A low bulk density soluble fibre product and a method for its preparation

Abstract

The application provides a preparation method of a soluble ceramic fiber product, comprising the following steps: melting raw materials; fiberizing the melted materials; needling the fiberized fibers to form a fiber blanket, so as to obtain the soluble ceramic fiber product; and the temperature range of the melt flowing out in the melting process fluctuates by no more than 150 DEG C. The application improves the material channel of the melt flowing out of the heating equipment, so as to control the temperature fluctuation range of the melt flowing out to be no more than 150 DEG C. The process parameters in the fiberizing process are controlled, so as to ensure that the temperature fluctuation range of the melt dropping to the spinning roller is 100-200 DEG C. The flow of the cooling water in the spinning roller in the fiberizing process is controlled, so as to ensure that the fiberizing temperature fluctuation range in the spinning process is no more than 2%. The soluble ceramic fiber product prepared by the method provided by the application contains less than 5 wt% of dust with an average particle size of less than 45 mu m. The application further provides a soluble ceramic fiber product.

Description

Technical Field

[0001] This invention belongs to the field of soluble fiber technology, and particularly relates to a low-density soluble fiber product and its preparation method. Background Technology

[0002] Soluble fibers are fibers with low biodegradability. Once inside the human body, they dissolve in physiological fluids, resulting in a short residence time within the body. They are gradually broken down and excreted by bodily fluids. Soluble fibers can be further processed into various products, including boards, mats, paper, blankets / felts, cotton / flour, molded / shaped products, coating materials, and amorphous compositions, as a major or minor component. Existing soluble fibers include soluble ceramic fibers, soluble glass fibers, and soluble basalt fibers. The operating temperature of soluble glass fibers is generally <400℃, soluble basalt fibers <600℃, and soluble ceramic fibers generally <1000℃. Current processes for preparing soluble ceramic fibers primarily utilize conventional spun fiber equipment. Products prepared using this process exhibit low thermal conductivity, solubility, and fire resistance.

[0003] The existing soluble ceramic fiber has a narrow fiber-forming temperature range, generally 1500-1600℃. The melt fiber-forming viscosity is greatly affected by temperature, which leads to a large amount of non-fiber material in soluble ceramic fiber products. This non-fiber material includes dust with an average particle size of <45μm, particles with an average particle size of 45-212μm, and slag balls with an average particle size of >212μm. This results in low fiber-forming rate, poor thermal insulation performance, and difficulty in reducing bulk density.

[0004] To address the aforementioned issues, existing technological improvements primarily focus on reducing particles and slag balls larger than 45μm, with less attention paid to removing and reducing dust with an average particle size of <45μm. However, dust with an average particle size of <45μm accounts for up to 10wt% of fiber products. The presence of this dust reduces the fiber formation rate, affects the thermal insulation performance of the fiber, and lowers the tensile strength of the product. It also causes severe dust shedding from the fiber products, impacting the on-site construction environment and consequently affecting the user's subsequent production under construction conditions, thus affecting the overall performance. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a soluble ceramic fiber product and a method for preparing the same. In the soluble ceramic fiber product prepared by the method provided by the present invention, the proportion of dust with an average particle size of <45μm in the fiber product is relatively small.

[0006] This invention provides a method for preparing soluble ceramic fiber products, comprising:

[0007] Melt the raw materials;

[0008] The molten material is then processed into fibers.

[0009] The fibers are needle-punched to form a fiber blanket, resulting in soluble ceramic fiber products; the temperature range of the melt flowing out during the melting process does not exceed 150°C.

[0010] Preferably, the raw materials include: calcium oxide, magnesium oxide and silicon oxide.

[0011] Preferably, the calcium oxide content in the raw material is 28-30% by mass;

[0012] The magnesium oxide content in the raw material is 4.5-6% by mass;

[0013] The silicon dioxide content in the raw material is 64-66% by mass.

[0014] Preferably, the internal temperature of the furnace body during the melting process is 1800-2000℃; the furnace body discharge temperature is 1650-1800℃; and the melt outflow rate is 460-780 kg / h.

