Glass fiber gypsum board and preparation method thereof

Abstract

The invention belongs to the field of building materials, and discloses a glass fiber gypsum board and a preparation method thereof.The glass fiber gypsum board comprises a core base material layer, a composite reinforcement layer and a surface protection layer which are sequentially arranged from inside to outside; the core base material layer is prepared from the following raw materials in parts by weight: 55-75 parts of building gypsum powder, 8-12 parts of rice hull ash, 3-6 parts of sisal fibers, 2-4 parts of nano calcium carbonate, 0.3-0.8 part of a PCA-R1 polycarboxylate superplasticizer and 25-35 parts of water; the composite reinforcing layer is of an interwoven structure of basalt fiber gridding cloth and a gypsum-silica sol composite adhesive, the aperture of the basalt fiber gridding cloth is 2-4 mm, and the monofilament tensile strength is larger than or equal to 4000 MPa; the surface protection layer is a gypsum-based nano-zinc oxide composite coating, and the thickness of the surface protection layer is 0.3-0.6 mm; the invention aims to overcome the defects of insufficient mechanical properties, low raw material utilization rate, backward preparation process and the like of the glass fiber gypsum board in the prior art, and provides the glass fiber gypsum board which is high in strength, good in toughness and excellent in environmental protection performance and the preparation method of the glass fiber gypsum board.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a glass fiber gypsum board and its preparation method. Background Technology

[0002] Gypsum board, as a lightweight interior wall partition material, has advantages such as fire resistance, sound insulation, and environmental friendliness, and is widely used in the building decoration field. In existing technologies, glass fiber is often used for reinforcement to improve the mechanical properties of gypsum board; however, traditional glass fiber gypsum board has the following drawbacks: 1. Insufficient interfacial bonding between reinforcing fibers and gypsum matrix leads to low flexural strength and impact toughness of the board, making it prone to cracking after long-term use. Second, the raw material composition is simple, mainly consisting of gypsum and glass fiber, without effectively utilizing industrial waste and natural plant fibers. This not only increases production costs but also does not conform to the trend of green and environmentally friendly development. Third, the curing method in the preparation process is singular, mostly using natural curing or single heat curing, resulting in low curing efficiency and easy generation of pores and microcracks inside the board, affecting the overall performance. To address the aforementioned problems, this invention provides a glass fiber gypsum board and its preparation method. By introducing novel composite reinforcing materials and optimizing the preparation process, the mechanical properties and durability of the gypsum board are significantly improved, while simultaneously realizing the resource utilization of industrial waste, thus possessing significant economic and environmental value. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing glass fiber gypsum boards, such as insufficient mechanical properties, low raw material utilization, and outdated preparation processes, and to provide a glass fiber gypsum board with high strength, good toughness, and excellent environmental performance, as well as its preparation method.

[0004] To achieve the above objectives, the present invention provides the following technical solution: The technical solution provided by this invention is: a glass fiber gypsum board, comprising a core substrate layer, a composite reinforcement layer, and a surface protective layer arranged sequentially from the inside out; the core substrate layer is made of the following raw materials in parts by weight: 55-75 parts of building gypsum powder, 8-12 parts of rice husk ash, 3-6 parts of sisal fiber, 2-4 parts of nano-calcium carbonate, 0.3-0.8 parts of PCA-R1 polycarboxylate superplasticizer, and 25-35 parts of water; the composite reinforcement layer is an interwoven structure of basalt fiber mesh and gypsum-silica sol composite adhesive, wherein the pore size of the basalt fiber mesh is 2-4 mm, and the tensile strength of a single filament is ≥4000 MPa; the surface protective layer is a gypsum-based nano-zinc oxide composite coating with a thickness of 0.3-0.6 mm.

[0005] After being calcined at 800-900℃ for 2-3 hours, rice husk ash is pulverized to a particle size ≤5μm by an air jet mill, with a silicon dioxide content ≥90%. As an industrial waste, rice husk ash is mainly composed of silicon dioxide. After calcination and ultrafine grinding, it can be used as an active admixture to fill the pores of gypsum matrix and improve the density and strength of the matrix.

[0006] Sisal fiber is produced through the following treatment: Sisal raw fiber is soaked in a 5% sodium hydroxide solution at 80°C for 2 hours, rinsed with clean water, and then soaked in a 2% silane coupling agent KH-570 solution for 30 minutes. After drying, it is cut into short fibers with a length of 1-3 mm. Alkali treatment can remove surface impurities and improve the surface roughness of the fiber. Further treatment with silane coupling agent can effectively improve the interfacial bonding force between the fiber and the gypsum matrix, and enhance the flexural strength and impact toughness of the board.

[0007] The composite reinforcement layer is an interwoven structure of basalt fiber mesh and gypsum-silica sol composite adhesive. The basalt fiber mesh has a pore size of 2-4 mm and a single filament tensile strength ≥4000 MPa. The gypsum-silica sol composite adhesive is composed of the following raw materials by weight: 100 parts hemihydrate gypsum powder, 15-20 parts silica sol, 5-8 parts aluminate cement, and 45-55 parts water. After mixing, the mixture is stirred until the pH value is 7.5-8.5. Basalt fiber has advantages such as high strength, high modulus, and high temperature resistance. Its mesh serves as the skeleton of the composite reinforcement layer and can effectively bear external forces. In the gypsum-silica sol composite adhesive, silica sol can react with gypsum to form hydrated calcium silicate gel, which improves the bonding strength and water resistance of the adhesive. The addition of aluminate cement can accelerate the curing speed of the adhesive and improve the bonding strength between the composite reinforcement layer and the core substrate layer.

[0008] The surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.3-0.6mm. This composite coating not only improves the surface smoothness and decorative properties of gypsum board, but also enhances the durability and hygiene of gypsum board by utilizing the antibacterial and ultraviolet shielding properties of nano zinc oxide.

[0009] The gypsum-based nano zinc oxide composite coating is made from the following raw materials in parts by weight: 60-70 parts desulfurized gypsum powder, 1-3 parts nano zinc oxide, 8-12 parts EP-44 waterborne epoxy resin emulsion, 1-2 parts propylene glycol methyl ether acetate, and 35-45 parts deionized water. The use of desulfurized gypsum powder realizes the resource utilization of industrial waste. EP-44 waterborne epoxy resin emulsion can improve the flexibility and water resistance of the coating. Propylene glycol methyl ether acetate, as a film-forming aid, can promote the film-forming process of the coating and improve the continuity and density of the coating.

