Wooden honeycomb and preparation method therefor

Abstract

The present invention provides a wooden honeycomb, comprising a white honeycomb and a first resin compounded on the surface of the white honeycomb. The white honeycomb comprises a plurality of pieces of wood fiber paper and a core strip adhesive; the plurality of pieces of wood fiber paper are bonded by means of the core strip adhesive; the plurality of pieces of wood fiber paper comprise unidirectional wood fiber paper and / or composite wood fiber paper; and the composite wood fiber paper comprises the unidirectional wood fiber paper and a second resin layer and / or a fiber reinforced layer compounded on the surface of the unidirectional wood fiber paper. Compared with the prior art, the core material i.e., wood fiber paper, of the wooden honeycomb provided in the present invention is a natural environment-friendly material, and has excellent mechanical properties in both directions parallel to and perpendicular to wood fibers, so that the obtained wooden honeycomb has excellent mechanical properties, light weight and low costs, and is green and environment-friendly.

Description

Wooden honeycomb and preparation method thereof

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on February 6, 2024, with application number 2024101716440 and invention name “A wood fiber reinforced material, its preparation method and application”, parts of which are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the field of honeycomb technology, and in particular relates to a wooden honeycomb and a preparation method thereof. Background Art

[0003] Honeycomb is a regular hexagonal structure, often used in conjunction with panels to form sandwich structures. Honeycomb core material has excellent specific strength and modulus, significantly increasing the rigidity of the overall structure while adding very little weight. Furthermore, due to the exceptional stability of the honeycomb structure, it significantly improves the overall structure's resistance to earthquakes, shocks, and fatigue.

[0004] Currently, high-performance honeycomb core materials primarily utilize aramid honeycombs made from aramid paper, which are used in high-end applications such as rail transit, aerospace, and military applications. Aramid honeycomb core materials are made from aramid paper, but the high price of aramid paper makes the resulting aramid honeycomb cores expensive, limiting their widespread adoption in low- and mid-range civilian applications, including construction, automotive, and consumer markets. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a wood honeycomb with excellent mechanical properties, light weight, low cost and environmental protection, and a preparation method thereof.

[0006] The present invention provides a wood honeycomb, comprising a white honeycomb and a first resin compounded on the surface of the white honeycomb; the white honeycomb comprises a plurality of wood fiber papers and core adhesive; the plurality of wood fiber papers are bonded together using the core adhesive;

[0007] The plurality of wood fiber papers include unidirectional wood fiber paper and / or composite wood fiber paper; the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper;

[0008] The density of the wood honeycomb is 29-144 kg / m 3 ;

[0009] The compressive strength of the wood honeycomb is 0.4-13.8 MPa.

[0010] Preferably, the wood fiber paper comprises wood fibers and / or fiber bundles; the wood fibers and / or fiber bundles are arranged or extended in a single direction as a whole at a microscopic level.

[0011] Preferably, the wood fiber paper has a tensile strength in a direction parallel to the wood fibers and / or fiber bundles of 6 to 30 kN / m;

[0012] and / or, the wood fiber paper has a tensile strength of 0.3 to 4 kN / m in a direction perpendicular to the wood fibers and / or fiber bundles;

[0013] And / or, the elastic modulus of the wood fiber paper in a direction parallel to the wood fibers and / or fiber bundles is 8 to 80 GPa;

[0014] And / or, the elastic modulus of the wood fiber paper in a direction perpendicular to the wood fibers and / or fiber bundles is 0.4 to 3 GPa.

[0015] Preferably, the unidirectional wood fiber paper is formed by shrinking the unidirectional wood veneer with some substances removed in at least one direction;

[0016] The partial substances include lignin and hemicellulose;

[0017] The decomposition of the shrinkage force includes lateral shrinkage and thickness shrinkage.

[0018] Preferably, the unidirectional veneer from which some substances have been removed is shrunk in at least two directions;

[0019] The shrinkage includes transverse shrinkage and thickness shrinkage;

[0020] The shrinkage force directions of the transverse shrinkage and the thickness shrinkage intersect;

[0021] The shrinkage force of the transverse shrinkage is a force in the horizontal direction of the unidirectional veneer, and is a force that intersects with the extension direction of the wood fibers and / or fiber bundles in the plane; and / or, the shrinkage force of the thickness shrinkage is a force in the vertical direction of the unidirectional veneer;

[0022] The horizontal force and the vertical force are each independently an originally applied force, and / or a force formed after synthesis or decomposition of forces.

[0023] Preferably, the thickness of the unidirectional wood fiber paper is less than or equal to 0.2 mm;

[0024] And / or, the surface density of the unidirectional wood fiber paper is 20 to 200 g / m 2 ;

[0025] And / or, the tensile strength of the unidirectional wood fiber paper parallel to the direction of the wood fibers and / or fiber bundles is 150-1000 MPa.

[0026] Preferably, the apparent thickness of the unidirectional wood fiber paper under a plane pressure of no more than 0.005 MPa is no more than 4 times the average thickness of the unidirectional wood fiber paper;

[0027] and / or, the weight loss of the unidirectional veneer after removing some substances is 10% to 60% relative to the unidirectional veneer;

[0028] And / or, the shrinkage rate of the transverse shrinkage is 2% to 40%; the shrinkage rate of the thickness shrinkage is 20% to 90%.

[0029] Preferably, the mass of the second resin layer is 0% to 30% of the mass of the composite wood fiber paper; and the mass of the fiber reinforcement layer is 0% to 10% of the mass of the composite wood fiber paper.

[0030] Preferably, the second resin layer comprises a thermosetting resin and / or a thermoplastic resin;

[0031] And / or, the surface density of the fiber reinforced layer is 1 to 20 g / m 2 .

[0032] Preferably, the thermosetting resin is selected from one or more of epoxy resin, unsaturated polyester, polybutadiene resin, phenolic resin, melamine resin and cross-linkable polyurethane;

[0033] and / or, the thermoplastic resin is selected from one or more of polyamide, polylactic acid, polyurethane, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer and copolyester;

[0034] And / or, the fiber reinforcement layer is selected from a fiber surface felt with low surface density; the fiber surface felt with low surface density is selected from one or more of a carbon fiber surface felt, a glass fiber surface felt and an aramid fiber surface felt.

[0035] Preferably, the surface density of the composite wood fiber paper is increased by 3 to 50 g / m2 compared with the surface density of the unidirectional wood fiber paper. 2 .

[0036] Preferably, the mass of the wood fiber paper is 30% to 84% of the mass of the wood honeycomb;

[0037] and / or, the mass of the first resin is 15% to 69% of the mass of the wood honeycomb;

[0038] And / or, the mass of the core strip glue is 1% to 30% of the mass of the wood honeycomb.

[0039] The present invention also provides a method for preparing a wood honeycomb, comprising the following steps:

[0040] S1) applying core strip glue to multiple sheets of wood fiber paper, stacking them in staggered layers, and hot pressing and curing them to obtain a honeycomb block;

[0041] S2) stretching the honeycomb block to obtain a white honeycomb;

[0042] S3) transferring the first resin to the white honeycomb and curing it to obtain a wood honeycomb;

[0043] The plurality of wood fiber papers include unidirectional wood fiber paper and / or composite wood fiber paper; the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper;

[0044] The density of the wood honeycomb is 29-144 kg / m 3 ;

[0045] The compressive strength of the wood honeycomb is 0.4-13.8 MPa.

[0046] Preferably, the method for preparing the unidirectional wood fiber paper comprises the following steps:

[0047] A1) chemically modifying the unidirectional veneer to obtain the unidirectional veneer from which some substances have been removed;

[0048] A2) shrinking the unidirectional veneer from which some substances have been removed in at least one direction to obtain unidirectional wood fiber paper;

[0049] The decomposition of the shrinkage force includes lateral shrinkage and thickness shrinkage.

[0050] Preferably, the thickness of the unidirectional veneer is 0.05 to 0.6 mm;

[0051] And / or, the chemical modification in A1) is carried out in a closed high-pressure system; the target temperature of the chemical modification is 100-150° C.; the target pressure of the chemical modification is 0.07-1.9 MPa; and the residence time of the chemical modification at the target temperature / target pressure is 1-12 hours;

[0052] Alternatively, the chemical modification is carried out under normal pressure; the residence time of the chemical modification at the target temperature / pressure is 24 to 72 hours; the temperature of the chemical modification is the boiling temperature of water at normal pressure;

[0053] And / or, the modification liquid for chemical modification in step A1) comprises an alkaline substance, a sulfonating agent and water;

[0054] The pH value of the modified liquid is 12 to 14;

[0055] The concentration of the alkaline substance in the modified solution is 0.01 to 5 kg / L;

[0056] The alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate and potassium bicarbonate;

[0057] The concentration of the sulfonating agent in the modified solution is 0.01 to 5 kg / L;

[0058] The sulfonating agent in the modified liquid is selected from one or more of sulfite, chlorosulfonic acid, hydroxymethylsulfonate, sulfuryl chloride and aminosulfonic acid;

[0059] And / or, the material ratio of the unidirectional veneer to the chemically modified modifying liquid is 4.6 to 184 cm 3 : 1L.

[0060] Preferably, the shrinkage process includes a lateral shrinkage process and a thickness shrinkage process; the force of the lateral shrinkage process and the force of the thickness shrinkage process intersect.

[0061] Preferably, the transverse shrinkage treatment includes applying external mechanical force in the transverse direction and / or spontaneous shrinkage due to dehydration;

[0062] The external mechanical force applied in the transverse direction intersects in the plane with the extending direction of the wood fibers and / or fiber bundles of the unidirectional veneer from which some substances have been removed.

[0063] Preferably, applying the external mechanical force in the transverse direction is specifically: using a film material that can produce transverse contraction, sticking it on the surface of the unidirectional veneer from which some substances have been removed, and applying pressure;

[0064] and / or, applying negative pressure to the one-way veneer with some of the material removed;

[0065] and / or, roller-rubbing the unidirectional veneer with some of the material removed;

[0066] and / or, applying transverse pressure to the unidirectional veneer with some of the material removed.

[0067] Preferably, the pressure of the external mechanical force applied in the lateral direction is 0.001 to 1.5 MPa;

[0068] and / or, the temperature of the transverse shrinkage treatment is 15° C. to 150° C.;

[0069] and / or, the transverse shrinkage treatment time is 1 second to 4 minutes;

[0070] And / or, the intensity of the negative pressure is less than or equal to one atmosphere.

[0071] Preferably, the thickness shrinkage treatment is to apply mechanical pressure in the thickness direction;

[0072] The mechanical pressure applied in the thickness direction is 0.01 to 80 MPa;

[0073] and / or, the thickness shrinkage treatment time is 0.1 to 4 minutes;

[0074] And / or, the temperature of the thickness shrinkage treatment is 15°C to 150°C.

[0075] Preferably, the thickness shrinkage is performed under single sheet or stacking conditions; the number of stacked layers is 2 to 20 sheets;

[0076] The pressure of thickness shrinkage under the stacking condition is 0.1 to 60 MPa.

[0077] Preferably, the shrinkage rate of the transverse shrinkage is 2% to 40%;

[0078] The shrinkage rate of the thickness shrinkage is 20% to 90%.

[0079] Preferably, the thickness shrinking comprises performing a hot pressing treatment under negative pressure conditions;

[0080] The pressure of the hot pressing treatment is 0.1 to 60 MPa;

[0081] And / or, the temperature of the hot pressing treatment is 50°C to 150°C;

[0082] And / or, the heat pressing treatment time is 0.5 to 20 minutes.

[0083] Preferably, the shrinkage treatment is followed by a leveling treatment;

[0084] The leveling process is to perform flat hot pressing in a negative pressure exhaust environment.

[0085] Preferably, during the leveling process, an exhaust channel is provided on the double contact surface or the single contact surface of the unidirectional wood fiber paper.

[0086] Preferably, the pressure of the plane hot pressing is 0.01 to 2 MPa;

[0087] And / or, the leveling treatment time is 0.1 to 4 minutes;

[0088] And / or, the temperature of the leveling treatment is 40°C to 150°C.

[0089] Preferably, the flattening treatment is selected from one or more of a blister treatment and a negative pressure hot pressing treatment;

[0090] And / or, the moisture content of the unidirectional wood fiber paper is less than or equal to 10%.

[0091] Preferably, the composite wood fiber paper comprises unidirectional wood fiber paper and a second resin layer composited on the surface of the unidirectional wood fiber paper; the preparation method of the composite wood fiber paper comprises:

[0092] transferring the diluted second resin raw material to the surface of the unidirectional wood fiber paper and curing the same to obtain a composite wood fiber paper;

[0093] The second resin raw material is selected from one or more of a second resin prepolymer, a second resin monomer, and a second resin.

[0094] Preferably, the composite wood fiber paper comprises unidirectional wood fiber paper and a second resin layer and a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper; the preparation method of the composite wood fiber paper comprises:

[0095] Transferring the diluted second resin raw material to the surface of the unidirectional wood fiber paper, then laminating the fiber reinforcement layer, and curing to obtain the composite wood fiber paper;

[0096] The second resin raw material is selected from one or more of a second resin prepolymer, a second resin monomer, and a second resin.

[0097] Preferably, in step S3), the first resin is transferred to the white honeycomb multiple times and cured multiple times to obtain a wood honeycomb; the multiple curing and shaping are located between two transfers, and the final step is curing and shaping; the transfer method is selected from one or more of dipping, shower coating and spraying.

[0098] Preferably, the resin is transferred to the white honeycomb in step S3) in accordance with the following steps:

[0099] The first resin is sprayed, flow-coated or dip-coated in the honeycomb through-holes of the white honeycomb, and then the honeycomb is stretched and extruded, and the first resin is evenly coated on the white honeycomb.

[0100] [Corrected 29.04.2025 according to Rule 91] The present invention also provides a composite wood fiber paper, comprising unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on at least one surface of the unidirectional wood fiber paper.

[0101] Preferably, the unidirectional wood fiber paper is formed by shrinking the unidirectional wood veneer with some substances removed in at least one direction;

[0102] The partial substances include lignin and hemicellulose;

[0103] The decomposition of the shrinkage force includes lateral shrinkage and thickness shrinkage;

[0104] The unidirectional wood fiber paper comprises wood fibers and / or fiber bundles; the wood fibers and / or fiber bundles are arranged or extended in a single direction as a whole at a microscopic level;

[0105] The composite wood fiber paper has a tensile strength of 6 to 30 kN / m in a direction parallel to the wood fibers and / or fiber bundles;

[0106] and / or, the composite wood fiber paper has a tensile strength of 0.7 to 4 kN / m in a direction perpendicular to the wood fibers and / or fiber bundles;

[0107] and / or, the elastic modulus of the composite wood fiber paper in a direction parallel to the wood fibers and / or fiber bundles is 8 to 80 GPa;

[0108] And / or, the elastic modulus of the composite wood fiber paper in a direction perpendicular to the wood fibers is 0.8 to 3 GPa.

[0109] Preferably, the mass of the second resin layer is 0% to 30% of the mass of the composite wood fiber paper; the mass of the fiber reinforcement layer is 0% to 10% of the mass of the composite wood fiber paper, and both are not 0 at the same time.

[0110] Preferably, the second resin layer comprises a thermosetting resin and / or a thermoplastic resin; the thermosetting resin is selected from one or more of epoxy resin, unsaturated polyester, polybutadiene resin, phenolic resin, melamine resin and cross-linkable polyurethane; the thermoplastic resin is selected from one or more of polyamide, polylactic acid, polyurethane, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer and copolyester;

[0111] The fiber reinforcement layer is selected from low-density fiber surface felt; the low-density fiber surface felt is selected from one or more of carbon fiber surface felt, glass fiber surface felt and aramid fiber surface felt.

[0112] Preferably, the surface density of the composite wood fiber paper is increased by 3 to 50 g / m2 compared with the surface density of the unidirectional wood fiber paper. 2 .

[0113] The present invention also provides a use of the above-mentioned wood honeycomb or the above-mentioned composite wood fiber paper in preparing one or more of building materials, furniture materials, sports equipment, stationary carriers, vehicles and aircraft.

[0114] The present invention provides a wood honeycomb comprising a white honeycomb and a first resin composited on the surface of the white honeycomb; the white honeycomb comprises multiple sheets of wood fiber paper and a core adhesive; the multiple sheets of wood fiber paper are bonded together using the core adhesive; the multiple sheets of wood fiber paper comprise unidirectional wood fiber paper and / or composite wood fiber paper; the composite wood fiber paper comprises unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper. Compared to the prior art, the wood fiber paper core material of the wood honeycomb provided by the present invention is a natural and environmentally friendly material, and has excellent mechanical properties both parallel to and perpendicular to the wood fiber directions. This results in a wood honeycomb with excellent mechanical properties, lightweight, low cost, and environmentally friendly properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0115] FIG1 is a schematic diagram of the preparation process of a wood honeycomb provided by the present invention;

[0116] FIG2 is a sample diagram of different stages in the wood honeycomb preparation process provided by the present invention;

[0117] FIG3 is a schematic structural diagram of a material frame for a vertical reactor provided by the present invention;

[0118] FIG4 is a schematic diagram of placing the unidirectional veneer provided by the present invention in a vertical reactor;

[0119] FIG5 is a schematic structural diagram of a material frame for a horizontal reactor provided by the present invention;

[0120] FIG6 is a schematic diagram of placing the unidirectional veneer provided by the present invention in a horizontal reactor;

[0121] FIG7 is a schematic diagram of the collapse and contraction of the spontaneously transversely contracting unidirectional wood fiber paper tube provided by the present invention;

[0122] FIG8 is a schematic diagram of a continuous hot pressing process of hot rolling rollers provided by the present invention;

[0123] FIG9 is a schematic diagram of a continuous hot pressing process performed by a continuous flat press provided by the present invention;

[0124] FIG10 is a schematic diagram of continuous hot pressing processing with a belt press provided by the present invention;

[0125] Figure 11 is a schematic diagram of unidirectional wood fiber paper splicing;

[0126] FIG12 is a physical picture of different composite wood fiber papers;

[0127] FIG13 is a schematic diagram of the structure of composite wood fiber paper;

[0128] FIG14 is a schematic diagram of splicing unidirectional wood fiber paper through a coating layer;

[0129] FIG15 is a schematic diagram of two coating directions of the core strip adhesive when applied to the composite wood fiber paper;

[0130] FIG16 is a schematic diagram of the gluing position of the core strip glue provided by the present invention on the wood fiber paper;

[0131] FIG17 is a schematic diagram of the preparation process of the white wood honeycomb provided by the present invention;

[0132] FIG18 is a schematic structural diagram of a wood honeycomb provided by the present invention;

[0133] FIG19 is a top view of a wood honeycomb provided by the present invention;

[0134] FIG20 is a top view of a wood honeycomb provided by the present invention;

[0135] FIG21 is a schematic structural diagram of a wood honeycomb component provided by the present invention;

[0136] [Corrected 31.12.2024 according to Rule 91] Figure 22 is a photograph of the unidirectional veneer obtained in Example 1 of the present invention in a wet state with some of the material removed;

[0137] [Corrected 31.12.2024 according to Rule 91] Figure 23 is a graph showing the spontaneous transverse shrinkage of the unidirectional veneer with some material removed in Example 1 of the present invention;

[0138] [Corrected 31.12.2024 according to Rule 91] FIG24 is a graph showing a tensile stress-strain test curve in the fiber direction of the wood fiber paper obtained in Example 1 of the present invention;

[0139] FIG. 25 is a physical picture showing that the veneer shrinks only in the thickness direction after chemical treatment in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0140] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0141] The present invention provides a wood honeycomb, comprising a white honeycomb and a first resin composited on the surface of the white honeycomb; the white honeycomb comprises a plurality of wood fiber papers and core strip glue; the plurality of wood fiber papers are bonded together by the core strip glue; the plurality of composite wood fiber papers comprise unidirectional wood fiber papers and / or composite wood fiber papers; the composite wood fiber papers comprise unidirectional wood fiber papers and a second resin layer and / or a fiber reinforcement layer composited on the surface of the unidirectional wood fiber papers.

