a solid content of 48%-50%, and is adjusted to a solid content of 20% with deionized water before use for standby use; put the board after balancing in step (2) into an impregnation pot, evacuate, and let stand for 1 hour with a vacuum degree of >0.08, then allow the impregnation pot to absorb the above-mentioned standby modifier with a solid content of 20%, release the vacuum, and then pressurize to 0.2MPa, 0.4MPa, 0.6MPa, and 0.8MPa in sequence, and release the pressure to discharge the modifier after each pressure is maintained for 2 hours, and take out the artificial forest red cone board obtained after impregnation;

[0033] (4) Heat treatment: the artificial forest red cone board obtained after the immersion in step (3) is placed in a ventilated place indoors, and after being ventilated and air-dried in a natural environment for 7 days, it is placed in a high-temperature heat treatment box and subjected to a staged heating heat treatment, which is sequentially divided into a pre-drying stage, a drying stage, a heat treatment stage, and a cooling stage;

[0034] Pre-drying stage: drying at 50℃, 70℃ and 90℃ for 24 hours respectively;

[0035] Drying stage: raise the temperature to 110℃ and 130℃, dry for 5 hours each, and the oxygen content is 8%-10%;

[0036] Heat treatment stage: the temperature is raised to 190°C, heat treatment is performed for 4 hours, and the oxygen content is 2%-3%;

[0037] Cooling stage: stop heating, wait until the temperature in the heat treatment box drops to room temperature, and take out the board; ventilate and balance the heat-treated board in a natural environment for 2 weeks. After balance, the moisture content is 7%-9%, and the anti-cracking and deformation red cone board is obtained.

[0038] Example 3

[0039] A method for preventing artificial forest red cone from cracking and deformation, the operation steps are as follows:

[0040] (1) Drying: Saw 25-year-old plantation red cone into 3 cm boards to obtain plantation red cone boards; heat the drying kiln to 37-41°C, put the sawn plantation red cone boards, pass superheated saturated steam for 30 minutes (superheated saturated steam is steam with a pressure of 0.5 MPa and a temperature of 158°C) to soften the boards and release the internal stress of the wood, turn on the fan in the drying kiln, adjust the direction of the fan every 2 hours, reduce the moisture content in the drying kiln, balance the air humidity in each area of ​​the drying kiln, and continue drying at the initial temperature for 20 days;

[0041] (2) Balance: The kiln is opened on the 21st day, and the dried boards are placed in the natural environment for 7 days to balance;

[0042] (3) Impregnation: Take the raw materials according to the molar ratio of melamine, urea and glyoxal of 0.2:0.6:1, heat glyoxal to 65°C, add melamine to react for 20 minutes, then add urea to mix and react, then adjust the pH to 7 with sodium hydroxide, cool and discharge to obtain a modifier; the obtained modifier has a solid content of 48%-50%, and is adjusted to a solid content of 30% with deionized water before use for standby use; put the board after balancing in step (2) into an impregnation pot, evacuate, and let stand for 1 hour with a vacuum degree of >0.08, then allow the impregnation pot to absorb the above-mentioned standby modifier with a solid content of 30%, release the vacuum, and then pressurize to 0.2MPa, 0.4MPa, 0.6MPa, and 0.8MPa in sequence, and release the pressure to discharge the modifier after each pressure is maintained for 2 hours, and then take out the artificial forest red cone board obtained after impregnation;

[0043] (4) Heat treatment: the artificial forest red cone board obtained after the immersion in step (3) is placed in a ventilated place indoors, ventilated and air-dried in a natural environment for 7 days, and then placed in a high-temperature heat treatment box, and subjected to a staged heating heat treatment, which is divided into a pre-drying stage, a drying stage, a heat treatment stage, and a cooling stage in sequence; the pre-drying stage: drying at 50° C., 70° C., and 90° C. for 24 hours each;

[0044] Drying stage: raise the temperature to 110℃ and 130℃, dry for 5 hours each, and the oxygen content is 8%-10%;

[0045] Heat treatment stage: the temperature is raised to 200°C, heat treatment is performed for 3 hours, and the oxygen content is 2%-3%;

[0046] Cooling stage: stop heating, wait until the temperature in the heat treatment box drops to room temperature, and take out the board; ventilate and balance the heat-treated board in a natural environment for 2 weeks. After balance, the moisture content is 7%-9%, and the anti-cracking and deformation red cone board is obtained.

