Asbestos-free reinforced calcium silicate facing board and its preparation method

Abstract

The application discloses a kind of non-asbestos reinforced calcium silicate veneer and preparation method thereof, comprising the following raw materials and weight parts: slaked lime powder 37-45 parts, cementing silica powder 19-26 parts, diatomite 9-14 parts, composite reinforcing fiber 11-17 parts, polyethylene glycol 2.5-5.5 parts, sodium silicate 1-3 parts and silicon calcium powder 0.1-0.2 parts;Composite reinforcing fiber is made of polypropylene resin, polyacrylate, calcium carbonate whisker, nano silicon dioxide, cellulose fiber and ceramic short fiber mixed melt spinning;It is prepared by pulping, pressure type normal temperature pressing, warming and pressurizing pre-curing, high temperature autoclave curing.The non-asbestos reinforced calcium silicate veneer of the application has excellent strength and thermal stability, is green and environmentally friendly, and also solves the cracking phenomenon in the use process of traditional calcium silicate board.

Description

Technical Field

[0001] The invention relates to an asbestos-free reinforced calcium silicate decorative panel and a preparation method thereof, belonging to the technical field of building materials. Background Art

[0002] Calcium silicate decorative panels are mainly made of silicon and calcium as the main binder materials, and are made through processes such as pulping, molding, and high-temperature autoclaving. They are a building material that is widely used in interior decoration, etc. They have excellent properties such as green environmental protection, sound insulation, moisture resistance, and fire resistance. They have gradually developed into one of the leading materials for panels in the construction field, and lightweight calcium silicate decorative panels are gradually becoming the trend of calcium silicate decorative panels.

[0003] Calcium silicate veneer panels are often manufactured using reinforcing materials such as mineral wool, wood pulp fiber, and glass fiber to enhance their performance. However, mineral wool, such as asbestos, is harmful to both humans and the environment. Wood pulp fiber is damaged during the high-temperature autoclaving process, affecting the veneer's strength. Glass fiber, due to its high density and high usage, makes it difficult to produce lightweight calcium silicate veneer panels. Furthermore, calcium silicate veneer panels using natural gypsum powder as the primary binder are prone to cracking, which compromises their strength. Therefore, an asbestos-free reinforced calcium silicate veneer panel and its preparation method were developed. Summary of the Invention

[0004] In order to address at least one problem existing in the above-mentioned prior art, the present invention provides an asbestos-free reinforced calcium silicate decorative panel and a preparation method thereof. The asbestos-free reinforced calcium silicate decorative panel has excellent strength and thermal stability, is green and environmentally friendly, and solves the cracking phenomenon of traditional calcium silicate boards during use; the preparation process is controllable, which is conducive to industrial production.

[0005] To achieve the above object, the present invention adopts the following technical solution: an asbestos-free reinforced calcium silicate decorative panel, comprising the following raw materials and their weight parts: 37-45 parts of slaked lime powder, 19-26 parts of cementitious silica powder, 9-14 parts of diatomaceous earth, 11-17 parts of composite reinforcing fiber, 2.5-5.5 parts of polyethylene glycol, 1-3 parts of sodium silicate and 0.1-0.2 parts of calcium silicate powder;

[0006] The composite reinforcing fiber is made by melt-spinning a mixture of polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, cellulose fiber and ceramic short fiber.

[0007] Preferably, the preparation process of the composite reinforcing fiber is as follows: polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, cellulose fiber and ceramic short fiber are stirred and evenly mixed in a mass ratio of 38-45:20-26:5-10:3-8:11-16:8-14, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch is melt-spun to obtain a composite reinforcing fiber.

[0008] Preferably, in the composite reinforcing fibers, the cellulose fibers are viscose cellulose and / or cellulose acetate.

[0009] Preferably, in the composite reinforcing fibers, the cellulose fibers have a diameter of 1 to 2 μm and a length of 1 to 2 mm.