[0015] Preferably, the melting is carried out in a melting device; the melting device includes a flow port body, which includes a flow port body and an intermediate channel for fluid outflow. The flow port body is externally connected to a circuit that can conduct electricity. The conductive flow port body is connected to the high-temperature molten liquid to form a closed circuit loop. By controlling the magnitude of the current I in the flow port body, the temperature of the molten liquid flowing out is controlled, and the temperature of the material channel from which the melt flows out is regulated to keep the temperature fluctuation range of the melt not exceeding 150°C.

[0016] Preferably, the current I is 100 to 500 A.

[0017] Preferably, the fiber-forming method is spun fiber forming.

[0018] Preferably, the fiber forming distance during the fiber spinning process is 1 to 1.5 m; the fiber spinning process uses a lifting spinning roller to control the temperature at the fiber forming point to be 100 to 150°C lower than the fluid outlet temperature.

[0019] Preferably, during the fiber spinning process, the flow rate of cooling water in the spinning roller is adjusted to 30-40 L / h so that the temperature fluctuation range during the spinning process does not exceed 2%, and the final fiber forming temperature is 1570-1620℃; the linear speed of the spinning roller during the fiber spinning process is 120-180 m / s.

[0020] This invention provides a soluble ceramic fiber product prepared by the method described above.

[0021] This invention improves the material channel of the melt outflow heating equipment, thereby controlling the temperature fluctuation range of the outflowing melt to not exceed 150°C; by controlling the process parameters during fiber formation, it ensures that the temperature fluctuation range of the melt dripping onto the spinning roller is 100-200°C; by controlling the cooling water flow rate in the spinning roller during fiber formation, it ensures that the temperature fluctuation range during the spinning process does not exceed 2%; the soluble ceramic fiber product prepared by the method provided by this invention has a dust content of <5wt% with an average particle size <45μm. Attached Figure Description

[0022] Figure 1 A schematic diagram of the structure of a melting device provided for the prior art;

[0023] Figure 2 This is a schematic diagram of the melting device provided in an embodiment of the present invention. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other instances that are improved or modified by those skilled in the art are within the scope of protection of the present invention. It should be understood that the embodiments of the present invention are only used to illustrate the technical effects of the present invention, and are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the methods used in the embodiments are conventional methods.

[0025] This invention provides a method for preparing soluble ceramic fiber products, comprising:

[0026] Melt the raw materials;

[0027] The molten material is then processed into fibers.

[0028] The fibers obtained after fiber formation are needle-punched to form a fiber blanket, resulting in soluble ceramic fiber products.

[0029] In this invention, the raw materials preferably include calcium oxide, magnesium oxide, and silicon oxide; the mass content of calcium oxide in the raw materials is preferably 28-30 wt%, more preferably 29 wt%; the mass content of magnesium oxide in the raw materials is preferably 4.5-6 wt%, more preferably 5-5.5 wt%, and most preferably 5.2 wt%; the mass content of silicon oxide in the raw materials is preferably 64-66 wt%, more preferably 65 wt%.

[0030] In this invention, the internal temperature of the furnace body during the melting process is preferably 1800-2000℃, more preferably 1850-1950℃, and most preferably 1900℃; the furnace body discharge temperature is preferably 1650-1800℃, more preferably 1700-1750℃, and most preferably 1730℃; the melt outflow rate is preferably 460-780 kg / h, more preferably 500-700 kg / h, more preferably 550-650 kg / h, and most preferably 600 kg / h.

[0031] In existing technologies, the melting method uses a resistance furnace in conjunction with molybdenum electrodes (see schematic diagram of existing resistance furnace structure). Figure 1 As shown, Figure 1 In the diagram, 1 represents the melt, 2 represents the outlet, 3 represents electrode A, 4 represents electrode B, and 5 represents electrode C. The melt flows out through the outlet. During the outflow process, the temperature of the melt will decrease due to the outlet structure and the fiber-forming distance of the melt, which will increase the viscosity of the melt and thus affect fiber formation and increase the dust content.

