Environment-friendly formaldehyde-free flame-retardant density board and preparation method thereof

Abstract

The environment-friendly formaldehyde-free flame-retardant density board comprises a board body and a coating board, multiple sets of fixing grooves are formed in the end face and the side wall of the board body, the multiple sets of fixing grooves are symmetrically arranged in pairs, two sets of sliding grooves are formed in the end face of the board body, and the two sets of sliding grooves communicate with the interiors of the adjacent fixing grooves correspondingly; the invention further provides a preparation method of the environment-friendly formaldehyde-free flame-retardant density board, and the preparation method comprises the following steps: S1, preparation of the base material layer, S2, preparation and coating of the flame-retardant layer, S3, preparation of the coating board, and S4, overall assembly of the board. The coating plate and the plate body are designed to be of a separable structure, so that when the coating is damaged or abraded, only the coating plate needs to be replaced, the whole plate body does not need to be replaced, the maintenance and replacement cost is effectively reduced, meanwhile, the replacement time is shortened, and the maintenance efficiency is improved; the high cost and the tedious process of comprehensively replacing the whole plate are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of density boards, and in particular to an environmentally friendly formaldehyde-free flame-retardant density board and a preparation method thereof. Background Art

[0002] Fiberboard, also known as density board, is a man-made board made from wood fiber or other plant fiber as raw materials, with urea-formaldehyde resin or other suitable adhesives applied.

[0003] In public places such as hotel lobbies, restaurants, shopping malls, and schools, density boards are often used as wall decoration boards or display boards. These areas are usually crowded with people, and the pushing and pulling of objects, collisions, and frequent friction between people will cause the coating to wear. However, the surface coating of most density boards on the market is designed as an integrated design with the board. Once the coating is damaged, the entire board usually needs to be replaced, which not only increases the maintenance cost, but also reduces the service life and maintenance efficiency of the board. Therefore, it is necessary to propose an environmentally friendly formaldehyde-free flame-retardant density board and a preparation method thereof to address the above problems. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an environmentally friendly formaldehyde-free flame-retardant density board and a preparation method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An environmentally friendly formaldehyde-free flame-retardant density board comprises a board body and a coating board, wherein the end face and side wall of the board body are provided with a plurality of groups of fixed grooves, and the plurality of groups of the fixed grooves are symmetrically arranged in pairs, and the end face of the board body is provided with two groups of slide grooves, and the two groups of the slide grooves are respectively connected to the interior of the adjacent fixed grooves, and the lower end face of the coating board is fixedly connected with a plurality of groups of fixed blocks 1 and fixed blocks 2, and the positions of the plurality of groups of fixed blocks 1 and fixed blocks 2 correspond one-to-one to the positions of the plurality of groups of fixed grooves, and are slidably connected one-to-one in the corresponding fixed grooves, and the two groups of the fixed blocks 1 are respectively advanced into the corresponding fixed grooves through the two groups of slide grooves, and the side wall of the board body is provided with two groups of limit grooves, and the two groups of the limit grooves are both equipped with limit mechanisms for limiting the coating board.

[0007] Preferably, the limiting mechanism comprises a limiting cylinder slidably connected in the limiting groove, one end of the limiting cylinder extends into the fixing groove, and the outer wall of the limiting cylinder is in close contact with the side wall of the coating plate.

[0008] Preferably, the two groups of fixing blocks 2 are both located at the edge of the coating plate, and there is a certain gap between them and the edge of the coating plate.

[0009] Preferably, the outer walls of the two groups of fixing blocks 1 and 2 and the inner walls of the fixing grooves are T-shaped, and the outer walls of the fixing blocks 1 and 2 fit in with the inner walls of the fixing grooves.

[0010] Preferably, one end of the limiting cylinder is open, a sliding rod is fixedly connected to the inner wall of the limiting groove, and the limiting cylinder is slidably connected to the outer wall of the sliding rod.

[0011] Preferably, a spring is fixedly connected to the end of the sliding rod, and the other end of the spring is fixedly connected to the inner wall of the limiting cylinder.