[0010] Preferably, in the composite reinforcing fiber, the ceramic short fibers have a diameter of 1.3 to 1.5.5 μm and a length of 0.5 to 1 mm.

[0011] Preferably, in the asbestos-free reinforced calcium silicate decorative panel, the diameter of the composite reinforcing fiber is 50-100 μm and the length is 2-3 mm.

[0012] Preferably, in the asbestos-free reinforced calcium silicate decorative panel, the particle size of the slaked lime powder and the cementitious silica powder is 20 to 50 μm.

[0013] Preferably, in the asbestos-free reinforced calcium silicate decorative panel, the sodium silicate has a modulus of 2.5 to 3.2 and is a powdery solid.

[0014] The present invention also provides a method for preparing an asbestos-free reinforced calcium silicate decorative panel, comprising the following steps:

[0015] (1) uniformly mixing the above-mentioned parts by weight of slaked lime powder, cementitious silica powder, diatomaceous earth, composite reinforcing fiber, sodium silicate and calcium silicate powder to obtain a solid mixture;

[0016] (2) uniformly mixing the above-mentioned polyethylene glycol and sodium carbonate in parts by weight with water to obtain a liquid mixture;

[0017] (3) mixing the solid mixture with the liquid mixture, stirring to form a slurry to obtain a slurry;

[0018] (4) injecting the above slurry into a mold and pressing it at room temperature with variable pressure, then heating and pressurizing it for pre-curing, forming and demolding it to obtain a blank;

[0019] (5) Saturated steam is introduced into the embryonic board for high-temperature autoclaving and curing, and then the board is dried until the moisture content is less than 5%, and then polished to obtain an asbestos-free reinforced calcium silicate decorative board.

[0020] Preferably, in step (2), the mass ratio of the amount of water added to the weight of the solid mixture is 1.3 to 1.5:1.

[0021] Preferably, in step (3), the stirring speed is 350-450 rpm, and the stirring time is 3-5 h.

[0022] Preferably, in step (4), the conditions for variable pressure pressing at room temperature are: first, maintaining the pressure at 5-10 MPa for 10-15 minutes, then gradually increasing the pressure to 25-30 MPa and maintaining the pressure for 5-10 minutes, and then gradually reducing the pressure to normal pressure;

[0023] Preferably, the rate of gradual pressure increase is 0.5-1 MPa / min, and the rate of gradual pressure reduction is 1-2 MPa / min.

[0024] Preferably, in step (4), the heating and pressurizing pre-curing conditions are: first control the temperature to 65-75°C and the humidity to 80-90%, then control the pressure to 2-3 MPa, and finally maintain the temperature and pressure for 6-8 hours.

[0025] Preferably, in step (5), the high-temperature autoclave curing conditions are as follows: the temperature is controlled at 200-210° C. and the pressure is 1.3-1.5 MPa, and then the heat and pressure are maintained for 8-12 hours.

[0026] Preferably, in step (5), the drying condition is 60-70°C.

[0027] Beneficial effects of the present invention:

[0028] 1. The raw materials of the present invention use slaked lime powder, slaked lime powder, and diatomaceous earth as the main binder, and composite reinforcing fiber, sodium silicate, etc. are added at the same time. The asbestos-free reinforced calcium silicate decorative panel prepared by such a composite system has the characteristics of lightness, is a lightweight building material, and has excellent strength and thermal stability, is green and environmentally friendly, and solves the cracking phenomenon of traditional calcium silicate boards during use.

[0029] 2. The composite reinforcing fiber of the present invention adopts polypropylene resin, polyacrylate, calcium carbonate whisker, nano-silica, cellulose fiber and ceramic short fiber raw materials, which is environmentally friendly and makes the composite reinforcing fiber have good high strength and toughness. The performance stability will not be damaged during processing. At the same time, it has good compatibility, which can promote the interface bonding between it and the calcium silicate matrix, effectively blocking cracks, and can achieve the lightweight effect of asbestos-free reinforced calcium silicate decorative panels while taking into account the high strength and anti-cracking effect of asbestos-free reinforced calcium silicate decorative panels.

