CN116079849B - Preparation method of high-strength and high-toughness wood based on combination of surface micro-nano reinforcement and densification - Google Patents

Abstract

The invention discloses a preparation method of high-strength and high-toughness wood based on combination of surface micro-nano reinforcement and densification, and belongs to the technical field of wood modification treatment. The preparation method comprises the following steps: (1) Dispersing inorganic micro-nano particles into water, adjusting the pH value to 8-10, and adding a silane coupling agent for modification treatment; re-dispersing the surface modified inorganic micro-nano particles into water, adding nano cellulose, and uniformly dispersing to obtain a mixed dispersion liquid; adding aqueous resin and a curing agent into the mixed dispersion liquid to obtain a high-viscosity mixed emulsion; (2) Introducing the mixed emulsion into wood through a spraying or extrusion process, and drying to obtain wood with the surface layer loaded with the micro-nano hybrid; (3) And compacting by a hot pressing process to obtain the high-strength and high-toughness wood. The invention utilizes the in-situ hybridization of the water-based resin and the inorganic micro-nano particles to strengthen the cell wall of the surface layer of the wood, and fuses the compression densification treatment to obtain the modified wood with both strength and toughness.

Description

Preparation method of high-strength and tough wood based on the combination of surface micro-nano reinforcement and densification

Technical field

The invention relates to the technical field of wood modification treatment, and specifically relates to a method for preparing high-strength and tough wood based on the combination of surface micro-nano reinforcement and densification.

Background technique

Wood is a natural material with good mechanical properties and beautiful texture. It is widely used in the field of furniture decoration and is favored by people. In recent years, with the improvement of people's quality of life, our demand for wood resources has been increasing day by day. However, natural high-quality wood has become increasingly scarce. Therefore, a large number of artificial forest wood has been widely used as substitutes to meet the acute contradiction between supply and demand. However, this type of wood has low density and strength, making it difficult to be directly used as building structural materials and furniture structural parts, and its application scope is limited. For this reason, people often use resin to fill the cell cavity to increase the density and mechanical strength of wood. However, the high amount of resin used in this method not only brings about a significant increase in cost, but also easily causes the wood to become more brittle, that is, it is difficult to achieve both strength and toughness.

Therefore, using simple and easy technical methods to obtain modified wood with both strength and toughness is expected to enable high value-added application of wood in the field of lightweight and high-strength structural materials.

Contents of the invention

In view of the above-mentioned prior art, the purpose of the present invention is to provide a method for preparing high-strength and tough wood based on the combination of surface micro-nano reinforcement and densification. The present invention uses in-situ hybridization of water-based resin and inorganic micro-nano particles to reinforce the surface cell walls of wood, and integrates compression and densification processing to obtain modified wood with both strength and toughness.

To achieve the above object, the present invention adopts the following technical solution:

A method for preparing high-strength wood based on the combination of surface micro-nano reinforcement and densification, including the following steps:

(1) Disperse the inorganic micro-nanoparticles into water, adjust the pH value to 8-10, add a silane coupling agent for modification, and obtain surface-modified inorganic micro-nanoparticles; add the surface-modified inorganic micro-nanoparticles again Disperse into water, add nanocellulose, and disperse evenly to obtain a mixed dispersion; add water-based resin and curing agent to the mixed dispersion, stir evenly, and obtain a high-viscosity mixed emulsion;

(2) Introduce the mixed emulsion of step (1) into the wood through a spraying or extrusion process, and dry it to obtain wood with micro-nano hybrids loaded on the surface;

(3) The wood obtained in step (2) is subjected to a compaction treatment by a hot pressing process to prepare a high-strength and tough wood.

Preferably, in step (1), the inorganic micro-nanoparticles are inorganic powdery particles with a particle size ranging from 1000 to 10000 mesh. Including but not limited to: shell powder, clay powder, mica flakes, etc.

Preferably, in step (1), amines or hydroxides are used to adjust the pH value to 8-10.

Preferably, in step (1), the silane coupling agent is a silane coupling agent with an amino or epoxy functional group, such as γ-aminopropyltriethoxysilane coupling agent, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane, etc.

Further, the added amount of the silane coupling agent is 0.1% to 10% by weight of the inorganic micro-nanoparticles.