[0142] According to the present invention, the wood fiber paper includes wood fibers and / or fiber bundles; the wood fibers and / or fiber bundles are arranged or extended in a single direction as a whole at the microscopic level; the wood fibers and / or fiber bundles are arranged or extended in a single direction as a whole at the microscopic level; specifically, greater than or equal to 70% of the wood fibers and / or fiber bundles are arranged or extended in a single direction at the microscopic level, and more specifically, greater than or equal to 80% of the wood fibers and / or fiber bundles are arranged or extended in a single direction at the microscopic level.

[0143] According to the present invention, the tensile strength of the wood fiber paper in a direction parallel to the wood fibers and / or fiber bundles is 6 to 30 kN / m; optionally, the tensile strength of the wood fiber paper in a direction parallel to the wood fibers and / or fiber bundles is 6 kN / m, 8 kN / m, 10 kN / m, 12 kN / m, 14 kN / m, 16 kN / m, 18 kN / m, 20 kN / m, 22 kN / m, 24 kN / m, 26 kN / m, 28 kN / m, 30 kN / m or a range between any two of the above values.

[0144] According to the present invention, the tensile strength of the wood fiber paper in a direction perpendicular to the wood fibers and / or fiber bundles is 0.3 to 4 kN / m; optionally, the tensile strength of the wood fiber paper in a direction perpendicular to the wood fibers and / or fiber bundles is 0.3 kN / m, 0.5 kN / m, 0.8 kN / m, 1.0 kN / m, 1.2 kN / m, 1.5 kN / m, 1.8 kN / m, 2.0 kN / m, 2.2 kN / m, 2.5 kN / m, 2.8 kN / m, 3.0 kN / m, 3.2 kN / m, 3.5 kN / m, 3.8 kN / m, 4 kN / m or a range between any two of the above values.

[0145] According to the present invention, the elastic modulus of the wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is 8 to 80 GPa; optionally, the elastic modulus of the wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is 8 GPa, 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa or a range between any two of the above values.

[0146] According to the present invention, the elastic modulus of the wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is 0.4 to 3 GPa. Optionally, the elastic modulus of the wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is 0.4 GPa, 0.6 GPa, 0.8 GPa, 1.0 GPa, 1.2 GPa, 1.5 GPa, 1.8 GPa, 2.0 GPa, 2.2 GPa, 2.4 GPa, 2.6 GPa, 2.8 GPa, 3 GPa or a range between any two of the above values.

[0147] According to the present invention, the unidirectional wood fiber paper is formed by shrinking the unidirectional wood bark with part of the material removed in at least one direction; the part of the material includes lignin and hemicellulose.

[0148] According to the present invention, the thickness of the unidirectional wood fiber paper is less than or equal to 0.2 mm.

[0149] According to the present invention, the density of the unidirectional wood fiber paper is 0.8-1.5 g / cm 3 ; Optionally, the density of the unidirectional wood fiber paper is 0.8g / cm 3 , 0.9g / cm 3 , 1.0g / cm 3 , 1.1g / cm 3 , 1.2g / cm 3 , 1.3g / cm 3 , 1.4g / cm 3 , 1.5g / cm3 Or the range between any two of the above values.

[0150] According to the present invention, the surface density of the unidirectional wood fiber paper is 20 to 200 g / m 2 Optionally, the surface density of the unidirectional wood fiber paper is 20g / m 2 , 30g / m 2 , 50g / m 2 , 70g / m 2 , 80g / m 2 , 100g / m 2 , 120g / m 2 , 140g / m 2 , 160g / m 2 , 180g / m 2 , 200g / m 2 Or the range between any two of the above values.

[0151] [Corrected on 29.04.2025 according to Rule 91] According to the present invention, the tensile strength of the unidirectional wood fiber paper parallel to the direction of the wood fibers and / or fiber bundles is 150 to 1000 MPa; optionally, the tensile strength of the unidirectional wood fiber paper parallel to the direction of the wood fibers and / or fiber bundles is 150 MPa, 250 MPa, 350 MPa, 450 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa or a range between any two of the above values.

[0152] According to the present invention, the Young's modulus of the unidirectional wood fiber paper parallel to the direction of the wood fibers and / or fiber bundles is preferably 20 to 70 GPa, more preferably 25 to 70 GPa; optionally, the Young's modulus of the unidirectional wood fiber paper parallel to the direction of the wood fibers and / or fiber bundles is 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa or a range between any two of the above values.

[0153] According to the present invention, the tensile strength of the unidirectional wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is preferably 6 to 30 kN / m, more preferably 11 to 25 kN / m; optionally, the tensile strength of the unidirectional wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is 11 kN / m, 12 kN / m, 13 kN / m, 14 kN / m, 15 kN / m, 16 kN / m, 17 kN / m, 18 kN / m, 19 kN / m, 20 kN / m, 21 kN / m, 22 kN / m, 23 kN / m, 24 kN / m, 25 kN / m or a range between any two of the above values.

[0154] According to the present invention, the elastic modulus of the unidirectional wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is preferably 8 to 80 GPa; optionally, the elastic modulus of the unidirectional wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is 8 GPa, 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa or a range between any two of the above values.

[0155] According to the present invention, the tensile strength of the unidirectional wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is preferably 0.3-4 kN / m, more preferably 0.3-1.5 kN / m; optionally, the tensile strength of the unidirectional wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is 0.3 kN / m, 0.4 kN / m, 0.5 kN / m, 0.6 kN / m, 0.7 kN / m, 0.8 kN / m, 0.9 kN / m, 1.0 kN / m, 1.1 kN / m, 1.2 kN / m, 1.3 kN / m, 1.4 kN / m, 1.5 kN / m or a range between any two of the above values.

[0156] According to the present invention, the elastic modulus of the unidirectional wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is preferably 0.4 to 3 GPa, more preferably 0.4 to 2 GPa; optionally, the elastic modulus of the unidirectional wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is 0.4 GPa, 0.6 GPa, 0.8 GPa, 1.2 GPa, 1.4 GPa, 1.6 GPa, 1.8 GPa, 2 GPa or a range between any two of the above values.

[0157] The unidirectional wood fiber paper provided by the present invention has high flatness. Specifically, the apparent thickness of the unidirectional wood fiber paper under a plane pressure of no more than 0.005 MPa is no more than 4 times the average thickness of the unidirectional wood fiber paper.

[0158] More specifically, the apparent thickness of the unidirectional wood fiber paper when pressed flat under a pressure of 0.005 MPa is preferably no more than three times the average thickness of the unidirectional wood fiber paper.

[0159] And those skilled in the art can understand that the apparent thickness is related to pressure. The greater the pressure, the smaller the apparent thickness, and the smaller the multiple between the apparent thickness and the average thickness. Therefore, the description of flatness can also be equivalent to the above description.

[0160] In a specific embodiment provided by the present invention, the flatness test method is as follows: unidirectional wood fiber paper is placed between two planar objects. Pressure is applied to the two surfaces, causing the unidirectional wood fiber paper to be subjected to a smaller flat pressure. The flat wood fiber paper tends to conform to the pressure-applying surfaces. The difference between the highest and lowest points of the compressed unidirectional wood fiber paper is the apparent thickness of the unidirectional wood fiber paper. The average thickness of the unidirectional wood fiber paper is the average thickness of the unidirectional wood fiber paper measured at different locations on the paper using a micrometer.

[0161] According to the present invention, the unidirectional wood fiber paper is formed by chemically modifying the unidirectional veneer to remove some substances and shrinking in two directions; the present invention uses natural unidirectional wood to produce unidirectional wood fiber paper, and the fibers of the unidirectional wood grow along the longitudinal direction of the trunk, and the fibers are arranged tightly and uniformly, forming parallel straight line characteristics. In the present invention, the thickness of the unidirectional veneer is less than or equal to 0.6mm, and can further be 0.05 to 0.6mm. Optionally, the thickness of the unidirectional veneer can be 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm or a range between any two of the above values; in the embodiment provided by the present invention, a unidirectional veneer with a thickness of 0.28mm is specifically used as an example for explanation; the surface density of the unidirectional veneer is preferably 20 to 200g / m 2 , more preferably 70 to 200 g / m 2 ; Optionally, the surface density of the unidirectional veneer is 20g / m 2 , 50g / m 2 , 70g / m 2 , 80g / m 2 , 90g / m 2 , 100g / m 2 , 110g / m 2 , 120g / m 2 , 130g / m 2 , 150g / m 2 , 180g / m 2 , 200g / m 2 Or the range between any two of the above values. Generally speaking, the thicker the unidirectional veneer, the greater the surface density.

[0162] According to the present invention, the weight loss of the unidirectional veneer after the removal of some substances is preferably 10% to 60% relative to the unidirectional veneer; optionally, the weight loss of the unidirectional veneer after the removal of some substances is 10%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, or a range between any two of the above values. The some substances include lignin and hemicellulose.

[0163] According to the present invention, the decomposition of the shrinkage in at least one direction includes lateral shrinkage and thickness shrinkage.

[0164] In a specific embodiment provided by the present invention, the shrinkage in at least one direction is specifically shrinkage in at least two directions; the shrinkage includes lateral shrinkage and thickness shrinkage; and the shrinkage force directions of the lateral shrinkage and thickness shrinkage intersect.

[0165] In a specific embodiment provided by the present invention, the shrinkage is bidirectional shrinkage; the bidirectional shrinkage includes transverse shrinkage and thickness shrinkage, that is, the unidirectional veneer with part of the material removed is formed into unidirectional wood fiber paper through bidirectional shrinkage.

[0166] The transverse shrinkage rate is preferably 2% to 40%; optionally, the transverse shrinkage rate is 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40% or a range between any two of the above values; as the transverse shrinkage rate increases, the tensile strength and modulus of the unidirectional wood fiber paper perpendicular to the fiber direction tend to increase, so it can be selected according to needs.

[0167] The shrinkage rate of the thickness shrinkage is preferably 20% to 90%, more preferably 20% to 86%; optionally, the shrinkage rate of the thickness shrinkage is 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 86%, 90% or a range between any two of the above values; a higher thickness shrinkage rate means a thinner unidirectional wood fiber paper, and its tensile strength and tensile modulus in the fiber direction tend to increase, and can be selected according to needs.

[0168] According to the present invention, the directions of the shrinkage forces of the lateral shrinkage and the thickness shrinkage intersect with each other; and the angle of the intersection is preferably 60° to 90°.

[0169] In a specific embodiment provided by the present invention, the unidirectional veneer with some substances removed includes wood fibers and / or fiber bundles; the wood fibers and / or fiber bundles are arranged or extended in a single direction as a whole at the microscopic level, and the force intersects with the extension direction of the wood fibers and / or fiber bundles within the plane; the intersection within the plane also belongs to the direction perpendicular to the fiber direction at the macroscopic level; the shrinkage force of the lateral shrinkage is the force in the horizontal direction of the unidirectional veneer; and / or, the shrinkage force of the thickness shrinkage is the force in the vertical direction of the unidirectional veneer; the horizontal force and the vertical force are each independently the original applied force, and / or, are the forces formed after the synthesis or decomposition of the forces.

[0170] The thickness and density of the unidirectional wood fiber paper obtained by shrinking in at least two directions will change; the thickness of the unidirectional wood fiber paper is less than the thickness of the unidirectional veneer, preferably 10% to 80% of the thickness of the unidirectional veneer. Optionally, the thickness of the unidirectional wood fiber paper can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% of the thickness of the unidirectional veneer, or a range between any two of the above values.

[0171] According to the present invention, the raw material of the unidirectional wood fiber paper is natural wood, which is 100% natural material.

[0172] According to the present invention, the size of the unidirectional wood fiber paper can theoretically be spliced ​​to an infinite width and length. Specifically, the length of a single unspliced ​​unidirectional wood fiber paper is preferably 0.1 to 5 m.

[0173] According to the present invention, the water content of the unidirectional wood fiber paper is preferably below 10 wt %; the unidirectional wood fiber paper does not wrinkle when placed at room temperature.

[0174] According to the present invention, the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on at least one surface of the unidirectional wood fiber paper; the mass of the second resin layer is 0% to 30% of the mass of the composite wood fiber paper; optionally, the mass of the second resin layer is 0%, 5%, 10%, 15%, 20%, 25%, 30% of the mass of the composite wood fiber paper, or a range between any two of the above values. The mass of the fiber reinforcement layer is 0% to 10% of the mass of the composite wood fiber paper; optionally, the mass of the fiber reinforcement layer is 0%, 2%, 4%, 6%, 8%, 10% or a range between any two of the above values. The second resin layer and the fiber reinforcement layer are preferably made of materials with lower surface density, so as not to significantly increase the overall density; the surface density of the composite wood fiber paper is increased by 3 to 50 g / m compared with the surface density of the unidirectional wood fiber paper. 2 Optionally, the surface density of the composite wood fiber paper is increased by 3g / m compared with the surface density of the unidirectional wood fiber paper 2 , 5g / m 2 , 10g / m 2 , 15g / m 2 , 20g / m 2 , 25g / m 2 , 30g / m 2 , 35g / m 2 , 40g / m 2 , 45g / m 2 , 50g / m 2Or the range between any two of the above values. Specifically, the surface density of the composite wood fiber paper is preferably 60 to 120 g / m 2 Optionally, the surface density of the composite wood fiber paper is 60g / m 2 , 70g / m 2 , 80g / m 2 , 90g / m 2 , 100g / m 2 , 110g / m 2 , 120g / m 2 Or the range between any two of the above values.

[0175] Compared to unidirectional wood fiber paper, composite wood fiber paper with a second resin layer and / or fiber reinforcement layer mainly improves the tensile strength perpendicular to the direction of the wood fibers and / or fiber bundles while still maintaining a very low density. In addition, it can also achieve overall dimensional changes.

[0176] Specifically, the tensile strength of the composite wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is increased by 5% to 100% compared to unidirectional wood fiber paper; optionally, it is increased by 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% or a range between any two of the above values.

[0177] Further specifically, the tensile strength of the composite wood fiber paper perpendicular to the direction of the wood fibers and / or fiber bundles is preferably 0.7 to 4 kN / m; optionally, the tensile strength of the composite wood fiber paper perpendicular to the direction of the wood fibers and / or fiber bundles is specifically 0.7 kN / m, 0.8 kN / m, 1.2 kN / m, 1.4 kN / m, 1.6 kN / m, 1.8 kN / m, 2.0 kN / m, 2.2 kN / m, 2.4 kN / m, 2.6 kN / m, 2.8 kN / m, 3.0 kN / m, 3.5 kN / m, 4.0 kN / m or a range between any two of the above values.

[0178] Specifically, the elastic modulus of the composite wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is increased by 5% to 100% compared to the unidirectional wood fiber paper; optionally, it is increased by 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% or a range between any two of the above values.

[0179] More specifically, the elastic modulus of the composite wood fiber paper perpendicular to the wood fiber direction is preferably 0.8 to 3 GPa; optionally, the elastic modulus of the composite wood fiber paper perpendicular to the wood fiber direction is 0.8 GPa, 1 GPa, 1.2 GPa, 1.4 GPa, 1.6 GPa, 1.8 GPa, 2 GPa, 2.2 GPa, 2.4 GPa, 2.6 GPa, 2.8 GPa, 3 GPa, or a range between any two of the above values. The thickness of the composite wood fiber paper is preferably 0.07 to 0.21 mm.

[0180] According to the present invention, the tensile strength of the composite wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is preferably 6 to 30 kN / m, more preferably 11 to 25 kN / m; optionally, the tensile strength of the composite wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is 11 kN / m, 12 kN / m, 13 kN / m, 14 kN / m, 15 kN / m, 16 kN / m, 17 kN / m, 18 kN / m, 19 kN / m, 20 kN / m, 21 kN / m, 22 kN / m, 23 kN / m, 24 kN / m, 25 kN / m or a range between any two of the above values.

[0181] According to the present invention, the elastic modulus of the composite wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is preferably 8 to 80 GPa; optionally, the elastic modulus of the composite wood fiber paper in the direction parallel to the wood fibers and / or fiber bundles is 8 GPa, 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa or a range between any two of the above values.

[0182] In a specific embodiment provided by the present invention, the composite wood fiber paper includes a unidirectional wood fiber paper and a second resin layer attached to at least one surface of the unidirectional wood fiber paper. Further specifically, the second resin layer is attached to both surfaces of the unidirectional wood fiber paper; the mass of the second resin layer is 0.1% to 30% of the mass of the composite wood fiber paper; the surface density of the composite wood fiber paper is increased by 3 to 40 g / m2 compared with the surface density of the unidirectional wood fiber paper. 2 .