[0010] The present invention also provides a method for preparing the above-mentioned glass fiber gypsum board, comprising the following steps: S1. Preparation of core substrate slurry: Mix building gypsum powder, rice husk ash, sisal fiber, nano calcium carbonate, PCA-R1 polycarboxylate superplasticizer and water in proportion, and stir at high speed at 1200-1500 r / min for 8-12 minutes to obtain a uniform slurry. High-speed stirring can fully mix the raw materials, improve the uniformity and fluidity of the slurry, and is beneficial to subsequent molding. S2. Preparation of composite adhesive: Mix hemihydrate gypsum powder, silica sol, aluminate cement and water in proportion, stir in a planetary mixer at 300-500 r / min for 10 minutes, let stand to defoam for 3-5 minutes. The stirring method of the planetary mixer can make the materials more uniformly mixed, and the standing to defoam can avoid the generation of air bubbles in the adhesive, which would affect the performance of the composite reinforcement layer. S3. Layered composite molding: First, a core substrate slurry with a thickness of 1 / 2 is laid in the mold, then basalt fiber mesh is laid and impregnated with composite adhesive, and then the remaining core substrate slurry with a thickness of 1 / 2 is laid to form a sandwich structure blank. This layered composite structure can make the composite reinforcement layer evenly distributed in the core substrate layer and give full play to its reinforcement effect. S4. Curing and Molding: The green body is pre-cured for 2 hours in an environment with a temperature of 40-50℃ and a relative humidity of 60-70%, and then pressurized and cured for 4-6 minutes under a pressure of 1.5-2.5MPa. Infrared radiation heating is carried out simultaneously, with a radiation wavelength of 2-5μm and a power of 300-500W. Pre-curing can initially solidify the green body and avoid deformation during pressurization. Pressurized curing can reduce the porosity and voids inside the green body and improve the density of the board. Infrared radiation heating has the characteristics of uniform heating and fast speed, which can promote the hydration reaction of gypsum, improve curing efficiency and mechanical properties of the board. Segmented heating is adopted. The first segment of 3 minutes uses a wavelength of 2-3μm, and the second segment of 3 minutes uses a wavelength of 3-5μm. It can provide appropriate energy according to the needs of different stages of gypsum hydration and further improve the curing effect. S5. Surface treatment: Mix and stir the gypsum-based nano zinc oxide composite coating raw materials until the fineness is ≤50μm, apply them to the surface of the blank by electrostatic spraying, and dry at 70-90℃ for 1.5-2.5 hours to obtain glass fiber gypsum board. Electrostatic spraying can make the coating adhere evenly to the surface of the blank, improve the smoothness and adhesion of the coating; drying can remove the moisture in the coating, let the coating cure and form, and improve its protective performance.

[0011] The beneficial effects of this technical solution are: (1) By introducing rice husk ash and sisal fiber into the core substrate layer, this invention not only realizes the resource utilization of industrial waste and natural plant fiber and reduces production costs, but also significantly improves the mechanical properties of gypsum board. Rice husk ash, as an active admixture, can react with gypsum to generate hydration products, fill the pores of the matrix, and improve the density of the matrix. After surface treatment, the interfacial bonding force between sisal fiber and gypsum matrix is ​​enhanced, which can effectively transfer stress and improve the flexural strength and impact toughness of the board.

[0012] (2) The present invention uses a composite reinforcement layer composed of basalt fiber mesh and gypsum-silica sol composite adhesive. Compared with traditional glass fiber reinforcement, basalt fiber has higher strength and modulus, and the reinforcement effect of the composite reinforcement layer is more significant. It can greatly improve the overall mechanical properties and deformation resistance of gypsum board. At the same time, the use of gypsum-silica sol composite adhesive improves the bonding strength between the composite reinforcement layer and the core substrate layer, and avoids the occurrence of delamination.

[0013] (3) The present invention adds nano zinc oxide to the surface protective layer, which gives the gypsum board good antibacterial and ultraviolet shielding properties, improves the durability and hygiene of the gypsum board, and expands its application range.

[0014] (4) The preparation method of the present invention adopts processes such as high-speed stirring, planetary stirring, pressure curing and infrared radiation heating, which improves the mixing uniformity of raw materials, the density of the blank and the curing efficiency, and ensures the performance stability of gypsum board. At the same time, the application of segmented infrared radiation heating provides appropriate energy according to the needs of different stages of gypsum hydration, further optimizing the curing effect. Attached Figure Description

[0015] Figure 1 This table shows the comparison of experimental parameters for various embodiments and comparative examples of the glass fiber gypsum board and its preparation method proposed in this invention. Figure 2 This is a comparison table of data differences among various embodiments of the glass fiber gypsum board and its preparation method proposed in this invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The specific implementation process is as follows: Example 1: Please see Figure 1-2The present invention provides a technical solution: a glass fiber gypsum board, wherein the core substrate layer is composed of the following raw materials in parts by weight: 55 kg of building gypsum powder, 12 kg of rice husk ash, 6 kg of sisal fiber, 4 kg of nano calcium carbonate, 0.8 kg of PCA-R1 polycarboxylate superplasticizer, and 35 kg of water; the basalt fiber mesh in the composite reinforcement layer has a pore size of 2 mm and a single filament tensile strength of 4000 MPa; the gypsum-silica sol composite adhesive is composed of 100 kg of hemihydrate gypsum powder, 20 kg of silica sol, 8 kg of aluminate cement, and 55 kg of water, and the pH value after mixing is 8.5; the surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.6 mm, made of 70 kg of desulfurized gypsum powder, 3 kg of nano zinc oxide, 12 kg of EP-44 waterborne epoxy resin emulsion, 2 kg of propylene glycol methyl ether acetate, and 45 kg of deionized water.

[0018] The preparation method is as follows: S1. Preparation of core substrate slurry: Weigh each raw material according to the above weight proportions, put them into a mixing device, and stir at high speed of 1500 r / min for 12 minutes to obtain a uniform slurry.

[0019] S2. Preparation of composite adhesive: Weigh out hemihydrate gypsum powder, silica sol, aluminate cement and water according to the proportion, put them into a planetary mixer, stir at 500 r / min for 10 minutes, and then let stand for 5 minutes to defoam.

[0020] S3. Layered composite molding: In a pre-prepared mold, first lay a core substrate slurry with a thickness of 1 / 2, then lay a basalt fiber mesh cloth, and impregnate the mesh cloth with a composite adhesive, and then lay the remaining core substrate slurry with a thickness of 1 / 2 to form a sandwich structure blank.

[0021] S4. Curing and molding: Place the blank in an environment with a temperature of 50℃ and a relative humidity of 70% for 2 hours for pre-curing, and then pressurize and cure under a pressure of 2.5MPa for 6 minutes. At the same time, infrared radiation heating is performed. The first 3 minutes uses a wavelength of 2-3μm, and the second 3 minutes uses a wavelength of 3-5μm with a power of 500W.

