A fibrous gypsum board, its method of manufacture and use

Abstract

The application provides a fiber gypsum board and a preparation method and application thereof, and belongs to the technical field of building materials, wherein the fiber gypsum board comprises, in terms of mass parts, alpha hemihydrate gypsum 80-120 parts, fibers 10-30 parts, a retarder 0-2 parts and a modifier 0.5-5 parts; the alpha hemihydrate gypsum has a length of 20-40 microns and an aspect ratio of 1:(1-5); the fibers have a pore structure, a cross-section pore diameter of 50-250 microns, a surface pore size of 50-200 nm and a pore wall thickness of 90-110 nm. The alpha hemihydrate gypsum with a specific aspect ratio, the fibers with certain pores and the retarder and the modifier are compounded to obtain the fiber gypsum board with high compressive strength, 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 particularly relates to a fiber gypsum board and a preparation method and application thereof. BACKGROUND

[0002] Gypsum board is a kind of building material made of building gypsum as the main raw material, which has been widely used in interior partition walls, wall covering panels (instead of wall plastering layer), ceilings, sound-absorbing panels, ground base plates and various decorative panels of various buildings such as houses, office buildings, shops, hotels and industrial plants. With the continuous improvement of people's living quality, the requirements for decoration materials are also getting higher and higher. Among them, the fiber gypsum board is a new type of building board which takes building gypsum powder as the main raw material and various fibers as the reinforcing material. However, due to the low strength of gypsum material itself, the reinforcing effect of the gypsum material after mixing with fibers is seriously limited, so that the current fiber gypsum board often has the problems of low strength and poor practicability. SUMMARY

[0003] In view of the technical problems in the background art, 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 practicability of the existing fiber gypsum board.

[0004] In a first aspect, the embodiments of the present application provide a fiber gypsum board, which comprises, in terms of mass parts, 80-120 parts of alpha hemihydrate gypsum, 10-30 parts of fiber, 0-2 parts of retarder and 0.5-5 parts of modifier; wherein the length of the alpha hemihydrate gypsum is 20-40 μm, and the aspect ratio is 1:(1-5); the fiber has a pore structure, the cross-sectional pore diameter is 50-250 μm, the surface pore diameter is 50-200 nm, and the pore wall thickness is 90-110 nm.

[0005] In the technical scheme of the embodiments of the present application, the fiber gypsum board is prepared by compounding alpha hemihydrate gypsum, fiber, retarder and modifier. The fiber with pore structure has a large specific surface area, which not only can increase the contact area with the alpha hemihydrate gypsum, increase the overall strength and stability of the fiber gypsum board, but also can increase the water absorption and reduce the early hydration rate of the hemihydrate gypsum, and play a synergistic retarding effect with the retarder. At the same time, the aspect ratio of the alpha hemihydrate gypsum affects the hydration speed and the mechanical properties of the hardened body. By controlling the aspect ratio of the alpha hemihydrate gypsum within a suitable range, the hydration speed can be controlled, and the compactness and durability of the fiber gypsum board can be improved. If the aspect ratio is too large, more micro-cracks 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 the alpha hemihydrate gypsum is ≥90%, the water content is 15-25%, and the particle size is 60-150 mesh.

[0007] In this embodiment, controlling the water content, purity and particle size of the α-hemihydrate gypsum is conducive to further improving the mechanical properties and durability of the fiber gypsum board. Among them, if the water content of the α-hemihydrate gypsum is too high, the setting time of the fiber gypsum board will be too long, which will reduce the strength of the fiber gypsum board prepared; and if the water content of the α-hemihydrate gypsum is too low, the α-hemihydrate gypsum cannot be fully hydrated, which is not conducive to the preparation and curing of the fiber gypsum board, and thus affects its processing performance and final use performance. At the same time, the α-hemihydrate gypsum with higher purity has better hydration activity, which can react with water to generate dihydrate gypsum faster, thereby accelerating the setting and hardening speed of the fiber gypsum board, and the α-hemihydrate gypsum with high purity can also improve the mechanical properties and durability of the fiber gypsum board. Further, the α-hemihydrate gypsum with smaller particle size can provide larger specific surface area, accelerate the hydration reaction, and improve the early strength of the fiber gypsum board, but too small 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) to (50:1).

[0009] In this embodiment, controlling the aspect ratio of the fiber within a reasonable range is conducive to enhancing the combination of the fiber with the gypsum matrix and improving the overall performance of the fiber gypsum board. If the aspect ratio is too large, the fiber will not be uniformly dispersed in the gypsum matrix, and if the aspect ratio is too small, the toughness and durability of the fiber gypsum board will be affected.