Preferably, in step (1), the nanocellulose has an aspect ratio of less than 1000, a diameter of 1 to 100 nm, and carries hydroxyl and carboxyl functional groups.

Further, the addition amount of the nanocellulose is 0.1% to 10% by weight of the inorganic micro-nanoparticles.

Preferably, in step (1), the mass concentration of surface-modified inorganic micro-nanoparticles in the mixed dispersion is 0.1% to 10%.

Preferably, in step (1), the water-based resin is selected from one or more of acrylic resin, phenolic resin, and melamine resin; the curing agent is selected from aziridine or ammonium chloride.

Further, in the mixed emulsion, the mass concentration of the water-based resin is 10-70%; the amount of the curing agent added is 5-10% by weight of the water-based resin.

Preferably, in step (1), the viscosity of the mixed emulsion is 100-1000 cps.

Preferably, in step (2), the spraying or extrusion process is 0.1-1.0MPa pressure, the inner diameter of the nozzle or extrusion port is 0.3-1.0mm, and the application amount is 100-500g/ ^m2 .

Preferably, in step (2), drying is to dry the sample at room temperature to 50°C until the moisture content is less than 20%.

Preferably, in step (3), the hot pressing pressure is 10-40MPa, the temperature is 70°C-120°C, and the sample is heated until the moisture content of the sample is less than or equal to 10%.

The high-strength wood preparation method of the present invention is suitable for wood of any size and any type, and is especially suitable for wood of fast-growing tree species, such as poplar, fir, eucalyptus, etc.

Beneficial effects of the present invention:

The present invention utilizes inorganic micro-nano particles, nanocellulose and water-based resin to carry out composite modification on the surface structure of wood, wherein the particle size of most of the inorganic micro-nano particles is higher than the inner diameter of the wood cell cavity pores (less than 100nm), so after being applied to the wood surface by spraying or extrusion process, the main body will remain in the cell cavity of the wood surface (within 1mm), and will be fixed by the resin through bonding with the functional groups modified on the surface, so as to reinforce the surface cell wall; the water-based resin will partially penetrate into the cell wall inside the wood, so as to fix the overall structure of the wood after compaction; the nanocellulose not only stabilizes the suspension dispersion of the inorganic particles, but also increases the shear rheological properties of the emulsion, thereby making the overall emulsion suitable for extrusion and spraying processes, and also toughens the resin and the wood cell wall; the compaction treatment reduces the pores in the wood, eliminates the pores in the surface hybrid and the wood cell cavity, forms a multi-phase composite dense structure, and gives the wood high toughness and high rigidity.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1: SEM photo of the filled cell cavity pores on the wood surface in Example 1.

Figure 2: SEM photograph of the inner wall of the cell cavity on the surface of wood in Example 1 being attached and fixed with micro-nanoparticles.

Detailed ways

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meanings commonly understood by one of ordinary skill in the art to which this application belongs.

As mentioned above, wood has low density and low strength, making it difficult to be used directly as building structural materials and furniture structural parts, and its application range is limited. The existing method of using resin to fill the cell cavity to improve the density and mechanical strength of wood, but the amount of resin used is large, the cost is high, and it is easy to cause the wood to become more brittle. Therefore, it is difficult to achieve simultaneous improvement of wood strength and toughness through existing modification treatments.

Based on this, in order to simultaneously improve the strength and toughness of wood, the present invention proposes a method for preparing high-strength and tough wood based on a combination of surface micro-nano reinforcement and densification.

In one embodiment of the present invention, a specific method for preparing high-strength and tough wood is provided, comprising the following steps:

1) Solution configuration:

First, the inorganic micro-nanoparticles are dispersed into the aqueous liquid, and the pH is further adjusted to 8-10, and then a silane coupling agent is added thereto. The amount of silane coupling agent added is 0.1%-10% of the weight of the inorganic micro-nanoparticles. , ultrasonic, stir, centrifuge, clean, and dry to obtain surface-modified inorganic micro-nanoparticles; then, the modified inorganic micro-nanoparticles are dispersed into the aqueous liquid again, and nanocellulose is added. The amount of nanocellulose added It is 0.1%-10% of the weight of the inorganic micro-nanoparticles, and is dispersed evenly by ultrasonic and stirring to obtain a mixed dispersion of nanocellulose and inorganic micro-nanoparticles; then, water-based resin and curing agent are introduced into the mixed dispersion, and stirred evenly. , to obtain a high-viscosity mixed emulsion; the mass concentration of the water-based resin in the mixed emulsion is 10 to 70%, and the addition amount of the curing agent is 5 to 10% of the weight of the water-based resin.

