Fiber gypsum board as well as preparation method and application thereof

Abstract

The invention provides a fiber gypsum board and a preparation method and application thereof, and belongs to the technical field of building materials, the fiber gypsum board comprises, by mass, 80-120 parts of alpha semi-hydrated gypsum, 10-30 parts of fiber, 0-2 parts of a retarder, and 0.5-5 parts of a modifier; the length of the alpha semi-hydrated gypsum is 20-40 [mu] m, and the length-diameter ratio is 1: (1-5); the fiber has a pore structure, the section aperture of the fiber is 50-250 [mu] m, the surface pore size is 50-200 nm, and the pore wall thickness is 90-110 nm. The fiber gypsum board with high compressive strength is prepared by compounding the alpha-semi-hydrated gypsum with a specific length-diameter ratio, the fibers with certain pores, the retarder and the modifier, and the fiber gypsum board is high in practicability and beneficial to popularization and application.

Description

Technical Field

[0001] The present application belongs to the technical field of building materials, and in particular relates to a fiber gypsum board and a preparation method and application thereof. Background Art

[0002] Gypsum board is a kind of building material made of building gypsum as the main raw material. It has been widely used in various buildings such as residences, office buildings, shops, hotels and industrial plants, such as interior partitions, wall covering panels (instead of wall plastering), ceilings, sound-absorbing panels, ground base panels and various decorative panels. With the continuous improvement of people's quality of life, the requirements for decoration materials are getting higher and higher. Among them, fiber gypsum board is a new type of building board with building gypsum powder as the main raw material and various fibers as reinforcing materials. However, due to the low strength of the gypsum material itself, the reinforcing effect of the gypsum material after adding fibers is severely limited, so that the current fiber gypsum board often has the problems of low strength and poor practicality. Summary of the invention

[0003] In view of the technical problems existing in the background technology, the present application provides a fiber gypsum board and a preparation method and application thereof, aiming to solve the technical problems of low strength and poor practicality of existing fiber gypsum boards.

[0004] In the first aspect, an embodiment of the present application provides a fiber gypsum board, which includes, by mass, 80 to 120 parts of α-hemihydrate gypsum, 10 to 30 parts of fibers, 0 to 2 parts of retarders, and 0.5 to 5 parts of modifiers; wherein the length of the α-hemihydrate gypsum is 20 to 40 μm, and the aspect ratio is 1: (1 to 5); the fibers have a porous structure, and their cross-sectional pore diameter is 50 to 250 μm, the surface pore diameter is 50-200 nm, and the pore wall thickness is 90 to 110 nm.

[0005] In the technical solution of the embodiment of the present application, a fiber gypsum board is prepared by compounding α-hemihydrate gypsum, fiber, retarder and modifier, wherein the fiber with a porous structure has a large specific surface area, which can not only increase the contact area with α-hemihydrate gypsum, increase the overall strength and stability of the fiber gypsum board, but also increase the water absorption, reduce the early hydration rate of hemihydrate gypsum, and synergize with the retarder to play a retarding effect. At the same time, the aspect ratio of α-hemihydrate gypsum affects the hydration rate and the mechanical properties of the hardened body. By controlling the aspect ratio of α-hemihydrate gypsum within a suitable range, it is helpful to control the hydration rate and improve the density and durability of the fiber gypsum board; if the aspect ratio is too large, more microcracks may be formed in the fiber gypsum board, thereby reducing its crack resistance; if the aspect ratio is too small, it is not conducive to forming a continuous network structure, thereby reducing its strength and toughness.

[0006] In some embodiments, the purity of α-hemihydrate gypsum is ≥90%, the moisture content is 15-25%, and the particle size is 60-150 mesh.

