Wood household spontaneous heating plate structure with efficient heat dissipation function and preparation method of wood household spontaneous heating plate structure

Abstract

The invention discloses an efficient heat dissipation wood household spontaneous heating plate structure and a preparation method thereof. The preparation method comprises the following steps: preparing a carbon nanotube / aluminum nitride / boron nitride modifier; wood base material pretreatment is conducted, specifically, wood veneers are completely immersed in a sodium chlorite solution, hydrothermal treatment, washing, re-freezing and vacuum drying are conducted, and a wood base material template is obtained; immersing the wood base material template in the carbon nanotube / aluminum nitride / boron nitride modifier, taking out the wood base material template after immersion treatment, and curing the wood base material template to obtain the high-thermal-conductivity base material; two grooves are milled in the surface of a high-heat-conduction base material to serve as a lower-layer base material, two protruding strips are milled in the surface of the high-heat-conduction base material to serve as an upper-layer base material, an adhesive is sprayed or sprayed, and the lower-layer base material, an electric heating film, a copper foil electrode and the upper-layer base material are sequentially stacked from bottom to top to be assembled. The invention has the advantages of efficient heat dissipation performance, high structural stability, no displacement of the electrode in the assembly hot-pressing process, process feasibility and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of artificial board preparation, and in particular relates to a wooden household self-heating board structure with high-efficiency heat dissipation and a preparation method thereof. Background Art

[0002] With the rapid development of smart home technology, self-heating wood panels have been widely used in areas such as floor heating, wall heating, and smart furniture due to their decorative and functional properties. Traditional self-heating panels mostly use a structural design in which electric heating film, carbon fiber heating wire, or metal heating elements are embedded in a wood substrate. However, the following technical defects have been found in actual applications: First, wood is a poor conductor of natural heat, which can easily cause heat to accumulate around the heating element, leading to localized excessive temperatures, carbonization of the wood layer, cracking, and fire hazards; second, existing laminated structures mostly use flat-bonded heating elements and copper foil electrodes, which can easily cause parts to shift due to uneven pressure, resulting in a high scrap rate during the preparation process; third, the thermal expansion coefficients of the wood substrate and the heating element differ significantly, and long-term hot and cold cycles can easily cause interface separation, resulting in increased thermal resistance and structural failure.

[0003] An existing invention patent (CN104818824 B) reports on an electric heated floor and its manufacturing method. This patent introduces the concept of self-heating flooring made from a composite of graphene or carbon crystal electric heating film and a wood substrate. However, this patent ignores the poor thermal conductivity of the wood substrate, necessitating further technological advancements in efficient heat dissipation. Invention patents such as CN110409750 B report on a wood electric heated floor and its large-format, efficient manufacturing method. However, the wood substrate used is fiberboard, which is susceptible to degradation due to the addition of thermally conductive fillers. Furthermore, an invention patent (CN 116277319 B) reports on an electric heated bamboo particleboard, an electric heated floor based on it, and its manufacturing method. However, this technology ignores the issue of electrode displacement during the hot pressing process, and the board is difficult to form and process. Therefore, there is an urgent need to develop a novel wood self-heating board structure and its manufacturing method that combines efficient heat dissipation, high structural stability, and process feasibility. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a wooden self-heating board structure for household use with high efficiency in heat dissipation and a preparation method thereof in response to the deficiencies of the above-mentioned prior art. It uses a high thermal conductivity wooden substrate that has been vacuum impregnated with carbon nanotubes / aluminum nitride / boron nitride modifiers as the upper and lower layers, and then forms a convex strip and groove structure after surface milling, which is then glued with the electric heating film and electrode stack to produce a new type of wooden self-heating board that has high efficiency in heat dissipation performance, high structural stability, no displacement of the electric heating film and electrodes during the hot pressing process of the assembly, and process feasibility.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0006] A method for preparing a wooden household self-heating plate structure with high heat dissipation efficiency comprises the following steps:

[0007] S1. Preparation of carbon nanotube / aluminum nitride / boron nitride modifier: aluminum nitride nanoparticles and boron nitride nanoparticles are separately blended with epoxy resin solution, magnetically stirred at a certain speed, and then carbon nanotube powder is added and ultrasonically treated; the ultrasonically treated blended solvent is uniformly stirred with epoxy resin curing agent and then ultrasonically treated a second time to finally obtain a carbon nanotube / aluminum nitride / boron nitride modifier;