[0030] 3. The present invention adds calcium silicate powder to the compound system, which can promote the grain refinement of calcium silicate and avoid the appearance of large crystals. At the same time, the use of sodium silicate with a modulus of 2.5 to 3.2 makes the asbestos-free reinforced calcium silicate decorative panel have stronger structural strength and suitable density and fineness, further improving the strength, anti-cracking effect and thermal stability of the asbestos-free reinforced calcium silicate decorative panel, and making it lightweight.

[0031] 4. The preparation method of the present invention adopts variable pressure normal temperature pressing, heating and pressurizing pre-curing, and high temperature autoclaving curing greater than 1.2MPa, which can promote the refinement of the number of micropores while enhancing the pore stability, and reduce the density of the asbestos-free reinforced calcium silicate decorative panel, which has the characteristics of lightness and further improves the mechanical properties and thermal stability of the asbestos-free reinforced calcium silicate decorative panel. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the implementation of the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer.

[0033] Example 1

[0034] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0035] 1) Preparation of composite reinforcing fiber: polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, viscose cellulose with a diameter of 1 to 2 μm and a length of 1 to 2 mm, and ceramic short fibers with a diameter of 1.3 to 1.5.5 μm and a length of 0.5 to 1 mm are uniformly stirred in a mass ratio of 42:23:7.5:5.5:13:12, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch is melt-spun to obtain a composite reinforcing fiber with a diameter of 50 to 100 μm and a length of 2 to 3 mm;

[0036] 2) 37 parts of slaked lime powder with a particle size of 20 to 50 μm, 19 parts of cementitious silica powder with a particle size of 20 to 50 μm, 9 parts of diatomaceous earth, 11 parts of composite reinforcing fiber, 1 part of powdered solid sodium silicate with a modulus of 3 to 3.2, and 0.1 part of calcium silicate powder are mixed uniformly to obtain a solid mixture;

[0037] 3) uniformly mixing 2.5 parts of the above-mentioned polyethylene glycol with 100.5 parts of water to obtain a liquid mixture;

[0038] 4) mixing the solid mixture with the liquid mixture, stirring at 450 rpm for 3 h to form a slurry to obtain a slurry;

[0039] 5) The slurry is injected into a mold and pressed at room temperature. The pressing conditions are: first, the pressure is maintained at 5 MPa for 10 minutes, then the pressure is increased to 25 MPa at a rate of 0.5 MPa / min and maintained for 5 minutes, then the pressure is reduced to normal pressure at a rate of 1 MPa / min, and then heated and pressurized for pre-curing. The pre-curing conditions are: first, the temperature is controlled at 65°C and the humidity is 80-90%, then the pressure is controlled at 2 MPa, and then the temperature and pressure are maintained for 6 hours. The mold is then formed and demolded to obtain a blank.

[0040] 6) Saturated steam is introduced into the embryonic board for high-temperature autoclaving. The curing conditions are as follows: the temperature is controlled at 200°C and the pressure is 1.3 MPa. The heat and pressure are then maintained for 8 hours. The embryonic board is then dried at 60°C until the moisture content is less than 5%. The embryonic board is then polished to obtain an asbestos-free reinforced calcium silicate decorative board.

[0041] Example 2

[0042] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0043] 1) The preparation of the composite reinforcing fiber is the same as that in Example 1;

[0044] 2) 41 parts of slaked lime powder with a particle size of 20 to 50 μm, 22.5 parts of cementitious silica powder with a particle size of 20 to 50 μm, 11.5 parts of diatomaceous earth, 14 parts of composite reinforcing fiber, 2 parts of powdered solid sodium silicate with a modulus of 3 to 3.2, and 0.15 parts of calcium silicate powder are mixed uniformly to obtain a solid mixture;

[0045] 3) uniformly mixing 4 parts of the above-mentioned polyethylene glycol with 128 parts of water to obtain a liquid mixture;