[0007] In this embodiment, controlling the moisture content, purity and particle size of α-hemihydrate gypsum is beneficial to further improve the mechanical properties and durability of the fiber gypsum board. Among them, if the moisture content of α-hemihydrate gypsum is too high, the setting time of the fiber gypsum board is too long, so that the strength of the prepared fiber gypsum board is reduced; and if the moisture content of α-hemihydrate gypsum is too low, the α-hemihydrate gypsum cannot be fully hydrated, which is not conducive to the blank making and maintenance of the fiber gypsum board, thereby affecting its processing performance and final use performance. At the same time, α-hemihydrate gypsum with higher purity has better hydration activity, and can react with water faster to generate dihydrate gypsum, thereby accelerating the setting and hardening speed of the fiber gypsum board, and high-purity α-hemihydrate gypsum can also improve the mechanical properties and durability of the fiber gypsum board. Furthermore, α-hemihydrate gypsum with a smaller particle size can provide a larger specific surface area, accelerate the hydration reaction, and improve the early strength of the fiber gypsum board, but too small a particle size may cause the fiber gypsum board to be too dense, affecting its air permeability and thermal insulation.

[0008] In some embodiments, the length of the fiber is 50-600 μm, and the aspect ratio is (10:1)-(50:1).

[0009] In this embodiment, the fiber aspect ratio is controlled within a reasonable range, which is conducive to enhancing the bonding between the fiber and the gypsum matrix and improving the overall performance of the fiber gypsum board. If the aspect ratio is too large, it is not conducive to the uniform dispersion of the fiber in the gypsum matrix, and if the aspect ratio is too small, it affects the toughness and durability of the fiber gypsum board.

[0010] In some embodiments, the fiber is one or more of paper fiber, wood fiber, bamboo fiber, straw fiber, glass fiber, polypropylene fiber.

[0011] In this embodiment, the above-mentioned types of fibers can be used to obtain a fiber gypsum board with relatively high strength.

[0012] In some embodiments, the retarder is one or more of sodium hexametaphosphate, sodium polyphosphate, potassium tartrate, and sodium citrate.

[0013] In this embodiment, the retarder has a retarding effect on α-hemihydrate gypsum, and prolongs its setting time by reducing the solubility of α-hemihydrate gypsum and forming a complex to limit the diffusion of ions near the gypsum crystals, thereby preventing it from hardening during a long period of blank forming, thereby meeting the process operation requirements and avoiding uneven crystal growth due to excessively fast hydration rate, thereby reducing strength loss.

[0014] In some embodiments, the modifier is one or more of slaked lime, quicklime, and chitosan.

[0015] In this embodiment, the modifier can promote the bonding performance between the fiber and α-hemihydrate gypsum, improve the strength of its hydrated hardened body, enhance the hardness and strength of the fiber gypsum board, and improve its durability.

[0016] In a second aspect, the present application provides a method for preparing the aforementioned fiber gypsum board, comprising the following steps: Mixing fiber, α-hemihydrate gypsum, retarder and water uniformly to obtain a first mixed slurry; The first mixed slurry and the modifier are mixed evenly to obtain a second mixed slurry; The second mixed slurry is subjected to blanking by a slurry flow method to obtain a formed plate; The formed board is cured to obtain a fiber gypsum board.

[0017] In the technical solution of the embodiment of the present application, the fibers, α-hemihydrate gypsum, modifier and retarder are first mixed to prepare a slurry, and then a slurry flow method is used to prepare blanks and perform curing. Compared with the casting method, the slurry flow method has higher continuous production efficiency, and the fibers are more evenly distributed in the gypsum board, and the strength of the fiber gypsum board is higher.

[0018] In some embodiments, the slurry flow method includes: vacuum filtering the second mixed slurry to obtain a third mixed slurry; pre-pressing the third mixed slurry to obtain a pre-pressed plate; pressing the pre-pressed plate to obtain a pressed plate; wherein the water content of the third mixed slurry is 50~75%; and / or the pressing pressure is 9~15MPa.

