Grade-A wood fireproof plate and preparation method thereof

Abstract

The invention discloses an A-grade wood fireproof plate and a preparation method thereof, and belongs to the technical field of fireproof plates. The grade-A wood fireproof plate comprises the following components in percentage by mass: 20%-40% of light calcined magnesia powder, 5%-30% of a magnesium sulfate solution, 10%-30% of wood fibers, 20%-40% of inorganic filler and 0.5%-1.5% of an additive. The inorganic filler is an inorganic mineral filler with the specific gravity larger than 4, the mass ratio of the inorganic filler to the light calcined magnesia is 1: (0.8-1.2), and the particle size of the inorganic filler is not smaller than 2000 meshes. By adopting the grade-A wood fireproof plate and the preparation method thereof, the problems that an existing wood fireproof plate is prone to cracking and poor in fireproof performance can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of fireproof board materials, and in particular to an A-grade wooden fireproof board material and a preparation method thereof. Background Art

[0002] Wood fireproof board is a building material that has been specially treated or composited to improve its fire resistance. Wood fireproof board is generally treated by physical or chemical methods on the outer surface of wood to make the wood have a higher fire resistance level. The commonly used physical or chemical methods are impregnation, coating or composite. The wood fireproof board produced by this method is still wood in nature, so its fire resistance is relatively poor.

[0003] Magnesium oxysulfate board is a board made of magnesium oxysulfate cement with magnesium oxide, magnesium sulfate and water as the main components, with a certain proportion of lightweight aggregate (such as perlite, expanded vitrified microspheres, etc.), reinforcing fibers (such as glass fiber, plant fiber, etc.) and additives added, and made through mixing, molding, curing and other processes. Magnesium oxysulfate board containing wood fiber has good fire resistance. The higher the content of wood fiber in the wood fireproof board of magnesium oxysulfate board, the higher its calorific value and the worse the fireproof performance. In order to improve the fireproof performance of wood fireproof board, the content of wood fiber needs to be controlled. However, reducing the content of wood fiber means that the content of magnesium oxide and brine needs to be increased, which leads to an increase in the reaction temperature, which is easy to cause cracking of the wood fireproof board, affecting the yield and fireproof performance of the wood fireproof board. Summary of the invention

[0004] The purpose of the present invention is to provide an A-grade wooden fireproof board and a preparation method thereof, so as to solve the problem that the existing wooden fireproof board is easy to crack and has poor fireproof performance.

[0005] To achieve the above-mentioned purpose, the present invention provides an A-grade wood fireproof board, comprising the following components in percentage by mass: 20%-40% light-burned magnesium oxide powder, 5%-30% magnesium sulfate solution, 10%-30% wood fiber, 20%-40% inorganic filler, and 0.5%-1.5% additives.

[0006] Preferably, the light-burned magnesium oxide has a magnesium content of 85wt%-90wt%, an activity of not less than 60%, and a calcium oxide content of less than 2wt%.

[0007] Preferably, the Baume degree of the magnesium sulfate solution is 21-30.

[0008] Preferably, the particle size of the wood fiber is 40-60 mesh.

[0009] Preferably, the inorganic filler is an inorganic mineral filler with a specific gravity greater than 4, the mass ratio of the inorganic filler to the light-burned magnesium oxide is 1:0.8-1.2, and the particle size of the inorganic filler is not less than 2000 meshes.

[0010] Preferably, the inorganic filler is one of barium sulfate and perovskite sulfate.

[0011] Preferably, the additive is 2%-4% of the mass of the light-burned magnesium oxide, and the additive includes soluble sulfate: soluble phosphate: polyvinyl alcohol: cellulose ether: silicone oil in a mass percentage of 1:1:3:3:0.02.