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

[0011] In this embodiment, the fiber of the above-mentioned types can be selected to obtain a fiber gypsum board with 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 the α-hemihydrate gypsum, which prolongs the setting time of the α-hemihydrate gypsum by reducing its solubility and forming a complex to limit the diffusion of ions to the vicinity of the gypsum crystal, thereby avoiding hardening during the preparation and forming process for a long time, meeting the process operation requirements, and avoiding uneven crystal growth due to too fast hydration speed, reducing the strength loss.

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

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

[0016] In a second aspect, the embodiment of the present application provides a preparation method of the fiber gypsum board, comprising the following steps:

[0017] Mixing the fiber, the α hemihydrate gypsum, the retarder and water uniformly to obtain a first mixed slurry;

[0018] Mixing the first mixed slurry with the modifier uniformly to obtain a second mixed slurry;

[0019] Using the flow slurry method to prepare the blank from the second mixed slurry to obtain a formed board;

[0020] Curing the formed board to obtain the fiber gypsum board.

[0021] In the technical scheme of the embodiment of the present application, the fiber, the α hemihydrate gypsum, the modifier and the retarder are mixed to prepare the slurry, and then the flow slurry method is used to prepare the blank and curing, compared with the casting method, the flow slurry method has higher continuous production efficiency, and the fiber is more uniformly distributed in the gypsum board, and the strength of the fiber gypsum board is higher.

[0022] In some embodiments, the flow slurry method comprises: vacuum filtering the second mixed slurry to obtain a third mixed slurry; pre-pressing the third mixed slurry to obtain a pre-pressed board; and pressing the pre-pressed board to obtain the formed board; wherein the water content of the third mixed slurry is 50-75%; and / or the pressure of the pressing is 9-15 MPa.

[0023] In the embodiment, the flow slurry method can continuously produce the board, thereby improving the production efficiency, and the slurry is uniformly spread on the conveying belt, thereby ensuring the thickness consistency and uniformity of the board, 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 water content has good fluidity, which is helpful for the uniform spreading and forming of the slurry on the production line, and the water content that is too high will cause the forming time of the blank to be prolonged, and the fiber gypsum board may have holes and cracks; and the water content that is too low and the slurry that is too dry will cause the slurry to be unable to be uniformly rolled up by the drum forming machine in the pre-pressing process, and the pre-pressed board cannot be formed, thereby affecting the production efficiency. If the pressure of the pressing is too large, the fiber may be arranged too tightly in the formed board, thereby reducing the effective contact area of the fiber and the gypsum matrix, and affecting the reinforcing effect; if the pressure of the pressing is too small, the internal structure of the fiber gypsum board may be non-uniform, thereby affecting the overall performance. In addition, the small pressure is difficult to fully discharge the bubbles in the formed board, thereby causing the fiber gypsum board to have holes, and reducing the mechanical properties and durability thereof.

[0024] In some embodiments, the curing conditions include: humidity 90-95%, temperature 20-25℃, and curing time 24-30h.

[0025] In this embodiment, too low humidity or too high temperature during curing will cause too fast water loss, which will result in insufficient hydration reaction and insufficient strength of the prepared fiber gypsum board, and even cracking or deformation; and too high humidity and too low temperature will prolong the curing time and reduce the production efficiency.

[0026] In a third aspect, the embodiments of the present application provide an application of the aforementioned fiber gypsum board in indoor or outdoor decoration.

[0027] In the technical solution of the embodiments of the present application, the fiber gypsum board of the first aspect is used as a decoration building material, which can exhibit good durability after being applied in decoration.

[0028] The above description is only a summary of the technical solutions of the present application, in order to more clearly understand the technical means of the present application, the embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. DETAILED DESCRIPTION

[0029] The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments of the present application, and are not intended to limit the present application.

[0031] 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 "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0032] In this document, the reference to "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean that the same embodiments are referred to, nor does it mean that the embodiments are mutually exclusive or alternative to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with each other.

[0033] In the description of the embodiments of the present application, the term "and / or" is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are an "or" relationship.

[0034] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0035] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0036] The hemihydrate gypsum in the prior art for forming fiber gypsum board will produce a large number of pores in the interior of the board during the process of hydration to form dihydrate gypsum. Compared with dense gypsum board, the high-porosity fiber gypsum board has a significantly reduced compressive strength, thereby limiting the practical application of fiber gypsum board.

[0037] In order to solve the problems of low strength and poor practicability of the existing fiber gypsum board, the present application provides a fiber gypsum board, a preparation method and application thereof. By using α hemihydrate gypsum with a specific morphology, fibers with a certain pore structure, and a modifier and a retarder, the compressive strength of the fiber gypsum board can be improved, which is conducive to popularization and application.

[0038] In a first aspect, the embodiments of the present application provide a fiber gypsum board, which comprises, in mass parts, 80-120 parts of α hemihydrate gypsum, 10-30 parts of fibers, 0-2 parts of a retarder, and 0.5-5 parts of a modifier; wherein the length of the α hemihydrate gypsum is 20-40 μm, and the aspect ratio is 1:(1-5); the fibers have a pore structure, the cross-sectional pore diameter is 50-250 μm, the surface pore diameter is 50-200 nm, and the pore wall thickness is 90-110 nm.