[0046] 4) mixing the solid mixture with the liquid mixture, stirring at 400 rpm for 4 hours to form a slurry to obtain a slurry;

[0047] 5) The slurry was injected into a mold and pressed at room temperature. The pressing conditions were: first, the pressure was maintained at 7.5 MPa for 12 minutes, then the pressure was increased to 27.5 MPa at a rate of 0.75 MPa / min and maintained for 8 minutes, then the pressure was reduced to normal pressure at a rate of 1.5 MPa / min, and then heated and pressurized for pre-curing. The pre-curing conditions were: first, the temperature was controlled at 70°C and the humidity was 80-90%, then the pressure was controlled at 2.5 MPa, and the heat and pressure were maintained for 7 hours. The mold was then formed and demolded to obtain a blank.

[0048] 6) Saturated steam is introduced into the embryonic board for high-temperature autoclaving. The curing conditions are as follows: the temperature is controlled at 205°C and the pressure is 1.4 MPa. The heat and pressure are then maintained for 10 hours. The embryonic board is then dried at 65°C until the moisture content is less than 5%. The embryonic board is then polished to obtain an asbestos-free reinforced calcium silicate decorative board.

[0049] Example 3

[0050] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0051] 1) The preparation of the composite reinforcing fiber is the same as that in Example 1;

[0052] 2) 45 parts of slaked lime powder with a particle size of 20 to 50 μm, 26 parts of cementitious silica powder with a particle size of 20 to 50 μm, 14 parts of diatomaceous earth, 17 parts of composite reinforcing fiber, 3 parts of powdered solid sodium silicate with a modulus of 3 to 3.2, and 0.2 parts of calcium silicate powder are mixed uniformly to obtain a solid mixture;

[0053] 3) uniformly mixing 5.5 parts of the above-mentioned polyethylene glycol with 157.5 parts of water to obtain a liquid mixture;

[0054] 4) mixing the solid mixture with the liquid mixture, stirring at 350 rpm for 5 h to form a slurry to obtain a slurry;

[0055] 5) The slurry is injected into a mold and pressed at room temperature. The pressing conditions are: first, maintain the pressure at 10 MPa for 15 minutes, then increase the pressure to 30 MPa at a rate of 1 MPa / min and maintain the pressure for 10 minutes, then reduce the pressure to normal pressure at a rate of 2 MPa / min, and then heat and pressurize for pre-curing. The pre-curing conditions are: first, control the temperature at 75°C and the humidity at 80-90%, then control the pressure at 3 MPa, and then maintain the temperature and pressure for 8 hours. The mold is then formed and demolded to obtain a blank.

[0056] 6) Saturated steam is introduced into the embryonic board for high-temperature autoclaving. The curing conditions are as follows: the temperature is controlled at 210° C. and the pressure is 1.5 MPa. The heat and pressure are then maintained for 12 hours. The embryonic board is then dried at 70° C. until the moisture content is less than 5%. The embryonic board is then polished to obtain an asbestos-free reinforced calcium silicate decorative board.

[0057] Example 4

[0058] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0059] 1) The preparation of the composite reinforcing fiber is the same as that in Example 1;

[0060] 2) 38 parts of slaked lime powder with a particle size of 20 to 50 μm, 25 parts of cementitious silica powder with a particle size of 20 to 50 μm, 12 parts of diatomaceous earth, 13 parts of composite reinforcing fiber, 2 parts of powdered solid sodium silicate with a modulus of 3 to 3.2, and 0.15 parts of calcium silicate powder are mixed uniformly to obtain a solid mixture;

[0061] 3) uniformly mixing 4 parts of the above-mentioned polyethylene glycol with 130 parts of water to obtain a liquid mixture;

[0062] 4) Mixing the solid mixture with the liquid mixture, stirring at 350 rpm for 3 hours to form a slurry to obtain a slurry;

[0063] 5) The slurry is injected into a mold and pressed at room temperature. The pressing conditions are: first, maintain the pressure at 5 MPa for 15 minutes, then increase the pressure to 30 MPa at a rate of 1 MPa / min and maintain the pressure for 5 minutes, then reduce the pressure to normal pressure at a rate of 1 MPa / min, and then heat and pressurize for pre-curing. The pre-curing conditions are: first, control the temperature at 65°C and the humidity at 80-90%, then control the pressure at 2 MPa, and then maintain the temperature and pressure for 8 hours. The mold is then formed and demolded to obtain a blank.