[0012] The method for preparing the above-mentioned Class A wood fireproof board comprises the following steps: S1. Add magnesium sulfate solution and additives into the brine pool according to mass percentage, and stir evenly to obtain a brine solution; S2, adding wood fiber and light-burned magnesium oxide powder into the first mixer according to the mass percentage, and adding brine solution into the first mixer, stirring once, the stirring time is 3min-8min; after the first stirring is completed, the mixture is sent into the second mixer for secondary stirring; S3, the raw materials mixed in the second mixer enter the first paving machine and the second paving machine respectively through the conveyor belt and the dividing belt, the first mechanical arm sends the recovered pad into the loading rail, the pad enters the first conveyor through the loading rail, and the first paving machine and the second paving machine perform two paving on the pad; S4. The paved plates are sent to the pre-pressing machine for pre-pressing via the first conveyor, and are trimmed by the trimming machine on the first conveyor; the trimmed plates are transferred to the bottom mold under the action of the second mechanical arm for stacking, and the number of stacked plates is not less than 100; S5. After the bottom mold is stacked, it is sent to the pressing machine through the second conveyor for mold closing and pressing. The pressed plate enters the curing conveyor track through the second conveyor and is sent to the curing room for primary curing; S6, after the first curing is completed, the plate and the bottom mold are returned to the pressing machine through the curing conveyor rail and the second conveyor for demolding, and the demolded plate and the bottom mold enter the first plate separator through the second conveyor and the curing conveyor rail for plate separation, and the first plate separator separates the plate and the pad, and the pad is stacked on one side of the first plate separator; S7, the bottom mold after the plate is separated is transported to the discharge end of the first conveyor through the first recovery rail and the second recovery rail for recycling; S8, the pads are dispersed one by one on the third conveyor under the action of the second plate separator, the bottom plates are cleaned by the cleaning machine arranged on the third conveyor, cooled by the cooler, shaped by the shaping machine, and then stacked, and then sent to the loading rail by the first mechanical arm for recycling; S9. The separated plates are transported to the cutting machine through a conveyor, and the four sides are cut by the cutting machine, and the plates are cut into two parts. After being stacked by a stacking machine, secondary curing is carried out at room temperature for 7 days. After the curing is completed, they are baked, shaped, and polished. The surface error of the plate after polishing is not more than 10 wires.

[0013] Preferably, in S3, the pad is a square aluminum plate with a side length of not less than 2600.

[0014] Preferably, in S5, the pressure of the press is 11 MPa-15 MPa; the primary curing temperature of the curing room is 40° C.-60° C., and the primary curing time is 3 h-5 h.

[0015] The advantages and positive effects of the Class A wood fireproof board and the preparation method thereof of the present invention are: 1. The present invention reduces the content of wood fiber, which is beneficial to improve the fire resistance of wood fireproof board and make its calorific value meet the standard. Using barium sulfate with high specific gravity and small particle size as filler can reduce the content of magnesium sulfate and magnesium oxide, reduce the reaction temperature, reduce the cracking of the board, and improve the yield and quality of the board.

[0016] 2. The additive of the present invention can lubricate the internal structure of the board, and the sulfate ions in the additive can inhibit alkali return and reduce the alkali return phenomenon of the board. Phosphate ions can absorb carbon dioxide and sulfur dioxide, form a passivation film on the surface of the board, wrap free magnesium oxide and magnesium sulfate, improve the anti-aging ability and water resistance of the board, and help improve the strength of the board.

[0017] 3. The present invention adopts a wide aluminum plate as a pad. The aluminum plate has good thermal conductivity, can improve the uniformity of the plate temperature, promote uniform reaction inside the plate, make the reaction inside the plate fully proceed, reduce the probability of subsequent secondary reaction, and reduce the deformation rate of the plate.

[0018] 4. The square wide pad is used. The pad is large in size and the produced board area is large, which improves the stability of the board stacking and the stacking height can be increased by 30%-50%. And after pressing once, it can be divided into two to get two boards, and the production capacity is increased by 160%-200%; and the automatic production of fireproof boards is realized, which is conducive to improving production efficiency.