[0039] The aspect ratio is the ratio of the length (lateral dimension) to the diameter (longitudinal dimension).

[0040] Specifically, the fiber gypsum board includes alpha hemihydrate 100 parts, fiber 15 parts, retarder 0.1 part, modifier 0.5 part in mass parts, or includes alpha hemihydrate 120 parts, fiber 30 parts, retarder 1 part, modifier 5 parts, or other mass parts within the above range. Among them, the fiber is beneficial to increase the mechanical properties of the fiber gypsum board, but too much fiber content will increase the water absorption of the fiber gypsum board, thereby causing the moisture resistance of the fiber gypsum board to decrease, and too low fiber content will cause the mechanical properties of the fiber gypsum board to decrease, which is not conducive to practical application; the retarder mainly affects the setting time of the alpha hemihydrate in the forming process of the fiber gypsum board, and if the amount of the retarder is too large, the setting time will be too slow, thereby reducing the production efficiency; the modifier mainly promotes the adhesion between the fiber and the alpha hemihydrate, thereby improving the mechanical properties of the fiber gypsum board, and if the amount of the modifier is too small, the adhesion between the fiber and the alpha hemihydrate will be insufficient, and the mechanical properties will decrease, and if the amount of the modifier is too large, the adhesion component will account for too large a proportion in the fiber gypsum board, thereby reducing the mechanical properties thereof.

[0041] In the technical scheme of the embodiment of the application, the fiber gypsum board is prepared by compounding alpha hemihydrate, fiber, retarder and modifier, wherein the fiber with a pore structure has a large specific surface area, which can not only increase the contact area with the alpha hemihydrate, increase the overall strength and stability of the fiber gypsum board, but also increase the water absorption and reduce the early hydration rate of the alpha hemihydrate, and the retarder plays a synergistic retarding effect. The aspect ratio of the alpha hemihydrate affects the hydration speed and the mechanical properties of the hardened body, and by controlling the aspect ratio of the alpha hemihydrate within a suitable range, the hydration speed can be controlled, and the compactness and durability of the fiber gypsum board can be improved; if the aspect ratio is too large, more microcracks can be formed in the fiber gypsum board, thereby reducing the crack resistance; and if the aspect ratio is too small, it is not conducive to forming a continuous network structure, thereby reducing the strength and toughness.

[0042] Further, in some embodiments, the purity of the alpha hemihydrate is ≥90%, the water content is 15-25%, and the particle size is 60-150 mesh.

[0043] In the technical scheme of the embodiments of the present application, by controlling the water content, purity and particle size of the α-hemihydrate gypsum, the mechanical properties and durability of the fiber gypsum board can be further improved. If the water content of the α-hemihydrate gypsum is too high, the setting time of the fiber gypsum board will be too long, which will reduce the strength of the fiber gypsum board. If the water content of the α-hemihydrate gypsum is too low, the α-hemihydrate gypsum may not be fully hydrated, which is not conducive to the preparation and curing of the fiber gypsum board, and affects the processing performance and final use performance. At the same time, the hemihydrate gypsum with higher purity has better hydration activity, which can react with water to generate dihydrate gypsum faster, thereby accelerating the setting and hardening speed of the fiber gypsum board, and the hemihydrate gypsum with high purity can also improve the mechanical properties and durability of the gypsum board. Further, the α-hemihydrate gypsum with smaller particle size can provide larger specific surface area, accelerate the hydration reaction, and improve the early strength of the fiber gypsum board, but the α-hemihydrate gypsum with too small particle size may cause the fiber gypsum board to be too dense, which affects its air permeability and thermal insulation.

[0044] Further, in some embodiments, the length of the fiber is 50-600 μm, and the aspect ratio is (10:1)-(50:1).

[0045] In the technical scheme of the embodiments of the present application, the aspect ratio of the fiber is controlled within a reasonable range, which is conducive to enhancing the combination of the fiber 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 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.

[0046] Specifically, the length of the fiber can be 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, or any value within the range of 50-600 μm, and the length-width ratio of the fiber can be 10:1, 20:1, 30:1, 40:1, 50:1, or any value within the range of 10:1-(50:1).

[0047] Further, in some embodiments, the fiber is one or more of paper fiber, wood fiber, bamboo fiber, straw fiber, glass fiber, and polypropylene fiber.

[0048] In the technical scheme of the embodiments of the present application, the fiber of the above-mentioned types can be selected to obtain a fiber gypsum board with higher strength.

[0049] Further, in some embodiments, the retarder is one or more of sodium hexametaphosphate, sodium polyphosphate, potassium tartrate, and sodium citrate.