[0022] S5. Surface treatment: Mix the raw materials of gypsum-based nano zinc oxide composite coating, stir until the fineness is 50μm, coat the surface of the blank by electrostatic spraying, and then dry at 90℃ for 2.5 hours to obtain glass fiber gypsum board.

[0023] In this embodiment, the proportions of each raw material and the process parameters are all at the higher end of the range defined in the claims. The addition of a larger amount of rice husk ash and sisal fiber, combined with a higher stirring speed and a longer stirring time, makes the core substrate slurry more uniformly mixed. The high proportion of silica sol and aluminate cement in the composite adhesive, as well as the high pressure and high-power infrared radiation during pressure curing, are beneficial to improving the bonding strength between the composite reinforcing layer and the core substrate layer and the overall density of the gypsum board. The thicker surface protective layer and its higher content of nano-zinc oxide can better exert the protective and antibacterial effects. Overall, the gypsum board prepared in this embodiment exhibits excellent performance in terms of strength, water resistance, and antibacterial properties.

[0024] Example 2: Please see Figure 1-2 The present invention provides a technical solution: a glass fiber gypsum board, wherein the core substrate layer is composed of the following raw materials in parts by weight: 60 kg of building gypsum powder, 11 kg of rice husk ash, 5 kg of sisal fiber, 3.5 kg of nano calcium carbonate, 0.6 kg of PCA-R1 polycarboxylate superplasticizer, and 32 kg of water; the basalt fiber mesh in the composite reinforcement layer has a pore size of 2.5 mm and a single filament tensile strength of 4200 MPa; the gypsum-silica sol composite adhesive is composed of 100 kg of hemihydrate gypsum powder, 18 kg of silica sol, 7 kg of aluminate cement, and 52 kg of water, and the pH value after mixing is 8.2; the surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.5 mm, made of 67 kg of desulfurized gypsum powder, 2.5 kg of nano zinc oxide, 10 kg of EP-44 waterborne epoxy resin emulsion, 1.8 kg of propylene glycol methyl ether acetate, and 42 kg of deionized water.

[0025] The preparation method is as follows: S1. Preparation of core substrate slurry: Weigh each raw material according to the above weight proportions, put them into a mixing device, and stir at high speed of 1400 r / min for 10 minutes to obtain a uniform slurry.

[0026] S2. Preparation of composite adhesive: Weigh out hemihydrate gypsum powder, silica sol, aluminate cement and water according to the proportion, put them into a planetary mixer, stir at 450 r / min for 10 minutes, and then let stand for 4.5 minutes to defoam.

[0027] S3. Layered composite molding: Same as in Example 1.

[0028] S4. Curing and molding: The preform is pre-cured in an environment with a temperature of 47℃ and a relative humidity of 67% for 2 hours, and then pressure-cured at a pressure of 2.2MPa for 5.5 minutes, while infrared radiation heating is performed. The first 3 minutes uses a wavelength of 2-3μm, and the second 3 minutes uses a wavelength of 3-5μm, with a power of 450W.

[0029] S5. Surface treatment: Mix the raw materials of gypsum-based nano zinc oxide composite coating, stir until the fineness is 45μm, coat the surface of the blank by electrostatic spraying, and then dry at 85℃ for 2.2 hours to obtain glass fiber gypsum board.

[0030] The parameters in this embodiment fall within the mid-to-high range of the claims. The rational combination of raw material ratios and process parameters allows for a good synergistic effect among the core substrate layer, composite reinforcement layer, and surface protective layer. Appropriate adjustments to the raw material ratio in the core substrate layer balance cost and performance; the parameter settings for the composite reinforcement layer ensure bonding strength while avoiding resource waste; and the moderate parameters of the curing and surface treatment processes improve production efficiency while ensuring performance. The gypsum board prepared in this embodiment exhibits balanced overall performance and is suitable for application in general building scenarios with high performance requirements.

[0031] Example 3: Please see Figure 1-2 The present invention provides a technical solution: a glass fiber gypsum board, wherein the core substrate layer is composed of the following raw materials in parts by weight: 65 kg of building gypsum powder, 10 kg of rice husk ash, 4.5 kg of sisal fiber, 3 kg of nano calcium carbonate, 0.5 kg of PCA-R1 polycarboxylate superplasticizer, and 30 kg of water; the basalt fiber mesh in the composite reinforcement layer has a pore size of 3 mm and a single filament tensile strength of 4300 MPa; the gypsum-silica sol composite adhesive is composed of 100 kg of hemihydrate gypsum powder, 17 kg of silica sol, 6.5 kg of aluminate cement, and 50 kg of water, and the pH value after mixing is 8.0; the surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.45 mm, made of 65 kg of desulfurized gypsum powder, 2 kg of nano zinc oxide, 10 kg of EP-44 waterborne epoxy resin emulsion, 1.5 kg of propylene glycol methyl ether acetate, and 40 kg of deionized water.

[0032] The preparation method is as follows: S1. Preparation of core substrate slurry: Weigh each raw material according to the above weight proportions, put them into a mixing device, and stir at high speed of 1350 r / min for 10 minutes to obtain a uniform slurry.

[0033] S2. Preparation of composite adhesive: Weigh out hemihydrate gypsum powder, silica sol, aluminate cement and water according to the proportion, put them into a planetary mixer, stir at 400 r / min for 10 minutes, and then let stand for 4 minutes to defoam.

[0034] S3. Layered composite molding: Same as in Example 1.

[0035] S4. Curing and molding: Place the blank in an environment with a temperature of 45℃ and a relative humidity of 65% for 2 hours for pre-curing, and then pressurize and cure under a pressure of 2.0MPa for 5 minutes. At the same time, infrared radiation heating is performed. The first 3 minutes uses a wavelength of 2-3μm, and the second 3 minutes uses a wavelength of 3-5μm with a power of 400W.

[0036] S5. Surface treatment: Mix the raw materials of gypsum-based nano zinc oxide composite coating, stir until the fineness is 40μm, coat the surface of the blank by electrostatic spraying, and then dry at 80℃ for 2 hours to obtain glass fiber gypsum board.

[0037] The parameter settings in this embodiment are relatively balanced, falling within the middle range of the claims. The proportions of each raw material and the process parameters work together to ensure that the gypsum board maintains performance while also being economical to produce. The proportions of each raw material in the core substrate layer are appropriate, allowing each to play its respective role without increasing costs or affecting other properties due to an excess of any one material. The parameter settings of the composite reinforcement layer and the surface protective layer achieve a good balance in terms of strength, water resistance, and surface properties, making the gypsum board suitable for a wide range of building applications.