[0183] In another specific embodiment provided by the present invention, the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer and a fiber reinforcement layer attached to at least one surface of the unidirectional wood fiber paper; the fiber reinforcement layer is located on the side of the second resin layer away from the unidirectional wood fiber paper; further specifically, the two surfaces of the unidirectional wood fiber paper are sequentially provided with a second resin layer and a fiber reinforcement layer; the mass of the second resin layer is 0.1% to 30% of the mass of the composite wood fiber paper; the mass of the fiber reinforcement layer is 0.1% to 10% of the mass of the composite wood fiber paper; the surface density of the composite wood fiber paper is increased by 10 to 50 g / m compared with the surface density of the unidirectional wood fiber paper. 2 .

[0184] According to the present invention, the second resin layer preferably includes a thermosetting resin and / or a thermoplastic resin; the thermosetting resin is preferably one or more of epoxy resin, unsaturated polyester, polybutadiene resin, phenolic resin, melamine resin and cross-linked polyurethane; the thermoplastic resin is selected from one or more of polyamide, polylactic acid, polyurethane, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer and copolyester.

[0185] According to the present invention, the surface density of the fiber reinforced layer is 1 to 20 g / m 2 ; Optionally, the surface density of the fiber reinforced layer is 1g / m 2 , 2g / m 2 , 5g / m 2 , 8g / m 2 , 10g / m 2 , 12g / m 2 , 15g / m 2 , 16g / m 2 , 18g / m 2 , 19g / m 2 , 20g / m 2 Or the range between any two of the above values.

[0186] According to the present invention, the fiber reinforcement layer is preferably a low-density fiber surface felt; the low-density fiber surface felt is preferably one or more of carbon fiber surface felt, glass fiber surface felt and aramid fiber surface felt.

[0187] The wood honeycomb provided by the present invention is composed of multiple sheets of wood fiber paper, a first resin, and core glue; the multiple sheets of wood fiber paper and the core glue form a white honeycomb; the first resin can be compounded on the surface of the white honeycomb and can also infiltrate and penetrate into the interior of the wood fiber paper that constitutes the white honeycomb. The mass of the wood fiber paper is preferably 30% to 84% of the mass of the wood honeycomb; optionally, the mass of the wood fiber paper is preferably 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 84% of the mass of the wood honeycomb, or a range between any two of the above values. The mass of the first resin is preferably 15% to 69% of the mass of the wood honeycomb; optionally, the mass of the first resin is preferably 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 69% of the mass of the wood honeycomb, or a range between any two of the above values. The mass of the core strip glue is preferably 1% to 3% of the mass of the wood honeycomb; optionally, the mass of the core strip glue is 1%, 1.5%, 2%, 2.5%, 3% of the mass of the wood honeycomb or a range between any two of the above values.

[0188] According to the present invention, the first resin is preferably one or more of epoxy resin, phenolic resin, unsaturated polyester resin, furfuryl alcohol resin and the like.

[0189] According to the present invention, the density of the wood honeycomb is preferably 29 to 144 kg / m 3 ; The compressive strength of the wood honeycomb is preferably 0.4 to 13.8 MPa.

[0190] More specifically, the standard density of wood honeycomb is 29, 32, 40, 48, 56, 64, 72, 80, 96, 128 or 144 kg / m 3 ; Different densities of wood honeycombs can provide different mechanical properties. 3 At a density of 32kg / m, the compressive strength of wood honeycomb is 0.4~1.0MPa; at a density of 32kg / m 3 At a density of 40kg / m, the compressive strength of wood honeycomb is 0.4~1.1MPa; at a density of 40kg / m 3 At a density of 48kg / m, the compressive strength of wood honeycomb is 0.6~1.3Mpa; at a density of 48kg / m 3 At a density of 56kg / m, the compressive strength of wood honeycomb is 0.8~1.6Mpa; at a density of 56kg / m 3 At a density of 64kg / m, the compressive strength of wood honeycomb is 0.8~2Mpa; at a density of 64kg / m 3 At a density of 72kg / m 3 At a density of 80kg / m 3At a density of 96kg / m 3 At a density of 128kg / m, the compressive strength of wood honeycomb is 1.8~7.2Mpa; at a density of 128kg / m 3 At a density of 144kg / m, the compressive strength of wood honeycomb is 1.8~11.5Mpa; at a density of 144kg / m 3 At a density of 2.5 ~ 13.8 MPa, the compressive strength of wood honeycomb is 2.2 ~ 13.8 MPa.

[0191] According to the present invention, the wood honeycomb has a continuous and regular pore structure; a single pore is preferably a hexagonal through-hole structure or a stretched quadrilateral through-hole structure; a plurality of continuous pores are combined to form the wood honeycomb.

[0192] According to the present invention, the side length of the cells of the wood honeycomb is preferably 1.83-9.6 mm; specifically, the side length of the standard cells may be 1.83 mm, 2.75 mm, 3.0 mm, 3.67 mm, 4.0 mm, 5.5 mm or 9.6 mm.

[0193] According to the present invention, the maximum size of the wood honeycomb can be 2600×1300×1000 mm, and any size can be obtained by cutting within this size range.

[0194] The present invention also provides a method for preparing the above-mentioned wood honeycomb, comprising the following steps: S1) applying core strip glue to multiple sheets of wood fiber paper, then stacking them in staggered layers, and hot-pressing and curing them to obtain a honeycomb block; S2) stretching the honeycomb block to obtain a white honeycomb; S3) transferring a first resin to the surface of the white honeycomb, curing and shaping it to obtain a wood honeycomb; the multiple sheets of wood fiber paper include unidirectional wood fiber paper and / or composite wood fiber paper; the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper.

[0195] Referring to FIG1 , FIG1 is a schematic diagram of the preparation process of the wood honeycomb provided by the present invention.

[0196] See FIG2 , which is a sample diagram of different stages in the wood honeycomb preparation process provided by the present invention.

[0197] The present invention has no particular limitation on the sources of all raw materials, and any commercially available raw materials may be used.

[0198] According to the present invention, the method for preparing the unidirectional wood fiber paper comprises the following steps: A1) chemically modifying the unidirectional veneer to obtain the unidirectional veneer with some substances removed; A2) shrinking the unidirectional veneer with some substances removed in at least one direction to obtain the unidirectional wood fiber paper; the shrinkage force decomposition includes lateral shrinkage and thickness shrinkage.

[0199] In the present invention, the unidirectional veneer can be any unidirectional veneer known to those skilled in the art, without particular limitation. Examples include, but are not limited to, walnut, oak, basswood, rosewood, ebony, teak, rosewood, catalpa, ebony, cherry, cork, poplar, beech, cedarwood, pine, maple, and ash. Unidirectional veneer is natural, avoiding the environmentally unfriendly effects of artificial engineered wood, which is often doped with excessive amounts of polymers and can cause structural separation during subsequent chemical reactions. Natural veneer is environmentally friendly, with cellulose, hemicellulose, and lignin cross-linked within the naturally formed structure, maintaining structural integrity during subsequent chemical reactions. Unidirectional veneer has a relatively regular fiber arrangement, with virtually all fibers oriented in the same direction, and the surface texture also oriented in the same direction, resulting in a highly anisotropic veneer. Unidirectional veneer is chosen over veneers with other fiber orientations because subsequent processing can result in significant internal stress release. Unidirectional veneer maintains better overall dimensional consistency and is less prone to defects. During the subsequent chemical reaction, some substances in the wood are removed from the structure, resulting in internal stress caused by contraction. Since the removed substances are primarily concentrated between the wood fibers, the internal stress release in unidirectional veneer after the chemical reaction is concentrated in a single direction. The veneer also contracts uniformly, perpendicular to the fibers, from the outside inward, making it less prone to defects. If non-unidirectional veneer with irregular fiber arrangement is used, the internal stress release will be directed in different directions, which can easily lead to excessive internal stress in localized areas, resulting in defects such as breakage and waste. The thickness of the unidirectional veneer is preferably 0.08-1 mm, more preferably 0.1-0.8 mm, more preferably 0.1-0.5 mm, more preferably 0.1-0.3 mm, and most preferably 0.2-0.8 mm. In the embodiment provided by the present invention, a unidirectional veneer with a thickness of 0.28 mm is specifically used as an example for explanation. The maximum surface size of the unidirectional veneer is preferably 3000×500 mm, and any size can be obtained by cutting within this size range. The surface density of the unidirectional veneer is preferably 20-200 g / m 2 , more preferably 70 to 200 g / m 2 , more preferably 70 to 180 g / m 2 , more preferably 70 to 150 g / m 2 , more preferably 80 to 120 g / m 2 , more preferably 90 to 110 g / m 2 , most preferably 100~110g / m 2 .

[0200] The unidirectional veneer is chemically modified to obtain the unidirectional veneer with some substances removed; the pH value of the chemically modified modification liquid is preferably 12-14; the chemically modified modification liquid preferably comprises an alkaline substance, a sulfonating agent and water; the alkaline substance is an alkaline substance well known to those skilled in the art and is not particularly limited. In the present invention, it preferably comprises but is not limited to one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate and potassium bicarbonate; the concentration of the alkaline substance in the modification liquid is preferably 0.01-5 kg / L, more preferably 0.05-3 kg / L, and even more preferably 0.1-2 kg / L; in some embodiments provided by the present invention, the concentration of the alkaline substance in the modification liquid is specifically 0.1 kg / L, 0.05 kg / L or 0.145 kg / L. L; the sulfonating agent is a sulfonating agent well known to those skilled in the art and is not particularly limited. In the present invention, it preferably includes but is not limited to one or more of sulfite, chlorosulfonic acid, hydroxymethylsulfonate, sulfuryl chloride and aminosulfonic acid; the sulfite is preferably sodium sulfite; the concentration of the sulfonating agent in the modifying liquid is preferably 0.01 to 5 kg / L, more preferably 0.01 to 3 kg / L, and even more preferably 0.01 to 1 kg / L; in some embodiments provided by the present invention, the concentration of the sulfonating agent in the modifying liquid is specifically 0.05 kg / L, 0.075 kg / L or 0.072 kg / L; the concentration of the sulfonating agent in the modifying liquid can be increased accordingly as the volume of the reaction solution increases, thereby compensating for the reduced mass transfer caused by the increase in the scale of the chemical reaction. The volume of the modified liquid can be any volume, depending on the production requirements and the specifications of the reactor equipment, including but not limited to 500mL, 2L, 4L, 20L, 100L, 500L, 1000L, 2000L, 5000L, 8000L, 10000L, etc.; the material ratio of the unidirectional veneer to the chemically modified modified liquid is preferably 4.6 to 184cm 3: 1L. The higher the material ratio, the higher the single reaction output, so it is generally necessary to maximize the material ratio of the reaction. However, the difficulty of mass transfer and the problem of excessive material accumulation in the reactor must also be considered. During the reaction, the alkaline substance will react with the lignin, hemicellulose, and cellulose in the unidirectional veneer. For example, if the alkaline substance is sodium hydroxide and the sulfonating agent is sodium sulfite, hemicellulose may react with sodium hydroxide to form sodium hemicellulose (as shown in Reaction Equation 1), and lignin may react with sodium hydroxide and sodium sulfite to form sodium lignin sulfonate (as shown in Reaction Equations 2 and 3). The byproducts of these reactions will separate from the unidirectional veneer structure and dissolve or suspend in the reaction solution. If the material ratio is too high, the reaction mass transfer efficiency is reduced, and the reaction byproducts are difficult to evenly disperse in the system. This will lead to a decrease in the reaction rate in local areas, resulting in a decrease in the uniformity of the properties of the unidirectional veneer after the reaction, affecting the stability of subsequent processes and the performance of the final product. Moreover, the problem of excessive material accumulation in the reactor will increase the friction between the unidirectional veneer and the internal structure of the reactor during the reaction, causing damage to the unidirectional veneer.

[0201] For small-scale reactions below 5L, the mass transfer and heat transfer in the system are relatively easy, and the number of one-way veneers is relatively small, so the whole veneer can be curled and attached to the wall of the reaction device. For reactions above 5L, due to the large scale of the reaction, the mass transfer and heat transfer rate in the system is reduced, and the number of one-way veneers is large, so the one-way veneer needs to be pre-layered and placed in the reactor. At the same time. The need to increase pre-layering can maximize the use of the internal space of the reactor and evenly arrange the one-way veneer throughout the reactor. In addition, through this partitioning, the one-way veneer in a single area can also be controlled to a certain number, reducing the damage to the one-way veneer caused by mutual friction and improving the mass transfer effect. The one-way veneer is preferably placed in a material frame for chemical modification; the material frame includes a frame, a partition and a frame cover; the partition is arranged in the frame; the side walls of the frame, the bottom of the frame, the partition and the frame cover are all provided with holes. In a specific embodiment provided by the present invention, the material frame is a cylindrical material frame; the number of the partitions is multiple; the multiple partitions are arranged in a concentric circle manner in the frame, and can be arranged along the same interval or along different intervals. In a specific embodiment provided by the present invention, the material frame is a rectangular material frame; the number of the partitions is multiple; the multiple partitions are arranged in parallel in the material frame, and can be arranged along the same interval or along different intervals. In the present invention, the one-way veneer can be pre-layered using upper and lower stacked material frames, see Figures 3 and 4. Figure 3 is a structural schematic diagram of a material frame for a vertical reactor, and Figure 4 is a schematic diagram of the placement of the one-way veneer in a vertical reactor, where 1 is the one-way veneer, 3 is the vertical reactor, and the main structure of the material frame is composed of a mesh plate with a certain aperture. The diameter of the hole should not be too small, which will affect the mass transfer effect, nor should it be too large, which will cause scratches on the veneer and reduce the structural strength. Generally, the diameter of the hole ranges from 3 to 5 mm, and the overall hole density is 4×10 5 ~3.5×10 5 pcs / m 3 , depending on the actual working conditions and equipment conditions. The thickness of the corresponding mesh plate must meet the requirement that the frame itself can maintain structural stability after loading the material. Generally, a 1 to 5 mm thick plate is selected according to the size of the material frame. The single-layer height is mainly determined by the width of the processed veneer, generally between 10 and 30 cm. The outermost radius and the innermost radius of the material frame are determined by the specific reactor structure and the amount of material. The intervals in the frame are not equidistant. Generally, the distance increases from the inside to the outside. The specific increase depends on the thickness and quantity of the veneer. The basic standard of this design is that it is convenient to operate when loading the veneer and will not damage the veneer. Figure 5 is a structural schematic diagram of the material frame for the horizontal reactor provided by the present invention. The overall appearance size of the material frame is determined by the structure of the horizontal reactor, the single-layer height is determined by the material width, and the thickness is determined by the material loading amount and the size of the material frame. The material frame needs to be designed as a porous structure. The diameter of the holes is generally in the range of 3 to 5 mm, and the overall hole density is 6.8×105 ~5.0×10 5 pcs / m 3 . The internal partition adopts a perforated plate with a thickness of 2mm. The partition distance should be equidistant, and the distance value is 10 to 50mm higher than the width of the veneer. Allow the substance to migrate freely in and out of the material frame, and the size of the hole should be as large as possible, so that the unidirectional veneer can be effectively layered without affecting mass transfer. The material frame needs to be designed to be close to the inner diameter of the reactor, so that the stacked multi-layer material frame can maximize the use of the space in the reactor. The material of the material frame needs to be alkali-resistant and temperature-resistant. Figure 6 is a schematic diagram of the placement of unidirectional veneer in a horizontal reactor, where 1 is unidirectional veneer and 2 is a horizontal reactor.

[0202] The reactor can be vertical or horizontal, and any heating method can be used, as long as the temperature accuracy within the system can be controlled within ±10°C. For large-volume reactors, additional stirring, solution reflux, overall reactor rotation, and external circulation pumps can be used to improve mass transfer. In the present invention, there are two options for the reaction temperature and pressure of the chemical modification: one is to heat to the boiling state of water at normal pressure, but this method requires an additional condensation reflux module, which increases the reaction energy consumption a lot. In addition, the reaction time at normal pressure, that is, the residence time at the target temperature / pressure, is 24 to 72 hours to ensure that the reaction is complete. In some embodiments provided by the present invention, the reaction time at normal pressure can be specifically 48 hours. Another option is to heat to a temperature exceeding the boiling point of water in a closed high-pressure system, that is, the target temperature is preferably 100 to 150°C, more preferably 110 to 150°C, more preferably 120 to 130°C, and most preferably 125°C, forming the entire system into a high-pressure system, so that there is no need to add a condensation reflux module, and the reaction time, that is, the residence time, can be reduced to 1 to 12 hours to complete the reaction, more preferably 3 to 10 hours, more preferably 4 to 8 hours, and most preferably 5 to 8 hours, which can greatly reduce the energy consumption of the reaction and reduce the process cost of the chemical reaction. In addition, the pumping capacity of the material pump is 1.4 to 3.5 t / h. The optimal reaction temperature depends on the wood species and the scale of the reactor. Different wood species have slightly different temperature windows due to different chemical compositions. Generally, the larger the scale of the reactor, the higher the reaction temperature is to compensate for the reduction in mass transfer and heat transfer. Generally, the higher the reaction temperature, the faster the reaction rate. However, since cellulose will gradually hydrolyze starting at 150°C, and the mechanical properties of cellulose are relatively high and need to be retained as much as possible, the reaction temperature needs to be set below 150°C. In some embodiments provided by the present invention, the temperature of the chemical modification in the closed high-pressure system, that is, the target temperature, is specifically 125°C, 116°C or 130°C; in some embodiments provided by the present invention, the target time of the chemical modification in the closed high-pressure system is specifically 6h, 8h or 6.5h; when the chemical modification is carried out in a closed high-pressure system, the pressure of the chemical modification is preferably 0.07~1.9MPa; the present invention has no special restrictions on the heating rate of the chemical modification. The specific chemical modification can be carried out under normal pressure or in a closed high-pressure system at a heating rate of 0.2~5°C / min, more preferably 0.5~5°C / min. In some embodiments provided by the present invention, the heating rate can be specifically 3°C / min, 2.5°C / min, 5°C / min, 2°C / min, 0.5°C / min or 0.2°C / min; when the temperature of the system reaches and stabilizes at the target temperature, the reaction in the closed high-pressure system needs to stay at the target temperature for 1 to 12 hours or under normal pressure conditions needs to stay at the target temperature for 24 to 72 hours, and then start to cool down.Because the modified unidirectional veneer reforms its intermolecular hydrogen bonds and begins crystallization during the cooling process, the cooling method significantly impacts the final performance. If the cooling rate is too rapid, the molecular chains of the unidirectional veneer, which has been partially degraded, will be prematurely fixed, intermolecular forces will not be fully established, resulting in low crystallinity and larger crystal particles, all of which will negatively impact performance. Therefore, in the present invention, after the chemical modification is completed, the reaction solution is preferably subjected to heat exchange with an external environment at room temperature to slowly cool it down. This cooling method can promote the establishment of intermolecular forces and simultaneously produce crystals with high crystallinity and larger grain size. Specifically, the cooling method includes one or more of water cooling, air cooling, and air cooling. More specifically, the cooling method includes indirect water cooling, indirect air cooling, or direct water cooling. The cooling rate is preferably 0.2-10°C / min, more preferably 1-10°C / min. In some embodiments provided herein, the cooling rate is specifically 0.2°C / min, 1°C / min, 0.5°C / min, 2°C / min, or 3°C / min.