[0050] In the technical scheme of the embodiment of the present application, the retarder plays a role of retarding the setting of the α hemihydrate gypsum, prolongs the setting time of the α hemihydrate gypsum by reducing the solubility of the α hemihydrate gypsum and forming a complex to limit the diffusion of ions to the vicinity of the gypsum crystals, avoids hardening of the α hemihydrate gypsum during the long-time forming process, meets the process operation requirements, and avoids uneven crystal growth due to too fast hydration speed and reduces the strength loss.

[0051] Further, in some embodiments, the modifier is one or more of slaked lime, quicklime, and chitosan.

[0052] In the technical scheme of the embodiment of the present application, the modifier can promote the bonding performance of the fiber and the α hemihydrate gypsum, improve the strength of the hydrated and hardened body, enhance the hardness and strength of the fiber gypsum board, and improve the durability.

[0053] In a second aspect, the embodiment of the present application provides a preparation method of the fiber gypsum board as described above, including the following steps:

[0054] Mixing the fiber, the α hemihydrate gypsum, the retarder, and water uniformly to obtain a first mixed slurry;

[0055] Mixing the first mixed slurry and the modifier uniformly to obtain a second mixed slurry;

[0056] Forming the second mixed slurry into a formed board by using a flow slurry method;

[0057] Curing the formed board to obtain the fiber gypsum board.

[0058] In the technical scheme of the embodiment of the present application, the fiber, the α hemihydrate gypsum, the modifier, and the retarder are first mixed to prepare a slurry, and then the flow slurry method is used to form the slurry and perform curing. Compared with the casting method, the flow slurry method has higher continuous production efficiency, the fiber is more uniformly distributed in the gypsum board, and the strength of the fiber gypsum board is higher.

[0059] Further, in some embodiments, the flow slurry 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 board; and pressing the pre-pressed board to obtain the formed board; wherein the water content of the third mixed slurry is 50-75%; and / or the pressure of the pressing is 9-15 MPa.

[0060] The slurry flow method can continuously produce the plate, improve the production efficiency, and ensure the thickness consistency and uniformity of the plate by uniformly spreading the slurry on the conveying belt, especially improve the dispersion uniformity of the fiber in the plate, and enhance the overall strength of the fiber gypsum board. The slurry with moderate water content has good fluidity, which is helpful for the uniform spreading and forming of the slurry on the production line. If the water content is too high, the forming time of the blank will be prolonged, and the fiber gypsum board may have holes and cracks. If the water content is too low and the slurry is too dry, the slurry cannot be uniformly rolled up by the roller forming machine in the pre-pressing forming process, and the pre-pressing plate cannot be formed, which affects the production efficiency. If the pressure of the press is too large, the fiber may be arranged too tightly in the forming plate, reducing the effective contact area of the fiber and the gypsum matrix, and affecting the reinforcing effect. If the pressure of the press is too small, the internal structure of the fiber gypsum board may be non-uniform, affecting the overall performance. In addition, small pressure is difficult to fully discharge the bubbles in the forming plate, resulting in holes in the fiber gypsum board, reducing its mechanical properties and durability.

[0061] Further, in some embodiments, the curing conditions include: humidity 90-95%, temperature 20-25℃, curing time 24-30h.

[0062] Specifically, the humidity of the curing is 90%, 92%, 94%, 95% or any humidity in the above range; the temperature of the curing is 20℃, 22℃, 24℃, 25℃ or any temperature in the above range; the time of the curing is 24h, 26h, 28h, 30h or any time in the above range.

[0063] In the technical scheme of the embodiment of the present application, too low humidity or too high temperature of the curing will cause too fast water loss, which will cause insufficient hydration reaction, resulting in insufficient strength of the prepared fiber gypsum board, and even cracking or deformation of the plate; and too high humidity and too low temperature will prolong the curing time and reduce the production efficiency.

[0064] In a third aspect, the embodiment of the present application provides an application of the aforementioned fiber gypsum board in indoor or outdoor decoration.

[0065] In the technical scheme of the embodiment of the present application, the fiber gypsum board with excellent strength performance is used as a decoration building material for decoration, and can exhibit good durability after application.

[0066] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are used to explain the present application, and cannot be understood as a limitation of the present application. If the specific technology or condition is not specified in the embodiments, the technology or condition described in the literature in the art or according to the product manual is used. If the reagent or instrument is not specified by the manufacturer, it is a conventional product that can be obtained by purchase.

[0067] In the following examples and comparative examples, the purity of the 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 size is 50-250 μm, the surface pore size is 50-200 nm, the pore wall thickness is 90-110 nm, the length of the fiber is 50-600 μm, and the aspect ratio is (10:1)-(50:1).

[0068] I. Preparation method

[0069] Example 1

[0070] A fibrous gypsum board is prepared as follows:

[0071] (1) 100 parts of α-hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water are added to a paddle-type mixer and mixed at a stirring speed of 950 rpm to obtain a first mixed slurry.