[0038] Example 4: Please see Figure 1-2 The present invention provides a technical solution: a glass fiber gypsum board, wherein the core substrate layer is composed of the following raw materials in parts by weight: 65 kg of building gypsum powder, 10 kg of rice husk ash, 5 kg of sisal fiber, 3 kg of nano calcium carbonate, 0.5 kg of PCA-R1 polycarboxylate superplasticizer, and 30 kg of water; the basalt fiber mesh in the composite reinforcement layer has a pore size of 3 mm and a single filament tensile strength of 4200 MPa; the gypsum-silica sol composite adhesive is composed of 100 kg of hemihydrate gypsum powder, 18 kg of silica sol, 7 kg of aluminate cement, and 50 kg of water, and the pH value after mixing is 8.0; the surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.5 mm, made of 65 kg of desulfurized gypsum powder, 2 kg of nano zinc oxide, 10 kg of EP-44 waterborne epoxy resin emulsion, 1.5 kg of propylene glycol methyl ether acetate, and 40 kg of deionized water.

[0039] The preparation method is as follows: S1. Preparation of core substrate slurry: Weigh each raw material according to the above weight proportions, put them into a mixing device, and stir at high speed of 1400 r / min for 11 minutes to obtain a uniform slurry.

[0040] S2. Preparation of composite adhesive: Weigh out hemihydrate gypsum powder, silica sol, aluminate cement and water according to the proportion, put them into a planetary mixer, stir at 450 r / min for 10 minutes, and then let stand for 4 minutes to defoam.

[0041] S3. Layered composite molding: Same as in Example 1.

[0042] S4. Curing and molding: The blank is pre-cured in an environment with a temperature of 45℃ and a relative humidity of 65% for 2 hours, and then pressure-cured for 5 minutes under a pressure of 2.0MPa, while infrared radiation heating is performed. The first 3 minutes use a wavelength of 2-3μm, and the second 3 minutes use a wavelength of 3-5μm, with a power of 450W.

[0043] S5. Surface treatment: Mix the raw materials of gypsum-based nano zinc oxide composite coating, stir until the fineness is 45μm, coat the surface of the blank by electrostatic spraying, and then dry at 80℃ for 2 hours to obtain glass fiber gypsum board.

[0044] Compared to Example 3, this embodiment differs slightly in the raw material ratio of the core substrate layer, with a slightly higher sisal fiber content. The stirring speed, time, and infrared radiation power have also been adjusted. The higher sisal fiber content helps to further improve the toughness of the gypsum board; the appropriately increased stirring speed and time allow for more thorough mixing of the raw materials; and the slightly higher infrared radiation power accelerates the hydration reaction of the gypsum. These adjustments suggest that the gypsum board prepared in this embodiment may have superior impact toughness compared to Example 3, making it suitable for applications requiring high toughness.

[0045] Example 5: Please see Figure 1-2 The present invention provides a technical solution: a glass fiber gypsum board, wherein the core substrate layer is composed of the following raw materials in parts by weight: 70 kg of building gypsum powder, 9 kg of rice husk ash, 4 kg of sisal fiber, 2.5 kg of nano calcium carbonate, 0.4 kg of PCA-R1 polycarboxylate superplasticizer, and 28 kg of water; the basalt fiber mesh in the composite reinforcement layer has a pore size of 3.5 mm and a single filament tensile strength of 4400 MPa; the gypsum-silica sol composite adhesive is composed of 100 kg of hemihydrate gypsum powder, 16 kg of silica sol, 6 kg of aluminate cement, and 48 kg of water, and the pH value after mixing is 7.8; the surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.4 mm, made of 63 kg of desulfurized gypsum powder, 1.5 kg of nano zinc oxide, 9 kg of EP-44 waterborne epoxy resin emulsion, 1.3 kg of propylene glycol methyl ether acetate, and 38 kg of deionized water.

[0046] The preparation method is as follows: S1. Preparation of core substrate slurry: Weigh each raw material according to the above weight proportions, put them into a mixing device, and stir at high speed of 1300 r / min for 9 minutes to obtain a uniform slurry.

[0047] S2. Preparation of composite adhesive: Weigh out hemihydrate gypsum powder, silica sol, aluminate cement and water according to the proportion, put them into a planetary mixer, stir at 350 r / min for 10 minutes, and then let stand for 3.5 minutes to defoam.

[0048] S3. Layered composite molding: Same as in Example 1.

[0049] S4. Curing and molding: The preform is placed in an environment with a temperature of 43℃ and a relative humidity of 63% for 2 hours for pre-curing, and then pressurized and cured at a pressure of 1.8MPa for 4.5 minutes. At the same time, infrared radiation heating is performed. The first 3 minutes uses a wavelength of 2-3μm, and the second 3 minutes uses a wavelength of 3-5μm with a power of 350W.

[0050] S5. Surface treatment: Mix the raw materials of gypsum-based nano zinc oxide composite coating, stir until the fineness is 42μm, coat the surface of the blank by electrostatic spraying, and then dry at 78℃ for 2 hours to obtain glass fiber gypsum board.

[0051] In this embodiment, the proportion of building gypsum powder is increased, while the proportions of raw materials such as rice husk ash and sisal fiber are appropriately reduced. The higher content of building gypsum powder ensures the basic strength of the gypsum board, while the reasonable proportion of other raw materials maintains good overall performance while reducing costs. The increased tensile strength of the basalt fiber mesh monofilament in the composite reinforcement layer compensates for the strength loss that might result from the reduced proportion of some raw materials. The gypsum board prepared in this embodiment is suitable for applications requiring high basic strength and with strict cost control.

[0052] Example 6: Please see Figure 1-2 The present invention provides a technical solution: a glass fiber gypsum board, wherein the core substrate layer is composed of the following raw materials in parts by weight: 75 kg of building gypsum powder, 8 kg of rice husk ash, 3 kg of sisal fiber, 2 kg of nano calcium carbonate, 0.3 kg of PCA-R1 polycarboxylate superplasticizer, and 25 kg of water; the basalt fiber mesh in the composite reinforcement layer has a pore size of 4 mm and a single filament tensile strength of 4500 MPa; the gypsum-silica sol composite adhesive is composed of 100 kg of hemihydrate gypsum powder, 15 kg of silica sol, 5 kg of aluminate cement, and 45 kg of water, and the pH value after mixing is 7.5; the surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.3 mm, made of 60 kg of desulfurized gypsum powder, 1 kg of nano zinc oxide, 8 kg of EP-44 waterborne epoxy resin emulsion, 1 kg of propylene glycol methyl ether acetate, and 35 kg of deionized water.

[0053] The preparation method is as follows: S1. Preparation of core substrate slurry: Weigh each raw material according to the above weight proportions, put them into a mixing device, and stir at high speed of 1200 r / min for 8 minutes to obtain a uniform slurry.

[0054] S2. Preparation of composite adhesive: Weigh out hemihydrate gypsum powder, silica sol, aluminate cement and water according to the proportion, put them into a planetary mixer, stir at 300 r / min for 10 minutes, and then let stand for 3 minutes to defoam.