[0019] In this embodiment, the slurry flow method can continuously produce boards, improve production efficiency, and ensure the thickness consistency and uniformity of the board by evenly spreading the slurry on the conveyor belt, especially improving the dispersion uniformity of the fibers in the board, and enhancing the overall strength of the fiber gypsum board. The slurry with moderate moisture content has good fluidity, which is conducive to the uniform spreading and molding of the slurry on the production line. Too high moisture content will lead to prolonged blank molding time and may cause holes and cracks in the fiber gypsum board; while too low moisture content and too dry slurry will cause the roller forming machine to be unable to roll up the slurry evenly during the pre-pressing molding process, and the pre-pressed board cannot be formed, affecting production efficiency. If the pressure of the pressurization is too large, the fibers may be arranged too closely in the molded board, reducing the effective contact area between the fibers and the gypsum matrix, affecting its reinforcement effect; if the pressure of the pressurization is too small, the internal structure of the fiber gypsum board may be uneven, affecting its overall performance. In addition, it is difficult to fully discharge the bubbles in the molded board with a small pressure, resulting in holes in the fiber gypsum board, reducing its mechanical properties and durability.

[0020] In some embodiments, the curing conditions include: humidity 90-95%, temperature 20-25° C., and curing time 24-30 hours.

[0021] In this embodiment, if the humidity is too low or the temperature is too high during curing, it will cause water loss too quickly, resulting in insufficient hydration reaction, insufficient strength of the prepared fiber gypsum board, and even cracking or deformation; while if the humidity is too high and the temperature is too low, the curing time will be extended and the production efficiency will be reduced.

[0022] In a third aspect, an embodiment of the present application provides an application of the aforementioned fiber gypsum board in indoor or outdoor decoration.

[0023] In the technical solution of the embodiment of the present application, the excellent strength performance of the fiber gypsum board described in the first aspect is utilized, and it can show good durability after being used as a decoration building material for decoration.

[0024] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. DETAILED DESCRIPTION

[0025] The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0027] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0030] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0032] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0033] In the prior art, the hemihydrate gypsum used to form the fiber gypsum board will produce a large number of pores inside the board during the hydration process to form dihydrate gypsum. Compared with the dense gypsum board, the compressive strength of the fiber gypsum board with high porosity is significantly reduced, thus limiting the practical application of the fiber gypsum board.

[0034] In order to solve the problems of low strength and poor practicality of existing fiber gypsum boards, the present application provides a fiber gypsum board and its preparation method and application, wherein the compressive strength of the fiber gypsum board can be improved by compounding α-hemihydrate gypsum with a specific morphology, fibers with a certain pore structure, and modifiers and retarders, which is conducive to promotion and application.

[0035] In a first aspect, an embodiment of the present application provides a fiber gypsum board, which comprises, by weight, 80 to 120 parts of α-hemihydrate gypsum, 10 to 30 parts of fiber, 0 to 2 parts of retarder, and 0.5 to 5 parts of modifier; wherein the length of the α-hemihydrate gypsum is 20 to 40 μm, and the aspect ratio is 1: (1 to 5); the fiber has a porous structure, and its cross-sectional pore diameter is 50 to 250 μm, the surface pore diameter is 50-200 nm, and the pore wall thickness is 90 to 110 nm.

[0036] The aspect ratio is the ratio of length (lateral dimension) to diameter (longitudinal dimension).

[0037] Specifically, in parts by mass, the fiber gypsum board includes 100 parts of α-hemihydrate gypsum, 15 parts of fiber, 0.1 parts of retarder, and 0.5 parts of modifier, or includes 120 parts of α-hemihydrate gypsum, 30 parts of fiber, 1 part of retarder, and 5 parts of modifier, or other parts by mass within the above range. Among them, fibers are beneficial to increasing the mechanical properties of fiber gypsum board, but too much fiber content will increase the water absorption rate of fiber gypsum board, thereby reducing the moisture resistance of fiber gypsum board, while too low fiber content will lead to a decrease in the mechanical properties of fiber gypsum board, which is not conducive to practical application; retarders mainly affect the setting time of α-hemihydrate gypsum during the molding process of fiber gypsum board. If the amount of retarder is too large, the setting time will be too slow, reducing production efficiency; modifiers mainly promote the bonding performance of fibers and α-hemihydrate gypsum, thereby improving the mechanical properties of fiber gypsum board. If the amount of modifier is too small, the bonding between fibers and α-hemihydrate gypsum will be insufficient, and the mechanical properties will be reduced. If the amount of modifier is too large, the proportion of bonding components in the fiber gypsum board will be too large, thereby reducing its mechanical properties.