[0012] Preferably, a paddle is fixedly connected to the outer wall of the limiting cylinder, and the side wall of the paddle is in a horizontal state with the side wall of the plate body.

[0013] Preferably, the board body consists of a flame retardant layer and a substrate layer, the substrate layer is formed by hot pressing at high temperature and high pressure with formaldehyde-free resin and wood fiber in a certain proportion, the flame retardant layer is formed by mixing formaldehyde-free resin and environmentally friendly flame retardant additives, the flame retardant layer is sprayed on the outer wall of the substrate layer, the coating board covers the surface of the flame retardant layer, and its outer wall is sprayed with environmentally friendly water-based paint, and the coating board adopts environmentally friendly alcohol-free density fiberboard.

[0014] The present invention also provides a method for preparing an environmentally friendly formaldehyde-free flame-retardant density board, comprising the following steps:

[0015] S1. Preparation of substrate layer

[0016] Raw material preparation: select wood fiber, screen it, remove impurities and oversized particles, ensure that the fiber length is between 1-5mm, and then dry it to control the moisture content to 5-10%; at the same time, prepare formaldehyde-free resin adhesive, and formaldehyde-free resin can be selected from isocyanate resin, etc., and prepare raw materials according to the mass ratio of wood fiber to formaldehyde-free resin of 8-10:1;

[0017] Mixing and molding: fully mix the dried wood fiber and the formaldehyde-free resin adhesive in a mixer at a stirring speed of 1000-1500rpm for 10-20 minutes; pour the mixed materials into a mold and perform hot pressing molding at a temperature of 180-220℃ and a pressure of 3-5MPa. The hot pressing time is determined according to the thickness of the board, generally 2-3 minutes per millimeter of thickness, to obtain a primary finished product of the substrate layer;

[0018] S2. Preparation and coating of flame retardant layer

[0019] Flame retardant mixing: select environmentally friendly flame retardant additives, such as magnesium hydroxide, aluminum hydroxide, etc., and mix them with formaldehyde-free resin adhesive; the mass ratio of flame retardant additive to formaldehyde-free resin is 3-5:1, and high-speed stirring equipment is used for stirring at a speed of 1500-2000rpm for 15-30 minutes to uniformly disperse the flame retardant additive in the formaldehyde-free resin to obtain a flame retardant coating;

[0020] Coating process: The prepared flame retardant coating is applied to the surface of the primary finished product of the substrate layer by spraying or roller coating, and the coating amount is controlled at 100-200g / m²; after coating, it is dried at a temperature of 60-80℃ for 2-4 hours to solidify the flame retardant layer to obtain a plate with a flame retardant layer;

[0021] S3. Coating plate preparation

[0022] Board selection: Use environmentally friendly alcohol-free density fiberboard as the base material of the coating board, with a thickness of 2-5mm; polish its surface to remove surface roughness, and clean the surface dust with a vacuum cleaner after polishing;

[0023] Paint spraying: spray environmentally friendly water-based paint on the polished surface of environmentally friendly alcohol-free density fiberboard. The paint can be water-based polyurethane paint, etc.; first mix the paint to a suitable viscosity, add an appropriate amount of deionized water to dilute it, and the dilution ratio is paint: water = 10: 1-2; use a spray gun for spraying, the spraying pressure is 0.3-0.5MPa, the spraying distance is 20-30cm, ensure the coating is uniform, and the coating thickness is controlled at 50-100μm; after spraying, dry it naturally at room temperature for 24-48 hours to obtain the finished coated board;

[0024] S4. Overall assembly of panels

[0025] Processing of fixed grooves and slide grooves: fixed grooves are processed on the end face and side wall of the plate with flame retardant layer. The fixed grooves are machined by mechanical milling and are symmetrically arranged in pairs. The groove type is T-shaped, the groove depth is 5-10mm, and the groove width is 8-12mm; two sets of slide grooves are processed on the end face of the plate. The slide grooves are connected with the adjacent fixed grooves. The width of the slide grooves is 5-8mm, and the depth is the same as that of the fixed grooves.