[0055] S3. Layered composite molding: Same as in Example 1.

[0056] S4. Curing and molding: Place the blank in an environment with a temperature of 40℃ and a relative humidity of 60% for 2 hours for pre-curing, and then pressurize and cure it under a pressure of 1.5MPa for 4 minutes. At the same time, infrared radiation heating is carried out. The first 3 minutes uses a wavelength of 2-3μm, and the second 3 minutes uses a wavelength of 3-5μm with a power of 300W.

[0057] S5. Surface treatment: Mix the raw materials of gypsum-based nano zinc oxide composite coating, stir until the fineness is 50μm, coat the surface of the blank by electrostatic spraying, and then dry at 70℃ for 1.5 hours to obtain glass fiber gypsum board.

[0058] The raw material ratios and process parameters in this embodiment are at the lower end of the scope defined in the claims. The highest proportion of building gypsum powder ensures the basic strength of the gypsum board; the lower proportions of other auxiliary raw materials reduce production costs; and the relatively mild process parameter settings are suitable for large-scale, low-cost production. Although the gypsum board prepared in this embodiment is slightly inferior to the previous embodiments in some performance aspects, it can meet the basic needs of general building scenarios and has a high cost-performance ratio.

[0059] Comparative Example 1 A gypsum board, whose composition and preparation method are basically the same as those in Example 3, except that rice husk ash and sisal fiber are not added to the core substrate layer.

[0060] In this comparative example, the lack of rice husk ash and sisal fiber affected the density and toughness of the core substrate layer. The absence of rice husk ash prevented the effective filling of pores in the gypsum matrix, leading to a decrease in strength; the lack of sisal fiber reduced the flexural strength and impact toughness of the gypsum board. Tests showed that its flexural strength was reduced by approximately 20% compared to Example 3, its impact toughness was reduced by approximately 25%, and its water resistance was also decreased.

[0061] Comparative Example 2 A gypsum board, whose composition and preparation method are basically the same as those in Example 3, except that the composite reinforcing layer uses ordinary glass fiber cloth instead of basalt fiber mesh cloth, and no gypsum-silica sol composite adhesive is used, only ordinary gypsum adhesive is used.

[0062] The strength and modulus of ordinary glass fiber cloth are lower than those of basalt fiber mesh cloth, and the bonding strength and water resistance of ordinary gypsum adhesive are poor, resulting in poor reinforcement effect of the composite reinforcement layer. The gypsum board prepared in this comparative example has a flexural strength that is about 15% lower than that of Example 3, and its performance stability in humid environments is significantly reduced, making it prone to delamination after a period of use.

[0063] Comparative Example 3 A gypsum board with the same composition as in Example 3, except that the curing and molding stage in the preparation method does not use segmented infrared radiation heating, but only natural curing.

[0064] Due to the lack of segmented infrared radiation heating, the hydration reaction of the gypsum was not sufficient or uniform, resulting in lower density of the blank and a tendency for microcracks to form inside. The flexural strength of the gypsum board prepared in this comparative example was reduced by about 10% compared to Example 3, and the drying time was prolonged, leading to reduced production efficiency. At the same time, the water resistance of the gypsum board was also reduced due to insufficient density.

[0065] All six embodiments achieved gradient optimization of the performance of glass fiber gypsum board by systematically controlling the proportioning parameters of the core substrate layer, composite reinforcement layer, and surface protective layer, as well as the curing process. In terms of raw material selection, all embodiments used building gypsum powder as the matrix material, combined with auxiliary raw materials such as rice husk ash and sisal fiber, forming a composite system that combines strength and toughness. Specifically, Embodiments 1 and 2, by increasing the content of rice husk ash (11-12 parts) and sisal fiber (5-6 parts), combined with high-speed stirring (1400-1500 r / min) and long stirring time (10-12 minutes), achieved nanoscale dispersion of the core substrate slurry. Electron microscopy observation showed that its matrix porosity was reduced by 15-20% compared to Embodiment 6. Regarding the composite reinforcement layer, the matching between the pore size (2-4 mm) and the tensile strength (4000-4500 MPa) of the basalt fiber mesh significantly affects the overall performance. In Example 3, a combination of 3 mm pore size mesh and 4300 MPa strength fiber was used, and the interfacial bonding strength was measured to be 3.2 MPa after a three-point bending test, which is 12% higher than that of Example 6 (4 mm pore size). In the surface protective layer, the synergistic effect of nano zinc oxide (1-3 parts) and EP-44 waterborne epoxy resin emulsion (8-12 parts) gives the board excellent antibacterial properties. In Example 1, the addition of 3 parts of nano zinc oxide resulted in an Escherichia coli inhibition rate of 99.2%, and after 500 hours of ultraviolet aging test, the surface coating integrity rate remained above 90%.

[0066] Optimization of the preparation process parameters, particularly the segmented infrared radiation heating during the curing stage (alternating wavelengths of 2-3 μm and 3-5 μm), significantly promoted the hydration process of gypsum. X-ray diffraction analysis showed that the characteristic peak intensity of the dihydrate gypsum in Example 3 was 25% higher than that in Comparative Example 3 (natural curing), and the crystal arrangement was more regular. The matching between the pressure during curing (1.5-2.5 MPa) and the pre-curing environment (40-50℃, 60-70% humidity) directly affected the density of the board. The green body formed in Example 2 under a pressure of 2.2 MPa achieved a density of 1.35 g / cm³. 3 Compared to Example 6 (1.5 MPa), the strength was improved by 8%. In the surface treatment process, the uniformity error of the 0.3-0.6 mm coating thickness formed by electrostatic spraying was ≤5%. Example 4, through the control of coating raw materials with a fineness of 45 μm, reduced the surface roughness Ra value to 1.2 μm, significantly better than the traditional brush coating process (Ra=3.5 μm). Comprehensive performance tests showed that the flexural strength of all six examples reached 8.5-12.0 MPa, and the impact toughness was 3.2-4.5 kJ / m. 2 With a water absorption rate of ≤12%, it fully meets the requirements of high-grade products in GB / T9775-2018 "Paper-faced Gypsum Board". Among them, Example 3 has the most balanced comprehensive performance, achieving the best balance between flexural strength (10.8MPa), water resistance (water absorption rate 9.2%) and production cost.

[0067] Examples 1 and 2, due to their high fiber content and high-strength reinforcement layer design, are suitable for partition walls in high-rise buildings, and their impact resistance meets the requirement of no cracking under a 10kJ impact load. Examples 5 and 6, by reducing the content of auxiliary raw materials (8-9 parts rice husk ash and 3-4 parts sisal fiber), reduce raw material costs by 10-15% while ensuring basic strength (flexural strength ≥ 8.5MPa), making them suitable for large-scale affordable housing construction. The medium-ratio schemes of Examples 3 and 4 perform exceptionally well in humid environments (such as bathrooms and kitchens), retaining over 85% of their strength after a 72-hour immersion test, far exceeding that of traditional gypsum board (60-65%). The performance gradient of each example covers the full range of needs from high-end customization to mass-market applications.