[0038] In the technical solution of the embodiment of the present application, a fiber gypsum board is prepared by compounding α-hemihydrate gypsum, fiber, retarder and modifier, wherein the fiber with a porous structure has a large specific surface area, which can not only increase the contact area with α-hemihydrate gypsum, increase the overall strength and stability of the fiber gypsum board, but also increase the water absorption, reduce the early hydration rate of α-hemihydrate gypsum, and synergize with the retarder to play a retarding effect. The aspect ratio of α-hemihydrate gypsum affects the hydration rate and the mechanical properties of the hardened body. By controlling the aspect ratio of α-hemihydrate gypsum within a suitable range, it is helpful to control the hydration rate and improve the density and durability of the fiber gypsum board; if the aspect ratio is too large, more microcracks may be formed in the fiber gypsum board, thereby reducing its crack resistance; if the aspect ratio is too small, it is not conducive to forming a continuous network structure, thereby reducing its strength and toughness.

[0039] Furthermore, in some embodiments, the purity of α-hemihydrate gypsum is ≥90%, the moisture content is 15-25%, and the particle size is 60-150 mesh.

[0040] In the technical scheme of the embodiment of the present application, by controlling the moisture content, purity and particle size of α-hemihydrate gypsum, it is beneficial to further improve the mechanical properties and durability of the fiber gypsum board. Among them, if the moisture content of α-hemihydrate gypsum is too high, the setting time of the fiber gypsum board will be too long, which will reduce its strength; while if the moisture content of α-hemihydrate gypsum is too low, it may cause the α-hemihydrate gypsum to be unable to fully hydrate, which is not conducive to the blank making and maintenance of the fiber gypsum board, and affects its processing performance and final use performance. At the same time, the semi-hydrated gypsum with higher purity has better hydration activity, and can react with water faster to generate dihydrate gypsum, thereby accelerating the setting and hardening speed of the fiber gypsum board, and the high-purity semi-hydrated gypsum can also improve the mechanical properties and durability of the gypsum board. Further, α-hemihydrate gypsum with a smaller particle size can provide a larger specific surface area, accelerate the hydration reaction, and improve the early strength of the fiber gypsum board, but α-hemihydrate gypsum with too small a particle size may cause the fiber gypsum board to be too dense, affecting its air permeability and thermal insulation.

[0041] Furthermore, in some embodiments, in some embodiments, the length of the fiber is 50-600 μm, and the aspect ratio is (10:1)-(50:1).

[0042] In the technical solution of the embodiment of the present application, the fiber aspect ratio is controlled within a reasonable range, which is conducive to enhancing its bonding with the gypsum matrix and improving the overall performance of the fiber gypsum board. If the aspect ratio is too large, it is not conducive to its uniform dispersion in the gypsum matrix, while if the aspect ratio is too small, it affects the toughness and durability of the fiber gypsum board.

[0043] Specifically, the length of the fiber can be 50μm, 100μm, 200μm, 300μm, 400μm, 500μm, 600μm or any value in the range of 50~600μm, and the aspect ratio of the fiber can be 10:1, 20:1, 30:1, 40:1, 50:1 or any value in the range of 10:1~(50:1).

[0044] Furthermore, in some embodiments, the fiber is one or more of paper fiber, wood fiber, bamboo fiber, straw fiber, glass fiber, and polypropylene fiber.

[0045] In the technical solutions of the embodiments of the present application, the above-mentioned types of fibers can be used to obtain fiber gypsum boards with higher strength.