[0064] 6) Saturated steam is introduced into the embryonic board for high-temperature autoclaving. The curing conditions are as follows: the temperature is controlled at 200°C and the pressure is 1.4 MPa. The heat and pressure are then maintained for 10 hours. The embryonic board is then dried at 65°C until the moisture content is less than 5%. The embryonic board is then polished to obtain an asbestos-free reinforced calcium silicate decorative board.

[0065] Example 5

[0066] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0067] 1) The preparation of the composite reinforcing fiber is the same as that in Example 1;

[0068] 2) 43 parts of slaked lime powder with a particle size of 20 to 50 μm, 24 parts of cementitious silica powder with a particle size of 20 to 50 μm, 13 parts of diatomaceous earth, 15.5 parts of composite reinforcing fiber, 2.5 parts of powdered solid sodium silicate with a modulus of 2.5 to 2.9, and 0.2 parts of calcium silicate powder are mixed uniformly to obtain a solid mixture;

[0069] 3) uniformly mixing 5 parts of the above-mentioned polyethylene glycol with 142 parts of water to obtain a liquid mixture;

[0070] 4) mixing the solid mixture with the liquid mixture, stirring at 400 rpm for 3 h to form a slurry to obtain a slurry;

[0071] 5) The slurry is injected into a mold and pressed at room temperature. The pressing conditions are: first, maintain the pressure at 10 MPa for 5 minutes, then increase the pressure to 25 MPa at a rate of 0.5 MPa / min and maintain the pressure for 5 minutes, then reduce the pressure to normal pressure at a rate of 2 MPa / min, and then heat and pressurize for pre-curing. The pre-curing conditions are: first, control the temperature at 70°C and the humidity at 80-90%, then control the pressure at 2.5 MPa, and then maintain the temperature and pressure for 6 hours. The mold is then formed and demolded to obtain a blank.

[0072] 6) Saturated steam is introduced into the embryonic board for high-temperature autoclaving. The curing conditions are as follows: the temperature is controlled at 200°C and the pressure is 1.4 MPa. The heat and pressure are then maintained for 10 hours. The embryonic board is then dried at 65°C until the moisture content is less than 5%. The embryonic board is then polished to obtain an asbestos-free reinforced calcium silicate decorative board.

[0073] Example 6

[0074] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0075] 1) Preparation of composite reinforcing fiber: polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, viscose cellulose with a diameter of 1 to 2 μm and a length of 1 to 2 mm, and ceramic short fibers with a diameter of 1.3 to 1.5.5 μm and a length of 0.5 to 1 mm are uniformly stirred in a mass ratio of 38:20:5:3:11:8, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch is melt-spun to obtain a composite reinforcing fiber with a diameter of 50 to 100 μm and a length of 2 to 3 mm;

[0076] Steps 2), 3), 4), 5), and 6) are identical to those in Example 1.

[0077] Example 7

[0078] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0079] 1) Preparation of composite reinforcing fiber: polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, viscose cellulose with a diameter of 1 to 2 μm and a length of 1 to 2 mm, and ceramic short fibers with a diameter of 1.3 to 1.5.5 μm and a length of 0.5 to 1 mm are uniformly stirred in a mass ratio of 38:20:5:3:11:8, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch is melt-spun to obtain a composite reinforcing fiber with a diameter of 50 to 100 μm and a length of 2 to 3 mm;

[0080] Steps 2), 3), 4), 5), and 6) are identical to those in Example 1.