2) Surface load:

The high-viscosity mixed emulsion obtained in step 1) is introduced into the wood through a spraying or extrusion process, and dried until the moisture content is less than 20%, to obtain wood with a surface layer loaded with micro-nano hybrids;

3) Compression treatment:

The wood obtained in step 2) is processed through a hot pressing process to obtain the target modified wood.

Since the mixed emulsion of the present invention for wood surface modification treatment has a viscosity of 100 to 1000 cps and is relatively high, it is not suitable for the traditional vacuum-pressure penetration process when applied to wood, and is more suitable for simple and convenient spraying or spraying. The extrusion process focuses on modifying the surface structure of wood. The particle size of inorganic micro-nanoparticles is mostly higher than the inner diameter of wood cell cavity pores (less than 100nm), so after being applied to the wood surface through spraying or extrusion processes, the main body will remain in the cell cavity on the surface of the wood (within 1mm) , and is fixed by water-based resin through bonding with surface-modified functional groups to strengthen the surface cell wall; the resin will partially penetrate into the internal cell wall of the wood, thereby fixing the overall structure of the compacted wood; nanocellulose not only stabilizes the inorganic particles Suspension and dispersion increase the shear rheology characteristics of the emulsion, making the overall emulsion suitable for extrusion and spraying processes, and toughening the resin and wood cell walls; the compaction treatment reduces the pores in the wood, making the surface hybrid and The pores in the wood cell cavity are eliminated, forming a multi-phase composite dense structure, giving the wood high toughness and high stiffness.

The modified wood of the present invention organically combines the structural stabilization effect of resin, the enhanced reinforcement effect and heat-resistant effect of inorganic particles on the inner cavity wall of the wood surface, the dispersion anchoring, thickening effect and toughening function of nanocellulose, and compresses the wood. The densification effect and other multiple synergistic effects make the final modified wood show excellent mechanical strength, impact toughness, structural stability and even heat resistance stability.

In order to enable those skilled in the art to understand the technical solutions of the present application more clearly, the technical solutions of the present application will be described in detail below with reference to specific embodiments.

The test materials used in the examples of the present invention are all conventional test materials in this field and can be purchased through commercial channels. Experimental methods without specifying detailed conditions were carried out in accordance with conventional experimental methods or in accordance with the operating instructions recommended by the supplier. in:

Shell powder, mica flakes, silane coupling agents, etc. are all commercial products; styrene-acrylic acid copolymer resin was purchased from BASF Co., Ltd. in Germany, and the trade name is JONCRYL 682 styrene acrylic resin; nanocellulose can be purchased through commercial channels. It can also be prepared with reference to the existing technology, for example, with reference to patent CN108931565 A or patent CN105755890A.

For wood performance testing methods, weight gain rate calculation methods and static bending strength, elastic modulus, wear resistance (i.e. abrasion value) testing standards: GB/T 17657-2013 Test methods for physical and chemical properties of artificial panels and veneer artificial panels ;

Impact toughness test is based on standards: GB/T 1940-2009 Wood Impact Toughness Test Method;

The tensile strength test is based on the standard: GB/T 1938-2009 Wood tensile strength test method along the grain;

Water absorption, water absorption thickness expansion rate and water absorption width expansion rate are tested according to the standard: GB/T 30364-2013 Restructured Bamboo Flooring;

The formaldehyde release test is based on the standard: GB/T 39600-2021 "Formaldehyde Release Classification of Artificial Panels and Their Products";

Flame retardant test is based on the standard: GB 8624-2012 "Classification of Combustion Performance of Building Materials and Products";

The maximum pyrolysis temperature is tested by thermogravimetric analyzer;

Limiting Oxygen Index is tested with a cone calorimeter.