[0072] (2) 1 part of slaked lime is added to the first mixed slurry and stirred uniformly to obtain a second mixed slurry.

[0073] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a moisture content of 70%.

[0074] (4) The third mixed slurry is pre-pressed by a roller pre-press to obtain a pre-pressed board.

[0075] (5) The pre-pressed board is moved into a pressure forming machine by a suction cup machine and is pressure-formed at a pressure of 13 MPa to obtain a formed board.

[0076] (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25°C for 28 h, is dried by ventilation, and is finally polished, edged, and polished to obtain a fibrous gypsum board.

[0077] Example 2

[0078] A fibrous gypsum board is prepared as follows:

[0079] (1) 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 are added to a paddle-type mixer and mixed at a stirring speed of 700 rpm to obtain a first mixed slurry.

[0080] (2) 2 parts of quicklime is added to the first mixed slurry and stirred uniformly to obtain a second mixed slurry.

[0081] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 60%.

[0082] (4) The third mixed slurry is pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0083] (5) The pre-pressed plate is moved into a pressure forming machine by a suction cup machine and is pressure-formed under a pressure of 10 MPa to obtain a formed plate.

[0084] (6) After the formed plate is naturally cured at a humidity of 90% and a temperature of 25°C for 24 hours, it is dried by ventilation, and finally, after polishing, edge cutting and polishing, a fiber gypsum board is obtained.

[0085] Example 3

[0086] A fiber gypsum board is prepared by the following method:

[0087] (1) 100 parts of α hemihydrate gypsum, 15 parts of rice straw fiber, 2 parts of sodium citrate and 1000 parts of water are added to a paddle mixer and mixed at a stirring speed of 800 rpm to obtain a first mixed slurry.

[0088] (2) 1.5 parts of quicklime is added to the first mixed slurry and stirred uniformly to obtain a second mixed slurry.

[0089] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 65%.

[0090] (4) The third mixed slurry is pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0091] (5) The pre-pressed plate is moved into a pressure forming machine by a suction cup machine and is pressure-formed under a pressure of 13 MPa to obtain a formed plate.

[0092] (6) After the formed plate is naturally cured at a humidity of 90% and a temperature of 25°C for 26 hours, it is dried by ventilation, and finally, after polishing, edge cutting and polishing, a fiber gypsum board is obtained.

[0093] Example 4

[0094] A fiber gypsum board is prepared by the following method:

[0095] (1) 120 parts of α hemihydrate gypsum, 30 parts of paper fiber, 2 parts of sodium hexametaphosphate and 1000 parts of water are added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a first mixed slurry.

[0096] (2) 5 parts of slaked lime is added to the first mixed slurry and stirred uniformly to obtain a second mixed slurry.

[0097] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0098] (4) The third mixed slurry is pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0099] (5) The pre-pressed plate is moved into a pressure forming machine by a suction cup machine and is pressure-formed under a pressure of 13 MPa to obtain a formed plate.

[0100] (6) After the formed plate is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, it is dried by ventilation, and finally polished, edged and polished to obtain a fiber gypsum board.

[0101] Example 5

[0102] A fiber gypsum board is prepared by the following method:

[0103] (1) 80 parts of α hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate and 1000 parts of water are added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a first mixed slurry.

[0104] (2) 0.5 parts of slaked lime are added to the first mixed slurry and stirred uniformly to obtain a second mixed slurry.

[0105] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0106] (4) The third mixed slurry is pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0107] (5) The pre-pressed plate is moved into a pressure forming machine by a suction cup machine and is pressure-formed under a pressure of 13 MPa to obtain a formed plate.

[0108] (6) After the formed plate is naturally cured at a humidity of 90% and a temperature of 25°C for 28 hours, it is dried by ventilation, and finally polished, edged and polished to obtain a fiber gypsum board.

[0109] Example 6

[0110] A fiber gypsum board is prepared by the following method:

[0111] (1) 100 parts of α hemihydrate gypsum, 10 parts of paper fiber and 750 parts of water are added to a paddle mixer and mixed at a stirring speed of 800 rpm to obtain a first mixed slurry.

[0112] (2) 1 part of quicklime was added into the first mixed slurry and stirred uniformly to obtain a second mixed slurry.

[0113] (3) The second mixed slurry was filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 65%.

[0114] (4) The third mixed slurry was pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0115] (5) 5 pre-pressed plates were stacked together and moved into a pressure forming machine, and were pressure-formed under a pressure of 10 MPa to obtain a formed plate with a thickness of 12 mm;

[0116] (6) After the formed plate was naturally cured at a humidity of 90% and a temperature of 25°C for 24 h, it was dried by ventilation, and finally was polished, edged and polished to obtain a fiber gypsum board.

[0117] Example 7

[0118] A fiber gypsum board was prepared by the following method:

[0119] (1) 100 parts of α hemihydrate gypsum, 15 parts of paper fiber and 750 parts of water were added into a paddle mixer and mixed, and the stirring speed was 800 rpm to obtain a first mixed slurry with uniform dispersion.