[0019] 5. The fireproof performance of the fireproof board described in the present invention reaches above the national standard A2 level, and the static bending strength of the board reaches above 28MPa, and the internal bonding strength is above 1.5MPa. It has excellent fireproof performance and strength and can be used as flooring.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a process flow chart of a wood fireproof board according to an embodiment of the present invention; Figure 2 This is a production flow chart of a wood fireproof board according to an embodiment of the present invention.

[0022] Reference numerals 1. Silo; 2. Brine pool; 3. First mixer; 4. Second mixer; 5. Conveyor belt; 6. First paving machine; 7. Second paving machine; 8. First conveyor; 9. Bottom mold; 10. Second conveyor; 11. Press; 12. Maintenance conveyor rail; 13. First panel separator; 14. First recovery rail; 15. Second recovery rail; 16. Second panel separator; 17. Third conveyor; 18. Cutting machine; 19. Panel stacking machine; 20. First robotic arm; 21. Second robotic arm; 22. Loading rail. DETAILED DESCRIPTION

[0023] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application. In the event of any inconsistency, the meaning described in this specification or the meaning derived from the contents recorded in this specification shall prevail. In addition, the terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application. In order to accurately describe the technical content in this application and to accurately understand the present invention, the following explanations or definitions are given to the terms used in this specification before describing the specific embodiments: The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] A class A wood fireproof board comprises the following components in percentage by mass: 20%-40% of lightly burned magnesium oxide powder, 5%-30% of magnesium sulfate solution, 10%-30% of wood fiber, 20%-40% of inorganic filler, and 0.5%-1.5% of additives.

[0026] Pigments can be added to the magnesium sulfate solution as needed, with the mass percentage of the pigment being 0.1%-0.5%.

[0027] The magnesium content in light-burned magnesium oxide is 85wt%-90wt%, the activity is not less than 60%, and the calcium oxide content is less than 2wt%.

[0028] The Baume degree of the magnesium sulfate solution is 21-30. The mass ratio of the magnesium sulfate solution to magnesium oxide is 0.3-0.9:1.

[0029] The particle size of wood fiber is 40-60 mesh. The content of wood fiber in wood fireproof board is controlled below 30% to reduce the calorific value of wood fireproof board and improve the fireproof performance of wood fireproof board.

[0030] The inorganic filler is an inorganic mineral filler with a specific gravity greater than 4, and the mass ratio of the inorganic filler to the light-burned magnesium oxide is 1:0.8-1.2, preferably 1:1. The particle size of the inorganic filler is not less than 2000 meshes.

[0031] The inorganic filler is one of barium sulfate and perovskite sulfate, preferably barium sulfate. Using barium sulfate with high specific gravity and small particle size as a filler can reduce the content of magnesium sulfate and magnesium oxide, reduce the reaction temperature, reduce the cracking of the board, and improve the yield and quality of the board. The use of high specific gravity and small particle size barium sulfate filler can reduce the influence of the filler on the performance of the wood fireproof board, which is beneficial to the improvement of the fireproof performance of the board. The mass of barium sulfate, light-burned magnesium oxide and magnesium sulfate in the wood fireproof board is not less than 70% of the mass of the wood fireproof board.

[0032] The additive is 2%-4% of the mass of light-burned magnesium oxide, and the additive includes soluble sulfate: soluble phosphate: polyvinyl alcohol: cellulose ether: silicone oil with a mass percentage of 1:1:3:3:0.02. The additive can lubricate the internal structure of the board, and the sulfate ions in the additive can inhibit alkali return and reduce the alkali return phenomenon of the board. Phosphate ions can absorb carbon dioxide and sulfur dioxide, form a passivation film on the surface of the board, wrap free magnesium oxide and magnesium sulfate, improve the anti-aging ability and water resistance of the board, and help improve the strength of the board.

[0033] The soluble sulfate is one or a mixture of sodium sulfate, magnesium sulfate, potassium sulfate, copper sulfate, and iron sulfate. The soluble phosphate is one or a mixture of sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate.