[0046] Furthermore, in some embodiments, the retarder is one or more of sodium hexametaphosphate, sodium polyphosphate, potassium tartrate, and sodium citrate.

[0047] In the technical solution of the embodiment of the present application, the retarder has a retarding effect on α-hemihydrate gypsum, and prolongs its setting time by reducing the solubility of α-hemihydrate gypsum and forming a complex to limit the diffusion of ions near the gypsum crystals, thereby preventing it from hardening during a long period of blank making and molding, thereby meeting the process operation requirements and avoiding uneven crystal growth due to excessively fast hydration rate, thereby reducing strength loss.

[0048] Furthermore, in some embodiments, the modifier is one or more of slaked lime, quicklime, and chitosan.

[0049] In the technical solution of the embodiment of the present application, the modifier can promote the bonding performance between the fiber and α-hemihydrate gypsum, improve the strength of its hydrated hardened body, enhance the hardness and strength of the fiber gypsum board, and improve its durability.

[0050] In a second aspect, the present application provides a method for preparing the aforementioned fiber gypsum board, comprising the following steps: Mixing fiber, α-hemihydrate gypsum, retarder and water uniformly to obtain a first mixed slurry; The first mixed slurry and the modifier are mixed evenly to obtain a second mixed slurry; The second mixed slurry is subjected to blanking by a slurry flow method to obtain a formed plate; The formed board is cured to obtain a fiber gypsum board.

[0051] In the technical solution of the embodiment of the present application, the fibers, α-hemihydrate gypsum, modifier and retarder are first mixed to prepare a slurry, and then a slurry flow method is used to prepare blanks and perform curing. Compared with the casting method, the slurry flow method has higher continuous production efficiency, and the fibers are more evenly distributed in the gypsum board, and the strength of the fiber gypsum board is higher.

[0052] Further, in some embodiments, the slurry flow method includes: vacuum filtering the second mixed slurry to obtain a third mixed slurry; pre-pressing the third mixed slurry to obtain a pre-pressed plate; pressing the pre-pressed plate to obtain a pressed plate; wherein the moisture content of the third mixed slurry is 50~75%; and / or the pressing pressure is 9~15MPa.

[0053] In the technical solution of the embodiment of the present application, the slurry flow method can continuously produce boards, improve production efficiency, and ensure the thickness consistency and uniformity of the board by evenly spreading the slurry on the conveyor belt, especially improving the dispersion uniformity of the fiber in the board, and enhancing the overall strength of the fiber gypsum board. The slurry with moderate moisture content has good fluidity, which is conducive to the uniform spreading and molding of the slurry on the production line. Too high moisture content will lead to prolonged blank molding time and may cause holes and cracks in the fiber gypsum board; while too low moisture content and too dry slurry will cause the roller forming machine to be unable to roll up the slurry evenly during the pre-pressing molding process, and the pre-pressing board cannot be formed, affecting production efficiency. If the pressure of the pressurization is too large, the fibers may be arranged too closely in the molded board, reducing the effective contact area between the fibers and the gypsum matrix, affecting its reinforcement effect; if the pressure of the pressurization is too small, it may cause the internal structure of the fiber gypsum board to be uneven, affecting its overall performance. In addition, it is difficult to fully discharge the bubbles in the molded board with a small pressure, resulting in holes in the fiber gypsum board, reducing its mechanical properties and durability.

[0054] Furthermore, in some embodiments, the curing conditions include: humidity 90-95%, temperature 20-25° C., and curing time 24-30 hours.

[0055] Specifically, the curing humidity is 90%, 92%, 94%, 95% or any humidity within the above range; the curing temperature is 20°C, 22°C, 24°C, 25°C or any temperature within the above range; the curing time is 24h, 26h, 28h, 30h or any time within the above range.