[0026] Installation of limit grooves and limit mechanisms: Two sets of limit grooves are processed on the side wall of the plate, with a depth of 10-15mm and a width of 8-10mm; the slide bar is installed on the inner wall of the limit groove, and the length of the slide bar is the same as the depth of the limit groove; the limit cylinder is put on the slide bar, one end of the limit cylinder is open, one end of the spring is fixed to the end of the slide bar, and the other end is fixed to the inner wall of the limit cylinder. When the spring is in a natural state, one end of the limit cylinder extends out of a part of the limit groove; a paddle is installed on the outer wall of the limit cylinder, and the paddle is parallel to the side wall of the plate;

[0027] Assembly of the coating plate and the plate body: align the fixed block 1 (T-shaped structure, the size is adapted to the fixed groove and the slide groove) on the lower end surface of the coating plate with the slide groove, insert the fixed block 1 into the slide groove and push it into the fixed groove. At this time, the fixed block 2 (also a T-shaped structure, located at the edge of the coating plate) is located at the notch of the fixed groove; turn the paddle to compress the spring to retract the limit cylinder into the limit groove, push the coating plate to make the fixed block 2 completely enter the fixed groove, release the paddle, the spring rebounds to make the limit cylinder extend out and clamp the fixed block 2, and the assembly is completed.

[0028] The present invention has the following beneficial effects:

[0029] 1. The present invention designs the coating plate and the plate body as a separable structure, so that when the coating is damaged or worn, only the coating plate needs to be replaced without replacing the entire plate body, which effectively reduces the cost of repair and replacement, and also shortens the replacement time, improves maintenance efficiency, and avoids the high cost and cumbersome process of fully replacing the entire plate.

[0030] 2. The present invention adopts formaldehyde-free resin and environmentally friendly materials, which not only improves the strength, stability and flame retardant properties of the board body, but also avoids the release of harmful substances, meets environmental protection standards, and minimizes the impact on the environment while ensuring safety. It is particularly suitable for application scenarios with high environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of an environmentally friendly formaldehyde-free flame-retardant density board proposed by the present invention;

[0032] Figure 2 for Figure 1 Structural diagram.

[0033] Figure 3 for Figure 1 Cross-sectional view of the middle plate body.

[0034] Figure 4 for Figure 1 Cross-sectional view of the middle plate body and coated plate.

[0035] Figure 5 for Figure 3 Cross-sectional view of the middle limit cylinder.

[0036] In the figure: 1. Plate body; 2. Coating plate; 3. Fixing groove; 4. Fixing block 1; 5. Sliding groove; 6. Fixing block 2; 7. Limiting groove; 8. Pick; 9. Flame retardant layer; 10. Base material layer; 11. Sliding rod; 12. Limiting cylinder; 13. Spring. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0038] Reference Figure 1-5, an environmentally friendly formaldehyde-free flame-retardant density board, including a board body 1 and a coating board 2, the board body 1 end surface and side wall are provided with multiple groups of fixed grooves 3, the multiple groups of fixed grooves 3 are symmetrically arranged in pairs, the board body 1 end surface is provided with two groups of slide grooves 5, the two groups of slide grooves 5 are respectively connected to the inner part of the adjacent fixed grooves 3, the lower end surface of the coating board 2 is fixedly connected with multiple groups of fixed blocks 1 4 and fixed blocks 2 6, the positions of the multiple groups of fixed blocks 1 4 and fixed blocks 2 6 correspond to the positions of the multiple groups of fixed grooves 3 one by one, and are slidably connected one by one in the corresponding fixing grooves 3, the two groups of fixed blocks 1 4 are respectively progressively inserted into the corresponding fixing grooves 3 through the two groups of slide grooves 5, the board body 1 side wall is provided with two groups of limiting grooves 7, the two groups of limiting grooves 7 are both equipped with limiting mechanisms for limiting the coating board 2; through the design that the coating board 2 and the board body 1 are detachable, when the coating is damaged or worn, only the coating board 2 can be replaced without replacing the entire board body 1, reducing the cost and time of replacement and improving maintenance efficiency.