[0008] S2. Pretreatment of the wood substrate: The wood veneer is completely immersed in a sodium chlorite solution, and then subjected to hydrothermal treatment for a certain period of time to remove lignin and hemicellulose, thereby increasing the pore size and porosity of the wood; the wood substrate is washed multiple times with deionized water, and then frozen for a certain period of time, and then vacuum dried to obtain a wood substrate template with three-dimensional through pores; the wood substrate template is completely immersed in the carbon nanotube / aluminum nitride / boron nitride modifier obtained in S1, immersed in a certain vacuum for a certain period of time, and then removed and cured at room temperature to obtain a high thermal conductivity substrate;

[0009] S3. Assembly of self-heating panels: Mill two grooves on the surface of a high thermal conductivity substrate as a lower substrate, mill two convex strips matching the grooves on the surface of the high thermal conductivity substrate as an upper substrate, mill the upper surface of the lower substrate with grooves and then apply or spray adhesive, mill the lower surface of the upper substrate with convex strips and then apply or spray adhesive, the lower substrate with adhesive applied or sprayed, the electric heating film, the electrode, and the upper substrate with adhesive applied or sprayed are stacked and assembled in sequence from bottom to top, and at the same time, the convex strips of the upper substrate are embedded in the grooves of the lower substrate, and the electric heating film and the electrode are located between the two grooves or the two convex strips; the stacked and assembled panels are hot-pressed at a certain temperature and pressure, and cooled for a certain period of time to obtain a new type of wood self-heating panel.

[0010] As a further improved technical solution of the present invention, the S1 is specifically:

[0011] Aluminum nitride nanoparticles and boron nitride nanoparticles were respectively blended with epoxy resin solution at a 1wt% addition amount, magnetically stirred at 500 rpm for 30 minutes, and carbon nanotube powder was added at a 1-3wt% addition amount, and ultrasonically treated at 500W for 30 minutes; the ultrasonically treated blended solvent and epoxy resin curing agent were stirred evenly in a mass ratio of 1:3, and then ultrasonically treated for a second time for 15 minutes to finally obtain a carbon nanotube / aluminum nitride / boron nitride modifier.

[0012] As a further improved technical solution of the present invention, the S2 is specifically:

[0013] The wood veneer was completely immersed in a sodium chlorite solution with a concentration of 2%-8% at a solid-liquid ratio of 4g / L and a pH value of 4-5. After hydrothermal treatment at 85℃ for 6 hours, lignin and hemicellulose were removed and the pore size and porosity of the wood were expanded; it was washed with deionized water multiple times, then frozen at -40℃ for 12 hours, and vacuum dried for 24 hours to obtain a wood substrate template with three-dimensional through pores; the wood substrate template was completely immersed in the carbon nanotube / aluminum nitride / boron nitride modifier obtained in S1, immersed in a vacuum degree of 0.08-0.1 MPa for 5-8 hours, and then taken out and cured at room temperature to obtain a high thermal conductivity substrate.

[0014] As a further improved technical solution of the present invention, in S3, the electric heating film is a graphene or carbon crystal electric heating film; the electrode is a copper foil electrode; the temperature of the hot pressing treatment is 120°C, the pressure of the hot pressing treatment is 0.9 MPa, the time of the hot pressing treatment is 6 minutes, and the cooling time is 24 hours.

[0015] In order to achieve the above technical objectives, another technical solution adopted by the present invention is:

[0016] A self-heating wooden panel structure for household use with high heat dissipation efficiency comprises a lower substrate, an upper substrate, an electric heating film, and electrodes, wherein the electrodes are respectively arranged at both ends of the electric heating film, the upper surface of the lower substrate is milled with two grooves, and the lower surface of the upper substrate is milled with two convex strips, the upper surface of the lower substrate and the lower surface of the upper substrate are coated with adhesive, and the lower substrate, the electric heating film, the electrodes, and the upper substrate are sequentially laminated and glued from bottom to top; at the same time, the convex strips of the upper substrate are embedded in the grooves of the lower substrate, and the electric heating film and the electrodes are located between the two grooves or the two convex strips;

[0017] The lower substrate and the upper substrate are made of high thermal conductivity substrates.