[0034] like Figure 1 , Figure 2 The method for preparing the above-mentioned Class A wood fireproof board comprises the following steps: S1. Add magnesium sulfate solution and additives into brine pool 2 according to mass percentage, and stir evenly to obtain brine solution.

[0035] S2, adding wood fiber and lightly burned magnesium oxide powder into the first mixer 3 according to the mass percentage, and adding brine solution into the first mixer 3, stirring once, the stirring time is 3min-8min. After the first stirring is completed, it is sent to the second mixer 4 for secondary stirring.

[0036] The first mixer 3 is a planetary mixer, which can mix at least 12,000 sheets of materials per day. The rotation of the mixer can effectively mix the materials. The two mixers take turns to mix to ensure the material supply. The second mixer 4 is a ring mixer with a diameter of 100 cm and a rotation speed of 1,200 rpm. It is used as the second mixing to break up the lumps and avoid the quality problems of the board surface caused by impurities.

[0037] S3, the raw materials mixed in the second mixer 4 enter the first paving machine 6 and the second paving machine 7 respectively through the conveyor belt 5 and the dividing belt, the first robot arm 20 sends the recovered pad into the loading rail 22, the pad enters the first conveyor 8 through the loading rail 22, the first paving machine 6 and the second paving machine 7 perform two paving on the pad.

[0038] The pad is a square aviation 8 series aluminum plate with a side length of not less than 2600. The wide aluminum plate is used as the pad. The aluminum plate has good thermal conductivity, which can improve the uniformity of the plate temperature, promote uniform reaction inside the plate, make the reaction inside the plate fully proceed, reduce the probability of subsequent secondary reaction, and reduce the deformation rate of the plate.

[0039] The size of the aluminum plate is a 2600mm*2600mm square wide pad. The pad is large in size, and the area of ​​the produced plate is large, which improves the stability of the plate stacking and increases the stacking height by 30%-50%. After pressing once, it can be divided into two plates, and the production capacity is increased by 160%-200%. In addition, the working frequency of the pressing machine 11 is reduced, which is conducive to increasing the service life of the pressing machine 11.

[0040] By using a large pad, the cutting of the two sides in the middle can be omitted when cutting the edges of the pad, which not only improves the cutting efficiency but also reduces the waste of materials. Saving two 50mm*2600mm edge strips, the cost of two pieces of waste raw materials is about 5 yuan, and a production line with a daily production capacity of 12,000 sheets can save 18 million yuan per year.

[0041] The paving width of the first paving machine 6 and the second paving machine 7 is 2600mm*2600mm. There are 6 sweeping crescent-shaped rollers inside. The crescent upward angle is 10 degrees. The paving rollers are serrated magnetic rollers. They adopt uniform snowfall paving. Two paving machines are used for paving twice to ensure paving uniformity.

[0042] S4. The paved sheet is sent to the pre-pressing machine for pre-pressing via the first conveyor 8, and trimmed by the trimming machine on the first conveyor 8. The excess paving material after cutting can be recycled. The trimmed sheet is transferred to the bottom mold 9 under the action of the second mechanical arm 21 for stacking, and the number of stacked sheets is not less than 100.

[0043] S5, after the bottom mold 9 stacks are completed, they are sent to the pressing machine 11 through the second conveyor 10 for mold closing and pressing. The pressing machine 11 is a 10-cylinder 6500-ton press with a width of 2800mm*2800mm, and the pressure of the pressing machine 11 is 11MPa-15MPa.

[0044] The pressed sheet enters the curing conveyor track 12 through the second conveyor 10 and is sent to the curing room for primary curing. The primary curing temperature of the curing room is 40°C-60°C, preferably 50°C. The primary curing time is 3h-5h, preferably 4h. Keeping the curing temperature at 50°C can accelerate the reaction and reduce the demoulding time.