Example 1:

1) Solution configuration:

First, 6000-mesh inorganic shell powder is dispersed in water (mass fraction is 50%), and the pH is adjusted to 10 with triethylamine, and 1% of the mass of γ-aminopropyltriethoxysilane coupling agent is added; then, it is ultrasonicated at 500 Hz for 30 minutes, and then stirred at room temperature at 1000 rpm for 12 hours, and then centrifuged at 8000 rpm for 20 minutes. The precipitate after centrifugation is repeatedly washed with deionized water until it is neutral, and dried at 103°C to obtain modified shell powder with surface modified amino groups.

Disperse the modified shell powder in water to form a suspension with a mass concentration of 25%, then add carboxyl-containing nanocellulose accounting for 10% of the mass of the shell powder (aspect ratio: 500, particle size: 10nm), and then operate at 500Hz Ultrasonicate for 30 minutes under the conditions, and then stir at room temperature for 1 hour at 1000 rpm to obtain a mixed dispersion of nanocellulose and shell powder.

After that, a styrene-acrylic acid copolymer resin with a molecular weight of 1700 and a carboxyl group and an aziridine curing agent were introduced into the mixed dispersion, and triethylamine was used to adjust an alkaline solution of pH=8.5 to form a resin with a solid content of 25%. The resin liquid, the curing agent accounts for 10% of the resin mass; further ultrasonic at 500 Hz for 30 minutes, and then stirred at room temperature for 1 hour at 1000 rpm to obtain a mixed emulsion with a viscosity of 800 cps.

2) Surface load:

The mixed emulsion obtained in step 1) is applied to the surface of poplar wood (length*width*thickness: 300mm*100mm*10mm) by extrusion process (extrusion pressure: 1.0MPa, inner diameter of extrusion port: 0.5mm), and the applied amount is 200g/ ^m2 ; the wood is then dried at 50℃ to a moisture content of 15%, to obtain wood with surface loaded micro-nano hybrids.

3) Compression treatment:

The wood obtained in step 2) is processed through a hot pressing process (hot pressing pressure is 20MPa, and the temperature is 100°C and heated to a sample moisture content of 10%) to obtain the target modified wood (high-strength wood with a combination of surface micro-nano reinforcement and internal densification). tough wood).

The modified wood surface microstructure observed using SEM found that the cell cavity pores on the wood surface have been filled with resin and micro-nano particles (Figure 1), and the structure has become denser; further magnification of the surface cross-section revealed that the inner wall of the wood cell cavity is attached Micro-nanoparticles, which are microscopic morphologies of shell powder, fill microscopic pores and thereby strengthen the cell wall (Figure 2).

After testing, the filler weight gain rate of the high-strength and tough wood produced above was 36%, the elastic modulus reached 25,600MPa, and the static bending strength was as high as 228MPa, respectively 3.2 times and 2.8 times higher than that of unmodified poplar wood; the impact toughness reached 25,600 MPa. 102KJ/m ² , 6.1 times higher than unmodified poplar; tensile strength is 212MPa, 2.7 times higher than unmodified poplar; wear value is only 36mg/100r, 91 times better than unmodified poplar %; water absorption rate is 24%, which is 78% better than unmodified poplar wood; water absorption thickness expansion rate is 4.1%, which is 42% improvement than unmodified poplar wood; water absorption width expansion rate is 3.4%, which is 3.4% better than unmodified poplar wood. Poplar wood has improved by 33%, with a formaldehyde release of 0.008 mg/m ³ ; the maximum pyrolysis temperature is 30°C higher than that of unmodified poplar wood, the limiting oxygen index is as high as 30%, and the flame retardant grade is B ₁ . Overall, the mechanical strength of modified poplar wood far exceeds the index value of the highest strength grade (TCT40) in GB 50005-2017 "Wood Structure Design Standard", and can be widely used in the field of building structural materials.

Embodiment 2:

1) Solution configuration:

First, disperse 1200-mesh inorganic mica flakes into the aqueous liquid (mass fraction: 30%), adjust the pH to 8.5 with NaOH, and add γ-aminopropyltriethoxysilane accounting for 1% of the mass of the mica flakes for coupling agent; then ultrasonicate at 500Hz for 30min, stir at room temperature at 1000rpm for 12h, and then centrifuge at 6000rpm for 20min. The precipitate after centrifugation is repeatedly washed with deionized water until neutral, and dried at 103°C until absolutely dry. Modified mica sheets with surface-modified amino groups were obtained.