[0039] The limiting mechanism includes a limiting cylinder 12 slidably connected in the limiting groove 7, one end of the limiting cylinder 12 extends into the fixing groove 3, the outer wall of the limiting cylinder 12 is in contact with the side wall of the coating plate 2, the two sets of fixing blocks 6 are located at the edge of the coating plate 2, and there is a certain gap between the two sets of fixing blocks 1 and 2 and the inner wall of the fixing groove 3. The outer walls of the two sets of fixing blocks 1 and 2 and the inner wall of the fixing groove 3 are all T-shaped, the outer walls of the fixing blocks 1 and 2 and the inner wall of the fixing groove 3 are in contact with each other, one end of the limiting cylinder 12 is open, and the inner wall of the limiting groove 7 is fixedly connected with a slide rod 1 1, the limiting cylinder 12 is slidably connected to the outer wall of the slide rod 11, the end of the slide rod 11 is fixedly connected to a spring 13, the other end of the spring 13 is fixedly connected to the inner wall of the limiting cylinder 12, the outer wall of the limiting cylinder 12 is fixedly connected to a paddle 8, and the side wall of the paddle 8 is in a horizontal state with the side wall of the plate body 1; the setting of the limiting cylinder 12 can limit the position of the coating plate 2 after the coating plate 2 and the plate body 1 are engaged, so as to ensure the stability of the two after installation, and the setting of the spring 13 can further limit the position of the limiting cylinder 12.

[0040] The board body 1 is composed of a flame retardant layer 9 and a base material layer 10. The base material layer 10 is formed by hot pressing at high temperature and high pressure with formaldehyde-free resin and wood fiber in a certain proportion. The flame retardant layer 9 is made of a mixture of formaldehyde-free resin and environmentally friendly flame retardant additives. The flame retardant layer 9 is sprayed on the outer wall of the base material layer 10. The coating board 2 covers the surface of the flame retardant layer 9, and its outer wall is sprayed with environmentally friendly water-based paint. The coating board 2 adopts environmentally friendly alcohol-free density fiberboard.

[0041] When the cam 12 is in the closed position, the spring 13 is pressed against the locking nut 14 and the locking nut 12 is engaged with the locking nut 14. When the cam 12 is in the closed position, the locking nut 12 is engaged with the locking nut 14 and the locking nut 12 is engaged with the locking nut 14. When the cam 12 is in the closed position, the locking nut 12 is engaged with the locking nut 14 and the locking nut 12 is engaged with the locking nut 14.

[0042] The substrate layer 10 is formed by hot pressing at high temperature and high pressure, which ensures the strength and stability of the board body 1. At the same time, the formaldehyde-free resin avoids the release of harmful substances and meets environmental protection standards. The flame retardant layer 9 is made of a mixture of formaldehyde-free resin and environmentally friendly flame retardant additives, which not only improves the flame retardant properties of the board, but also maintains the environmental protection characteristics and avoids harmful components that may be contained in common flame retardant materials. The coating board 2 uses environmentally friendly alcohol-free density fiberboard and sprays environmentally friendly water-based paint on the surface, which further improves the durability and wear resistance of the surface, while avoiding harmful substances in traditional solvent-based paints, ensuring safe and efficient performance in all kinds of use environments. The overall design not only enhances the functionality of the board body 1, but also minimizes the impact on the environment.