[0068] Three comparative examples, by specifically eliminating key technical features, clearly reveal the irreplaceable nature of the innovative points of this invention. Comparative Example 1 (lacking rice husk ash and sisal fiber) showed the most significant performance degradation, the core issue being the disruption of the matrix structure's integrity. Rice husk ash, as an active admixture, forms amorphous SiO2 after calcination at 800-900℃, which reacts with gypsum hydration products to generate hydrated calcium silicate gel, filling 20-50nm micropores. However, due to the lack of this component, the matrix porosity of Comparative Example 1 increased to 25% (18% in Example 3), leading to a decrease in flexural strength from 10.8MPa to 8.6MPa. The absence of sisal fiber disrupted the "fiber bridging" effect. Impact tests showed no fiber pull-out marks on the fracture surface of Comparative Example 1, while the fiber pull-out length in Example 3 reached 0.5-1mm, absorbing over 70% of the impact energy. This significantly reduced the impact toughness of Comparative Example 1 (2.4kJ / m²). 2 The water absorption rate was reduced by 25% compared to Example 3. In addition, the hydrophilic groups (-OH) of rice husk ash can reduce the water absorption rate of the matrix capillary. The water absorption rate of Comparative Example 1 reached 18.5% in 24 hours, which far exceeded the 9.2% of Example 3, verifying the necessity of the synergistic effect of natural fibers and industrial waste residue.

[0069] The performance shortcomings of Comparative Example 2 (glass fiber cloth + ordinary adhesive) are mainly reflected in the failure of the composite reinforcement layer. The monofilament tensile strength (2800 MPa) of ordinary glass fiber cloth is only 65-70% of that of basalt fiber, and its surface is not pretreated with epoxy, resulting in a decrease in the interfacial bond strength with the adhesive to 1.8 MPa (3.2 MPa in Example 3). The difference in the adhesive system is even more critical. In the gypsum-silica sol composite adhesive, the nanoparticles (5-20 nm) of silica sol can penetrate to the fiber surface to form a chemical bond, while the ordinary gypsum adhesive used in Comparative Example 2 only achieves bonding through physical encapsulation. After 25 freeze-thaw cycles (-20℃ to 20℃), the peel strength of its composite layer decreased by 40%, and obvious delamination occurred. Dynamic mechanical analysis showed that the energy storage modulus of Comparative Example 2 dropped to 2.5 GPa at 80°C, which was 34% lower than that of Example 3 (3.8 GPa), indicating that its high-temperature stability was insufficient. This is directly related to the lack of high-temperature resistance (operating temperature ≤600°C) of basalt fiber.

[0070] The performance defects of Comparative Example 3 (without infrared radiation heating) stemmed from kinetic obstacles in the curing process. Under natural curing conditions, the gypsum hydration reaction cycle was extended to 24 hours (6 hours in Example 3), and the hydration products were unevenly distributed. The aspect ratio (3-5) of the dihydrate gypsum crystals formed was much smaller than that of Example 3 (8-10), resulting in a decrease in crystal bonding strength. Thermogravimetric analysis showed that the crystal water content of Comparative Example 3 (18.2%) was lower than that of Example 3 (20.5%), indicating incomplete hydration. This led to poor volume stability and a drying shrinkage rate of 0.35% (0.18% in Example 3). In terms of production efficiency, the curing time of Comparative Example 3 was four times that of Example 3, and the compactness of the green body was insufficient (1.22 g / cm³). 3 In subsequent processing, corner chipping and cracking are prone to occur, resulting in a scrap rate as high as 8%, which is three times higher than that of Example 3 (2%). The comparative results of the three comparative examples fully demonstrate that the raw material combination and process innovation of the present invention have a synergistic effect and are indispensable.

[0071] This invention achieves a breakthrough over existing technologies through multi-dimensional innovation, with its creativity manifested in three aspects. In terms of material system innovation, a ternary composite reinforcement system of "industrial waste residue-natural fiber-high-performance fiber" is constructed, where the nanoscale filling effect (particle size below 5μm) of rice husk ash complements the macroscopic reinforcement effect of sisal fiber. The surface protective layer employs a desulfurized gypsum-nano zinc oxide composite system, realizing the high-value utilization of industrial by-products (desulfurized gypsum). Its dosage of 60-70 parts is 30% higher than existing technologies, and through the film-forming control of propylene glycol methyl ether acetate, the coating's weather resistance reaches C4 level (ISO12944 standard).

[0072] The technological innovation is reflected in the establishment of a "gradient curing-precise control" preparation system. Segmented infrared radiation heating is designed based on two key stages of gypsum hydration (induction and acceleration phases). A 2-3 μm wavelength (corresponding to hydroxyl stretching vibrations) promotes initial hydration, while a 3-5 μm wavelength (corresponding to crystal growth) accelerates the formation of dihydrate gypsum. This mechanism was confirmed by differential scanning calorimetry (DSC). In Example 3, the hydration exothermic peak area increased by 18% compared to single-wavelength heating. The combination of high-speed stirring (1200-1500 r / min) and planetary stirring achieved multi-scale dispersion. Laser particle size analyzer testing showed that the dispersion uniformity (coefficient of variation) of sisal fibers in the slurry was controlled within 8%, solving the industry pain point of natural fiber agglomeration. The matching process of electrostatic spraying and low-temperature drying (70-90℃) avoids high-temperature cracking of the coating. By controlling the fineness of the raw materials below 50 μm, the adhesion between the coating and the substrate reaches 1.5 MPa (ASTM D3359 standard), meeting high decorative requirements.

[0073] In terms of performance improvement and application value, the technical solution of this invention enables a leapfrog improvement in the overall performance of gypsum board, with flexural strength (8.5-12.0MPa) increasing by 40-70% compared to the GB / T9775-2018 standard, and impact toughness (3.2-4.5kJ / m²). 2 The carbon emission rate is more than 1.5 times that of existing fiberglass gypsum boards. Life cycle assessment shows that using a raw material system of rice husk ash and desulfurized gypsum can reduce carbon emissions by 18-22%, which aligns with the development trend of green building materials. Economic feasibility analysis indicates that the production cost of Example 6 (85 yuan / m²) is... 2 Compared to similar high-end products, the material consumption is reduced by 15%, while still meeting the Class A fire resistance requirements (fire resistance limit ≥1.5h). This technical solution has passed pilot-scale verification. Continuous operation data on the production line shows that the control accuracy of the board size deviation (length ±2mm, thickness ±0.5mm) has reached the industry-leading level, making it suitable for large-scale industrial application.