[0081] Example 8

[0082] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, and the steps are as follows:

[0083] 1) Preparation of composite reinforcing fiber: polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, cellulose acetate with a diameter of 1 to 2 μm and a length of 1 to 2 mm, and ceramic short fibers with a diameter of 1.3 to 1.5.5 μm and a length of 0.5 to 1 mm were stirred and uniformly mixed in a mass ratio of 45:20:7:5:11:14, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch was melt-spun to obtain a composite reinforcing fiber with a diameter of 50 to 100 μm and a length of 2 to 3 mm;

[0084] Steps 2), 3), 4), 5), and 6) are identical to those in Example 1.

[0085] Comparative Example 1

[0086] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts. The difference from Example 1 is that polypropylene fibers with a diameter of 50 to 100 μm and a length of 2 to 3 mm are used instead of composite reinforcing fibers.

[0087] Comparative Example 2

[0088] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts. The difference from Example 1 is that viscose cellulose with a diameter of 50 to 100 μm and a length of 2 to 3 mm is used instead of the composite reinforcing fiber.

[0089] Comparative Example 3

[0090] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts. The difference from Example 1 is that ceramic short fibers with a diameter of 50 to 100 μm and a length of 2 to 3 mm are used instead of composite reinforcing fibers.

[0091] Comparative Example 4

[0092] An asbestos-free reinforced calcium silicate decorative panel is prepared using the following raw materials and their weight parts. The difference from Example 1 is that calcium carbonate whiskers are used instead of composite reinforcing fibers.

[0093] Comparative Example 5

[0094] A non-asbestos reinforced calcium silicate decorative panel differs from Example 1 in that: 1) Preparation of composite reinforcing fibers: Polypropylene resin, calcium carbonate whiskers, viscose cellulose with a diameter of 1 to 2 μm and a length of 1 to 2 mm, and ceramic short fibers with a diameter of 1.3 to 1.5.5 μm and a length of 0.5 to 1 mm are uniformly stirred and mixed in a mass ratio of 65:7.5:13:12, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch is melt-spun to obtain a composite reinforcing fiber with a diameter of 50 to 100 μm and a length of 2 to 3 mm.

[0095] Comparative Example 6

[0096] A non-asbestos reinforced calcium silicate decorative panel differs from Example 1 in that: 1) Preparation of composite reinforcing fibers: Polypropylene resin, calcium carbonate whiskers, nano-silica, viscose cellulose with a diameter of 1 to 2 μm and a length of 1 to 2 mm, and ceramic short fibers with a diameter of 1.3 to 1.5.5 μm and a length of 0.5 to 1 mm are uniformly stirred and mixed in a mass ratio of 65:7.5:5.5:13:12, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch is melt-spun to obtain a composite reinforcing fiber with a diameter of 50 to 100 μm and a length of 2 to 3 mm.

[0097] Comparative Example 7

[0098] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts, which is different from Example 1 in that the calcium silicate powder in Comparative Example 1 is 0.

[0099] Comparative Example 8

[0100] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts. The difference from Example 1 is that the sodium silicate in Comparative Example 2 has a modulus of 1 to 1.5.

[0101] Comparative Example 9

[0102] An asbestos-free reinforced calcium silicate decorative panel is prepared by using the following raw materials and their weight parts. The difference from Example 1 is that the sodium silicate in Comparative Example 3 has a modulus of 3.4 to 3.7.

[0103] Comparative Example 10

[0104] An asbestos-free reinforced calcium silicate decorative panel is prepared using the following raw materials and their weight parts, and differs from Example 1 in that: 5) the above-mentioned slurry is injected into a mold and pressed at room temperature. The pressing conditions are: maintaining a constant pressure of 30 MPa for 25 minutes, releasing the pressure, and then heating and pressurizing for pre-curing. The pre-curing conditions are: first controlling the temperature to 65°C and the humidity to 80-90%, then controlling the pressure to 2 MPa, and finally maintaining the heat and pressure for 6 hours, forming and demolding to obtain a blank board.