[0018] As a further improved technical solution of the present invention, the high thermal conductivity substrate is prepared from the following raw materials: wood veneer, sodium chlorite solution, deionized water, and carbon nanotube / aluminum nitride / boron nitride modifier;

[0019] The carbon nanotube / aluminum nitride / boron nitride modifier is prepared from the following raw materials: aluminum nitride nanoparticles, boron nitride nanoparticles, epoxy resin solution, carbon nanotube powder and epoxy resin curing agent.

[0020] The beneficial effects of the present invention are:

[0021] In this method, wood veneer is completely immersed in a 2-8% sodium chlorite solution (pH 4-5) at a solid-to-liquid ratio of 4g / L. After hydrothermal treatment at 85°C for 6 hours, lignin and hemicellulose are removed, increasing the pore size and porosity of the wood. The wood veneer is then washed multiple times with deionized water, frozen at -40°C for 12 hours, and vacuum-dried for 24 hours to produce a wood substrate template with three-dimensional through-pores.

[0022] The carbon nanotube / aluminum nitride / boron nitride modifier prepared in this invention is a high-thermal-conductivity impregnation modifier. This impregnation modifier fills the wood cell cavity (the cell cavity of a wood substrate template with three-dimensional through-pores), reducing the volume of low-thermal-conductivity air in the cell cavity, thereby improving the thermal conductivity of the wood substrate. The impregnation modifier consists of multi-walled carbon nanotubes (50 μm in length), aluminum nitride (spherical with a diameter of 2-8 μm), and boron nitride (hexagonal with a diameter of 100-300 nm) in different morphologies, overlapping to form a complete, through-hole thermal pathway.

[0023] In the self-heating sheet structure of the present invention, the grooves of the lower substrate and the ridges of the upper substrate confine the heating film and copper foil electrodes to a defined position, facilitating better assembly. This prevents slippage of the heating film and electrodes during hot pressing, while the margins on both sides facilitate tongue-and-groove processing around the sheet without damaging the heating layer, resulting in excellent workability. The resulting self-heating sheet, formed after hot pressing, exhibits excellent integrity and structural stability.

[0024] The self-heating plate prepared by the present invention has a high thermal conductivity coefficient and has broad application prospects in the fields of wall heating, floor heating, partitions, cabinets, etc., and can play the role of heating, dehumidification and health care.

[0025] In summary, the present invention uses a high thermal conductivity wooden substrate that has been vacuum impregnated with carbon nanotubes / aluminum nitride / boron nitride modifiers as the upper and lower layers, and then forms a convex and groove structure after surface milling, and then laminates and glues it with an electric heating film and copper foil electrodes to produce a new type of wooden self-heating board that has high efficiency heat dissipation performance, high structural stability, no electrode displacement during assembly and hot pressing, and process feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flow chart for preparing the self-heating plate structure of the present invention.

[0027] Figure 2 Schematic diagram of the microstructure of the self-heating plate.

[0028] Figure 3 Schematic diagram of the self-heating plate structure.

[0029] Figure 3 (a) is the exploded cross-section of the self-heating plate structure.

[0030] Figure 3 Middle (b) is a cross-sectional view of the self-heating board after lamination and gluing.

[0031] Figure 4 This is a comparison chart of the thermal conductivity of ordinary plywood and self-heating board structures.

[0032] Figure 5 This is a comparison chart of the surface temperature rise and fall curves of ordinary plywood and self-heating board structure.

[0033] Figure 6 Schematic diagram of the application of self-heating plate structure. DETAILED DESCRIPTION

[0034] The specific embodiments of the present invention are further described below with reference to the accompanying drawings:

[0035] The present invention uses a high thermal conductivity wooden substrate that has been vacuum impregnated with carbon nanotubes / aluminum nitride / boron nitride modifiers as the upper and lower layers, and then forms a convex and groove structure after surface milling. After lamination and gluing with electric heating film and copper foil electrodes, a new type of wooden self-heating board with high efficiency heat dissipation performance, structural stability and process feasibility is produced.