[0203] After cooling to operating temperature (e.g., 60°C), the partially debonded veneer is preferably washed and dried. Specifically, the reactor is opened to remove the partially debonded veneer, or the material frame containing the partially debonded veneer is removed. The obtained material is then placed in water for cleaning, or the material frame containing the material is placed in water for cleaning. Cleaning removes residual chemicals on the surface and simultaneously reacts sodium cellulose that may have formed during the reaction back into cellulose, thereby maintaining the natural chemical composition of the wood. Multiple rounds of cleaning can be performed depending on the material. After cleaning, the material is dried to obtain a unidirectional veneer with some substances removed. The material can be dried naturally or placed in an oven for accelerated drying. The mass of the unidirectional veneer with some substances removed is reduced by 10% to 60% compared to the unidirectional veneer, and further reduced by 35% to 55%. In some embodiments provided by the present invention, the mass of the unidirectional veneer with some substances removed is specifically reduced by 50%, 42%, 46.8%, 49.1%, 49% or 48.2% compared to the unidirectional veneer.

[0204] During the chemical modification process, the mass of unidirectional veneer decreases by 10% to 60%, creating numerous voids in its microstructure. These voids impart excellent plastic deformation to the depleted veneer, allowing it to be easily compressed to a smaller size under external forces. This decrease in mass is also due to the significant removal of lignin and hemicellulose from the veneer, resulting in an increase in the proportion of cellulose in the overall composition. Since cellulose possesses the best mechanical properties of the three main components of veneer, this adjustment in proportion offers potential for material enhancement. Unmodified wood has relatively poor plastic deformation capacity. Significant plastic deformation of unmodified wood generally requires 2 to 24 hours of steam heating and humidification to achieve sufficient softening. Shrinkage densification is a critical process, requiring the material to achieve volume compression in a short period of time, requiring excellent plastic deformation capacity, which is not readily apparent in unmodified wood. Furthermore, the chemically treated material must maintain its morphology intact and flat, requiring controlled reaction progress during the chemical reaction. If the reaction is excessive, the veneer will form a lot of wrinkles and cannot be leveled; if the reaction is insufficient, the veneer will be compressed to a low degree and the mechanical properties of the densified material will be poor.

[0205] In the present invention, after chemical modification of the unidirectional veneer, the removal ratio of lignin is 20% to 80%, and the removal ratio of hemicellulose is 30% to 80%. Specifically, within the temperature and time range of the chemical modification provided by the present invention, the removal ratios of hemicellulose and lignin are roughly positively correlated with the temperature and time.

[0206] The partially dematerialized unidirectional veneer is subjected to a shrinkage treatment in at least one direction; this shrinkage, through force decomposition, includes transverse shrinkage and thickness shrinkage. Transverse shrinkage and thickness shrinkage refer to shrinkage in both the transverse direction and the thickness direction perpendicular to the fiber direction of the unidirectional wood fiber paper, thereby producing a densification effect. The number of shrinkage treatments can be selected based on the direction of the force, as long as the force decomposition can actually achieve transverse (horizontal) and vertical (thickness) shrinkage.

[0207] In a specific embodiment of the present invention, the shrinkage process includes both transverse shrinkage and thickness shrinkage, i.e., bidirectional shrinkage; the forces of the transverse shrinkage process and the thickness shrinkage process intersect. Bidirectional shrinkage of unidirectional wood fiber paper can be achieved by separate devices, or by a single device simultaneously or alternately shrinking in both directions.

[0208] When the thickness of the raw veneer being treated is less than 0.8mm, transverse shrinkage is necessary. Within this thinner thickness range, the cellulose density and the distribution of lignin and hemicellulose in the transverse direction at any given location in unidirectional veneer are uneven, whereas the distribution of the reaction medium during chemical or biological treatment is relatively more uniform. If there is less cellulose in a certain transverse area and more lignin and hemicellulose are removed, chemical modification will inevitably cause a significant loss of connecting substances in some areas, causing the cellulose structure in this area to fall apart. Unidirectional shrinkage in the thickness direction can easily cause cracks in this area due to the lack of the necessary transverse connecting force.

[0209] According to the present invention, the transverse shrinkage treatment is preferably to apply external mechanical force and / or dehydration spontaneous shrinkage in the transverse direction; the application of external mechanical force in the transverse direction intersects with the direction of extension of the wood fibers and / or fiber bundles of the unidirectional veneer from which part of the material has been removed.

[0210] Among them, the method of applying external mechanical force in the transverse direction is a method well known to those skilled in the art, and there is no special limitation. Basically, any method can be applied as long as the parameters such as pressure meet the process requirements. For example, a membrane material that can produce transverse shrinkage is attached to the surface of a one-way veneer with some substances removed and pressure is applied, and then the membrane material is removed; when the transverse shrinkage of the membrane material is controlled, the friction between the membrane and the surface of the one-way veneer with some substances removed will drive the transverse shrinkage of the one-way veneer with some substances removed; in this process, the tension of the membrane material affects the degree of transverse shrinkage, and it is specifically preferred to control the tension of the membrane material to achieve an equivalent transverse shrinkage pressure of 0.001 to 1.5 MPa, more preferably 0.01 to 1.5 MPa; optionally, the tension of the membrane material is controlled to achieve an equivalent transverse shrinkage pressure of 0.001 MPa, 0.002 MPa, 0.005 MPa, 0.01 MPa, 0.05 MPa, 0.08 MPa, 0.1 MPa, 0.2 MPa, 0.5 MPa, 0.8MPa, 1.0MPa, 1.2MPa, 1.4MPa, 1.5MPa or a range between any two of the above values; at the same time, the friction force exerted on the surface of the one-way veneer with some substances removed away from the membrane material will also affect the lateral shrinkage of the one-way veneer with some substances removed. Therefore, the lower the roughness of the contact surface of the one-way veneer with some substances removed away from the membrane material, the better. Specifically, it is preferred to contact with a surface with a surface roughness less than or equal to Ra6.3. Optionally, the roughness of the contact surface is Ra0.0063, Ra0.025, Ra0.05, Ra0.1, Ra0.2, Ra0.4, Ra0.8, Ra1.6, Ra3.2 or Ra6.3; in addition, the external force can also be achieved by mechanical force, such as roller rubbing, direct pressure and the like. The pressure of the external mechanical force applied in the lateral direction is preferably 0.001-1.5 MPa, more preferably 0.01-1.5 MPa; optionally, the pressure of the external mechanical force applied in the lateral direction is 0.001 MPa, 0.002 MPa, 0.005 MPa, 0.01 MPa, 0.05 MPa, 0.08 MPa, 0.1 MPa, 0.2 MPa, 0.5 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa, 1.4 MPa, 1.5 MPa or a range between any two of the above values.

[0211] Transverse shrinkage can also be achieved through spontaneous forces within the partially dehydrated unidirectional veneer, also known as dehydration-induced spontaneous shrinkage. Thinner wood paper undergoes spontaneous transverse shrinkage during dehydration, as shown in Figure 7, which illustrates the collapse and shrinkage of the lumen of wood fiber paper during spontaneous transverse shrinkage. This is due to the removal of some of the lignin and hemicellulose supporting the lumen from the chemically modified, dehydrated unidirectional veneer, resulting in a large number of voids in the microstructure that are easily filled with water. Furthermore, since cellulose is the dominant component in the continuous veneer, its chemical structure contains numerous hydroxyl groups, making it hydrophilic, thus facilitating the entry of water molecules into the microstructure voids. During dehydration, water is removed from these voids, which disappear due to capillary forces. The distance between the cellulose microfibrils is rapidly shortened, and hydrogen bonds between the microfibrils are reestablished. This structural contraction and chemical bond formation produce the effect of spontaneous transverse shrinkage. Macroscopically, the wood fiber paper develops wrinkles, with a reduced transverse width and increased density.

[0212] In another embodiment of the present invention, the transverse external mechanical force is specifically applied by applying a negative pressure to the unidirectional veneer from which some material has been removed; the intensity of the negative pressure is less than or equal to one atmosphere. Under the action of the negative pressure, the material shrinks and deforms in the transverse direction, achieving a transverse densification effect. During this process, since the material is subjected to negative pressure in all directions, shrinkage deformation also occurs in the thickness direction.

[0213] In the present invention, the transverse shrinkage can be carried out at room temperature or at high temperature. The specific temperature of the transverse shrinkage treatment is preferably 15°C to 150°C, more preferably 25°C to 130°C; optionally, the temperature of the transverse shrinkage treatment is 20°C, 25°C, 30°C, 50°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or a range between any two of the above values; the time of the transverse shrinkage treatment is preferably 1s to 4min; optionally, the time of the transverse shrinkage treatment is 1s, 10s, 30s, 1min, 2min, 3min, 4min or a range between any two of the above values; after the transverse shrinkage treatment, the shrinkage rate is preferably 2% to 40% compared with the unidirectional veneer raw material; optionally, the shrinkage rate of the transverse shrinkage is 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40% or a range between any two of the above values.

[0214] In a specific embodiment provided by the present invention, the lateral shrinkage treatment is specifically spontaneous lateral shrinkage, specifically: the unidirectional veneer with some substances removed is dried in a wet state to spontaneously achieve a spontaneous lateral shrinkage effect. After one or more spontaneous lateral shrinkages, the unidirectional veneer with some substances removed is filled with water again, and the lateral shrinkage perpendicular to the fiber direction is obvious, and the lateral tensile performance is improved.

[0215] Normal wood boards can be densified by hot pressing after being softened with steam, but this densification process requires applying relatively large pressure to the wood boards for a long time. For the veneer in the present invention, the veneer is relatively thin, and the veneer is prone to cracking when directly hot pressed, and the densification effect obtained is also limited. After chemical modification, the weight of the veneer decreases by 10% to 60%, and further decreases by 35% to 55%, and a large number of cavities are formed inside. Moreover, since the chemical cost removed is mainly hydrophobic lignin, the hydrophilicity of the modified unidirectional veneer with some substances removed is significantly improved, the internal cavities will be quickly filled with water molecules, the overall structure becomes soft, and it is easy to densify through natural water loss. The densification process has low energy consumption and short time, which is conducive to mass production.

[0216] This spontaneous lateral shrinkage process can even completely eliminate the need for external mechanical forces. Modified unidirectional veneer with some material removed can also achieve spontaneous lateral shrinkage through a microstructural hydration-dehydration process, also known as wood keratinization. This process occurs because the chemically modified wood microstructure contains numerous voids, which are easily filled with water. Furthermore, since cellulose is the dominant component in the continuous veneer, its chemical structure contains numerous hydroxyl groups, making it a hydrophilic material, which also facilitates the entry of water molecules into the microstructural voids. During this hydration process, the voids between the cellulose microfibrils expand significantly. During the subsequent drying process, water is removed from these voids, which disappear due to capillary forces. The distance between the cellulose microfibrils is rapidly shortened, and hydrogen bonds between the microfibrils are re-established. This structural contraction and chemical bonding results in spontaneous lateral shrinkage, which is particularly pronounced in the lateral direction of the veneer, perpendicular to the fiber axis, where the lateral shrinkage and densification effect is most pronounced.

[0217] According to the present invention, the spontaneous transverse shrinkage process does not require the use of any external pressure-applying equipment, and the densification effect is achieved entirely through the chemical and physical changes that spontaneously occur during the drying process of the modified unidirectional veneer with some substances removed. Specifically, the spontaneous transverse shrinkage is to dry the unidirectional veneer with some substances removed in a wet state, that is, the spontaneous transverse shrinkage includes water filling treatment and dehydration treatment; the water filling treatment makes the unidirectional veneer with some substances removed in a wet state; the water filling treatment preferably makes the moisture content 60 to 120 wt%; optionally, the water filling treatment makes the moisture content 60 wt%, 80 wt%, 100 wt%, 120 wt% or a range between any two of the above values; the dehydration treatment is natural drying and / or heating drying; when the dehydration treatment is performed by natural drying in the environment During the natural drying process, the ambient humidity is preferably less than 50% RH; otherwise, the structure of the partially dematerialized unidirectional veneer will retain a significant amount of moisture after drying. Using heat drying for dehydration can shorten the dehydration process, thereby shortening the process time. Furthermore, the partially dematerialized unidirectional veneer can be dried to a moisture content of less than 10 wt%, resulting in improved densification. The dehydration process preferably achieves a moisture content of 2 to 20 wt%. The present invention does not have specific requirements for the drying temperature and time during the spontaneous transverse shrinkage process, as long as the target moisture content is ultimately achieved. The spontaneous transverse shrinkage process can be performed once or repeated 2 to 10 times, more preferably 2 to 6 times. Repeated spontaneous transverse shrinkage involves refilling the partially dematerialized unidirectional veneer with water after one round of spontaneous transverse shrinkage, and then repeating the same spontaneous transverse shrinkage process. Repeated spontaneous transverse shrinkage can achieve improved densification of the material because the spontaneous transverse shrinkage process is uncontrollable, so the intermolecular forces in the partially dematerialized unidirectional veneer structure may not be fully established after a single round of spontaneous transverse shrinkage. After one or more spontaneous transverse shrinkages, when the unidirectional veneer with some substances removed is filled with water again, the transverse width of the unidirectional veneer perpendicular to the fiber direction will shrink to a certain extent, and the transverse fiber bonding force will become stronger, indicating that a partial irreversible transverse shrinkage densification effect has occurred.

[0218] [Corrected 29.04.2025 in accordance with Rule 91] According to the present invention, the thickness reduction treatment involves applying mechanical pressure in the thickness direction. Specifically, any method capable of applying external mechanical pressure in the thickness direction of the chemically treated veneer to cause the veneer to shrink in that direction, and any method that satisfies the process requirements, such as pressure, is generally applicable. Applicable equipment includes, but is not limited to, flat presses, blister presses, hot presses, cold presses, continuous flat presses, and continuous belt presses. By applying external mechanical pressure, the veneer becomes flatter and thinner in the thickness direction due to the force, squeezing out excess moisture and producing a smooth, dense veneer with a moisture content below 30%. Furthermore, the thickness reduction treatment can be performed on a single sheet or in a stack. This process is more efficient when performed on multiple sheets. Depending on the process, the number of sheets stacked is generally preferably 2 to 20, and more preferably 3 to 20. The pressure of the thickness shrinkage treatment is preferably 0.01 to 80 MPa; under the condition of stacking, the pressure of the thickness shrinkage is preferably 0.1 to 60 MPa, more preferably 3 to 10 MPa; optionally, the pressure of the thickness shrinkage treatment is 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 8 MPa, 10 MPa, 12 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60 MPa or a range between any two of the above values; according to the calculation formula of pressure and area, under the condition of a certain required pressure, the more stacks of one-way veneer with some substances removed, the greater the gauge pressure of the press. If a press is used, it should also be considered that the one-way veneer with some substances removed will be easily broken by the instantaneous high pressure, so the pressure needs to be slowly increased to the target pressure. The thickness shrinkage treatment can be performed at room temperature or at an elevated temperature. The specific process temperature range is preferably 15-150°C, more preferably 25-130°C. Optionally, the thickness shrinkage treatment temperature is 15°C, 25°C, 35°C, 50°C, 80°C, 100°C, 120°C, 130°C, 150°C, or a range between any two of the above values. To reduce process costs, the thickness shrinkage treatment time is preferably 1s to 4min. Optionally, the thickness shrinkage treatment time is 0.1min, 0.5min, 1min, 2min, 3min, 4min, or a range between any two of the above values. Performing the treatment at an elevated temperature shortens the process time, but also increases equipment costs.

[0219] [Corrected 29.04.2025 according to Rule 91] In a specific embodiment provided by the present invention, the thickness shrinkage treatment is carried out by roller pressing; specifically, a pair of counter-rotating hot rolling rollers are used for continuous hot pressing, as shown in Figure 8, which is a schematic diagram of continuous hot pressing processing with hot rolling rollers, wherein 6 is a unidirectional veneer with some materials removed, and 7 is a pair of counter-rotating hot rolling rollers; the force direction of the unidirectional wood fiber paper is not determined during rolling, but is decomposed into a transverse or thickness direction after the force is decomposed.

[0220] In a specific embodiment provided by the present invention, the thickness shrinkage treatment is performed using a continuous flat press for continuous hot pressing, as shown in Figure 9, which is a schematic diagram of continuous hot pressing of a continuous flat press, wherein 6 is a unidirectional veneer with some material removed, 8 is a flat press, and 9 is a driving roller.

[0221] In a specific embodiment provided by the present invention, the thickness shrinkage treatment is performed using a belt press for continuous hot pressing, as shown in Figure 10, which is a schematic diagram of continuous hot pressing using a belt press, wherein 6 is a unidirectional veneer with some material removed, and 10 is a belt press.

[0222] In the present invention, the lateral shrinkage treatment and thickness shrinkage treatment will result in different process times and process times depending on the different processes used. It can be multiple times or a single time, can be performed alternately or simultaneously, and ultimately the process operation time and operation times are designed to achieve the target parameters.