[0056] In the technical solution of the embodiment of the present application, if the humidity is too low or the temperature is too high during curing, it will cause too rapid water loss, resulting in insufficient hydration reaction, insufficient strength of the prepared fiber gypsum board, and even cracking or deformation of the board; while if the humidity is too high and the temperature is too low, the curing time will be prolonged and the production efficiency will be reduced.

[0057] In a third aspect, an embodiment of the present application provides an application of the aforementioned fiber gypsum board in indoor or outdoor decoration.

[0058] In the technical solution of the embodiment of the present application, the excellent strength performance of the fiber gypsum board described in the first aspect is utilized and it is used as a decoration building material for decoration, and it can show good durability after application.

[0059] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0060] In the following embodiments and comparative examples, the purity of α-hemihydrate gypsum is ≥90%, the moisture content is 15-25%, the particle size is 60-150 mesh, the length is 20-40 μm, and the aspect ratio is 1:(1-5); the fiber has a porous structure, the cross-sectional pore diameter is 50-250 μm, the surface pore diameter is 50-200 nm, the pore wall thickness is 90-110 nm, the fiber length is 50-600 μm, and the aspect ratio is (10:1)-(50:1).

[0061] 1. Preparation method Example 1 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0062] (2) Add 1 part of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0063] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0064] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0065] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0066] Example 2 A fiber gypsum board, the preparation method is as follows: (1) In parts by mass, 100 parts of α-hemihydrate gypsum, 10 parts of rice straw fiber, 0.5 parts of sodium hexametaphosphate, 0.5 parts of sodium polyphosphate, and 750 parts of water were added to a paddle mixer and mixed at a stirring speed of 700 rpm to obtain a uniformly dispersed first mixed slurry.

[0067] (2) Add 2 parts of quicklime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0068] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 60%.

[0069] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0070] (5) The pre-pressed plate is moved into the pressure forming machine through a suction cup machine and press-formed at a pressure of 10 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 24 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0071] Example 3 A fiber gypsum board, the preparation method is as follows: (1) Add 100 parts by mass of α-hemihydrate gypsum, 15 parts by mass of rice straw fiber, 2 parts by mass of sodium citrate, and 1000 parts by mass of water into a paddle mixer and mix at a stirring speed of 800 rpm to obtain a first mixed slurry that is evenly dispersed.

[0072] (2) Add 1.5 parts of quicklime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0073] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 65%.

[0074] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0075] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 26 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0076] Example 4 A fiber gypsum board, the preparation method is as follows: (1) By weight, 120 parts of α-hemihydrate gypsum, 30 parts of paper fiber, 2 parts of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0077] (2) Add 5 parts of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0078] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0079] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0080] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0081] Example 5 A fiber gypsum board, the preparation method is as follows: (1) By weight, 80 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0082] (2) Add 0.5 parts of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0083] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0084] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0085] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0086] Example 6 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, and 750 parts of water were added to a paddle mixer and mixed at a stirring speed of 800 rpm to obtain a uniformly dispersed first mixed slurry.

[0087] (2) Add 1 part of quicklime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0088] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 65%.

[0089] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0090] (5) Stack the five pre-pressed plates together and move them into a pressure forming machine for pressure forming at a pressure of 10 MPa to obtain a formed plate with a thickness of 12 mm; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 24 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0091] Example 7 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 15 parts of paper fiber, and 750 parts of water were added to a paddle mixer and mixed at a stirring speed of 800 rpm to obtain a uniformly dispersed first mixed slurry.

[0092] (2) Add 2 parts of quicklime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0093] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 75%.

[0094] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0095] (5) Stack the five pre-pressed plates together and move them into a pressure forming machine for pressure forming at a pressure of 15 MPa to obtain a formed plate with a thickness of 10 mm; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 24 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0096] Example 8 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 30 parts of wood fiber, and 500 parts of water were added to a paddle mixer and mixed at a stirring speed of 800 rpm to obtain a uniformly dispersed first mixed slurry.

[0097] (2) Add 1 part of quicklime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0098] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 50%.