[0036] like Figure 3 The present embodiment provides a wooden self-heating panel structure for household use with high heat dissipation efficiency, comprising a lower substrate 4, an upper substrate 1, an electric heating film 3, and a copper foil electrode 2. The copper foil electrodes 2 are respectively arranged at both ends of the electric heating film 3. Two grooves are milled on the upper surface of the lower substrate 4, and two convex strips are milled on the lower surface of the upper substrate 1. The upper surface of the lower substrate 4 and the lower surface of the upper substrate 1 are coated with an adhesive 5. The lower substrate 4, the electric heating film 3, the copper foil electrode 2, and the upper substrate 1 are sequentially stacked and glued from bottom to top; at the same time, the convex strips of the upper substrate 1 are embedded in the grooves of the lower substrate 4, and the electric heating film 3 and the copper foil electrode 2 are located between the two grooves or the two convex strips; the lower substrate 4 and the upper substrate 1 are made of a high thermal conductivity substrate.

[0037] The high thermal conductivity substrate is prepared from the following raw materials: wood veneer, sodium chlorite solution, deionized water, and carbon nanotube / aluminum nitride / boron nitride modifier; wherein the carbon nanotube / aluminum nitride / boron nitride modifier is prepared from the following raw materials: aluminum nitride nanoparticles, boron nitride nanoparticles, epoxy resin solution, carbon nanotube powder, and epoxy resin curing agent.

[0038] This embodiment also provides a method for preparing a wooden household self-heating plate structure with high heat dissipation efficiency. The preparation process is as follows: Figure 1 :

[0039] S1. Preparation of carbon nanotube / aluminum nitride / boron nitride modifier: 1 wt% of aluminum nitride (spherical, 2-8 μm in diameter) and 1 wt% of boron nitride (hexagonal, 100-300 nm in diameter) nanoparticles were blended with epoxy resin solution (Solution A). After magnetic stirring at 500 rpm for 30 minutes, carbon nanotube powder (approximately 50 μm in length) was added at 2 wt% and sonicated at 500 W for 30 minutes. The blended solvent and epoxy resin curing agent (Solution B) were mixed in a 1:3 mass ratio and sonicated a second time for 15 minutes to obtain the carbon nanotube / aluminum nitride / boron nitride modifier (also known as a high thermal conductivity impregnation modifier).

[0040] S2. Pretreatment of wood substrate: Pine wood veneer (100 cm long, 18 cm wide, 3 mm thick) was completely immersed in a 4-5% sodium chlorite solution (pH 4-5) at a solid-liquid ratio of 4 g / L. After hydrothermal treatment at 85°C for 6 hours, lignin and hemicellulose were removed and the pore size and porosity of the wood were expanded. The wood substrate template was washed with deionized water several times, and then frozen at -40°C for 12 hours and vacuum dried for 24 hours to obtain a wood substrate template with three-dimensional through pores. The wood substrate template was completely immersed in the carbon nanotube / aluminum nitride / boron nitride modifier obtained in S1, and was taken out after immersion treatment at a vacuum degree of 0.08-0.1 MPa for 5-8 hours. After curing at room temperature, a high thermal conductivity substrate was obtained (see the microstructure of carbon nanotube / aluminum nitride / boron nitride modifier-epoxy resin). Figure 2 ).

[0041] S3, self-heating plate assembly: Figure 3 As shown, two grooves are milled on the surface of the high thermal conductivity substrate to form the lower substrate 4, and two convex strips are milled on the surface to form the upper substrate. The upper surface of the lower substrate 4 and the lower surface of the upper substrate 1 are coated or sprayed with adhesive 5 (the amount of adhesive applied on one side is 90-100 g / m 2 ) and then composited with electric heating film 3 (carbon crystal electric heating film) and copper foil electrode 2. After lamination and assembly, it was hot-pressed at 120℃ and 0.9 MPa for 6 min. After cooling for 24 h, a new type of wood self-heating board with high efficiency heat dissipation performance, structural stability and process feasibility was obtained (composite structure see Figure 3 , test results see Figure 4 and Figure 5 Before assembly, the copper foil electrode 2 is placed (fixed) on the electric heating film 3, and the copper foil electrode 2 and the electric heating film 3 are electrically connected. After assembly, the copper foil electrode 2 and the electric heating film 3 are located between two grooves or two ridges. The arrangement of the grooves and ridges prevents the copper foil electrode 2 and the electric heating film 3 from slipping during hot pressing of the assembly.