[0223] The effect of the biaxial shrinkage treatment is mainly reflected in the decrease in moisture content and thickness of the unidirectional veneer from which some substances have been removed. After the biaxial shrinkage treatment, the thickness of the unidirectional veneer from which some substances have been removed becomes thinner; the thickness of the veneer treated with biaxial shrinkage is preferably 15% to 80% of the thickness of the unidirectional veneer; the moisture content of the veneer that has been cleaned and soaked after chemical modification is preferably reduced to below 30% after the biaxial shrinkage treatment, and more preferably reduced to 20% to 30%.

[0224] The present invention adopts a bidirectional shrinkage process to achieve shrinkage and densification of wood fiber paper in thickness and transverse (width) directions through external or spontaneous physical effects. Transverse shrinkage can increase the transverse bonding strength and compactness of wood fiber paper, avoiding transverse cracking of wood fiber paper; shrinkage in the thickness direction can increase the compactness of wood fiber paper and improve the performance of wood fiber paper; through simultaneous or sequential shrinkage in two directions, a significant improvement in the performance of wood fiber paper can be achieved. Further combined with temperature control, the wood fiber paper can be rapidly shrunk and densified while being rapidly dehydrated, avoiding the occurrence of wrinkles and transverse cracks. The bidirectional shrinkage process proposed by the present invention can generally be completed within 5 minutes, with high process efficiency.

[0225] In a specific embodiment provided by the present invention, the thickness shrinkage includes hot pressing under negative pressure conditions; by performing hot pressing under negative pressure conditions, thickness shrinkage and flattening and dehydration of unidirectional wood fiber paper can be achieved simultaneously; the pressure of the hot pressing treatment is preferably 0.1-60 MPa, more preferably 0.1-15 MPa; optionally, the pressure of the hot pressing treatment is 0.01 MPa, 0.05 MPa, 0.1 MPa, 0.5 MPa, 1 MPa, 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60 MPa or a range between any two of the above values; the flow rate under the negative pressure condition is preferably 50-500 L / min; optionally, the The flow rate under the negative pressure condition is 50 L / min, 80 L / min, 100 L / min, 150 L / min, 200 L / min, 250 L / min, 300 L / min, or a range between any two of the above values; the temperature of the hot pressing treatment is preferably 50°C to 150°C; optionally, the temperature of the hot pressing treatment is 50°C, 80°C, 100°C, 120°C, 130°C, 150°C, or a range between any two of the above values; the time of the hot pressing treatment is preferably 0.5 to 20 minutes; optionally, the time of the hot pressing treatment is 0.5 minutes, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 8 minutes, 10 minutes, 12 minutes, 15 minutes, 18 minutes, 20 minutes, or a range between any two of the above values. If the thickness shrinkage treatment is achieved only by hot pressing under negative pressure conditions, the time required is longer due to the lower pressure.

[0226] In the present invention, splicing is performed before or after the bidirectional shrinkage treatment according to the requirements for the size of the unidirectional wood fiber paper. The flatness of the wood fiber paper after the bidirectional shrinkage treatment is improved and the moisture content is reduced. However, due to the size limitations of the veneer raw materials, the veneer used for chemical treatment is discontinuous. In order to meet the requirements of use, the wood fiber paper needs to be connected to make different sizes. When used, it can also be cut according to actual needs and then used to prepare products of different sizes. The whole size can theoretically be spliced ​​to an infinite width and length. The length of the unidirectional wood fiber paper used for splicing is preferably 0.1 to 5m, and the width is preferably 0.01 to 1m. In the present invention, the splicing of unidirectional wood fiber paper can be between two sheets or between multiple sheets, mainly ensuring that the size of the spliced ​​wood fiber paper meets the requirements. The splicing specifically involves marking the splicing outline on the unidirectional veneer with some substances removed or the wood fiber paper after shrinkage treatment, and then splicing the corresponding parts. More specifically, before splicing, the splicing parts are first designed on the unidirectional veneer with some substances removed or the wood fiber paper after shrinkage treatment to be spliced, mainly by marking their respective splicing outlines. Then, some splicing techniques are used to connect the multiple scattered unidirectional veneer with some substances removed or the wood fiber paper after shrinkage treatment to form a large-sized unidirectional wood fiber paper. After splicing, the thickness of the wood fiber paper at the splicing part is about 0.08 to 0.12 mm.

[0227] In the present invention, the unidirectional wood fiber paper can be spliced ​​in a partial area overlap manner, as shown in the upper figure in FIG11 , or can be spliced ​​in a non-area overlap manner, as shown in the lower figure in FIG11 .

[0228] In the present invention, the splicing process may be one or more of glue splicing, glue line seam splicing, wet extrusion splicing and film splicing.

[0229] In a specific embodiment provided by the present invention, glue splicing can be used. Specifically, glue is applied to the overlapping portion of one of the debonded unidirectional veneer or shrunk wood fiber paper sheets to be spliced, and then the overlapping portion of the other debonded unidirectional veneer or shrunk wood fiber paper is pressed against it. In this way, the overlapping portions of the two debonded unidirectional veneer or shrunk wood fiber paper sheets are spliced ​​together after the glue cures, thereby increasing the size of the continuous unidirectional wood fiber paper. Because the overlapping portion is the thickness of the two debonded unidirectional veneer or shrunk wood fiber paper sheets and is thicker than other portions, pressure can be applied to the overlapping portion to reduce its thickness and improve the thickness uniformity of the entire wood fiber paper sheet.

[0230] In a specific embodiment provided by the present invention, glue line splicing can be used. Specifically, the contours of the debonded unidirectional veneer or shrunken wood fiber paper to be spliced ​​are designed to fit perfectly together. The contours of the two debonded unidirectional veneers or shrunken wood fiber papers to be spliced ​​are then aligned together. Glue line is then moved back and forth along the two aligned contours. The glue line adheres to the surfaces of the unidirectional wood fiber papers, and the glue line is continuous, thereby fixing the positions of the two debonded unidirectional veneers or shrunken wood fiber papers, thereby achieving the purpose of splicing the wood fiber papers. To improve the strength of the splicing, on the one hand, the number of glue lines connecting the two debonded unidirectional veneers or shrunken wood fiber papers can be increased during the splicing process. On the other hand, the two sides of the debonded unidirectional veneers or shrunken wood fiber papers can be spliced ​​together. The advantage of glue seams is that there is no overlapping of two unidirectional wood fiber papers during seams. Instead, the size of the wood fiber paper can be increased simply by fitting the contours, so that the thickness of the wood fiber paper at the seams remains basically consistent with that at other parts.

[0231] In a specific embodiment provided by the present invention, wet extrusion splicing can be adopted. Specifically: the method of wet extrusion splicing is similar to glue splicing, but glue is not used, and only water is used. Water is applied to the overlapping parts of the one-way veneer or the wood fiber paper after shrinkage treatment, so that they are wet, and then the overlapping parts are stacked together, and a large plane pressure (≥5MPa) is applied thereto, supplemented by heating and drying, until the one-way wood fiber paper is dry and adhered together to achieve the purpose of splicing. The one-way veneer or the wood fiber paper after shrinkage treatment that has been partially removed in a wet state has a soft texture. Under the action of large pressure, the textures of the two pieces of one-way veneer or the wood fiber paper after shrinkage treatment that have been partially removed are tightly pressed together, and they adhere to each other to the point of hydrogen bonding. This pressure is maintained until the one-way wood fiber paper is dry, thereby fixing this bonding force and completing the splicing. The advantage of wet extrusion splicing is that it well maintains the pure natural properties of wood fiber paper. It can easily produce wood fiber paper of any size and width. After the subsequent process of lamination / pre-preg, it can theoretically produce continuous prepregs of unlimited size.

[0232] In one specific embodiment of the present invention, a film-laminated splicing method can be employed. Specifically, a continuous adhesive film is selected based on the desired large size. Smaller unidirectional wood fiber papers are then pressed against the film. Through the film's connection, the smaller unidirectional wood fiber papers are spliced ​​together, achieving the goal of increasing the size. The type of adhesive film can be selected as needed; a thin layer of felt mixed with glue can also be used to create a homemade prepreg. The principle is to attach a film layer to connect the smaller unidirectional wood fiber papers. This method can theoretically produce continuous prepregs of unlimited size.

[0233] According to the present invention, if the thickness shrinkage treatment does not include the above-mentioned hot pressing treatment under negative pressure conditions, a flattening treatment is further performed after the shrinkage treatment to obtain unidirectional wood fiber paper.

[0234] The leveling treatment can make the unidirectional veneer after shrinkage treatment more efficient and rapid dehydration, and at the same time achieve relatively good flatness during the dehydration process to obtain unidirectional wood fiber paper; the effect of leveling is mainly reflected in quickly and efficiently improving the flatness of the unidirectional wood fiber paper and reducing the moisture content to obtain dry and flat unidirectional wood fiber paper.

[0235] According to the present invention, more specifically, the moisture content of the obtained unidirectional wood fiber paper can be made less than or equal to 10 wt % through the leveling treatment.

[0236] According to the present invention, exhaust channels are provided on the double contact surfaces or single contact surface of the unidirectional wood fiber paper during the leveling process. Specifically, it can be implemented using various types of equipment such as a heatable negative pressure membrane press, a vacuum hot press, etc., such as a vacuum hot press with multiple exhaust channels. The characteristic of the leveling process is that the processing process can be heated, and exhaust channels are directly provided on both sides or one side of the pressurized unidirectional wood fiber paper, so that water vapor can be discharged. Generally, the pressure in the leveling process will be significantly lower than the pressure used in thickness shrinkage, because if the pressure is too high, the discharge rate of water vapor will be reduced, which will reduce the leveling efficiency. When using the leveling process, the pressure is selected with the purpose of preventing the unidirectional wood fiber paper from generating wrinkles during the drying process. The pressure used in the leveling process is 0.01 to 2 MPa. Optionally, the pressure is 0.01 MPa, 0.05 MPa, 0.1 MPa, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, or any range between the above two values. The heating temperature is 40°C to 150°C. Optionally, the heating temperature is 40°C, 50°C, 70°C, 80°C, 100°C, 120°C, 150°C, or any range between the above two values. By properly setting the exhaust channel on the contact surface of the unidirectional wood fiber paper, leveling can be completed within 0.1 to 4 minutes. Optionally, the leveling time is 0.1 minute, 0.5 minute, 1 minute, 2 minutes, 3 minutes, 4 minutes, or any range between the above two values.

[0237] According to the present invention, the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer composited on the surface of the unidirectional wood fiber paper; the preparation method of the composite wood fiber paper includes: transferring a diluted second resin raw material to the surface of the unidirectional wood fiber paper, and curing to obtain the composite wood fiber paper; the second resin raw material is preferably one or more of a second resin monomer, a second resin prepolymer and a second resin; the solid content of the diluted second resin raw material is preferably 1% to 40%, more preferably 3% to 30%; by increasing the dilution ratio, a second resin layer with a very low surface density is obtained; in some embodiments provided by the present invention, the solid content of the diluted second resin raw material is specifically 11.7% or 6.8%; the transfer method is a method well known to those skilled in the art. The method can be carried out by dipping transfer, or by spraying or showering; after the diluted second resin raw material is transferred to the surface of the unidirectional wood fiber paper, the solvent evaporates to form a film of the second resin raw material, and then it is cured under its curing conditions to obtain a second resin layer; the second resin raw material can be a monomer small molecule, specifically a monomer small molecule of the above-mentioned thermosetting resin or a monomer small molecule of the above-mentioned thermoplastic resin; after being compounded on the surface of the unidirectional wood fiber paper, the monomer small molecule is cured under its curing conditions; the second resin can be the above-mentioned thermosetting resin or the above-mentioned thermoplastic resin, and the solvent used for dilution can be selected according to the type of the second resin. If it is water-soluble, the solvent used for dilution is water; the curing conditions are selected according to the type of raw materials.

[0238] In a specific embodiment provided by the present invention, the composite wood fiber paper is prepared by a rolling method: the diluted second resin raw material is evenly sprayed onto the surface of the unidirectional wood fiber paper, the unidirectional wood fiber paper is placed parallel and overlapped with each other according to the required width, and most of the solvent in the diluted second resin raw material is volatilized by drying in a drying oven at a certain temperature or airing, and then the hot pressing rollers are overheated at a certain temperature, and the hot pressing rollers are dried by heating and squeezing force to ensure surface flatness. After 2 to 3 rollings, a composite wood fiber paper containing a second resin layer is obtained. After adding the second resin layer, the surface density of the composite wood fiber paper is increased by 3 to 40 g / m2 compared to the unidirectional wood fiber paper. 2 .

[0239] According to the present invention, the composite wood fiber paper is a unidirectional wood fiber paper and a second resin layer and a fiber reinforcement layer are composited on the surface of the unidirectional wood fiber paper. Preferably, the two surfaces of the unidirectional wood fiber paper are sequentially attached with a second resin layer and a fiber reinforcement layer; the preparation method of the composite wood fiber paper includes: transferring the diluted second resin raw material to the surface of the unidirectional wood fiber paper, and then laminating the fiber reinforcement layer, and after curing, obtaining the composite wood fiber paper; the diluted second resin raw material is the same as described above and will not be repeated here; the material used for lamination is preferably a solid film material, which is bonded to the surface of the unidirectional wood fiber paper through the second resin raw material, thereby playing a cross-linking role on the unidirectional wood fiber paper. The material used for lamination needs to be a material with low surface density. Carbon fiber surface felt or glass fiber surface felt and other surface materials with low surface density and excellent mechanical properties can be selected.

[0240] In a specific embodiment provided by the present invention, the composite wood fiber paper is prepared by a rolling method: the diluted second resin raw material is evenly sprayed onto the surface of the unidirectional wood fiber paper, the unidirectional wood fiber paper is placed parallel and overlapped with each other according to the required width, the fiber reinforcement layer is coated by a coating process, and most of the solvent in the diluted second resin raw material is volatilized by drying in a drying oven at a certain temperature or airing. Then, the hot pressing rollers are heated and pressed at a certain temperature, and the hot pressing rollers are dried by heating and squeezing force to ensure surface flatness. After 2 to 3 rolling operations, a composite wood fiber paper comprising a second resin layer and a fiber reinforcement layer is obtained. After the second resin layer and the fiber reinforcement layer are composited, the surface density of the composite wood fiber paper is increased by 10 to 50 g / m2 compared to the unidirectional wood fiber paper. 2 .

[0241] See Figure 12, which is a physical picture of different composite wood fiber papers; see Figure 13, which is a schematic diagram of the structure of composite wood fiber paper; see Figure 14, which is a schematic diagram of unidirectional wood fiber paper spliced ​​through a coating layer.

[0242] Wood is a highly anisotropic material, with significantly better mechanical properties parallel to the fiber direction than perpendicular to the fiber direction. The cross-linking process is designed to enhance the mechanical properties perpendicular to the fiber direction, thereby improving the stability of subsequent processes and the mechanical properties of the resulting wood honeycomb. The method proposed in this invention uses a low-density resin layer and a coating layer to composite with unidirectional wood fiber paper. The second resin layer and fiber reinforcement layer connect the wood fibers, similar to cross-linking the wood fibers.

[0243] Core glue is applied to multiple sheets of wood fiber paper, which are then stacked in staggered layers and cured by hot pressing to obtain a honeycomb block. Specifically, core glue is applied to designated locations on the surfaces of the multiple sheets of wood fiber paper, which are then stacked. After stacking, the core glue is cured by hot pressing to bond the multiple sheets of wood fiber paper into a whole, thereby obtaining a honeycomb block. The honeycomb is able to form a pore structure by staggering and stretching the bonding areas of adjacent upper and lower papers. The effect of glued paper stacking is mainly reflected in the increase in overall thickness. The number of papers contained in a honeycomb block and the distance between the staggered core glues ultimately determine the pore size of the final honeycomb. See Figure 15, which is a schematic diagram of two gluing directions when the core strip glue is applied to wood fiber paper, wherein the left figure is the wood fiber paper before gluing, and the right figure is the wood fiber paper after gluing. The upper right figure is that the direction of the core strip glue is perpendicular to the main direction of the fiber, and the lower right figure is that the direction of the core strip glue is parallel to the main direction of the fiber; see Figure 16, which is a schematic diagram of the gluing position of the core strip glue provided by the present invention on the wood fiber paper, and the core strip glues on adjacent wood fiber papers are staggered.

[0244] In a specific embodiment provided by the present invention, the core strip glue coating process can be specifically (1) screen printing, (2) roller transfer or (3) flat plate transfer; the above process can transfer the core strip glue of a certain width and thickness to the wood fiber paper evenly according to a certain step distance, and has good parallelism, and the core strip glue has no extension and burrs; wherein the core strip glue can be one of the resins such as epoxy resin, acrylic resin, etc.

[0245] More specifically, the screen printing method involves selecting a screen with an appropriate mesh size based on the designed honeycomb cell dimensions, determining the depth of the adhesive strips, and designing the adhesive strip pitch so that the width meets the honeycomb cell dimensions. Wood fiber paper is cut to a predetermined length and width based on the designed honeycomb dimensions. The core adhesive strips are then transferred to the wood fiber paper using a screen printer by doctor blade coating. Multiple sheets of wood fiber paper are then interlaced and bonded together to form a honeycomb stack, with the adhesive strips of odd-numbered layers overlapping and the adhesive strips of even-numbered layers overlapping.

[0246] To be more specific, the roller transfer method is as follows: according to the designed honeycomb cell size, a suitable diameter of the plate roller is selected, and the pitch, width and depth of the plate roller groove are designed, the other smooth roller is immersed in the core strip glue, the core strip glue is brought to the groove roller by rotating the roller, and the resin on the surface of the groove roller is removed by a scraper, leaving only the core strip glue in the groove, and wood fiber paper of a certain length and width is passed through the gap between the groove roller and the other smooth roller, and the core strip glue in the groove roller is transferred to the surface of the wood fiber paper, and then multiple sheets of wood fiber paper coated with core strip glue are continuously staggered and bonded to obtain a honeycomb block; the glue strips of the odd-numbered layers of wood fiber paper overlap, and the glue strips of the even-numbered layers of wood fiber paper overlap.