[0120] (2) 2 parts of quicklime was added into the first mixed slurry and stirred uniformly to obtain a second mixed slurry.

[0121] (3) The second mixed slurry was filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 75%.

[0122] (4) The third mixed slurry was pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0123] (5) 5 pre-pressed plates were stacked together and moved into a pressure forming machine, and were pressure-formed under a pressure of 15 MPa to obtain a formed plate with a thickness of 10 mm;

[0124] (6) After the formed plate was naturally cured at a humidity of 90% and a temperature of 25°C for 24 h, it was dried by ventilation, and finally was polished, edged and polished to obtain a fiber gypsum board.

[0125] Example 8

[0126] A fiber gypsum board was prepared by the following method:

[0127] (1) 100 parts of α hemihydrate gypsum, 30 parts of wood fiber and 500 parts of water were added into a paddle type mixer to mix, and the stirring speed was 800 rpm to obtain a first mixed slurry with uniform dispersion.

[0128] (2) 1 part of quicklime was added into the first mixed slurry to stir uniformly to obtain a second mixed slurry.

[0129] (3) The second mixed slurry was filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 50%.

[0130] (4) The third mixed slurry was pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0131] (5) Five pre-pressed plates were stacked together and moved into a pressure forming machine to be pressure formed under a pressure of 15 MPa to obtain a formed plate with a thickness of 10 mm.

[0132] (6) After the formed plate was naturally cured at a humidity of 90% and a temperature of 25°C for 24 h, it was dried by ventilation, and finally polished, edged and polished to obtain a fiber gypsum board.

[0133] Example 9

[0134] A fiber gypsum board was prepared by the following method:

[0135] (1) 120 parts of α hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate and 1000 parts of water were added into a paddle type mixer to mix, and the stirring speed was 950 rpm to obtain a first mixed slurry with uniform dispersion.

[0136] (2) 1 part of slaked lime was added into the first mixed slurry to stir uniformly to obtain a second mixed slurry.

[0137] (3) The second mixed slurry was filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0138] (4) The third mixed slurry was pre-pressed by a roller pre-press to obtain a pre-pressed plate.

[0139] (5) The pre-pressed plate was moved into a pressure forming machine by a suction cup machine to be pressure formed under a pressure of 13 MPa to obtain a formed plate.

[0140] (6) After the formed plate was naturally cured at a humidity of 90% and a temperature of 25°C for 28 h, it was dried by ventilation, and finally polished, edged and polished to obtain a fiber gypsum board.

[0141] Example 10

[0142] A fiber gypsum board is prepared by the following method:

[0143] (1) 80 parts of α hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate and 1000 parts of water are added into a paddle mixer for mixing, and the stirring speed is 950 rpm to obtain a first mixed slurry with uniform dispersion.

[0144] (2) 1 part of slaked lime is added into the first mixed slurry for uniform stirring to obtain a second mixed slurry.

[0145] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0146] (4) The third mixed slurry is pre-pressed by a roller pre-press to obtain a pre-pressed board.

[0147] (5) The pre-pressed board is moved into a pressure forming machine by a suction cup machine, and is pressure-formed under a pressure of 13 MPa to obtain a formed board.

[0148] (6) The formed board is naturally cured for 28 h under a humidity of 90% and a temperature of 25℃, is dried by ventilation, and finally is polished, edged and polished to obtain a fiber gypsum board.

[0149] Example 11

[0150] A fiber gypsum board is prepared by the following method:

[0151] (1) 100 parts of α hemihydrate gypsum, 30 parts of paper fiber, 1 part of sodium hexametaphosphate and 1000 parts of water are added into a paddle mixer for mixing, and the stirring speed is 950 rpm to obtain a first mixed slurry with uniform dispersion.

[0152] (2) 1 part of slaked lime is added into the first mixed slurry for uniform stirring to obtain a second mixed slurry.

[0153] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0154] (4) The third mixed slurry is pre-pressed by a roller pre-press to obtain a pre-pressed board.

[0155] (5) The pre-pressed board is moved into a pressure forming machine by a suction cup machine, and is pressure-formed under a pressure of 13 MPa to obtain a formed board.

[0156] (6) The formed board is naturally cured for 28 h under a humidity of 90% and a temperature of 25℃, is dried by ventilation, and finally is polished, edged and polished to obtain a fiber gypsum board.

[0157] Example 12

[0158] A fiber gypsum board is prepared by the following method:

[0159] (1) 100 parts of α hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water are added to a paddle mixer for mixing, and the stirring speed is 950 rpm to obtain a first mixed slurry with uniform dispersion.

[0160] (2) 0.5 parts of slaked lime is added to the first mixed slurry for uniform stirring to obtain a second mixed slurry.