[0042] like Figure 2 As shown, Figure 2The cell wall structure is based on the cell wall of the wood substrate template. A carbon nanotube / aluminum nitride / boron nitride modifier (a high thermal conductivity impregnation modifier) fills the wood's cell cavity, reducing the volume of low-thermal-conductivity air within the cell cavity, thereby improving the thermal conductivity of the wood substrate. The high thermal conductivity impregnation modifier consists of multi-walled carbon nanotubes (approximately 50 μm in length), aluminum nitride (spherical with a diameter of 2-8 μm), and boron nitride (hexagonal with a diameter of 100-300 nm) in different forms, overlapping to form a complete, continuous thermal pathway.

[0043] like Figure 3 As shown in (a)-(b), the grooves and ridges constrain the heating film 3 and copper foil electrode 2 in a defined position, facilitating better assembly. This prevents slippage of the heating layer during hot pressing, and the margins on both sides facilitate tongue-and-groove processing around the sheet without damaging the heating layer, resulting in excellent machinability.

[0044] like Figure 4 As shown, the thermal conductivity of the self-heating board (high thermal conductivity wood substrate) is about 2.93 times that of ordinary plywood of the same thickness (such as Figure 4 As shown, ordinary plywood is 0.1372 W / (m·K) and self-heating board is 0.4018 W / (m·K).

[0045] 500W / m 2 The maximum surface temperature of a 5 mm thick wooden self-heating floor can reach 62°C under power, and the average stable temperature is about 58°C, which is much higher than the average stable temperature of ordinary plywood of 50°C ( Figure 5 This is a trend chart of the temperature rise and fall curve, showing the average stable temperature).

[0046] Preparation process of ordinary plywood (similar to S3, reference Figure 3 ): Mill two grooves on the surface of a pine veneer of the same material and size (length 100cm, width 18cm, thickness 3mm) as the lower substrate, and mill two convex strips on the surface as the upper substrate. The upper surface of the lower substrate and the lower surface of the upper substrate 1 are coated or sprayed with adhesive (single-sided adhesive coating amount 90-100 g / m 2 ) and then composited with a heating film (carbon crystal heating film) and copper foil electrodes. After lamination and assembly, the panels were hot-pressed at 120°C and 0.9 MPa for 6 minutes. After cooling for 24 hours, the control heating sheet was produced. The dimensions and specifications of the heating film and copper foil electrodes in the ordinary plywood were the same as those in the self-heating panels.

[0047] like Figure 6 As shown, wooden self-heating panels have broad application prospects in wall heating, floor heating, partitions, cabinets and other fields, and can play a role in heating, dehumidification and health care.

[0048] The protection scope of the present invention includes but is not limited to the above embodiments. The protection scope of the present invention is based on the claims. Any replacement, deformation, and improvement of the technology that can be easily thought of by those skilled in the art fall within the protection scope of the present invention.

Claims

1. A method for preparing a wooden household self-heating board structure with high heat dissipation efficiency, characterized in that: The following steps are involved: S1. Preparation of carbon nanotube / aluminum nitride / boron nitride modifier: aluminum nitride nanoparticles and boron nitride nanoparticles are separately blended with epoxy resin solution, magnetically stirred at a certain speed, and then carbon nanotube powder is added and ultrasonically treated; the ultrasonically treated blended solvent is uniformly stirred with epoxy resin curing agent and then ultrasonically treated a second time to finally obtain a carbon nanotube / aluminum nitride / boron nitride modifier; S2. Pretreatment of the wood substrate: The wood veneer is completely immersed in a sodium chlorite solution, and then subjected to hydrothermal treatment for a certain period of time to remove lignin and hemicellulose, thereby increasing the pore size and porosity of the wood; the wood substrate is washed multiple times with deionized water, and then frozen for a certain period of time, and then vacuum dried to obtain a wood substrate template with three-dimensional through pores; the wood substrate template is completely immersed in the carbon nanotube / aluminum nitride / boron nitride modifier obtained in S1, immersed in a certain vacuum for a certain period of time, and then removed and cured at room temperature to obtain a high thermal conductivity substrate; S3. Self-heating board assembly: two grooves are milled on the surface of the high thermal conductivity substrate as the lower substrate, two convex strips matching the grooves are milled on the surface of the high thermal conductivity substrate as the upper substrate, the upper surface of the lower substrate with grooves is coated or sprayed with adhesive, and the lower surface of the upper substrate with convex strips is coated or sprayed with adhesive, the lower substrate, electric heating film, electrode, and upper substrate are stacked and assembled from bottom to top, and the convex strips of the upper substrate are embedded in the grooves of the lower substrate, and the electric heating film and electrode are located between the two grooves or two convex strips; the stacked and assembled boards are hot-pressed at a certain temperature and pressure, and cooled for a certain period of time to obtain a new type of wood self-heating board.