[0043] The present invention also provides a method for preparing an environmentally friendly formaldehyde-free flame-retardant density board, comprising the following steps:

[0044] S1. Preparation of substrate layer

[0045] Raw material preparation: select wood fiber, screen it, remove impurities and oversized particles, ensure that the fiber length is between 1-5mm, and then dry it to control the moisture content to 5-10%; at the same time, prepare formaldehyde-free resin adhesive, and formaldehyde-free resin can be selected from isocyanate resin, etc., and prepare raw materials according to the mass ratio of wood fiber to formaldehyde-free resin of 8-10:1;

[0046] Mixing and molding: fully mix the dried wood fiber and the formaldehyde-free resin adhesive in a mixer at a stirring speed of 1000-1500rpm for 10-20 minutes; pour the mixed materials into a mold and perform hot pressing molding at a temperature of 180-220℃ and a pressure of 3-5MPa. The hot pressing time is determined according to the thickness of the board, generally 2-3 minutes per millimeter of thickness, to obtain a primary finished product of the substrate layer;

[0047] S2. Preparation and coating of flame retardant layer

[0048] Flame retardant mixing: select environmentally friendly flame retardant additives, such as magnesium hydroxide, aluminum hydroxide, etc., and mix them with formaldehyde-free resin adhesive; the mass ratio of flame retardant additive to formaldehyde-free resin is 3-5:1, and high-speed stirring equipment is used for stirring at a speed of 1500-2000rpm for 15-30 minutes to uniformly disperse the flame retardant additive in the formaldehyde-free resin to obtain a flame retardant coating;

[0049] Coating process: The prepared flame retardant coating is applied to the surface of the primary finished product of the substrate layer by spraying or roller coating, and the coating amount is controlled at 100-200g / m²; after coating, it is dried at a temperature of 60-80℃ for 2-4 hours to solidify the flame retardant layer to obtain a plate with a flame retardant layer;

[0050] S3. Coating plate preparation

[0051] Board selection: Use environmentally friendly alcohol-free density fiberboard as the base material of the coating board, with a thickness of 2-5mm; polish its surface to remove surface roughness, and clean the surface dust with a vacuum cleaner after polishing;

[0052] Paint spraying: spray environmentally friendly water-based paint on the polished surface of environmentally friendly alcohol-free density fiberboard. The paint can be water-based polyurethane paint, etc.; first mix the paint to a suitable viscosity, add an appropriate amount of deionized water to dilute it, and the dilution ratio is paint: water = 10: 1-2; use a spray gun for spraying, the spraying pressure is 0.3-0.5MPa, the spraying distance is 20-30cm, ensure the coating is uniform, and the coating thickness is controlled at 50-100μm; after spraying, dry it naturally at room temperature for 24-48 hours to obtain the finished coated board;

[0053] S4. Overall assembly of panels

[0054] Processing of fixed grooves and slide grooves: fixed grooves are processed on the end face and side wall of the plate with flame retardant layer. The fixed grooves are machined by mechanical milling and are symmetrically arranged in pairs. The groove type is T-shaped, the groove depth is 5-10mm, and the groove width is 8-12mm; two sets of slide grooves are processed on the end face of the plate. The slide grooves are connected with the adjacent fixed grooves. The width of the slide grooves is 5-8mm, and the depth is the same as that of the fixed grooves.

[0055] Installation of limit grooves and limit mechanisms: Two sets of limit grooves are processed on the side wall of the plate, with a depth of 10-15mm and a width of 8-10mm; the slide bar is installed on the inner wall of the limit groove, and the length of the slide bar is the same as the depth of the limit groove; the limit cylinder is put on the slide bar, one end of the limit cylinder is open, one end of the spring is fixed to the end of the slide bar, and the other end is fixed to the inner wall of the limit cylinder. When the spring is in a natural state, one end of the limit cylinder extends out of a part of the limit groove; a paddle is installed on the outer wall of the limit cylinder, and the paddle is parallel to the side wall of the plate;

[0056] Assembly of the coating plate and the plate body: align the fixed block 1 (T-shaped structure, the size is adapted to the fixed groove and the slide groove) on the lower end surface of the coating plate with the slide groove, insert the fixed block 1 into the slide groove and push it into the fixed groove. At this time, the fixed block 2 (also a T-shaped structure, located at the edge of the coating plate) is located at the notch of the fixed groove; turn the paddle to compress the spring to retract the limit cylinder into the limit groove, push the coating plate to make the fixed block 2 completely enter the fixed groove, release the paddle, the spring rebounds to make the limit cylinder extend out and clamp the fixed block 2, and the assembly is completed.