[0105] Comparative Example 11

[0106] An asbestos-free reinforced calcium silicate decorative panel is prepared using the following raw materials and their weight parts, and differs from Example 1 in that: 5) the pressure is first maintained at 5 MPa for 10 minutes, then the pressure is increased to 25 MPa at a rate of 0.5 MPa / min and maintained for 5 minutes, and then the pressure is reduced to normal pressure at a rate of 1 MPa / min, and then heated for pre-curing. The pre-curing conditions are as follows: first, the temperature is controlled at 65°C and the humidity is 80-90%, and then the heat is maintained for 6-8 hours, and the panel is formed and demolded to obtain a blank panel.

[0107] Comparative Example 12

[0108] An asbestos-free reinforced calcium silicate decorative panel is prepared using the following raw materials and their weight parts, and is different from Example 1 in that: 6) the temperature is controlled to 200°C and the pressure is 1.2 MPa, and then the heat and pressure are maintained for 8 hours, and then dried at 60°C to a moisture content of less than 5%, and then polished to obtain an asbestos-free reinforced calcium silicate decorative panel.

[0109] Performance testing:

[0110] The asbestos-free reinforced calcium silicate decorative panels obtained in Examples 1 to 8 and Comparative Examples 1 to 12 were tested for the following performance indicators:

[0111] Referring to JC / T564.1-2018 "Fiber-reinforced calcium silicate board" and T / CBMF79-2020 "Calcium silicate board for fire protection", the apparent density, flexural strength, impact strength, thermal conductivity and thermal stability after high-temperature treatment at 950°C for 4 hours were tested.

[0112] The results are shown in Table 1 for apparent density, flexural strength, impact strength and thermal conductivity, and Table 2 for thermal stability.

[0113] Table 1 Apparent density, flexural strength, impact strength and thermal conductivity

[0114]

[0115] Table 2 Thermal stability

[0116]

[0117]

[0118] From the data in Tables 1 and 2, it can be seen that compared with Comparative Examples 1 to 6, Example 1 uses a composite composite reinforcing fiber prepared by melt spinning of raw materials of polypropylene resin, polyacrylate, calcium carbonate whisker, nano-silica, cellulose fiber and ceramic short fiber, which has good high strength, toughness and compatibility, can promote the interface bonding between it and the calcium silicate matrix, effectively block cracks, and make the asbestos-free reinforced calcium silicate decorative panel have high strength and good anti-cracking effect, and also have excellent thermal stability, achieving a lighter calcium silicate decorative panel; compared with Comparative Example 7, Example 1 uses calcium silicate powder, which can promote the grain refinement of calcium silicate, avoid the appearance of larger crystals, and improve the strength, anti-cracking effect and thermal stability of the asbestos-free reinforced calcium silicate decorative panel; compared with Comparative Examples 8 and 9 In comparison, Example 1 uses sodium silicate with a modulus of 2.5 to 3.2, which can enhance the bonding strength between the calcium silicate matrix, so that the asbestos-free reinforced calcium silicate decorative panel has stronger structural strength and appropriate density and fineness, thereby improving the mechanical properties and thermal stability of the asbestos-free reinforced calcium silicate decorative panel, and can also obtain a lighter calcium silicate board; compared with Comparative Examples 10, 11 and 12, Example 1 uses variable pressure room temperature pressing, heating and pressurizing pre-curing, and high temperature autoclave curing greater than 1.2 MPa, which can promote the increase in the number of micropores while enhancing the pore stability, thereby reducing the density of the asbestos-free reinforced calcium silicate decorative panel, having a lightweight characteristic, and further improving the asbestos-free reinforced calcium silicate decorative panel with stronger mechanical properties and thermal stability.