[0047] Comparative Example 1

[0048] The 25-year-old plantation red cone was sawn into 3 cm boards to obtain the plantation red cone boards, which were then placed in a natural environment for air drying.

[0049] Comparative Example 2

[0050] The kiln dried plantation red cone wood includes the following steps:

[0051] (1) Drying: Saw the 25-year-old red cone plantation into 4 cm boards. Raise the initial temperature of the drying kiln to 37-41°C, put the boards in, and pass superheated saturated steam for 30 minutes to soften the wood, release the internal stress of the wood, and improve the subsequent drying quality. After the wood is naturally cooled to the initial temperature, turn on the fan in the drying kiln, adjust the direction of the fan every 2 hours, and continue drying at the initial temperature for 20 days;

[0052] (2) Balance: The kiln is opened on the 21st day, and the dried boards are balanced for 7 days to obtain kiln-dried boards.

[0053] Comparative Example 3

[0054] The specific steps of kiln drying, impregnation and secondary drying of artificial forest red cone board are as follows:

[0055] (3) Impregnation: Place the plate after balancing in step (2) into an impregnation pot, evacuate the pot, and place the pot at a vacuum degree of >0.08 for 1 hour. Then, allow the pot to absorb a modifier with a solid content of 20% (the modifier used is the same as the modifier prepared in Example 2). Release the vacuum and pressurize the pot to 0.2 MPa, 0.4 MPa, 0.6 MPa, and 0.8 MPa in sequence. Each pressure is maintained for 2 hours. After the pressure is released, the modifier is discharged and the plate is taken out.

[0056] (4) Secondary drying: The artificial forest red cone board obtained after the impregnation in step (3) is ventilated and air-dried in a natural environment for 7 days, and then placed in a drying kiln for staged temperature drying, respectively at 40° C., 60° C., and 80° C. for 24 hours each, and finally dried at 103° C. to constant weight, and placed in a natural environment for moisture content balance. After balance, the moisture content is 7%-9%, thereby obtaining an impregnated board;

[0057] The remaining operations are the same as those in Example 2.

[0058] Comparative Example 4

[0059] The plantation red cone board is directly heat-treated after being dried in a drying kiln. The specific steps are as follows:

[0060] (1) Drying: Saw 25-year-old plantation red cone into 3 cm boards to obtain plantation red cone boards; heat the drying kiln to 37-41°C, put the sawn plantation red cone boards, pass superheated saturated steam for 30 minutes (superheated saturated steam is steam with a pressure of 0.5 MPa and a temperature of 158°C) to soften the boards and release the internal stress of the wood, turn on the fan in the drying kiln, adjust the direction of the fan every 2 hours, reduce the moisture content in the drying kiln, balance the air humidity in each area of ​​the drying kiln, and continue drying at the initial temperature for 20 days;

[0061] (2) Heat treatment: The dried artificial forest red cone board is placed in a high-temperature heat treatment box, and a staged heating heat treatment method is adopted, which is divided into a pre-drying stage, a drying stage, a heat treatment stage, and a cooling stage in sequence; the preheating stage is preheated at 80°C for 6 hours; the drying stage is raised to 110°C and 130°C, and each is dried for 5 hours, and the oxygen content is 8%-10%; the heat treatment stage is raised to 180°C, and the heat treatment is performed for 4 hours, and the oxygen content is 2%-3%; in the cooling stage, the heating is stopped, and the board is taken out after the temperature in the heat treatment box drops to room temperature. The heat-treated board is balanced in the atmospheric environment for 2 weeks, and the moisture content after balance is 7%-9%.

[0062] Comparative Example 5

[0063] In step (3), the modifier is replaced with commercially available melamine-urea-formaldehyde resin (solid content is 20%), and the heat treatment in step (4) is omitted. The remaining operations are the same as in Example 2.