[0045] S6, after the primary curing, the plate and the bottom mold 9 are returned to the pressing machine 11 through the curing conveyor rail 12 and the second conveyor 10 for demolding, and the demolded plate and the bottom mold 9 enter the first plate separator 13 through the second conveyor 10 and the curing conveyor rail 12 for plate separation, and the first plate separator 13 separates the plate and the pad, and the pad is stacked on one side of the first plate separator 13. Using silicone oil as a release agent can ensure that the plate and the bottom plate are easily separated.

[0046] S7. The bottom mold 9 after the plate separation is transported to the discharge end of the first conveyor 8 through the first recovery rail 14 and the second recovery rail 15 for recycling.

[0047] S8. The pads are dispersed one by one on the third conveyor 17 under the action of the second plate separator 16. The bottom plates are cleaned by the cleaning machine arranged on the third conveyor 17, cooled by the cooler, and shaped by the shaping machine before being stacked. Then, they are sent to the loading rail 22 by the first robot arm 20 for recycling.

[0048] S9. The separated plates are transported to the cutting machine 18 by the conveyor. The four sides are cut by the cutting machine 18, and the plates are cut into two. After being stacked by the stacking machine 19, secondary curing is carried out at room temperature for 7 days. After the curing is completed, baking and shaping are carried out. The pressure of the baking and shaping press is 160 tons, the thickness of the hot pressing plate is 10 cm, and the upper and lower plates are provided with prismatic grooves to facilitate the release of moisture. The baking temperature is between 120℃-130℃, and the baking time is 5 minutes-12 minutes. Polishing is also carried out. The polishing adopts fixed thickness + fine sanding + surface fine polishing to ensure that it is in place at one time. The surface error of the plate after polishing is no more than 10 wires. After polishing, it is stored.

[0049] Example 1 A class A wood fireproof board comprises the following components in percentage by mass: 30% of lightly burned magnesium oxide powder, 16% of magnesium sulfate solution, 23% of wood fiber, 30% of inorganic filler and 1% of additive.

[0050] The Baume degree of magnesium sulfate solution is 25.

[0051] The particle size of the wood fiber is 50 mesh.

[0052] The inorganic filler is barium sulfate, and the particle size of the barium sulfate is 2500 meshes.

[0053] The mass percentage of sodium sulfate: trisodium phosphate: polyvinyl alcohol: cellulose ether: silicone oil in the additive is 1:1:3:3:0.02.

[0054] The preparation method of Class A wood fireproof board comprises the following steps: S1. Add magnesium sulfate solution and additives into brine pool 2 according to mass percentage, and stir evenly to obtain brine solution.

[0055] S2, adding the wood fiber and lightly burned magnesium oxide powder in silo 1 into a planetary mixer according to the mass percentage, and adding the brine solution into the planetary mixer, stirring once, the stirring time is 5min. After the first stirring is completed, it is sent to the ring mixer for secondary stirring.

[0056] S3, the raw materials mixed in the ring mixer enter the first paving machine 6 and the second paving machine 7 through the conveyor belt 5 and the dividing belt respectively, the first mechanical arm 20 sends the recovered pad to the loading rail 22, the pad enters the first conveyor 8 through the loading rail 22, and the first paving machine 6 and the second paving machine 7 perform two paving on the pad. The pad is a square aluminum plate of 2600mm*2600mm.

[0057] S4, the paved plate is sent to the pre-pressing machine for pre-pressing through the first conveyor 8, and is trimmed by the trimming machine on the first conveyor 8. The trimmed plate is transferred to the bottom mold 9 under the action of the second mechanical arm 21 for stacking, and the number of stacked plates is 130.

[0058] S5. After the bottom mold 9 is stacked, it is sent to the pressing machine 11 through the second conveyor 10 for mold closing and pressing. The pressure of the pressing machine 11 is 13MPa. The pressed plate enters the curing conveying track 12 through the second conveyor 10 and is sent to the curing room for primary curing. The primary curing temperature is 50℃ and the primary curing time is 4h.