[0099] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0100] (5) Stack the five pre-pressed plates together and move them into a pressure forming machine for pressure forming at a pressure of 15 MPa to obtain a formed plate with a thickness of 10 mm; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 24 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0101] Example 9 A fiber gypsum board, the preparation method is as follows: (1) By weight, 120 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0102] (2) Add 1 part of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0103] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0104] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0105] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0106] Example 10 A fiber gypsum board, the preparation method is as follows: (1) By weight, 80 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0107] (2) Add 1 part of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0108] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0109] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0110] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0111] Embodiment 11 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 30 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0112] (2) Add 1 part of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0113] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0114] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0115] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0116] Example 12 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0117] (2) Add 0.5 parts of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0118] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0119] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0120] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0121] Embodiment 13 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0122] (2) Add 5 parts of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0123] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0124] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0125] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0126] Embodiment 14 A fiber gypsum board, the preparation method is as follows: (1) In parts by mass, 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 2 parts of sodium hexametaphosphate, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0127] (2) Add 1 part of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0128] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0129] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0130] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0131] Embodiment 15 A fiber gypsum board, the preparation method is as follows: (1) By weight, 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, and 1000 parts of water were added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a uniformly dispersed first mixed slurry.

[0132] (2) Add 1 part of slaked lime to the first mixed slurry and stir evenly to obtain a second mixed slurry.

[0133] (3) The second mixed slurry is filtered through a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0134] (4) The third mixed slurry is pre-pressed and formed by a roller pre-pressing machine to obtain a pre-pressed plate.

[0135] (5) The pre-pressed plate is moved into a pressure forming machine through a suction cup machine and press-formed at a pressure of 13 MPa to obtain a formed plate; (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, then ventilated and dried, and finally grinded, trimmed, and polished to obtain a fiber gypsum board.

[0136] Comparative Example 1 A gypsum board comprises, by weight, 100 parts of alpha hemihydrate gypsum, 0 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1 part of slaked lime. The preparation method is the same as that of Example 1.

[0137] Comparative Example 2 A fiber gypsum board comprises, by weight, 100 parts of alpha hemihydrate gypsum, 40 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1 part of slaked lime. The preparation method is the same as that of Example 1.

[0138] Comparative Example 3 A fiber gypsum board comprises, by weight, 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, and 1 part of sodium hexametaphosphate. The preparation method is the same as that of Example 1.

[0139] Comparative Example 4 A fiber gypsum board comprises, by weight, 100 parts of alpha hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 10 parts of slaked lime. The preparation method is the same as that of Example 1.

[0140] 2. Test Method According to the standard JC / T2702-2022 "Fiber-reinforced gypsum board", the physical properties of the fiber gypsum boards prepared in Examples 1 to 15 of the present invention and Comparative Examples 1 to 4 were tested.

[0141] III. Analysis of test results of various embodiments and comparative examples Table 1 Performance test results of Examples 1 to 8

[0142] Table 2 Performance test results of Examples 9 to 15

[0143] Table 3 Performance test results of comparative examples 1 to 4

[0144] As can be seen from Tables 1 and 2, the fiber gypsum board prepared by compounding α-hemihydrate gypsum, fiber, modifier, and / or retarder in the present invention has the properties of fire resistance, moisture resistance, high strength, strong nail holding force, etc., is light in weight, easy to carry, not easy to damage, has good processing performance, can be fixed with screws and round nails, making the construction faster and more convenient, has a long service life, is non-toxic, environmentally friendly, and recyclable. Compared with Example 1, in Examples 9-10, with the increase of the amount of α-hemihydrate gypsum, the mechanical properties of the prepared fiber gypsum board, such as shear force and breaking load, tend to increase, and the water absorption of the fiber gypsum board increases slightly; in Example 11, compared with Example 1, with the increase of the fiber content, the mechanical properties and water absorption of the prepared fiber gypsum board both increase; in Examples 12-13, compared with Example 1, with the increase of the modifier content, the mechanical properties of the prepared fiber gypsum board, such as shear force and breaking load, tend to increase; in Examples 14-15, compared with Example 1, with the increase of the amount of retarder, the mechanical properties of the prepared fiber gypsum board do not change much, because the retarder mainly affects the setting time of α-hemihydrate gypsum, avoiding its hardening during the mixing and blanking process and affecting the production of the fiber gypsum board.