[0247] More specifically, the flatbed transfer method involves cutting wood fiber paper to a specific length and width based on the designed honeycomb size. A transfer plane with multiple parallel rows of raised strips is designed based on the size of the wood fiber paper, with the width and pitch of the raised strips matching the designed honeycomb model. During glue application, the raised portions are brought into contact with the core glue liquid surface to a specific depth. A specific force is then applied to transfer the resin picked up by the raised portions to the wood fiber paper. This action is repeated multiple times, and multiple sheets of wood fiber paper are continuously interlaced and bonded together to form a honeycomb block. The glue strips of odd-numbered layers overlap, and the glue strips of even-numbered layers overlap.

[0248] According to the present invention, before stretching, ear straps are bonded to both ends of the honeycomb block, secured to a stretching device, and then stretched to form a whitewood honeycomb. This stretching can be performed directly to the target length or to 1 / 3 to 1 / 2 of the target length. This stretching forms a regular pore structure. Because the paper is only locally bonded in the previous process, the non-bonded areas can expand under the action of the stretching force, thus forming a honeycomb structure. See Figure 17, which is a schematic diagram of the whitewood honeycomb preparation process.

[0249] According to the present invention, a first resin is transferred to the surface of a white wood honeycomb and cured to form a wood honeycomb. The resin coating serves to define the honeycomb shape and to increase density, thereby improving mechanical properties. The raw material for the first resin can be a polymer prepolymer or a small monomer molecule, preferably one or more of epoxy resin, phenolic resin, unsaturated polyester resin, and furfuryl alcohol resin. The method for transferring the first resin is well known to those skilled in the art and is not particularly limited. The method can be selected based on the type of first resin. If the resin viscosity is relatively low, the first resin can be evenly applied to the honeycomb structure of the white wood honeycomb through repeated dip coating processes. If the resin viscosity is relatively high, the first resin can be sprayed, shower coated, or dip coated into the honeycomb through-holes of the white wood honeycomb. The white honeycomb is then stretched and extruded, and the first resin is evenly applied to the honeycomb structure.

[0250] In a specific embodiment provided by the present invention, the first resin is a low-viscosity resin, and the first resin is transferred to a white honeycomb multiple times and cured multiple times to obtain a wood honeycomb; the multiple curing and shaping are located between two transfers, and the curing and shaping is finally performed; the transfer method is selected from one or more of dip coating, flow coating and spraying; more specifically, the first resin is dipped, flow coated or sprayed onto the white honeycomb multiple times and cured multiple times (curing is performed before each dip coating, flow coating or spraying) to obtain a wood honeycomb.

[0251] In a specific embodiment of the present invention, the resin is a low-viscosity resin. Step S3) specifically comprises: transferring the white honeycomb to an oven to dry and remove moisture; then immersing the white honeycomb in a first resin for a predetermined period of time; lifting the honeycomb to drain excess first resin; and curing the honeycomb at the curing temperature of the first resin. After curing, the above-described dipping and curing process is repeated multiple times until the target density of the honeycomb is reached. This method is suitable for gluing low- to high-density honeycombs.

[0252] In a specific embodiment provided by the present invention, the first resin is a high-viscosity resin, and the resin is transferred to the white honeycomb in step S3) according to the following steps: the first resin is sprayed, flow-coated or dip-coated into the honeycomb through-holes of the white honeycomb, and then the first resin is evenly coated on the white honeycomb after stretching and extrusion.

[0253] In another specific embodiment provided by the present invention, the resin is a high-viscosity resin, and step S3) specifically comprises: uniformly transferring the first resin to the honeycomb through-hole walls of the white honeycomb stretched to 1 / 3 to 1 / 2 of the target length by any method such as spraying, flow coating, or dipping; then starting the stretching device in a return stroke until the honeycomb through-hole walls contact each other; applying a certain force to squeeze the two sides of the honeycomb block ear bands to squeeze out the excess first resin from the honeycomb cells; repeating the stretching, return stroke, and squeezing sequence 3 to 4 times to evenly apply a certain amount of resin to the honeycomb through-hole walls to achieve the target honeycomb density; then starting the stretching device again to slowly stretch the honeycomb block to a certain length to form a regular hexagonal internal cavity structure, and finally curing at the curing temperature of the first resin. This method is suitable for gluing low- and medium-density wood honeycombs.

[0254] See Figure 18, which is a schematic structural diagram of the wood honeycomb provided by the present invention, wherein 11 is a cellular structure; see Figure 19, which is a top view of the wood honeycomb provided by the present invention, wherein the units of the wood honeycomb are hexagonal; see Figure 20, which is a top view of the wood honeycomb provided by the present invention, wherein the units of the wood honeycomb are quadrilateral.

[0255] The wood fiber paper, the core material of the wood honeycomb provided by the present invention, is a natural and environmentally friendly material. In particular, the unidirectional wood fiber paper is entirely composed of wood, and the composite wood fiber paper is mostly composed of wood. The wood fiber paper has excellent mechanical properties in both the directions parallel to and perpendicular to the wood fibers. As a result, the obtained wood honeycomb has excellent mechanical properties, is lightweight, low-cost, and is environmentally friendly.

[0256] The present invention further provides a wood honeycomb component, which includes the above-mentioned wood honeycomb; see FIG21 , which is a schematic diagram of the sandwich structure of the wood honeycomb component provided by the present invention.

[0257] The present invention also provides a use of the above-mentioned wood honeycomb or the above-mentioned composite wood fiber paper in preparing one or more of building materials, furniture materials, sports equipment, stationary carriers, vehicles and aircraft.

[0258] In the present invention, unless otherwise specified, the pressure referred to refers to the pressure exerted on the unidirectional veneer and the unidirectional wood fiber paper.

[0259] In order to further illustrate the present invention, a wood honeycomb and a preparation method thereof provided by the present invention are described in detail below with reference to embodiments.

[0260] The reagents used in the following examples are all commercially available; the PU solution used in the examples: Shenzhen Yoshida Chemical F0409; epoxy resin: Yituo Composite Materials YTCC302; epoxy structural adhesive: Shanghai Haiying SK-2012; PO hot melt adhesive: Xingxia hot melt adhesive film XJO115; PA hot melt adhesive: Xingxia hot melt adhesive film XWA116; acrylic resin: 3M-AD118; phenolic resin: Sumitomo PR-43204.

[0261] Preparation of unidirectional wood fiber paper / composite wood fiber paper:

[0262] Example 1

[0263] 1) Chemical treatment

[0264] First, prepare the reaction solution with a total solution volume of 100L. The reactor is a vertical reactor (with an external circulation pump), and the material frame of the vertical reactor proposed by the present invention is used to load the unidirectional veneer for chemical treatment. Sodium hydroxide and sodium sulfite are dissolved in water. The concentration of sodium hydroxide in the reaction solution is 100g / L, the concentration of sodium sulfite is 50g / L, and the pH value of the reaction solution is 14. Then the reaction solution and unidirectional basswood veneer with a thickness of 0.28mm are mixed at a material ratio of 0.49m 2 The reaction vessel was placed in a reactor under a pressure of 125°C. The reactor was heated to 125°C, placing the entire internal system under high pressure. After maintaining the target temperature and high pressure for 6 hours, the temperature was lowered to normal temperature and pressure. The reactor was then opened and the partially dematerialized unidirectional veneer was removed. The partially dematerialized veneer was washed with water to complete the chemical modification process. See Figure 22, which shows a photograph of the partially dematerialized unidirectional veneer in its wet state. The weight of the resulting partially dematerialized unidirectional veneer was reduced by 50%.

[0265] 2) Spontaneous lateral contraction

[0266] Take a 10cm wide piece of partially debonded unidirectional veneer obtained in step 1). Place the veneer in an oven and heat it to 80°C. After 2-3 minutes, the veneer reaches a dry state and exhibits significant transverse shrinkage perpendicular to the fiber direction, with the apparent width reduced by 50% and noticeable wrinkling. Even after re-immersion in water and expansion, the width does not fully recover, indicating that some irreversible transverse shrinkage has occurred. See Figure 23, which shows the spontaneous transverse shrinkage of the partially debonded unidirectional veneer.

[0267] 3) Shrinkage and leveling in the thickness direction

[0268] [Corrected 31.12.2024 according to Rule 91] The transversely shrunk veneer (raw material thickness of about 0.28 mm) obtained in step 2) is shrunk in the thickness direction using a vacuum hot press in a wet state, with a pressure of 6 MPa, a compression time of 0.5 minutes, and a temperature of 110°C. The pressure needs to rise slowly during the compression process to prevent the veneer from being crushed by excessive impact. The compression direction is perpendicular to the thickness direction of the veneer fibers. Due to the chemical modification in step 1) that removes most of the hemicellulose and lignin, the pore structure of the wood is fully opened, and the hydroxyl groups on the surface of the hydrophilic cellulose are induced to form new hydrogen bonds during the process of water infiltration and extrusion. Therefore, adjacent wood fibers are tightly bonded to obtain a dense veneer with greatly enhanced mechanical properties. After shrinking in the thickness direction, the thickness of the veneer is reduced to about 0.08 mm, and the moisture content is 20%. Then, negative pressure was turned on and additional positive pressure was added (the pressure in the thickness direction of the wood fiber paper was about 0.5 MPa), the flow rate was about 150 L / min, the temperature was still 110 degrees Celsius, and it was maintained for 4 minutes to obtain dry and flat unidirectional wood fiber paper. There were very few cracks, with a probability of less than 5%. The average thickness of the unidirectional wood fiber paper was 0.08 mm. According to the flatness test method described in the instructions, the wood fiber paper was placed between two smooth and flat glass plates, and a small plane pressure of about 4500 Pa was applied to the glass surface. The gap between the glass plates was measured (considering that the glass plates were not completely flat, the gap was the maximum apparent thickness of the highest and lowest points of the wood fiber paper) and was between 0.15 and 0.2 mm. The average moisture content was 4%, and the final width was about 30% smaller than that of the wet veneer after chemical treatment. Based on the plastic tensile testing standard GB / T1040.1-2006, mechanical tensile testing was conducted on the paper. The wood fiber paper strips were 4 mm wide and stretched at a rate of 2 mm / min. The resulting tensile curve is shown in Figure 24, which shows the tensile stress-strain test curve in the fiber direction of the unidirectional wood fiber paper. Figure 24 shows an average breaking strength of 381 MPa and an average elastic modulus of 32 GPa. The tensile strength perpendicular to the fiber direction was 8.7 MPa, and the tensile modulus was 1.74 GPa.

[0269] Comparative Example 1

[0270] The chemical treatment was the same as in Example 1. Without the transverse shrinkage step, the chemically treated wet veneer (10 cm wide) was directly shrunk in the thickness direction using a vacuum hot press, with the pressure remaining at 6 MPa and the cold pressing time at 0.5 minutes. As in Example 2, negative pressure was then applied with additional positive pressure (the pressure in the thickness direction of the unidirectional wood fiber paper was approximately 0.5 MPa), with a flow rate of approximately 150 L / min and the temperature remaining at 110 degrees Celsius for 4 minutes. Upon opening the press, cracks were observed in some unidirectional wood fiber papers, with a probability of occurrence of approximately 40%. The average thickness was 0.07 mm, thinner than the veneer that had undergone transverse shrinkage, and the width remained essentially unchanged. See Figure 25, which shows a photo of the chemically treated veneer that had undergone only thickness shrinkage. Mechanical tensile testing revealed the following tensile properties for the unidirectional wood fiber paper: an average tensile strength of 348 MPa and an average tensile modulus of 30 GPa in the fiber direction; a tensile strength of 4.8 MPa and a tensile modulus of 1.1 GPa perpendicular to the fiber direction.

[0271] The average parameters and properties of the unidirectional wood fiber papers obtained in Example 1 and Comparative Example 1 from the same batch and specification are shown in Table 1 below.

[0272] Table 1 Average parameters and properties of unidirectional wood fiber paper

[0273] Example 2

[0274] The chemical treatment is the same as that in Example 1, with a different method for lateral shrinkage and the same method for thickness compression: the unidirectional wood fiber paper is placed on a smooth metal table with a surface roughness of Ra1.6, and a cover plate is placed on top. The cover plate is made of a pre-tensioned silicone soft film, the tension is perpendicular to the fiber direction of the unidirectional wood fiber paper, and the tightness is adjustable. A pressure of about 0.5 MPa is applied to the cover plate to make the film close to the unidirectional wood fiber paper to generate pressure. In the process of releasing the tension of the silicone film, the unidirectional wood fiber paper shrinks laterally under the action of friction. In this case, the equivalent shrinkage pressures achieved by controlling the tension of the silicone mold are approximately 0.002 MPa, 0.2 MPa, and 1.2 MPa. The thickness shrinkage rate and lateral shrinkage rate of the unidirectional wood fiber paper obtained in this comparative example were tested, and then its tensile mechanical properties were tested. The results are shown in Table 2.

[0275] Table 2 Average parameters and properties of unidirectional wood fiber paper

[0276] Example 3

[0277] The chemical treatment and transverse shrinkage methods are exactly the same as those in Example 1, and the thickness compression adopts the roller pressing method. By adjusting the gap between the rollers, the effect of adjusting the pressure in the thickness direction can be achieved, as shown in Figure 8. During the rolling process, the unidirectional wood fiber paper is subjected to a combined force composed of pressure and friction in the thickness direction, and the combined force is in the direction shown by the dotted line in the figure. The component force (pressure) in the thickness direction can make the unidirectional wood fiber paper have a better shrinkage effect. In this comparative example, the last gap between the rollers is set to 0.07mm, and the average thickness of the unidirectional wood fiber paper after compression is 0.08mm. The tensile properties of the unidirectional wood fiber paper were tested, and the results are shown in Table 3.

[0278] Table 3 Average parameters and properties of unidirectional wood fiber paper obtained by different thickness shrinkage methods

[0279] To compare the effect of pressure on thickness shrinkage, veneer materials of the same specifications as in Example 1 were selected. The chemical treatment, transverse shrinkage method, and thickness shrinkage method were identical to those in Example 1, with the only difference being that the thickness shrinkage pressure was 0.02 MPa, compared to 6 MPa in Example 2. Furthermore, to compare the thickness shrinkage effect under higher pressures, unidirectional veneer materials of the same specifications were selected. The chemical treatment and transverse shrinkage methods were identical to those in Example 1, but a higher pressure of 18 MPa was used for thickness compression. The wood fiber paper was then flattened using a vacuum press equipped with an exhaust channel. The flattening parameters were a pressure of 0.2 MPa, a temperature of 110°C, and a vacuum pump flow rate of approximately 150 L / min for 1 minute. The parameters of the unidirectional wood fiber paper obtained by the above process are shown in Table 4 below.

[0280] Table 4 Average parameters and properties of unidirectional wood fiber paper obtained under different thickness shrinkage conditions

[0281] Example 4

[0282] The chemical treatment was the same as in Example 1, the thickness compression method was the same, and the transverse shrinkage method was the same as in Example 2. The difference was that thickness compression was performed first, followed by transverse shrinkage. For details, see above. The thickness shrinkage-first method also produced unidirectional wood fiber paper with excellent performance. The performance test results are shown in Table 5.

[0283] Table 5 Average parameters and properties of unidirectional wood fiber paper

[0284] The chemical treatments in Examples 5 to 9 are different from those in Example 1, but the other processes are the same.

[0285] Example 5

[0286] First, prepare the reaction solution with a total solution volume of 20L. The reactor is a vertical reactor, and the unidirectional veneer can be placed directly against the wall of the reactor for reaction. Sodium hydroxide and sodium sulfite are dissolved in water. The concentration of sodium hydroxide in the reaction solution is 100g / L, the concentration of sodium sulfite is 50g / L, and the pH value of the reaction solution is 14. Then the reaction solution and the unidirectional veneer of basswood with a thickness of 0.28mm are mixed at a temperature of 0.29m. 2 The materials were placed in a reactor at a ratio of 1 / L. The reactor was heated to 125°C, creating a high-pressure state within the entire system. After maintaining the target temperature and pressure for 6 hours, the reactor was cooled to ambient temperature and pressure within the system. The reactor was then opened and the partially debonded unidirectional veneer was removed. The debonded veneer was then washed and the chemical modification process was completed. The resulting debonded veneer had a mass reduction of 42.0%.

[0287] Example 6

[0288] First, prepare the reaction solution with a total solution volume of 100L. The reactor is a vertical reactor (with an external circulation pump), and the material frame of the vertical reactor proposed by the present invention is used to load the unidirectional veneer for chemical treatment. Sodium hydroxide and sodium sulfite are dissolved in water. The concentration of sodium hydroxide in the reaction solution is 100g / L, the concentration of sodium sulfite is 50g / L, and the pH value of the reaction solution is 14. Then the reaction solution and the unidirectional veneer of basswood with a thickness of 0.28mm are mixed at a temperature of 0.12m. 2 The materials were placed in a reactor at a ratio of 1 / L. The reactor was heated to 125°C, creating a high-pressure state within the entire system. After maintaining the target temperature and pressure for 4 hours, the reactor was cooled to ambient temperature and pressure. The reactor was then opened and the partially debonded unidirectional veneer was removed. The debonded veneer was then washed and the chemical modification process was completed. The resulting debonded veneer had a mass reduction of 46.8%.

[0289] Example 7

[0290] First, prepare the reaction solution with a total solution volume of 100L. The reactor is a vertical reactor (with an external circulation pump), and the material frame of the vertical reactor proposed by the present invention is used to load the unidirectional veneer for chemical treatment. Sodium hydroxide and sodium sulfite are dissolved in water. The concentration of sodium hydroxide in the reaction solution is 100g / L, the concentration of sodium sulfite is 50g / L, and the pH value of the reaction solution is 14. Then the reaction solution and the unidirectional basswood veneer with a thickness of 0.28mm are mixed with 0.12m 2The materials were placed in a reactor at a ratio of 1000 ppm to 1000 ppm. The reactor was heated to 125°C, creating a high-pressure state within the entire system. After maintaining the target temperature and pressure for 5 hours, the reactor was cooled to ambient temperature and pressure. The reactor was then opened and the partially debonded unidirectional veneer was removed. The debonded veneer was then washed and the chemical modification process was completed. The resulting modified unidirectional veneer had a mass reduction of 49.1%.