[0059] S6. After one curing is completed, the plate and the bottom mold 9 are returned to the pressing machine 11 for demolding through the curing conveyor rail 12 and the second conveyor 10. After demolding, the plate and the bottom mold 9 enter the first plate separator 13 for plate separation through the second conveyor 10 and the curing conveyor rail 12. The first plate separator 13 separates the plate and the pad, and the pad is stacked on one side of the first plate separator 13.

[0060] S7. The bottom mold 9 after the plate separation is transported to the discharge end of the first conveyor 8 through the first recovery rail 14 and the second recovery rail 15 for recycling.

[0061] S8. The pads are dispersed one by one on the third conveyor 17 under the action of the second plate separator 16. The bottom plates are cleaned by the cleaning machine arranged on the third conveyor 17, cooled by the cooler, and shaped by the shaping machine before being stacked. Then, they are sent to the loading rail 22 by the first robot arm 20 for recycling.

[0062] S9. The separated plates are conveyed to the cutting machine 18 by a conveyor, and the four sides are cut by the cutting machine 18, and the plates are cut into two parts. After being stacked by the stacking machine 19, secondary curing is carried out at room temperature, and the secondary curing time is 7 days. After the curing is completed, the plates are baked, shaped, and polished. The surface error of the plates after polishing is not more than 10 wires.

[0063] The obtained boards were subjected to fireproofing and mechanical property tests. The fireproofing grade of the boards reached the national standard A1 grade. The static bending strength of the boards was 30MPa, and the internal bonding strength of the boards was 2.2MPa.

[0064] Example 2 A class A wood fireproof board comprises the following components in percentage by mass: 32% of lightly burned magnesium oxide powder, 18% of magnesium sulfate solution, 19% of wood fiber, 30% of inorganic filler and 1% of additive.

[0065] The Baume degree of magnesium sulfate solution is 28.

[0066] The particle size of the wood fiber is 60 mesh.

[0067] The inorganic filler is barium sulfate, and the particle size of the barium sulfate is 2000 meshes.

[0068] The mass percentage of potassium sulfate: potassium dihydrogen phosphate: polyvinyl alcohol: cellulose ether: silicone oil in the additive is 1:1:3:3:0.02.

[0069] The preparation method of Class A wood fireproof board is the same as that in Example 1.

[0070] The obtained boards were subjected to fireproofing and mechanical property tests. The fireproofing grade of the boards reached the national standard A1 grade. The static bending strength of the boards was 33MPa, and the internal bonding strength of the boards was 2.5MPa.

[0071] Example 3 A class A wood fireproof board comprises the following components in percentage by mass: 26% of lightly burned magnesium oxide powder, 23% of magnesium sulfate solution, 25% of wood fiber, 25% of inorganic filler and 1% of additive.

[0072] The Baume degree of magnesium sulfate solution is 25.

[0073] The particle size of the wood fiber is 50 mesh.

[0074] The inorganic filler is barium sulfate, and the particle size of the barium sulfate is 2500 meshes.

[0075] The mass percentage of soluble sulfate: soluble phosphate: polyvinyl alcohol: cellulose ether: silicone oil in the additive is 1:1:3:3:0.02.

[0076] The soluble sulfate is a mixture of sodium sulfate and potassium sulfate in a mass ratio of 1:1, and the soluble phosphate is a mixture of sodium dihydrogen phosphate and trisodium phosphate in a mass ratio of 1:1.

[0077] The preparation method of Class A wood fireproof board is the same as that in Example 1.

[0078] The obtained boards were subjected to fire resistance and mechanical property tests. The fire resistance grade of the boards reached the national standard A2 grade. The static bending strength of the boards was 29MPa, and the internal bonding strength of the boards was 1.8MPa.

[0079] Therefore, the use of the A-grade wood fireproof board and the preparation method thereof described in the present invention can solve the problem that the existing wood fireproof board is easy to crack and has poor fireproof performance.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A Class A wood fireproof board, characterized in that: The invention comprises the following components in percentage by mass: 20%-40% of light-burned magnesium oxide powder, 5%-30% of magnesium sulfate solution, 10%-30% of wood fiber, 20%-40% of inorganic filler and 0.5%-1.5% of additives.