[0145] Furthermore, compared with Example 1, it can be seen that the surface density of the gypsum board without adding fiber increases, resulting in a larger weight, and the screw holding force, shear force and breaking load are significantly reduced. At the same time, the impact resistance is insufficient and cannot meet the mechanical requirements of the board from production to construction. The moisture resistance is poor and it is easy to deform in a humid environment, which is not conducive to long-term use.

[0146] Furthermore, it can be seen from the comparison between Comparative Example 2 and Example 1 that the fiber content mainly affects the dimensional stability of the fiber gypsum board in a humid environment. If the fiber content is too much, the water absorption rate of the fiber gypsum board is too large, which makes it easy to deform and has poor moisture resistance.

[0147] Furthermore, compared with Example 1, Comparative Examples 3 to 4 show that the modifier mainly promotes the bonding performance between the fiber and α-hemihydrate gypsum, thereby improving the mechanical properties of the fiber gypsum board; too little modifier leads to insufficient bonding between the fiber and α-hemihydrate gypsum, and a decrease in the breaking load; too much modifier leads to a large proportion of bonding components in the fiber gypsum board, thereby reducing the maximum load it can withstand.

[0148] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A fiber gypsum board, characterized in that: The invention comprises 80-120 parts of α-hemihydrate gypsum, 10-30 parts of fiber, 0-2 parts of retarder and 0.5-5 parts of modifier in parts by mass; wherein the length of the α-hemihydrate gypsum is 20-40 μm, and the aspect ratio is 1:(1-5); the fiber has a porous structure, and its cross-sectional pore diameter is 50-250 μm, the surface pore size is 50-200 nm, and the pore wall thickness is 90-110 nm.

2. The fiber gypsum board according to claim 1, characterized in that: The purity of the α-hemihydrate gypsum is ≥90%, the moisture content is 15-25%, and the particle size is 60-150 meshes.

3. The fiber gypsum board according to claim 1, characterized in that: The length of the fiber is 50-600 μm, and the aspect ratio is (10:1)-(50:1).

4. The fiber gypsum board according to claim 3, characterized in that: The fiber is one or more of paper fiber, wood fiber, bamboo fiber, straw fiber, glass fiber and polypropylene fiber.

5. The fiber gypsum board according to claim 1, characterized in that: The retarder is one or more of sodium hexametaphosphate, sodium polyphosphate, potassium tartrate and sodium citrate.

6. The fiber gypsum board according to claim 1, characterized in that The modifier is one or more of slaked lime, quicklime and chitosan.

7. A method for preparing a fiber gypsum board according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mixing fiber, α-hemihydrate gypsum, retarder and water uniformly to obtain a first mixed slurry; Evenly mixing the first mixed slurry and the modifier to obtain a second mixed slurry; The second mixed slurry is subjected to blanking by a slurry flow method to obtain a formed plate; The molded board is cured to obtain a fiber gypsum board.

8. The method for preparing the fiber gypsum board according to claim 7, characterized in that: The slurry flow method comprises: Performing vacuum filtration on the second mixed slurry to obtain a third mixed slurry; Pre-pressing the third mixed slurry to obtain a pre-pressed plate; Pressing and molding the pre-pressed plate to obtain the molded plate; Wherein, the moisture content of the third mixed slurry is 50-75%; and / or The pressure of the pressing molding is 9-15 MPa.

9. The method for preparing the fiber gypsum board according to claim 7, characterized in that: The curing conditions include: humidity 90-95%, temperature 20-25°C, and curing time 24-30h.

10. Use of the fiber gypsum board according to any one of claims 1 to 6 in indoor or outdoor decoration.

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