[0291] Example 8

[0292] First, prepare the reaction solution with a total solution volume of 3T. The reactor is a vertical reactor (with an external circulation pump), and the material frame of the vertical reactor proposed by the present invention is used to load the unidirectional veneer for chemical treatment. Sodium hydroxide and sodium sulfite are dissolved in water. The concentration of sodium hydroxide in the reaction solution is 100g / L, the concentration of sodium sulfite is 50g / L, and the pH value of the reaction solution is 14. Then the reaction solution and the unidirectional basswood veneer with a thickness of 0.28mm are mixed with 0.25m 2 The materials were placed in a reactor at a ratio of 1 / L. The reactor was heated to 125°C, placing the entire internal system under high pressure. After maintaining the target temperature and pressure for 5 hours, the reactor was cooled to ambient temperature and pressure. The reactor was then opened and the partially debonded unidirectional veneer was removed. The debonded veneer was then washed and the chemical modification process was completed. The resulting debonded veneer had a mass reduction of 49.0%.

[0293] Example 9

[0294] First, prepare the reaction solution with a total solution volume of 3T. The reactor is a horizontal reactor (with an external circulation pump), and the material frame of the horizontal reactor proposed by the present invention is used to load the one-way veneer for chemical treatment. Sodium hydroxide and sodium sulfite are dissolved in water. The concentration of sodium hydroxide in the reaction solution is 100g / L, the concentration of sodium sulfite is 50g / L, and the pH value of the reaction solution is 14. Then the reaction solution and the one-way basswood veneer with a thickness of 0.28mm are mixed with 0.37m 2 The materials were placed in a reactor at a ratio of 1 / L. The reactor was heated to 125°C, creating a high-pressure state within the entire system. After maintaining the target temperature and pressure for 5 hours, the reactor was cooled to ambient temperature and pressure. The reactor was then opened and the partially debonded unidirectional veneer was removed. The debonded veneer was then washed and the chemical modification process was completed. The resulting debonded veneer had a mass reduction of 48.2%.

[0295] The unidirectional veneers obtained in Examples 5 to 9 from which some substances were removed were subsequently treated according to the method of Example 1 to obtain unidirectional wood fiber paper. The tensile properties of the unidirectional wood fiber paper in the fiber direction were tested, and the results are shown in Table 6.

[0296] Table 6 Performance test results of unidirectional wood fiber paper obtained in Examples 6 to 10

[0297] Example 10

[0298] A method for preparing wood fiber paper comprises the following steps:

[0299] Made of 0.25mm thick basswood unidirectional veneer with a surface density of 102g / m 2 The concentration of alkaline substances in the chemical treatment solution was 10%. A solution suitable for a 30L reactor was prepared using sodium hydroxide and sodium sulfite in a ratio of 2:1. The chemical treatment was carried out under the process conditions of 125°C for 5 hours to obtain a unidirectional veneer with a weight loss of 43% after the removal of some substances.

[0300] The cleaned unidirectional veneer with some substances removed was placed in an oven at 100°C for 30 minutes, then soaked in water for 5 minutes, and then placed in an oven at 100°C for 30 minutes. The soaking and drying were repeated three times to achieve self-densification of the unidirectional veneer with some substances removed. The veneer that was filled with water again was then densified using a cold press with a pressure of 6 MPa and a compression time of 1 minute.

[0301] The dense veneer was smoothed with 75% alcohol and placed on a blister machine. It was heated at 120°C and given a certain negative pressure (flow rate of about 150L / min) to drain the remaining water in the dense veneer. The surface density of the veneer was 66g / m 2 Unidirectional wood fiber paper.

[0302] Example 11

[0303] A method for preparing composite wood fiber paper specifically comprises the following steps:

[0304] Made of 0.25mm thick basswood unidirectional veneer with a surface density of 102g / m 2 The concentration of alkaline substances in the chemical treatment solution was 11%. A solution suitable for a 100L reactor was prepared using sodium hydroxide and sodium sulfite in a ratio of 2:1. The chemical treatment was carried out under the process conditions of 125°C for 6 hours to obtain a unidirectional veneer with a weight loss of 47% after the removal of some substances.

[0305] The cleaned unidirectional veneer with some substances removed was placed in an oven at 100°C for 30 minutes, then soaked in water for 5 minutes, and then placed in an oven at 100°C for 30 minutes. The soaking and drying were repeated twice to achieve self-densification of the unidirectional veneer with some substances removed. The veneer that was filled with water again was then densified using a cold press with a pressure of 10 MPa and a compression time of 30 seconds.

[0306] The dense veneer was immersed in an aqueous PU solution with a solid content of 6.8% for 3 minutes, and then the dense veneer was taken out and smoothed. It was heated at 100°C and a certain negative pressure (flow rate of about 150L / min) was applied to drain the remaining water in the dense veneer to obtain a composite wood fiber paper. The moisture content of the composite wood fiber paper was reduced to 9%, and the surface density was 68g / m 2 .

[0307] Example 12

[0308] A method for preparing composite wood fiber paper specifically comprises the following steps:

[0309] Made of 0.25mm thick basswood unidirectional veneer with a surface density of 102g / m 2 The concentration of alkaline substances in the chemical treatment solution was 9.5%. A solution suitable for a 3-ton reactor was prepared using sodium hydroxide and sodium sulfite in a ratio of 2:1. The chemical treatment was carried out under the process conditions of 125°C for 6 hours to obtain a unidirectional veneer with a weight loss of 43% after the removal of some substances.

[0310] The cleaned unidirectional veneer with some substances removed is placed in a room temperature environment, subjected to two self-densification and water filling processes, and then fed into a continuous hot pressing roller set at 130°C in 5 layers. The thickness gradually decreases after each hot pressing roller. After 5 roller presses, the densification process of the unidirectional veneer with some substances removed is completed;

[0311] The dense veneer was immersed in an aqueous PU solution with a solid content of 11.7% for 3 minutes, and then the dense veneer was taken out and aired for 30 minutes. The temperature of the hot pressing roller was adjusted to 120°C, and the PU-soaked dense veneer was fed into the roller three times to obtain a composite wood fiber paper. The moisture content of the composite wood fiber paper was reduced to 9%, and the surface density was 80g / m 2 .

[0312] Example 13

[0313] A method for preparing composite wood fiber paper specifically comprises the following steps:

[0314] Made of 0.25mm thick basswood unidirectional veneer with a surface density of 102g / m 2 The concentration of alkaline substances in the chemical treatment solution was 9%. A solution suitable for a 100L reactor was prepared using a ratio of sodium hydroxide to sodium sulfite of 2.1:1. The chemical treatment was carried out at 125°C for 4 hours to obtain a unidirectional veneer with a weight loss of 40% after the removal of some substances.

[0315] The cleaned and partially decontaminated unidirectional veneer is placed in a room temperature environment, subjected to three self-densification and water filling processes, and then placed on a flat press according to a thickness of 20 layers per stack. The temperature is raised to 100°C and hot pressed at a pressure of 12 MPa for 3 minutes. After the process is completed, part of the water is squeezed out and part is lost to the air. The above process is repeated three times to complete the densification process.

[0316] The densified veneer was immersed in an aqueous PU solution with a solid content of 22% for 5 minutes, and then the densified veneer was taken out and aired for 30 minutes. The temperature of the hot pressing roller was adjusted to 120°C, and the densified veneer was fed into the roller three times to obtain a composite wood fiber paper. The moisture content of the composite wood fiber paper was reduced to 9%, and the surface density was 115g / m 2 .

[0317] Example 14

[0318] A method for preparing composite wood fiber paper specifically comprises the following steps:

[0319] Made of 0.25mm thick basswood unidirectional veneer with a surface density of 102g / m 2 The concentration of alkaline substances in the chemical treatment solution was 11%. A solution suitable for a 100L reactor was prepared using sodium hydroxide and sodium sulfite in a ratio of 2:1. The chemical treatment was carried out under the process conditions of 125°C for 4 hours to obtain a unidirectional veneer with a weight loss of 47% after the removal of some substances.

[0320] The cleaned unidirectional veneer with some substances removed is placed in a room temperature environment, subjected to two self-densification and water filling processes, and then placed on a cold press according to a thickness of 20 layers per stack, and cold pressed at room temperature at a pressure of 10 MPa for 3 minutes to complete the densification process;

[0321] The PU prepolymer aqueous solution with a solid content of 6.8% is evenly sprayed on both sides of the dense veneer, and then the dense veneer is covered with 8g / m 2 The carbon fiber surface felt is dried in an 80℃ oven and then passed through a 120℃ hot pressing roller. After 2-3 times of rolling, the surface density is 78g / m 2 Composite wood fiber paper.

[0322] Example 15

[0323] A method for preparing composite wood fiber paper specifically comprises the following steps:

[0324] Made of 0.25mm thick basswood unidirectional veneer with a surface density of 102g / m 2The concentration of alkaline substances in the chemical treatment solution was 9%. A solution suitable for a 500L reactor was prepared using sodium hydroxide and sodium sulfite in a ratio of 2:1. The chemical treatment was carried out under the process conditions of 125°C for 6 hours to obtain a unidirectional veneer with a weight loss of 47% after the removal of some substances.

[0325] The cleaned unidirectional veneer with some substances removed is placed in a room temperature environment, subjected to two self-densification and water filling processes, and then placed on a cold press according to a thickness of 20 layers per stack, and cold pressed at room temperature at a pressure of 10 MPa for 3 minutes to complete the densification process;

[0326] The PU prepolymer aqueous solution with a solid content of 11.7% is evenly sprayed on both sides of the dense veneer, and then the dense veneer is covered with 10g / m 2 The glass fiber surface felt is dried in an 80℃ oven and then passed through a 120℃ hot pressing roller. After 2-3 times of rolling, the surface density is 84g / m 2 Composite wood fiber paper.

[0327] The performance test results of the wood fiber paper and composite wood fiber paper prepared according to the example method are shown in Table 7 below.

[0328] Table 7: Performance parameters of wood fiber paper or composite wood fiber paper corresponding to the examples

[0329] Preparation of wood honeycomb:

[0330] Example 16

[0331] A method for preparing a wood honeycomb specifically comprises the following steps:

[0332] PO glue was used as the core glue, which was applied to the unidirectional wood fiber paper prepared in Example 10 by a double-roll transfer method. After gluing, a honeycomb laminate was made by staggered stacking to bond the ear straps.

[0333] Place the honeycomb laminate in an oven with a weight less than 10kg, set the temperature at 90°C, and bond for 5 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented perpendicular to the height of the honeycomb.

[0334] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 200mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0335] The honeycomb and frame are placed in an oven for curing at 80°C for 60 minutes.

[0336] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 500×500×300mm, and the density is 56kg / m 3 .

[0337] Example 17

[0338] A method for preparing a wood honeycomb specifically comprises the following steps:

[0339] The core strip glue uses PO glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by roller transfer method. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0340] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 90°C, and bond for 5 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is perpendicular to the height of the honeycomb.

[0341] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 200mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0342] The honeycomb and frame are placed in an oven for curing at 80°C for 60 minutes.

[0343] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 500×500×500mm, and the density is 128kg / m 3 .

[0344] Example 18

[0345] A method for preparing a wood honeycomb specifically comprises the following steps:

[0346] The core strip glue uses PO glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by roller transfer method. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0347] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 90°C, and bond for 5 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0348] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 200mm. Pour the prepared unsaturated polyester resin evenly into the honeycomb cells, start the return and extrusion device on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of polyester resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0349] The honeycomb and frame are placed in an oven for curing at 80°C for 60 minutes.

[0350] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 500×500×300mm, and the density is 48kg / m 3 .

[0351] Example 19

[0352] A method for preparing a wood honeycomb specifically comprises the following steps:

[0353] The core strip glue uses PO glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by roller transfer method. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0354] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 90°C, and bond for 5 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0355] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 500mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0356] The honeycomb and frame are placed in an oven for curing at 80°C for 60 minutes.

[0357] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 1000×1000×1000mm, and the density is 56kg / m 3 .

[0358] Example 20

[0359] A method for preparing a wood honeycomb specifically comprises the following steps:

[0360] The core strip glue uses PA glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by roller transfer method. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0361] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 120°C, and bond for 10 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0362] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 500mm. Pour the prepared acrylic resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of acrylic resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0363] The honeycomb and frame are placed in an oven for curing at 60°C for 90 minutes.

[0364] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 1000×1000×500mm, and the density is 64kg / m 3 .

[0365] Example 21

[0366] A method for preparing a wood honeycomb specifically comprises the following steps:

[0367] The core strip glue uses PO glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by roller transfer method. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0368] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 90°C, and bond for 10 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0369] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 700mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0370] The honeycomb and frame are placed in an oven for curing at 80°C for 60 minutes.

[0371] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 1200×2200×300mm, and the density is 64kg / m 3 .

[0372] Example 22

[0373] A method for preparing a wood honeycomb specifically comprises the following steps:

[0374] The core strip glue uses PA glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by roller transfer method. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0375] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 120°C, and bond for 10 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0376] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 700mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0377] The honeycomb and frame are placed in an oven for curing at 80°C for 60 minutes.

[0378] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 1220×2440×500mm, and the density is 72kg / m 3 .

[0379] Example 23

[0380] A method for preparing a wood honeycomb specifically comprises the following steps:

[0381] The core strip glue uses PO glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by roller transfer method. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0382] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 10 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0383] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 700mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0384] The honeycomb and frame are placed in an oven for curing at 80°C for 120 minutes.

[0385] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 1300×2600×400mm, and the density is 128kg / m 3 .

[0386] Example 24

[0387] A method for preparing a wood honeycomb specifically comprises the following steps:

[0388] The core strip glue is epoxy glue, and the core strip glue is applied to the surface density of 66g / m prepared in Example 10 by screen printing. 2 The unidirectional wood fiber paper is coated with glue and then stacked in an offset manner to make a honeycomb laminate to bond the ear straps.

[0389] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 120 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented parallel to the height of the honeycomb.

[0390] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 400mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0391] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0392] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 1000×2000×300mm, and the density is 64kg / m 3 .

[0393] Example 25

[0394] A method for preparing a wood honeycomb specifically comprises the following steps:

[0395] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 68g / m2) prepared in Example 11 by screen printing. 2 ) and glued on the surface, and then the honeycomb laminate is made into an ear strap in a staggered stacking manner.

[0396] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 120 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented parallel to the height of the honeycomb.

[0397] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 300mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0398] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0399] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 500×500×300mm, and the density is 48kg / m 3 .

[0400] Example 26

[0401] A method for preparing a wood honeycomb specifically comprises the following steps:

[0402] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 68g / m2) obtained in Example 11 by screen printing. 2 ) is coated with glue and then stacked in an offset manner to form a honeycomb laminate to bond the ear straps.

[0403] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 150 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0404] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 600mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0405] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0406] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 1000×1000×300mm, and the density is 80kg / m 3 .

[0407] Example 27

[0408] A method for preparing a wood honeycomb specifically comprises the following steps:

[0409] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 80g / m2) prepared in Example 12 by screen printing. 2 ) is coated with glue and then stacked in an offset manner to form a honeycomb laminate to bond the ear straps.

[0410] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 180 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented parallel to the height of the honeycomb.

[0411] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 400mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0412] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0413] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 1200×1200×600mm, and the density is 64kg / m 3 .

[0414] Example 28

[0415] A method for preparing a wood honeycomb specifically comprises the following steps:

[0416] The core glue is acrylic resin, and the core glue is applied to the composite wood fiber paper (surface density 115g / m2) prepared in Example 13 by flat plate transfer method. 2 ) is coated with glue and then stacked in an offset manner to form a honeycomb laminate to bond the ear straps.

[0417] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 60°C, and bond for 20 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0418] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 200mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action 3 times. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0419] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0420] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 5.5mm, the size is 500×500×400mm, and the density is 72kg / m 3 .

[0421] Example 29

[0422] A method for preparing a wood honeycomb specifically comprises the following steps:

[0423] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 78g / m2) prepared in Example 14 by screen printing. 2 ) on the composite wood fiber paper, the carbon fiber felt is compounded as the coating surface layer, and after being coated with glue, it is made into a honeycomb laminate and bonded ear straps in a staggered stacking manner.

[0424] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 120 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented parallel to the height of the honeycomb.

[0425] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 600mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0426] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0427] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 1200×2000×800mm, and the density is 64kg / m 3 .

[0428] Example 30

[0429] A method for preparing a wood honeycomb specifically comprises the following steps:

[0430] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 78g / m2) prepared in Example 14 by screen printing. 2 ) on the composite wood fiber paper, the carbon fiber felt is compounded as the coating surface layer, and after being coated with glue, it is made into a honeycomb laminate and bonded ear straps in a staggered stacking manner.

[0431] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 90 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0432] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 300mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion device on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0433] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0434] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 500×500×600mm, and the density is 72kg / m 3 .

[0435] Example 31

[0436] A method for preparing a wood honeycomb specifically comprises the following steps:

[0437] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 78g / m2) prepared in Example 14 by screen printing. 2 ) on the composite wood fiber paper, the carbon fiber felt is compounded as the coating surface layer, and after being coated with glue, it is made into a honeycomb laminate and bonded ear straps in a staggered stacking manner.

[0438] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 80 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0439] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 300mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion device on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0440] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0441] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 500×500×500mm, and the density is 80kg / m 3 .

[0442] Example 32

[0443] A method for preparing a wood honeycomb specifically comprises the following steps:

[0444] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 84g / m2) prepared in Example 15 by screen printing. 2 ) on the composite wood fiber paper, the glass fiber felt is compounded as the coating surface layer, and after being coated with glue, it is made into a honeycomb laminate with ear straps bonded in a staggered stacking manner.

[0445] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 120 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented parallel to the height of the honeycomb.

[0446] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 400mm. Pour the prepared epoxy resin evenly into the honeycomb cells, start the return and extrusion devices on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of epoxy resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0447] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes.

[0448] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 4mm, the size is 600×600×600mm, and the density is 64kg / m 3 .

[0449] Example 33

[0450] A method for preparing a wood honeycomb specifically comprises the following steps:

[0451] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 78g / m2) prepared in Example 14 by screen printing. 2 ) on the composite wood fiber paper, the carbon fiber felt is compounded as the coating surface layer, and after being coated with glue, it is made into a honeycomb laminate and bonded ear straps in a staggered stacking manner.