[0161] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0162] (4) The third mixed slurry is pre-pressed and formed by a roller pre-press to obtain a pre-pressed board.

[0163] (5) The pre-pressed board is moved into a pressure forming machine by a suction cup machine, and is pressure-formed under a pressure of 13 MPa to obtain a formed board.

[0164] (6) The formed board is naturally cured for 28 h under a humidity of 90% and a temperature of 25°C, is dried by ventilation, and finally is polished, edged, and polished to obtain a fiber gypsum board.

[0165] Example 13

[0166] A fiber gypsum board is prepared by the following method:

[0167] (1) 100 parts of α hemihydrate gypsum, 10 parts of paper fiber, 1 part of sodium hexametaphosphate, and 1000 parts of water are added to a paddle mixer for mixing, and the stirring speed is 950 rpm to obtain a first mixed slurry with uniform dispersion.

[0168] (2) 5 parts of slaked lime is added to the first mixed slurry for uniform stirring to obtain a second mixed slurry.

[0169] (3) The second mixed slurry is filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0170] (4) The third mixed slurry is pre-pressed and formed by a roller pre-press to obtain a pre-pressed board.

[0171] (5) The pre-pressed board is moved into a pressure forming machine by a suction cup machine, and is pressure-formed under a pressure of 13 MPa to obtain a formed board.

[0172] (6) The formed board is naturally cured for 28 h under a humidity of 90% and a temperature of 25°C, is dried by ventilation, and finally is polished, edged, and polished to obtain a fiber gypsum board.

[0173] Example 14

[0174] A fiber gypsum board is prepared by the following method:

[0175] (1) 100 parts of α hemihydrate gypsum, 10 parts of paper fiber, 2 parts of sodium hexametaphosphate, and 1000 parts of water are added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a first mixed slurry.

[0176] (2) 1 part of slaked lime is added to the first mixed slurry and stirred to obtain a second mixed slurry.

[0177] (3) The second mixed slurry is vacuum filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0178] (4) The third mixed slurry is pre-pressed by a drum pre-press to obtain a pre-pressed board.

[0179] (5) The pre-pressed board is moved into a pressure forming machine by a suction cup machine and is pressure formed at a pressure of 13 MPa to obtain a formed board.

[0180] (6) The formed board is naturally cured at a humidity of 90% and a temperature of 25℃ for 28 hours, is dried by ventilation, and is finally polished, edged, and polished to obtain a fiber gypsum board.

[0181] Example 15

[0182] A fiber gypsum board is prepared by the following method:

[0183] (1) 100 parts of α hemihydrate gypsum, 10 parts of paper fiber, and 1000 parts of water are added to a paddle mixer and mixed at a stirring speed of 950 rpm to obtain a first mixed slurry.

[0184] (2) 1 part of slaked lime is added to the first mixed slurry and stirred to obtain a second mixed slurry.

[0185] (3) The second mixed slurry is vacuum filtered by a vacuum belt filter to obtain a third mixed slurry with a water content of 70%.

[0186] (4) The third mixed slurry is pre-pressed by a drum pre-press to obtain a pre-pressed board.

[0187] (5) The pre-pressed board is moved into a pressure forming machine by a suction cup machine and is pressure formed at a pressure of 13 MPa to obtain a formed board.

[0188] (6) After the forming plate is naturally cured at a humidity of 90% and a temperature of 25℃ for 28h, it is dried by ventilation, and finally polished, trimmed and polished to obtain the fiber gypsum board.

[0189] Comparative Example 1

[0190] A gypsum board, comprising, in mass parts, 100 parts of α 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.

[0191] Comparative Example 2

[0192] A fiber gypsum board, comprising, in mass parts, 100 parts of α 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.

[0193] Comparative Example 3

[0194] A fiber gypsum board, comprising, in mass parts, 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.

[0195] Comparative Example 4

[0196] A fiber gypsum board, comprising, in mass parts, 100 parts of α 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.

[0197] II. Test method

[0198] The fiber gypsum boards prepared in Examples 1-15 and Comparative Examples 1-4 of the application are subjected to physical performance detection according to the standard JC / T 2702-2022 “Fiber-reinforced gypsum board”.