[0057] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An environmentally friendly formaldehyde-free flame-retardant density board, comprising a board body (1) and a coating board (2), characterized in that: The plate body (1) has a plurality of groups of fixed grooves (3) on its end surface and side wall, and the plurality of groups of fixed grooves (3) are symmetrically arranged in pairs. The plate body (1) has two groups of slide grooves (5) on its end surface, and the two groups of slide grooves (5) are respectively connected to the inside of the adjacent fixed grooves (3). The coating plate (2) has a plurality of groups of fixed blocks (4) and fixed blocks (6) fixedly connected to its lower end surface, and the positions of the plurality of groups of fixed blocks (4) and fixed blocks (6) correspond to the positions of the plurality of groups of fixed grooves (3) one by one, and are slidably connected one by one in the corresponding fixed grooves (3). The two groups of fixed blocks (4) are respectively progressively advanced into the corresponding fixed grooves (3) through the two groups of slide grooves (5). The plate body (1) has two groups of limit grooves (7) on its side wall, and the two groups of limit grooves (7) are both equipped with limit mechanisms for limiting the coating plate (2).

2. The environmentally friendly formaldehyde-free flame-retardant density board according to claim 1, characterized in that: The limiting mechanism comprises a limiting cylinder (12) slidably connected in the limiting groove (7), one end of the limiting cylinder (12) extends into the fixing groove (3), and the outer wall of the limiting cylinder (12) is in close contact with the side wall of the coating plate (2).

3. The environmentally friendly formaldehyde-free flame-retardant density board according to claim 2, characterized in that: The two groups of fixing blocks 2 (6) are both located at the edge of the coating plate (2), and there is a certain gap between them and the edge of the coating plate (2).

4. The environmentally friendly formaldehyde-free flame-retardant density board according to claim 3, characterized in that: The outer walls of the two groups of fixing blocks 1 (4) and 2 (6) and the inner walls of the fixing grooves (3) are all T-shaped, and the outer walls of the fixing blocks 1 (4) and 2 (6) fit in with the inner walls of the fixing grooves (3).

5. The environmentally friendly formaldehyde-free flame-retardant density board according to claim 4, characterized in that: One end of the limiting cylinder (12) is open, the inner wall of the limiting groove (7) is fixedly connected to a sliding rod (11), and the limiting cylinder (12) is slidably connected to the outer wall of the sliding rod (11).

6. The environmentally friendly formaldehyde-free flame-retardant density board according to claim 5, characterized in that: A spring (13) is fixedly connected to the end of the sliding rod (11), and the other end of the spring (13) is fixedly connected to the inner wall of the limiting cylinder (12).

7. The environmentally friendly formaldehyde-free flame-retardant density board according to claim 6, characterized in that: The outer wall of the limiting cylinder (12) is fixedly connected with a paddle (8), and the side wall of the paddle (8) is in a horizontal state with the side wall of the plate body (1).

8. The environmentally friendly formaldehyde-free flame-retardant density board according to claim 7, characterized in that: The board body (1) is composed of a flame retardant layer (9) and a base material layer (10); the base material layer (10) is formed by hot pressing at high temperature and high pressure with formaldehyde-free resin and wood fiber in a certain proportion; the flame retardant layer (9) is formed by mixing formaldehyde-free resin and environmentally friendly flame retardant additives; the flame retardant layer (9) is sprayed on the outer wall of the base material layer (10); the coating board (2) covers the surface of the flame retardant layer (9), and its outer wall is sprayed with environmentally friendly water-based paint; the coating board (2) is made of environmentally friendly alcohol-free density fiberboard.