Disperse the modified mica flakes in water to form a suspension with a mass concentration of 20%, then add carboxyl-containing nanocellulose (aspect ratio of 800, particle size of 20nm) accounting for 10% of the mass of the mica flakes, and then operate at 500Hz Ultrasonicate for 30 minutes, and then stir at room temperature for 1 hour at 1000 rpm to obtain a mixed dispersion of nanocellulose and mica flakes.

After that, a phenolic resin with a molecular weight of 400 and an ammonium chloride curing agent were introduced into the mixed dispersion, and sodium hydroxide was used to adjust an alkaline solution with a pH of 9.0 to form a resin liquid with a resin solid content of 20%. The curing agent accounted for 8% of the resin mass; further ultrasonic at 500 Hz for 30 minutes, and then stirred at room temperature for 1 hour at 1000 rpm to obtain a mixed emulsion with a viscosity of 500 cps;

2) Surface load:

The mixed emulsion obtained in step 1) is applied to the surface of poplar wood (length*width*thickness is 500mm*150mm*10mm) through a spraying process (spraying pressure is 0.8MPa, inner diameter of the nozzle is 0.5mm), and the application amount is 500g/m ² ; Then dry at room temperature until the moisture content is 12% to obtain wood with micro-nano hybrids loaded on the surface;

3) Compression treatment:

The wood obtained in step 2) is treated by hot pressing (hot pressing pressure is 30 MPa, heated at 120°C until the moisture content of the sample is 10%) to obtain the target modified wood (high-strength and tough wood with surface micro-nano reinforcement and internal densification).

After testing, the filler weight gain rate of the high-strength and tough wood produced above was 40%, the elastic modulus reached 27800MPa, and the static bending strength was as high as 233MPa, respectively 3.4 times and 3.1 times higher than that of unmodified poplar wood; the impact toughness reached 108KJ/m ² , 6.5 times higher than unmodified poplar; tensile strength is 225MPa, 3.1 times higher than unmodified poplar; wear value is only 42mg/100r, 86 times better than unmodified poplar %; water absorption rate is 5%, which is 96% better than unmodified poplar wood; water absorption thickness expansion rate is 2.1%, which is 86% better than unmodified poplar wood; water absorption width expansion rate is 1.9%, which is 1.9% better than unmodified poplar wood. Poplar wood has improved by 88%, with a formaldehyde release of 0.008 mg/m ³ ; the maximum pyrolysis temperature is 42°C higher than that of unmodified poplar wood, the limiting oxygen index is as high as 33%, and the flame retardant grade is B ₁ . Overall, the mechanical strength of modified poplar wood far exceeds the index value of the highest strength grade (TCT40) in GB 50005-2017 "Wood Structure Design Standard", and can be widely used in the field of building structural materials.

Comparative Example 1:

1) Solution configuration:

First, disperse 1200-mesh inorganic mica flakes into the aqueous liquid (mass fraction: 30%), adjust the pH to 8.5 with NaOH, and add γ-aminopropyltriethoxysilane accounting for 1% of the mass of the mica flakes for coupling agent; then ultrasonicate at 500Hz for 30min, stir at room temperature at 1000rpm for 12h, and then centrifuge at 6000rpm for 20min. The precipitate after centrifugation is repeatedly washed with deionized water until neutral, and dried at 103°C until absolutely dry. Modified mica sheets with surface-modified amino groups were obtained.

The modified mica flakes were dispersed in water to form a suspension with a mass concentration of 20%, and then carboxyl nanocellulose (aspect ratio of 800, particle size of 20 nm) accounting for 10% of the mass of the mica flakes was added, followed by ultrasonication at 500 Hz for 30 minutes, and then stirring at 1000 rpm at room temperature for 1 hour to obtain a mixed dispersion of nanocellulose and mica flakes.

2) Surface load:

The mixed dispersion of nanocellulose and mica flakes obtained in step 1) is applied to poplar wood (length*width*thickness is 500mm*150mm*10mm) through a spraying process (spraying pressure is 0.8MPa, inner diameter of nozzle is 0.5mm) On the surface, the application amount is 500g/m ² ; then dry at room temperature until the moisture content is 12% to obtain surface-loaded wood;

3) Compression treatment:

The wood obtained in step 2) is processed through a hot pressing process (hot pressing pressure is 30 MPa, heated at 120°C until the sample moisture content is 10%) to obtain modified wood A.