[0064] Treatment effect of plantation red cone wood in the embodiment and comparative example

[0065] The red cone wood obtained from the three groups of embodiments and the five groups of comparative examples was processed into small wooden blocks with a tangential length of 2 cm, a radial length of 2 cm, and a longitudinal length of 2 cm, as well as long strips with a tangential length of 2 cm, a radial length of 2 cm, and a longitudinal length of 30 cm. The test methods were carried out according to GB / T1927.7-2021 "Test methods for physical and mechanical properties of small defective specimens of wood - Part 7: Determination of water absorption", GB / T1927.6-2021 "Test methods for physical and mechanical properties of small defective specimens of wood - Part 6: Determination of shrinkage The water absorption rate, shrinkage rate and mechanical properties of each group of small wood blocks were tested according to GB / T1927.9-2021 "Test methods for physical and mechanical properties of small defective wood samples Part 10: Determination of flexural elastic modulus", GB / T1927.9-2021 "Test methods for physical and mechanical properties of small defective wood samples Part 9: Determination of flexural strength", and GB / T1927.11-2022 "Test methods for physical and mechanical properties of small defective wood samples Part 11: Determination of compressive strength along the grain". The Baidu test method was used to test the cracking of the board; the specific operation method was to process the board into wood blocks with a chord length of 10 cm, a radial length of 2 cm, and a longitudinal length of 20 cm. Wood blocks with no obvious defects on the surface (worm-eaten, knotted, cracked, etc.) were selected for soaking in water so that the moisture content of the wood blocks was higher than the fiber saturation point (moisture content greater than 30%), and the soaked wood blocks were placed in an oven at 103℃±2℃ for drying, and the cracking of the wood blocks before and after drying was recorded. The treatment effects of the wood from the plantation Castanopsis hystrix of the embodiments and comparative examples are shown in Table 1.

[0066] Table 1: Treatment effects of plantation wood in the examples and comparative examples

[0067]

[0068]

[0069] The results in Table 1 show that the treatment method for preventing the artificial forest red cone wood from cracking and deformation in the embodiment has significantly lower water absorption, tangential, radial and volume shrinkage rates than the control example, significantly reduced the number of cracks, significantly improved the dimensional stability of the wood, and enhanced the mechanical properties. This method can effectively inhibit the deformation and cracking of the artificial forest red cone wood, indicating that the impregnation treatment method provided by the present invention can effectively inhibit the deformation and cracking of the artificial forest red cone wood caused by humidity changes during the application process, and has a good effect on improving the material properties of the artificial forest red cone wood. At the same time, no formaldehyde is released, and both are environmentally friendly.

[0070] The modifier for impregnation of artificial forest red cone is made of formaldehyde-free raw materials, does not have the problem of harmful gas release, is green and environmentally friendly, and has good thermal stability. After the artificial forest red cone logs are cut down, radial cracks are easily generated at the ends due to the release of growth stress and the rapid decrease in moisture content at the ends of the logs. Therefore, the logs are immediately processed into boards after being cut down, and put into a drying kiln to pass saturated steam to soften the wood and release the growth stress of the wood. At the same time, low-temperature drying can reduce the moisture content gradient in the thickness direction of the wood, reduce the drying stress of the wood, prevent the drying stress from being too large and exceeding the transverse tensile limit of the wood, resulting in drying defects such as internal cracks and surface cracks, reduce the cracking caused by drying before the wood is impregnated, and improve the drying quality of the wood. After the wood is dried, the modifier is introduced into the wood cells by vacuum-pressurized full cell impregnation method. The air and part of the extract in the wood pores are first discharged by vacuum, and the partially blocked pits in the wood are opened. Then the modifier is introduced into the wood by staged pressurization. The modifier fills the macropores and part of the mesopores in the wood, cross-links with the wood cell wall material and adheres to the cell wall, reducing the flow of water and adsorption sites, and improving the shrinkage and swelling of the wood; at the same time, the cell wall is thickened, the hygroscopicity of the wood is reduced and the dimensional stability is improved, and the mechanical properties of the cell wall are enhanced to prevent the cracking and deformation of the wood due to moisture absorption during use, and improve the overall performance of the wood; high-temperature heat treatment can change the main chemical components of the wood, mainly including the degradation of hemicellulose and the reorganization of the non-crystalline area of ​​cellulose. The degradation of hemicellulose with strong hygroscopicity and the increase in cellulose crystallinity caused by the reorganization of the non-crystalline area of ​​cellulose can significantly reduce the hygroscopicity of the wood. Therefore, high-temperature heat treatment while drying the impregnated board can further improve the dimensional stability of the board and reduce the cracking and deformation of the board.