[0074] The testing method is as follows: The flexural strength test method was performed according to the flexural strength test standard in GB / T9775-2018 "Paper-faced Gypsum Board". Glass fiber gypsum boards prepared in each embodiment and comparative example were tested. The test sample size was 250mm × 50mm × 12mm, and at least 5 samples were prepared for each test group to ensure the reliability of the results. The sample was placed on the support platform of the flexural testing machine with a support span of 200mm. The loading speed was controlled at (50±5)mm / min. A vertically downward force was applied to the middle of the sample through the indenter of the testing machine until the sample broke. The maximum load at breakage was recorded. The flexural strength was calculated using the following formula: Rf = 3PL / (2bh) 2 ), where Rf is the flexural strength (MPa), P is the maximum load (N), L is the support span (mm), b is the sample width (mm), and h is the sample thickness (mm). During the test, it is necessary to ensure that the sample surface is flat and free of obvious defects, and that the loading process is kept stable to avoid impact loads affecting the test results.

[0075] The impact toughness test method adopts the simply supported beam impact test method, referring to GB / T1449-2005 "Test Method for Bending Properties of Fiber Reinforced Plastics". The sample size is 120mm×15mm×10mm, and at least 5 samples are tested in each group. The two ends of the sample are fixed on the support of the impact testing machine, with a support span of 100mm. A pendulum impact testing machine is used, and a pendulum with appropriate energy is selected (selected according to the estimated impact toughness; a 15J pendulum is used in this test). The pendulum is raised to the specified height, released, and allowed to fall freely to impact the middle of the sample. The energy difference before and after the impact is recorded, and this energy difference is the impact energy absorbed by the sample. The impact toughness is calculated by the following formula: αk=W / (bh), where αk is the impact toughness (kJ / m).2 W represents the impact energy (J), b represents the sample width (mm), and h represents the sample thickness (mm). After the test, the fracture surface of the sample is observed, and phenomena such as fiber pull-out and breakage are recorded as auxiliary evidence for analyzing the differences in impact toughness.

[0076] The water absorption rate test method shall be conducted according to the 24-hour water absorption rate test method in GB / T17657-2013 "Test Methods for Physical and Chemical Properties of Wood-based Panels and Decorative Wood-based Panels". The sample size is 50mm×50mm×12mm, and at least 3 samples shall be tested in each group. First, the sample shall be dried in an oven at (60±2)℃ to constant weight (the difference between two weighings shall not exceed 0.1%), and its dried mass (m0) shall be weighed. Then, the sample shall be completely immersed in distilled water at (23±2)℃, with the water level at least 20mm above the sample. After soaking for 24 hours, the sample shall be removed, and the surface moisture shall be gently wiped off with a damp towel. The mass after water absorption (m1) shall be weighed immediately. The water absorption rate shall be calculated by the following formula: W=(m1-m0) / m0×100%, where W is the water absorption rate (%). During the test, it is necessary to ensure that the sample is completely submerged in water to avoid floating. At the same time, attention shall be paid to maintaining a stable water temperature and strictly controlling the soaking time to ensure the accuracy of the test results.

[0077] The interfacial bonding strength test method uses the three-point bending method to indirectly evaluate the interfacial bonding strength between the composite reinforcement layer and the core substrate layer. The test sample has a size of 100mm×25mm×12mm, and a crack (approximately 1 / 3 of the sample thickness) is pre-fabricated along the thickness direction in the middle of the sample to penetrate the composite reinforcement layer. The sample is placed on a flexural testing machine with a support span of 80mm and a loading speed of (10±2)mm / min. A load is applied to one side of the crack through an indenter until the crack expands and the sample fractures. The maximum load at fracture is recorded. The interfacial bonding strength is estimated by the following formula: τ=P / (bL), where τ is the interfacial bonding strength (MPa), P is the maximum load (N), b is the sample width (mm), and L is the crack length (mm). In addition, the morphology of the fracture surface is observed by scanning electron microscopy to analyze the bonding between the composite reinforcement layer and the core substrate layer. If there are many fiber pull-outs and matrix tearing phenomena on the fracture surface, it indicates that the interfacial bonding strength is high.

[0078] The water resistance test method assesses the water resistance of gypsum board through a 72-hour immersion strength retention rate test. The sample specifications are the same as those for the flexural strength test, i.e., 250mm × 50mm × 12mm, with at least 5 samples per group. First, the initial flexural strength (R0) of the sample is tested. Then, the remaining samples are completely immersed in distilled water at (23±2)℃ for 72 hours. After soaking, the samples are removed, surface moisture is wiped off with a damp towel, and dried in an oven at (60±2)℃ until constant weight. The flexural strength (R1) is then tested again. Water resistance is expressed as strength retention rate: K = R1 / R0 × 100%, where K is the strength retention rate (%). During the test, it is essential to ensure that the samples are completely submerged during immersion and that the drying process is carried out at a uniform temperature to prevent cracking due to sudden temperature changes.

[0079] The porosity of gypsum board was determined using the mercury intrusion porosimetry method. A mercury intrusion porosimeter was used to test the sample. The sample was cut into 10mm × 10mm × 10mm pieces, dried to constant weight in an oven at (60±2)℃, and then placed in the sample cell of the mercury intrusion porosimeter. During testing, the mercury intrusion porosimeter applied different pressures to inject mercury into the pores of the sample. The porosity and pore distribution were calculated based on the relationship between pressure and mercury intrusion volume. The porosity was calculated using the following formula: P = Vv / Vt × 100%, where P is the porosity (%) and Vv is the total pore volume in the sample (cm³). 3 Vt is the total volume of the sample (cm³). 3 The testing range covers micropores (<2nm), mesopores (2-50nm), and macropores (>50nm) in the sample to provide a comprehensive understanding of the sample's pore structure characteristics.

[0080] The antibacterial performance test method, targeting the antibacterial properties of the surface protective layer, was conducted using the shaking flask method as specified in GB / T21866-2008 "Determination of Antibacterial Properties and Antibacterial Effects of Antibacterial Coatings (Films)". The test strain was *Escherichia coli* (ATCC25922). The sample was cut into 50mm × 50mm pieces, sterilized, and placed in a sterile Erlenmeyer flask. 100mL of a solution with a concentration of (1-5) × 10⁻⁶ was added. 5 A bacterial suspension of cfu / mL was cultured with shaking in a constant temperature incubator at (37±1)℃ for 24 h. After the culture, 1 mL of the bacterial suspension was serially diluted, and then an appropriate dilution was spread onto nutrient agar medium and cultured at (37±1)℃ for 48 h. The colony count was then performed. The antibacterial rate was calculated using the following formula: R = (AB) / A × 100%, where R is the antibacterial rate (%), A is the colony count (cfu / mL) of the blank control group (without sample) after culture, and B is the colony count (cfu / mL) of the experimental group (with sample) after culture. Strict aseptic techniques must be followed during the testing process to avoid contamination by other microorganisms that could affect the test results.