2. The method for preparing a wooden household self-heating board structure with high heat dissipation efficiency according to claim 1, characterized in that: The S1 is specifically: Aluminum nitride nanoparticles and boron nitride nanoparticles were respectively blended with epoxy resin solution at a 1wt% addition amount, magnetically stirred at 500 rpm for 30 minutes, and carbon nanotube powder was added at a 1-3wt% addition amount, and ultrasonically treated at 500W for 30 minutes; the ultrasonically treated blended solvent and epoxy resin curing agent were stirred evenly in a mass ratio of 1:3, and then ultrasonically treated for a second time for 15 minutes to finally obtain a carbon nanotube / aluminum nitride / boron nitride modifier.

3. The method for preparing a wooden household self-heating board structure with high heat dissipation efficiency according to claim 1, characterized in that: The S2 is specifically: The wood veneer was completely immersed in a sodium chlorite solution with a concentration of 2%-8% at a solid-liquid ratio of 4g / L and a pH value of 4-5. After hydrothermal treatment at 85℃ for 6 hours, lignin and hemicellulose were removed and the pore size and porosity of the wood were expanded; it was washed with deionized water multiple times, then frozen at -40℃ for 12 hours, and vacuum dried for 24 hours to obtain a wood substrate template with three-dimensional through pores; the wood substrate template was completely immersed in the carbon nanotube / aluminum nitride / boron nitride modifier obtained in S1, immersed in a vacuum degree of 0.08-0.1 MPa for 5-8 hours, and then taken out and cured at room temperature to obtain a high thermal conductivity substrate.

4. The method for preparing a wooden household self-heating board structure with high heat dissipation efficiency according to claim 1, characterized in that: In the S3, the electric heating film is a graphene or carbon crystal electric heating film; the electrode is a copper foil electrode; the temperature of the hot pressing treatment is 120°C, the pressure of the hot pressing treatment is 0.9 MPa, the time of the hot pressing treatment is 6 minutes, and the cooling time is 24 hours.

5. A self-heating wooden board structure for household use with high efficiency heat dissipation, characterized in that: It includes a lower substrate, an upper substrate, an electric heating film and electrodes, wherein the electrodes are respectively arranged at both ends of the electric heating film, the upper surface of the lower substrate is milled with two grooves, and the lower surface of the upper substrate is milled with two convex strips, the upper surface of the lower substrate and the lower surface of the upper substrate are coated with adhesive, and the lower substrate, the electric heating film, the electrodes and the upper substrate are sequentially stacked and glued from bottom to top; at the same time, the convex strips of the upper substrate are embedded in the grooves of the lower substrate, and the electric heating film and the electrodes are located between the two grooves or the two convex strips; The lower substrate and the upper substrate are made of high thermal conductivity substrates.

6. The high-efficiency heat dissipation wooden household self-heating board structure according to claim 5, characterized in that: The high thermal conductivity substrate is prepared from the following raw materials: Wood veneer, sodium chlorite solution, deionized water, and carbon nanotube / aluminum nitride / boron nitride modifier; The carbon nanotube / aluminum nitride / boron nitride modifier is prepared from the following raw materials: Aluminum nitride nanoparticles, boron nitride nanoparticles, epoxy resin solution, carbon nanotube powder and epoxy resin curing agent.

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