[0199] III. Analysis of test results of each example and comparative example

[0200] Table 1: Performance test results of Examples 1-8

[0201]

[0202] Table 2: Performance test results of Examples 9-15

[0203]

[0204] Table 3: Performance test results of Comparative Examples 1-4

[0205]

[0206] As can be seen from Tables 1-2, the fiber gypsum board prepared by compounding alpha hemihydrate gypsum, fibers, a modifier, and / or a retarder has the properties of fireproofing, moisture-proofing, high strength, strong nail holding force, etc., and has the advantages of light weight, easy to carry, not easy to damage, good processing performance, long service life, non-toxic and environmentally friendly, and recyclability. Compared with Example 1, as the amount of alpha hemihydrate gypsum increases, the mechanical properties such as shear force and breaking load of the fiber gypsum board prepared in Examples 9-10 increase, and the water absorption of the fiber gypsum board slightly increases; compared with Example 1, as the fiber content increases, the mechanical properties and water absorption of the fiber gypsum board prepared in Example 11 increase; compared with Example 1, as the modifier content increases, the mechanical properties such as shear force and breaking load of the fiber gypsum board prepared in Examples 12-13 increase; compared with Example 1, as the amount of retarder increases, the mechanical properties of the fiber gypsum board prepared in Examples 14-15 change little, because the retarder mainly affects the setting time of alpha hemihydrate gypsum, avoiding hardening during mixing and blank preparation and affecting the production of fiber gypsum board.

[0207] Further, compared with Example 1, it can be seen from Comparative Example 1 that the gypsum board without adding fibers has an increased surface density, resulting in a larger weight, a significant decrease in screw holding force, shear force and breaking load, insufficient impact resistance, and poor moisture resistance, which can easily deform in a humid environment, and is not conducive to long-term use.

[0208] Further, compared with Example 1, it can be seen from Comparative Example 2 that the fiber content mainly affects the dimensional stability of the fiber gypsum board in a humid environment, and too much fiber content results in too large water absorption of the fiber gypsum board, which can easily deform and has poor moisture resistance.

[0209] Further, compared with Example 1, it can be seen from Comparative Examples 3-4 that the modifier mainly promotes the bonding performance of fibers and alpha hemihydrate gypsum, thereby improving the mechanical properties of the fiber gypsum board; too little modifier results in insufficient bonding of fibers and alpha hemihydrate gypsum, and a decrease in breaking load; and too much modifier results in too large a proportion of bonding components in the fiber gypsum board, which reduces the maximum load that can be borne.

[0210] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and substantially the same function and effect within the scope of the technical solutions of the present application are all included in the technical scope of the present application. In addition, within the scope of the main idea of the present application, various modifications that can be thought of by those skilled in the art, and other ways constructed by combining part of the components of the embodiments are also included in the scope of the present application.

Claims

1. A fibrous gypsum board, characterized in that, The α hemihydrate gypsum, the fiber, the retarder and the water are mixed uniformly to obtain a first mixed slurry. The modified agent is one or more of slaked lime, quicklime and chitosan. The preparation method of the fiber gypsum board comprises the following steps: The α hemihydrate gypsum, the fiber, the retarder and the water are mixed uniformly to obtain a first mixed slurry. The first mixed slurry and the modified agent are mixed uniformly to obtain a second mixed slurry. The second mixed slurry is subjected to a flow slurry method to obtain a formed board. The formed board is cured to obtain the fiber gypsum board. The flow slurry method comprises: The second mixed slurry is subjected to vacuum water filtration to obtain a third mixed slurry. The third mixed slurry is subjected to pre-pressing to obtain a pre-pressed board. The pre-pressed board is subjected to press forming to obtain the formed board. The water content of the third mixed slurry is 50-75%. The pressure of the press forming is 9-15 MPa. The purity of the α hemihydrate gypsum is greater than or equal to 90%, the water content is 15-25%, and the particle size is 60-150 mesh.

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

3. The fibrous gypsum board according to claim 1, characterized in that, The fiber is one or more of paper fiber, wood fiber, bamboo fiber, straw fiber, glass fiber and polypropylene fiber.

4. The fibrous gypsum board according to claim 3, characterized in that, The retarder is one or more of sodium hexametaphosphate, sodium polyphosphate, potassium tartrate and sodium citrate.

5. The fibrous gypsum board of claim 1, wherein, The preparation method of the fiber gypsum board comprises the following steps:

6. A method of producing a fibrous gypsum board according to any one of claims 1 to 5, characterized in that, The α hemihydrate gypsum, the fiber, the retarder and the water are mixed uniformly to obtain a first mixed slurry. The first mixed slurry and the modified agent are mixed uniformly to obtain a second mixed slurry. The second mixed slurry is subjected to a flow slurry method to obtain a formed board. The formed board is cured to obtain the fiber gypsum board. The flow slurry method comprises:

7. The method of manufacturing fibrous gypsum board according to claim 6, characterized in that, The second mixed slurry is subjected to vacuum water filtration to obtain a third mixed slurry. The third mixed slurry is subjected to pre-pressing to obtain a pre-pressed board. The pre-pressed board is subjected to press forming to obtain the formed board. The water content of the third mixed slurry is 50-75%. The pressure of the press forming is 9-15 MPa. The curing conditions comprise a humidity of 90-95%, a temperature of 20-25℃, and a curing time of 24-30 h.

8. The method of manufacturing a fibrous gypsum board according to claim 6, characterized in that, 9. Application of the fiber gypsum board according to any one of claims 1-5 in indoor or outdoor decoration. ​

Images