2. The Class A wood fireproof board according to claim 1, characterized in that: The light-burned magnesium oxide has a magnesium content of 85wt%-90wt%, an activity of not less than 60%, and a calcium oxide content of less than 2wt%.

3. The Class A wood fireproof board according to claim 1, characterized in that: The Baume degree of the magnesium sulfate solution is 21-30.

4. The Class A wood fireproof board according to claim 1, characterized in that: The particle size of the wood fiber is 40 meshes to 60 meshes.

5. The Class A wood fireproof board according to claim 1, characterized in that: The inorganic filler is an inorganic mineral filler with a specific gravity greater than 4, the mass ratio of the inorganic filler to the light-burned magnesium oxide is 1:0.8-1.2, and the particle size of the inorganic filler is not less than 2000 meshes.

6. The Class A wood fireproof board according to claim 5, characterized in that: The inorganic filler is one of barium sulfate and perovskite sulfate.

7. The Class A wood fireproof board according to claim 1, characterized in that: The additive is 2%-4% of the mass of light-burned magnesium oxide, and the additive includes soluble sulfate: soluble phosphate: polyvinyl alcohol: cellulose ether: silicone oil in a mass percentage of 1:1:3:3:0.

02.

8. A method for preparing a Class A wood fireproof board according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Add magnesium sulfate solution and additives into the brine pool according to mass percentage, and stir evenly to obtain a brine solution; S2, adding wood fiber and light-burned magnesium oxide powder into the first mixer according to the mass percentage, and adding brine solution into the first mixer, stirring once, the stirring time is 3min-8min; after the first stirring is completed, the mixture is sent into the second mixer for secondary stirring; S3, the raw materials mixed in the second mixer enter the first paving machine and the second paving machine respectively through the conveyor belt and the dividing belt, the first mechanical arm sends the recovered pad into the loading rail, the pad enters the first conveyor through the loading rail, and the first paving machine and the second paving machine perform two paving on the pad; S4. The paved plates are sent to the pre-pressing machine for pre-pressing via the first conveyor, and are trimmed by the trimming machine on the first conveyor; the trimmed plates are transferred to the bottom mold under the action of the second mechanical arm for stacking, and the number of stacked plates is not less than 100; S5. After the bottom mold is stacked, it is sent to the pressing machine through the second conveyor for mold closing and pressing. The pressed plate enters the curing conveyor track through the second conveyor and is sent to the curing room for primary curing; S6, after the first curing is completed, the plate and the bottom mold are returned to the pressing machine through the curing conveyor rail and the second conveyor for demolding, and the demolded plate and the bottom mold enter the first plate separator through the second conveyor and the curing conveyor rail for plate separation, and the first plate separator separates the plate and the pad, and the pad is stacked on one side of the first plate separator; S7, the bottom mold after the plate is separated is transported to the discharge end of the first conveyor through the first recovery rail and the second recovery rail for recycling; S8, the pads are dispersed one by one on the third conveyor under the action of the second plate separator, the bottom plates are cleaned by the cleaning machine arranged on the third conveyor, cooled by the cooler, shaped by the shaping machine, and then stacked, and then sent to the loading rail by the first mechanical arm for recycling; S9. The separated boards are transported to the cutting machine through a conveyor, and the four sides are cut by the cutting machine, and the boards are cut into two parts. After being stacked by a stacking machine, secondary curing is carried out at room temperature for 7 days. After curing, the plate is baked, shaped and polished. The surface error of the plate after polishing is no more than 10 wires.

9. The method for preparing a Class A wood fireproof board according to claim 8, characterized in that: In S3, the pad is a square aluminum plate with a side length of not less than 2600.

10. The method for preparing a Class A wood fireproof board according to claim 8, characterized in that: In S5, the pressure of the press is 11MPa-15MPa; the primary curing temperature of the curing room is 40°C-60°C, and the primary curing time is 3h-5h.

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