[0071] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for preventing artificial forest red cone from cracking and deformation, characterized in that: The following steps are included: (1) Drying: Place the artificial forest red cone board in an environment with a certain initial temperature, and then soften it with superheated saturated steam. After softening, let the board cool naturally to the initial temperature, ventilate, reduce the moisture content in the drying kiln, and continue to dry it in the initial temperature environment for 20 days; (2) Balance: The kiln is opened on the 21st day, and the dried boards are placed in a natural environment for balance; (3) Impregnation: The plate after balancing in step (2) is placed in a vacuum environment, and then the modifier is impregnated, the vacuum is released, and then the pressure is increased to 0.2 MPa, 0.4 MPa, 0.6 MPa, and 0.8 MPa in sequence; (4) Heat treatment: the artificial forest red cone board obtained after the immersion in step (3) is placed in a ventilated place indoors, ventilated and air-dried in a natural environment, and then subjected to a staged heating heat treatment, which is divided into a pre-drying stage, a drying stage, a heat treatment stage, and a cooling stage in sequence; the pre-drying stage: drying at 50° C., 70° C., and 90° C. for 24 hours each; the drying stage, raising the temperature to 110° C. and 130° C., drying for 4-6 hours each, and the oxygen content is 8%-10%; During the heat treatment stage, the temperature is raised to 180-200°C and the heat treatment is carried out for 2-4 hours with an oxygen content of 2%-3%. During the cooling stage, the heating is stopped and the plate is taken out after the temperature drops to room temperature. The heat-treated plate is ventilated and balanced in a natural environment for 2 weeks.

2. The method for preventing artificial forest red cone from cracking and deformation according to claim 1, characterized in that: The artificial forest red cone board described in step (1) is obtained by sawing 25-40 year-old artificial forest red cone into 3-5 cm boards.

3. The method for preventing artificial forest red cone from cracking and deformation according to claim 1, characterized in that: The initial temperature in step (1) is 37-41° C.; the ventilation is performed by turning on the fan, and adjusting the direction of the fan every 2 hours to reduce the moisture content in the drying kiln.

4. The method for preventing artificial forest red cone from cracking and deformation according to claim 1, characterized in that: The superheated saturated steam softening described in step (1) is to pass superheated saturated steam for 30 minutes to soften the artificial forest red cone board; the superheated saturated steam has a steam pressure of 0.5MPa and a steam temperature of 158°C.

5. The method for preventing artificial forest red cone from cracking and deformation according to claim 1, characterized in that: The modifier described in step (3) is a melamine-urea-glyoxal (MUG) resin for impregnation, that is, glyoxal is heated to 45-65° C., melamine is added to react for 10-20 minutes, urea is added to fully mix and react, and then the pH is adjusted to 5-7 with sodium hydroxide, and the material is cooled to obtain the modifier; wherein the molar ratio of melamine, urea and glyoxal is (0.05-0.2):(0.4-0.6):1; the obtained modifier has a solid content of 48%-50%, and is adjusted to a solid content of 10-30% with deionized water before use.

6. The method for preventing artificial forest red cone from cracking and deformation according to claim 1, characterized in that: In step (3), the vacuum environment has a vacuum degree of >0.08, and after standing for 1 hour, a modifier with a solid content of 10%-30% is added and immersed for 2 hours; the pressure is sequentially increased to 0.2MPa, 0.4MPa, 0.6MPa, and 0.8MPa, and each pressure is maintained for 2 hours.

7. The method for preventing artificial forest red cone from cracking and deformation according to claim 1, characterized in that: In step (4), the mixture is dried under ventilation in a natural environment for 7 days.

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