9. A method for preparing an environmentally friendly formaldehyde-free flame-retardant density board and its preparation method: characterized in that, The following steps are included: S1. Preparation of substrate layer Raw material preparation: select wood fiber, screen it, remove impurities and oversized particles, ensure that the fiber length is between 1-5mm, and then dry it to control the moisture content to 5-10%; at the same time, prepare formaldehyde-free resin adhesive, and the formaldehyde-free resin can be selected from isocyanate resin, etc., and prepare the raw materials according to the mass ratio of wood fiber to formaldehyde-free resin of 8-10:1; Mixing and molding: fully mix the dried wood fiber and the formaldehyde-free resin adhesive in a mixer at a stirring speed of 1000-1500rpm for 10-20 minutes; pour the mixed materials into a mold and perform hot pressing molding at a temperature of 180-220℃ and a pressure of 3-5MPa. The hot pressing time is determined according to the thickness of the board, generally 2-3 minutes per millimeter of thickness, to obtain a primary finished product of the substrate layer; S2. Preparation and coating of flame retardant layer Flame retardant mixing: select environmentally friendly flame retardant additives, such as magnesium hydroxide, aluminum hydroxide, etc., and mix them with formaldehyde-free resin adhesive; the mass ratio of flame retardant additive to formaldehyde-free resin is 3-5:1, and high-speed stirring equipment is used for stirring at a speed of 1500-2000rpm for 15-30 minutes to uniformly disperse the flame retardant additive in the formaldehyde-free resin to obtain a flame retardant coating; Coating process: The prepared flame retardant coating is applied to the surface of the primary finished product of the substrate layer by spraying or roller coating, and the coating amount is controlled at 100-200g / m²; after coating, it is dried at a temperature of 60-80℃ for 2-4 hours to solidify the flame retardant layer to obtain a plate with a flame retardant layer; S3. Coating plate preparation Board selection: Use environmentally friendly alcohol-free density fiberboard as the base material of the coating board, with a thickness of 2-5mm; polish its surface to remove surface roughness, and clean the surface dust with a vacuum cleaner after polishing; Paint spraying: spray environmentally friendly water-based paint on the polished surface of environmentally friendly alcohol-free density fiberboard. The paint can be water-based polyurethane paint, etc.; first mix the paint to a suitable viscosity, add an appropriate amount of deionized water to dilute it, and the dilution ratio is paint: water = 10: 1-2; use a spray gun for spraying, the spraying pressure is 0.3-0.5MPa, the spraying distance is 20-30cm, ensure that the coating is uniform, and the coating thickness is controlled at 50-100μm; after spraying, dry it naturally at room temperature for 24-48 hours to obtain a finished coated board; S4. Overall assembly of panels Processing of fixed grooves and slide grooves: fixed grooves are processed on the end face and side wall of the plate with flame retardant layer. The fixed grooves are machined by mechanical milling and are symmetrically arranged in pairs. The groove type is T-shaped, the groove depth is 5-10mm, and the groove width is 8-12mm; two sets of slide grooves are processed on the end face of the plate. The slide grooves are connected with the adjacent fixed grooves. The width of the slide grooves is 5-8mm, and the depth is the same as that of the fixed grooves. Installation of limit grooves and limit mechanisms: Two sets of limit grooves are processed on the side wall of the plate, with a depth of 10-15mm and a width of 8-10mm; the slide bar is installed on the inner wall of the limit groove, and the length of the slide bar is the same as the depth of the limit groove; the limit cylinder is put on the slide bar, one end of the limit cylinder is open, one end of the spring is fixed to the end of the slide bar, and the other end is fixed to the inner wall of the limit cylinder. When the spring is in a natural state, one end of the limit cylinder extends out of a part of the limit groove; a paddle is installed on the outer wall of the limit cylinder, and the paddle is parallel to the side wall of the plate; Assembly of the coating plate and the plate body: align the fixed block 1 (T-shaped structure, the size is adapted to the fixed groove and the slide groove) on the lower end surface of the coating plate with the slide groove, insert the fixed block 1 into the slide groove and push it into the fixed groove. At this time, the fixed block 2 (also a T-shaped structure, located at the edge of the coating plate) is located at the notch of the fixed groove; turn the paddle to compress the spring to retract the limit cylinder into the limit groove, push the coating plate to make the fixed block 2 completely enter the fixed groove, release the paddle, the spring rebounds to make the limit cylinder extend out and clamp the fixed block 2, and the assembly is completed.

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