[0119] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be embodied in other specific forms without departing from the spirit and essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0120] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A non-asbestos reinforced calcium silicate decorative panel, characterized in that: The invention comprises the following raw materials and their weight parts: 37-45 parts of slaked lime powder, 19-26 parts of cementitious silica powder, 9-14 parts of diatomaceous earth, 11-17 parts of composite reinforcing fiber, 2.5-5.5 parts of polyethylene glycol, 1-3 parts of sodium silicate and 0.1-0.2 parts of calcium silicate powder; The composite reinforcing fiber is made by melt-spinning a mixture of polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, cellulose fiber and ceramic short fiber; The preparation process of the composite reinforcing fiber is as follows: polypropylene resin, polyacrylate, calcium carbonate whiskers, nano-silica, cellulose fiber and ceramic short fiber are uniformly stirred and mixed in a mass ratio of 38-45:20-26:5-10:3-8:11-16:8-14, melt-blended and extruded into granules through a twin-screw extruder to obtain a composite masterbatch, and then the composite masterbatch is melt-spun to obtain a composite reinforcing fiber; The sodium silicate has a modulus of 2.5 to 3.2 and is a powdery solid.

2. The asbestos-free reinforced calcium silicate decorative panel according to claim 1, characterized in that: In the composite reinforcing fiber, the cellulose fiber is viscose cellulose and / or cellulose acetate; the diameter of the cellulose fiber is 1 to 2 μm and the length is 1 to 2 mm; the diameter of the ceramic short fiber is 1.3 to 1.5.5 μm and the length is 0.5 to 1 mm.

3. The asbestos-free reinforced calcium silicate decorative panel according to claim 1, characterized in that: The composite reinforcing fiber has a diameter of 50 to 100 μm and a length of 2 to 3 mm.

4. A method for preparing the asbestos-free reinforced calcium silicate decorative panel according to claim 1, characterized in that: The following steps are involved: (1) uniformly mixing the above-mentioned parts by weight of slaked lime powder, cementitious silica powder, diatomaceous earth, composite reinforcing fiber, sodium silicate and calcium silicate powder to obtain a solid mixture; (2) uniformly mixing the polyethylene glycol in the above-mentioned parts by weight with water, wherein the mass ratio of the added water to the weight of the solid mixture is 1.3 to 1.5:1, to obtain a liquid mixture; (3) mixing the solid mixture with the liquid mixture, stirring to form a slurry to obtain a slurry; (4) injecting the above slurry into a mold and pressing it at room temperature with variable pressure, then heating and pressurizing it for pre-curing, forming and demolding it to obtain a blank; (5) Saturated steam is introduced into the embryonic board for high-temperature autoclaving and curing, and then the board is dried until the moisture content is less than 5%, and then polished to obtain an asbestos-free reinforced calcium silicate decorative board.

5. The method for preparing a non-asbestos reinforced calcium silicate decorative panel according to claim 4, characterized in that: Step (4), the conditions for variable pressure pressing at room temperature are: first, maintain the pressure at 5-10 MPa for 10-15 minutes, then gradually increase the pressure to 25-30 MPa and maintain the pressure for 5-10 minutes, and then gradually reduce the pressure to normal pressure.

6. The method for preparing the asbestos-free reinforced calcium silicate decorative panel according to claim 5, characterized in that: The rate of gradual pressure increase is 0.5-1 MPa / min, and the rate of gradual pressure reduction is 1-2 MPa / min.

7. The method for preparing a non-asbestos reinforced calcium silicate decorative panel according to claim 4, characterized in that: Step (4), heating and pressurizing pre-curing conditions: first control the temperature to 65-75°C and the humidity to 80-90%, then control the pressure to 2-3 MPa, and finally maintain the temperature and pressure for 6-8 hours.

8. The method for preparing the asbestos-free reinforced calcium silicate decorative panel according to claim 4, characterized in that: Step (5), high temperature autoclave curing conditions: control the temperature to 200-210° C. and the pressure to 1.3-1.5 MPa, and then maintain the heat and pressure for 8-12 hours.

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