The strength index and toughness index of modified wood A were tested. Its elastic modulus was 11000MPa, static bending strength was 104MPa, impact toughness was 44.6KJ/m ² , and tensile strength was 95MPa.

Comparative example 2:

1) Solution configuration:

A phenolic resin with a molecular weight of 400 and an ammonium chloride curing agent were dissolved in water, and an alkaline solution with a pH of 9.0 was adjusted with sodium hydroxide to form a resin liquid with a resin solid content of 20%, and the curing agent accounted for 8% of the resin mass; further ultrasonicated at 500 Hz for 30 minutes, and then stirred at 1000 rpm at room temperature for 1 hour to obtain a resin emulsion;

2) Surface load:

The resin emulsion obtained in step 1) is applied to the surface of poplar wood (length*width*thickness is 500mm*150mm*10mm) through a spraying process (spraying pressure is 0.8MPa, inner diameter of the nozzle is 0.5mm), and the application amount is 500g/m ² ; Then dry at room temperature until the moisture content is 12% to obtain surface-loaded wood;

3) Compression treatment:

The wood obtained in step 2) is treated by a hot pressing process (the hot pressing pressure is 30 MPa, and the sample is heated at 120° C. until the moisture content of the sample is 10%) to obtain modified wood B.

The strength and toughness indexes of the modified wood B were tested, and its elastic modulus was 12000MPa, static bending strength was 110MPa, impact toughness was 39.2KJ/m ² , and tensile strength was 104MPa.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims (1)

1. The preparation method of the high-strength and high-toughness wood based on the combination of surface micro-nano reinforcement and densification is characterized by comprising the following steps of:

1) Solution preparation:

dispersing micron-sized powder particles into water to form a dispersion with the mass fraction of 30% -50%, further regulating the pH value to 8-10, then adding a silane coupling agent into the dispersion, wherein the addition amount of the silane coupling agent is 1% of the weight of the inorganic micro-nano particles, and carrying out ultrasonic treatment, stirring, centrifugation, cleaning and drying to obtain surface-modified micron-sized powder particles;

the micron-sized powdery particles are selected from shell powder or mica flakes; the mesh number of the shell powder is 6000 meshes, and the mesh number of the mica sheet is 1200 meshes;

the silane coupling agent is gamma-aminopropyl triethoxy silane coupling agent;

re-dispersing the surface modified micron-sized powder particles into water to form suspension with the mass concentration of 20-25%, adding nanocellulose with the addition amount of 10% of the weight of the inorganic micro-nano particles, and carrying out ultrasonic treatment and stirring and dispersing uniformly to obtain mixed dispersion liquid of the nanocellulose and the inorganic micro-nano particles; then, introducing aqueous resin and a curing agent into the mixed dispersion liquid, and adjusting the aqueous resin and the curing agent into an alkaline solution with pH=8.5-9.0 to form resin liquid with the resin solid content of 20-25%, wherein the curing agent accounts for 10% of the mass of the resin; further performing ultrasonic treatment at 500Hz for 30min, and stirring at 1000rpm at room temperature for 1 hr to obtain mixed emulsion with viscosity of 500-800 cps;

the length-diameter ratio of the nano cellulose is smaller than 1000, the diameter is 1-100 nm, and the nano cellulose is provided with carboxyl functional groups;

the aqueous resin is selected from one or more of acrylic resin, phenolic resin and melamine resin; the curing agent is selected from aziridine or ammonium chloride;

2) Surface layer load:

introducing the high-viscosity mixed emulsion obtained in the step 1) into wood through a spraying or extrusion process, and drying until the water content is 12% -15%, so as to obtain the wood with the surface layer loaded with the micro-nano hybrid;

the spraying pressure of the spraying process is 0.8MPa, and the inner diameter of the nozzle is 0.5mm; the extrusion pressure of the extrusion process is 1.0MPa, and the inner diameter of an extrusion port is 0.5mm;

3) Compacting:

and (3) treating the wood obtained in the step (2) through a hot pressing process, wherein the hot pressing pressure is 20-30MPa, and the temperature of 100-120 ℃ is heated until the water content of a sample is 10%, so that the high-strength and high-toughness wood is obtained.