[0081] The dimensional deviation test method follows the dimensional deviation test requirements in GB / T9775-2018 "Paper-faced Gypsum Board," measuring the length, width, and thickness of the gypsum board. Length and width are measured using a steel tape measure with an accuracy of 1 mm, three times at different locations on the sample, and the average value is taken as the test result. Thickness is measured using a vernier caliper with an accuracy of 0.01 mm, once at each of the four corners and the center of the sample, for a total of five measurements, and the average value is taken as the test result. Dimensional deviation is calculated using the following formula: ΔL = Li - L0, where ΔL is the length deviation (mm), Li is the actual measured length (mm), and L0 is the specified length (mm). The calculation method for width and thickness deviations is similar. The dimensional deviation test evaluates the production accuracy and stability of the gypsum board.

[0082] Thermogravimetric analysis (TGA) was used to assess the degree of hydration of gypsum board samples. The samples were ground into powder, passed through a 100-mesh sieve, and approximately 10 mg of the sample was placed in the crucible of the TGA analyzer. The test conditions were: nitrogen atmosphere, flow rate of 50 mL / min, heating rate of 10 °C / min, and temperature range from room temperature to 800 °C. The mass change curve of the sample with temperature was recorded. By analyzing the weight loss of water of crystallization in the thermogravimetric curve, the water of crystallization content in the sample was calculated. The water of crystallization content was calculated using the following formula: Ww = (m0 - m1) / m0 × 100%, where Ww is the water of crystallization content (%), m0 is the initial mass of the sample (mg), and m1 is the mass of the sample at 200 °C (mg, at which point the water of crystallization has been completely lost). The degree of hydration of the gypsum was determined based on the water of crystallization content; a higher water of crystallization content indicated more complete hydration.

[0083] A dynamic mechanical analysis method was used to test the dynamic mechanical properties of gypsum board samples and evaluate their high-temperature stability. The test samples were 50mm × 10mm × 5mm in size, the test mode was three-point bending with a support span of 30mm, the frequency was 1Hz, and the temperature range was from room temperature to 100℃ at a heating rate of 2℃ / min. The storage modulus (E'), loss modulus (E''), and loss factor (tanδ) of the samples were recorded as a function of temperature. The storage modulus reflects the material's ability to store elastic deformation energy; a higher storage modulus indicates better rigidity. The loss factor reflects the material's damping performance. By analyzing the changes in storage modulus at different temperatures, the performance stability of the samples under high-temperature conditions was evaluated; a smaller decrease in storage modulus indicates better high-temperature stability.

[0084] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A type of fiberglass gypsum board, characterized in that, It includes a core substrate layer, a composite reinforcement layer, and a surface protective layer arranged sequentially from the inside out; the core substrate layer is made of the following raw materials in parts by weight: 55-75 parts building gypsum powder, 8-12 parts rice husk ash, 3-6 parts sisal fiber, 2-4 parts nano calcium carbonate, 0.3-0.8 parts PCA-R1 polycarboxylate superplasticizer, and 25-35 parts water; The composite reinforcement layer is an interwoven structure of basalt fiber mesh and gypsum-silica sol composite adhesive, wherein the pore size of the basalt fiber mesh is 2-4mm and the tensile strength of a single filament is ≥4000MPa. The surface protective layer is a gypsum-based nano zinc oxide composite coating with a thickness of 0.3-0.6 mm.

2. The glass fiber gypsum board according to claim 1, characterized in that, The rice husk ash is calcined at 800-900℃ for 2-3 hours and then pulverized by air jet mill to a particle size ≤5μm, wherein the silicon dioxide content is ≥90%.

3. The glass fiber gypsum board according to claim 1 or 2, characterized in that, The sisal fiber is made by the following treatment: the sisal raw fiber is soaked in a 5% sodium hydroxide solution at 80°C for 2 hours, washed with water, soaked in a 2% silane coupling agent KH-570 solution for 30 minutes, dried, and then cut into short fibers with a length of 1-3 mm.

4. The glass fiber gypsum board according to claim 1 or 2, characterized in that, The gypsum-silica sol composite adhesive is composed of the following raw materials in parts by weight: 100 parts hemihydrate gypsum powder, 15-20 parts silica sol, 5-8 parts aluminate cement, and 45-55 parts water, which are mixed and stirred until the pH value is 7.5-8.

5.

5. The glass fiber gypsum board according to claim 1 or 2, characterized in that, The gypsum-based nano zinc oxide composite coating is made from the following raw materials in parts by weight: 60-70 parts of desulfurized gypsum powder, 1-3 parts of nano zinc oxide, 8-12 parts of EP-44 waterborne epoxy resin emulsion, 1-2 parts of propylene glycol methyl ether acetate, and 35-45 parts of deionized water.

6. A method for preparing glass fiber gypsum board as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Preparation of core substrate slurry: Mix building gypsum powder, rice husk ash, sisal fiber, nano calcium carbonate, PCA-R1 polycarboxylate superplasticizer and water in proportion, and stir at high speed at 1200-1500 r / min for 8-12 minutes to obtain a uniform slurry; S2. Preparation of composite adhesive: Mix hemihydrate gypsum powder, silica sol, aluminate cement and water in proportion, stir in a planetary mixer at 300-500 r / min for 10 minutes, and let stand to defoam for 3-5 minutes; S3. Layered composite molding: First, lay a core substrate slurry with a thickness of 1 / 2 in the mold, then lay basalt fiber mesh cloth and impregnate it with composite adhesive, and then lay the remaining core substrate slurry with a thickness of 1 / 2 to form a sandwich structure blank. S4. Curing and molding: The blank is pre-cured for 2 hours in an environment with a temperature of 40-50℃ and a relative humidity of 60-70%, and then cured under pressure of 1.5-2.5MPa for 4-6 minutes, while infrared radiation heating is carried out simultaneously with a radiation wavelength of 2-5μm and a power of 300-500W. S5. Surface treatment: Mix and stir the gypsum-based nano zinc oxide composite coating raw materials until the fineness is ≤50μm, apply them to the surface of the blank by electrostatic spraying, and dry at 70-90℃ for 1.5-2.5 hours to obtain the glass fiber gypsum board.

7. The preparation method according to claim 5, characterized in that, In step S4, the infrared radiation is applied using segmented heating. The first segment lasts 3 minutes and uses a wavelength of 2-3 μm, while the second segment lasts 3 minutes and uses a wavelength of 3-5 μm.

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