[0452] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 120 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented parallel to the height of the honeycomb.

[0453] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 600mm. Pour the prepared phenolic resin evenly into the honeycomb cells, start the return and extrusion device on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of phenolic resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0454] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 100°C for 30 minutes.

[0455] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 3.67mm, the size is 1000×1000×500mm, and the density is 64kg / m 3 .

[0456] Example 34

[0457] A method for preparing a wood honeycomb specifically comprises the following steps:

[0458] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 84g / m2) prepared in Example 15 by screen printing. 2 ) on the composite wood fiber paper, the glass fiber felt is compounded as the coating surface layer, and after being coated with glue, it is made into a honeycomb laminate with ear straps bonded in a staggered stacking manner.

[0459] Place the honeycomb laminate in an oven with a heavy object, set the temperature at 80°C, and bond for 120 minutes. After bonding, trim the edges of the excess glue. The wood fibers are oriented parallel to the height of the honeycomb.

[0460] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 1200mm. Pour the prepared phenolic resin evenly into the honeycomb cells, start the return and extrusion device on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of phenolic resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to meet the requirements of a regular hexagon.

[0461] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes, and finally at 100°C for 30 minutes.

[0462] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 3.67mm, the size is 1200×2400×500mm, and the density is 72kg / m 3 .

[0463] Example 35

[0464] A method for preparing a wood honeycomb specifically comprises the following steps:

[0465] The core strip glue is epoxy glue, and the core strip glue is applied to the composite wood fiber paper (surface density 68g / m2) prepared in Example 11 by screen printing. 2 ) is coated with glue and then stacked in an offset manner to form a honeycomb laminate to bond the ear straps.

[0466] Place the honeycomb laminate in an oven with a heavy object, and bond it at 80°C for 120 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0467] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 300mm. Pour the prepared phenolic resin evenly into the honeycomb cells, start the return and extrusion device on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of phenolic resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0468] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes, and finally at 100°C for 30 minutes.

[0469] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 2.75mm, the size is 500×500×400mm, and the density is 48kg / m 3 .

[0470] Example 36

[0471] A method for preparing a wood honeycomb specifically comprises the following steps:

[0472] The core strip glue uses epoxy glue, and the core strip glue is applied to the surface with a density of 78g / m by screen printing. 2 The composite wood fiber paper is compounded with carbon fiber felt as the coating surface layer, and after being coated with glue, it is made into a honeycomb laminate and bonded ear straps in a staggered stacking manner.

[0473] Place the honeycomb laminate in an oven with a heavy object, and bond it at 80°C for 120 minutes. After bonding, trim the edges of the excess glue. The orientation of the wood fibers is parallel to the height direction of the honeycomb.

[0474] Pass the pin through the ear strap and fix it on the stretching machine, then slowly stretch it to a length of 500mm. Pour the prepared phenolic resin evenly into the honeycomb cells, start the return and extrusion device on the stretching machine, control the extrusion force and repeat the stretching and extrusion action twice. After that, a certain amount of phenolic resin is evenly distributed on the honeycomb cell wall, and then the honeycomb cells are stretched to a state that meets the requirements of a regular hexagon.

[0475] The honeycomb and frame are put into an oven for curing, first at 60°C for 30 minutes, then at 80°C for 30 minutes, and finally at 100°C for 30 minutes.

[0476] The prepared wood honeycomb is trimmed to complete the preparation. The cell side length of the wood honeycomb is 2.75mm, the size is 1000×1000×800mm, and the density is 64kg / m 3 .

[0477] The wood honeycomb prepared in the above embodiment was sliced ​​into 15 mm thick slices, and its compressive strength was tested.

[0478] The test results of the compressive strength (GB / T 12914-2008) of the wood honeycomb prepared according to the example method are shown in Table 8 below.

[0479] Table 8: Compression properties of wood honeycombs corresponding to the examples

[0480] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wooden honeycomb, characterized in that: It includes a white honeycomb and a first resin compounded on the surface of the white honeycomb; the white honeycomb includes multiple wood fiber papers and core glue; the multiple wood fiber papers are bonded by the core glue; The plurality of wood fiber papers include unidirectional wood fiber paper and / or composite wood fiber paper; the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper; The density of the wood honeycomb is 29-144 kg / m 3 ; The compressive strength of the wood honeycomb is 0.4-13.8 MPa.

2. The wood honeycomb according to claim 1, characterized in that The wood fiber paper includes wood fibers and / or fiber bundles; the wood fibers and / or fiber bundles are arranged or extended along a single direction as a whole in a microscopic sense.

3. The wood honeycomb according to claim 2, characterized in that: The wood fiber paper has a tensile strength in a direction parallel to the wood fibers and / or fiber bundles of 6 to 30 kN / m; and / or, the wood fiber paper has a tensile strength of 0.3 to 4 kN / m in a direction perpendicular to the wood fibers and / or fiber bundles; And / or, the elastic modulus of the wood fiber paper in a direction parallel to the wood fibers and / or fiber bundles is 8 to 80 GPa; And / or, the elastic modulus of the wood fiber paper in a direction perpendicular to the wood fibers and / or fiber bundles is 0.4 to 3 GPa.

4. The wood honeycomb according to claim 1, characterized in that The unidirectional wood fiber paper is formed by shrinking the unidirectional wood veneer with some substances removed in at least one direction; The partial substances include lignin and hemicellulose; The decomposition of the shrinkage force includes lateral shrinkage and thickness shrinkage.

5. The wood honeycomb according to claim 4, characterized in that: The unidirectional veneer from which some substances have been removed shrinks in at least two directions; The shrinkage includes transverse shrinkage and thickness shrinkage; The shrinkage force directions of the transverse shrinkage and the thickness shrinkage intersect; The shrinkage force of transverse shrinkage is a force in the horizontal direction of the unidirectional veneer, and intersects with the extension direction of the wood fibers and / or fiber bundles in the plane; and / or, the shrinkage force of the thickness shrinkage is a unidirectional force in the vertical direction of the veneer; The horizontal force and the vertical force are each independently an originally applied force, and / or a force formed after synthesis or decomposition of forces.

6. The wood honeycomb according to claim 5, characterized in that: The thickness of the unidirectional wood fiber paper is less than or equal to 0.2 mm; And / or, the surface density of the unidirectional wood fiber paper is 20 to 200 g / m 2 ; And / or, the tensile strength of the unidirectional wood fiber paper parallel to the direction of the wood fibers and / or fiber bundles is 150-1000 MPa.

7. The wood honeycomb according to claim 4, characterized in that: The apparent thickness of the unidirectional wood fiber paper under a plane pressure of no more than 0.005 MPa is no more than 4 times the average thickness of the unidirectional wood fiber paper; and / or, the weight loss of the unidirectional veneer after removing some substances is 10% to 60% relative to the unidirectional veneer; And / or, the shrinkage rate of the transverse shrinkage is 2% to 40%; the shrinkage rate of the thickness shrinkage is 20% to 90%.

8. The wood honeycomb according to claim 1, characterized in that The mass of the second resin layer is 0% to 30% of the mass of the composite wood fiber paper; the mass of the fiber reinforcement layer is 0% to 10% of the mass of the composite wood fiber paper.

9. The wood honeycomb according to claim 8, characterized in that: The second resin layer includes a thermosetting resin and / or a thermoplastic resin; And / or, the surface density of the fiber reinforced layer is 1 to 20 g / m 2 .

10. The wood honeycomb according to claim 9, characterized in that: The thermosetting resin is selected from one or more of epoxy resin, unsaturated polyester, polybutadiene resin, phenolic resin, melamine resin and cross-linkable polyurethane; and / or, the thermoplastic resin is selected from one or more of polyamide, polylactic acid, polyurethane, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer and copolyester; And / or, the fiber reinforcement layer is selected from a fiber surface felt with low surface density; the fiber surface felt with low surface density is selected from one or more of a carbon fiber surface felt, a glass fiber surface felt and an aramid fiber surface felt.

11. The wood honeycomb according to claim 1, characterized in that: The surface density of the composite wood fiber paper is increased by 3 to 50 g / m compared with the surface density of the unidirectional wood fiber paper. 2 .

12. The wood honeycomb according to claim 1, characterized in that The mass of the wood fiber paper is 30% to 84% of the mass of the wood honeycomb; and / or, the mass of the first resin is 15% to 69% of the mass of the wood honeycomb; And / or, the mass of the core strip glue is 1% to 30% of the mass of the wood honeycomb.

13. A method for preparing a wood honeycomb, characterized in that: The following steps are involved: S1) applying core strip glue to multiple sheets of wood fiber paper, stacking them in staggered layers, and hot pressing and curing them to obtain a honeycomb block; S2) stretching the honeycomb block to obtain a white honeycomb; S3) transferring the first resin to the white honeycomb and curing it to obtain a wood honeycomb; The plurality of wood fiber papers include unidirectional wood fiber paper and / or composite wood fiber paper; the composite wood fiber paper includes unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper; The density of the wood honeycomb is 29-144 kg / m 3 ; The compressive strength of the wood honeycomb is 0.4-13.8 MPa.

14. The preparation method according to claim 13, characterized in that The preparation method of the unidirectional wood fiber paper comprises the following steps: A1) chemically modifying the unidirectional veneer to obtain the unidirectional veneer from which some substances have been removed; A2) shrinking the unidirectional veneer from which some substances have been removed in at least one direction to obtain unidirectional wood fiber paper; The decomposition of the shrinkage force includes lateral shrinkage and thickness shrinkage.

15. The preparation method according to claim 14, characterized in that The thickness of the unidirectional veneer is 0.05-0.6 mm; And / or, the chemical modification in A1) is carried out in a closed high-pressure system; the target temperature of the chemical modification is 100-150° C.; the target pressure of the chemical modification is 0.07-1.9 MPa; and the residence time of the chemical modification at the target temperature / target pressure is 1-12 hours; Alternatively, the chemical modification is carried out under normal pressure; the residence time of the chemical modification at the target temperature / pressure is 24 to 72 hours; the temperature of the chemical modification is the boiling temperature of water at normal pressure; And / or, the modification liquid for chemical modification in step A1) comprises an alkaline substance, a sulfonating agent and water; The pH value of the modified liquid is 12 to 14; The concentration of the alkaline substance in the modified solution is 0.01 to 5 kg / L; The alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate and potassium bicarbonate; The concentration of the sulfonating agent in the modified solution is 0.01 to 5 kg / L; The sulfonating agent in the modified liquid is selected from one or more of sulfite, chlorosulfonic acid, hydroxymethylsulfonate, sulfuryl chloride and aminosulfonic acid; And / or, the material ratio of the unidirectional veneer to the chemically modified modifying liquid is 4.6 to 184 cm 3 : 1L.

16. The preparation method according to claim 14, characterized in that The shrinkage process includes a transverse shrinkage process and a thickness shrinkage process; the force of the transverse shrinkage process and the force of the thickness shrinkage process intersect.

17. The preparation method according to claim 16, characterized in that The transverse shrinkage treatment includes applying external mechanical force in the transverse direction and / or spontaneous shrinkage due to dehydration; The external mechanical force applied in the transverse direction intersects in the plane with the extending direction of the wood fibers and / or fiber bundles of the unidirectional veneer from which some substances have been removed.

18. The preparation method according to claim 17, characterized in that: The external mechanical force applied in the transverse direction is specifically: using a film material that can produce transverse contraction, sticking it on the surface of the unidirectional veneer with some materials removed and applying pressure; and / or, applying negative pressure to the one-way veneer with some of the material removed; and / or, roller-rubbing the unidirectional veneer with some of the material removed; and / or, applying transverse pressure to the unidirectional veneer with some of the material removed.

19. The preparation method according to claim 17, characterized in that The pressure of the external mechanical force applied in the lateral direction is 0.001 to 1.5 MPa; and / or, the temperature of the transverse shrinkage treatment is 15° C. to 150° C.; and / or, the transverse shrinkage treatment time is 1 second to 4 minutes; And / or, the intensity of the negative pressure is less than or equal to one atmosphere.

20. The preparation method according to claim 16, characterized in that The thickness shrinkage treatment is to apply mechanical pressure in the thickness direction; The mechanical pressure applied in the thickness direction is 0.01 to 80 MPa; And / or, the thickness shrinkage treatment time is 0.1 to 3 minutes; And / or, the temperature of the thickness shrinkage treatment is 15°C to 150°C.

21. The preparation method according to claim 16, characterized in that The thickness shrinkage is carried out under the condition of single sheet or stacking; the number of layers of the stacking is 2 to 20 sheets; The pressure of thickness shrinkage under the stacking condition is 0.1 to 60 MPa.

22. The preparation method according to claim 14, characterized in that The shrinkage rate of the transverse shrinkage is 2% to 40%; The shrinkage rate of the thickness shrinkage is 20% to 90%.

23. The preparation method according to claim 16, characterized in that The thickness shrinkage includes heat pressing under negative pressure; The pressure of the hot pressing treatment is 0.1 to 60 MPa; And / or, the temperature of the hot pressing treatment is 50°C to 150°C; And / or, the heat pressing treatment time is 0.5 to 20 minutes.

24. The preparation method according to claim 16, characterized in that After the shrinkage treatment, a leveling treatment is performed; The leveling process is to perform flat hot pressing in a negative pressure exhaust environment.

25. The preparation method according to claim 24, characterized in that During the leveling process, exhaust channels are provided on the double contact surfaces or the single contact surface of the unidirectional wood fiber paper.

26. The preparation method according to claim 24, characterized in that The pressure of the plane hot pressing is 0.01 to 2 MPa; And / or, the leveling treatment time is 0.1 to 4 minutes; And / or, the temperature of the leveling treatment is 40°C to 150°C.

27. The preparation method according to claim 24, characterized in that The flattening treatment is selected from one or more of a blister treatment and a negative pressure hot pressing treatment; And / or, the moisture content of the unidirectional wood fiber paper is less than or equal to 10%.

28. The preparation method according to claim 13, characterized in that The composite wood fiber paper comprises unidirectional wood fiber paper and a second resin layer composited on the surface of the unidirectional wood fiber paper; The preparation method of the composite wood fiber paper comprises: transferring the diluted second resin raw material to the surface of the unidirectional wood fiber paper and curing it to obtain a composite wood fiber paper; The second resin raw material is selected from one or more of a second resin prepolymer, a second resin monomer, and a second resin.

29. The preparation method according to claim 13, characterized in that The composite wood fiber paper comprises unidirectional wood fiber paper, a second resin layer and a fiber reinforcement layer composited on the surface of the unidirectional wood fiber paper; The preparation method of the composite wood fiber paper comprises: Transferring the diluted second resin raw material to the surface of the unidirectional wood fiber paper, then laminating the fiber reinforcement layer, and curing to obtain the composite wood fiber paper; The second resin raw material is selected from one or more of a second resin prepolymer, a second resin monomer, and a second resin.

30. The preparation method according to claim 13, characterized in that In step S3), the first resin is transferred to the white honeycomb multiple times and cured multiple times to obtain a wood honeycomb; the multiple curing and shaping are located between two transfers, and the final step is curing and shaping; the transfer method is selected from one or more of dip coating, flow coating and spraying.

31. The preparation method according to claim 13, characterized in that In step S3), the resin is transferred to the white honeycomb according to the following steps: The first resin is sprayed, flow-coated or dip-coated in the honeycomb through-holes of the white honeycomb, and then the honeycomb is stretched and extruded, and the first resin is evenly coated on the white honeycomb.

32. A composite wood fiber paper, characterized in that: It comprises a unidirectional wood fiber paper and a second resin layer and / or a fiber reinforcement layer composited on at least one surface of the unidirectional wood fiber paper; The tensile strength of the composite wood fiber paper in the direction perpendicular to the wood fibers and / or fiber bundles is increased by 5% to 100% compared to unidirectional wood fiber paper; The elastic modulus of the composite wood fiber paper in a direction perpendicular to the wood fibers is increased by 5% to 100% compared with unidirectional wood fiber paper.

33. The composite wood fiber paper according to claim 32, wherein The unidirectional wood fiber paper is formed by shrinking the unidirectional wood veneer with some substances removed in at least one direction; The partial substances include lignin and hemicellulose; The decomposition of the shrinkage force includes lateral shrinkage and thickness shrinkage; The unidirectional wood fiber paper comprises wood fibers and / or fiber bundles; the wood fibers and / or fiber bundles are arranged or extended in a single direction as a whole at a microscopic level; The composite wood fiber paper has a tensile strength in a direction parallel to the wood fibers and / or fiber bundles of 6 to 30 kN / m; and / or, the composite wood fiber paper has a tensile strength of 0.7 to 4 kN / m in a direction perpendicular to the wood fibers and / or fiber bundles; and / or, the elastic modulus of the composite wood fiber paper in a direction parallel to the wood fibers and / or fiber bundles is 8 to 80 GPa; And / or, the elastic modulus of the composite wood fiber paper in a direction perpendicular to the wood fibers is 0.8 to 3 GPa.

34. The composite wood fiber paper according to claim 32, wherein The mass of the second resin layer is 0% to 30% of the mass of the composite wood fiber paper; the mass of the fiber reinforcement layer is 0% to 10% of the mass of the composite wood fiber paper, and both are not 0 at the same time.

35. The composite wood fiber paper according to claim 32, wherein The second resin layer comprises a thermosetting resin and / or a thermoplastic resin; the thermosetting resin is selected from one or more of epoxy resin, unsaturated polyester, polybutadiene resin, phenolic resin, melamine resin and cross-linkable polyurethane; the thermoplastic resin is selected from one or more of polyamide, polylactic acid, polyurethane, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer and copolyester; The fiber reinforcement layer is selected from low-density fiber surface felt; the low-density fiber surface felt is selected from one or more of carbon fiber surface felt, glass fiber surface felt and aramid fiber surface felt.

36. The composite wood fiber paper according to claim 32, wherein The surface density of the composite wood fiber paper is increased by 3 to 50 g / m compared with the surface density of the unidirectional wood fiber paper. 2 .

37. Use of the wood honeycomb according to any one of claims 1 to 12, the wood honeycomb prepared by the preparation method according to any one of claims 13 to 31, or the composite wood fiber paper according to any one of claims 32 to 36 in the preparation of one or more of building materials, furniture materials, sports equipment, stationary carriers, vehicles, and aircraft.

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