[0032] In this invention, the melting is preferably carried out in a melting device; a schematic diagram of the melting device is shown below. Figure 2 As shown ( Figure 2 (1 is the outlet, 2 is the temperature control), the... Figure 2 The flow outlet preferably includes a flow outlet body and an intermediate channel for fluid outflow. The flow outlet body is connected to an external circuit that can conduct electricity. The conductive flow outlet body is connected to the high-temperature molten liquid to form a closed circuit loop. By controlling the current I of the flow outlet body, the temperature of the molten liquid outflow is controlled, and the temperature of the material channel outflowing the melt is regulated to keep the melt temperature fluctuation range not exceeding 150°C.

[0033] In this invention, the current I is preferably 100-500A, more preferably 200-400A, even more preferably 250-350A, and most preferably 300A.

[0034] In this invention, the fiber-forming method is preferably spun fiber forming. In this invention, the distance from the furnace body to the spun roller during the spun fiber forming process is the fiber-forming distance, which is preferably 1-1.5m, more preferably 1.1-1.4m, even more preferably 1.2-1.3m, and most preferably 1.25m. During the spun fiber forming process, a lifting spun roller is preferably used to control the temperature at the fiber forming point to be 100-150℃ lower than the fluid outlet (melting equipment) temperature, more preferably 110-140℃, even more preferably 120-130℃, and most preferably 125℃.

[0035] In this invention, during the fiber spinning process, the inlet flow rate of cooling water in the spinning roller is preferably adjusted to 30-40 L / h, more preferably 32-38 L / h, even more preferably 34-36 L / h, and most preferably 35 L / h, so that the temperature fluctuation range during the spinning process does not exceed 2%, and the final fiber forming temperature range is preferably 1570-1620℃, more preferably 1580-1610℃, even more preferably 1590-1600℃, and most preferably 1595℃; the linear speed of the spinning roller during the fiber spinning process is preferably 120-180 m / s, more preferably 130-170 m / s, even more preferably 140-160 m / s, and most preferably 150 m / s.

[0036] In this invention, the needle density during the acupuncture process is preferably 6 to 20 needles / cm. 2 More preferably, 10-15 stitches / cm 2 The optimal value is 13 stitches / cm. 2 .

[0037] In this invention, the needle-punched blanket preferably contains less than 5 wt% of dust with an average particle size <45 μm, and less than 35 wt% of particles and slag balls with an average particle size >45 μm; its tensile strength is 40–100 kPa, preferably 50–90 kPa, more preferably 60–80 kPa, and most preferably 70 kPa; its thermal conductivity is 0.09–0.12 W / mK (average 500°C), preferably 0.1–0.11 W / mK, more preferably 0.105 W / mK; and its bulk density is 96–128 kg / m³. 3 Preferably 100-120 kg / m 3 More preferably, it is 105–115 kg / m³. 3 The optimal value is 110 kg / m 3 .

[0038] In this invention, the biosolubility of the needled blanket is 200-240 mg / L, preferably 210-230 mg / L, and more preferably 220 mg / L.

[0039] The present invention also provides a soluble ceramic fiber product prepared by the method described above.

[0040] This invention improves the material channel of the melt outflow heating equipment, thereby controlling the temperature fluctuation range of the outflowing melt to not exceed 150°C; by controlling the process parameters during fiber formation, it ensures that the temperature fluctuation range of the melt dripping onto the spinning roller is 100-200°C; by controlling the cooling water flow rate in the spinning roller during fiber formation, it ensures that the temperature fluctuation range during the spinning process does not exceed 2%; the soluble ceramic fiber product prepared by the method provided by this invention has a dust content of <5wt% with an average particle size <45μm.

[0041] Example 1

[0042] The raw material containing 29.5 wt% calcium oxide, 5.12 wt% magnesium oxide, and 65.38 wt% silicon oxide was melted. During the melting process, the internal temperature of the furnace was 1850–1900℃, the outlet current was controlled at 300A, the furnace outlet temperature was 1650–1750℃, and the melt flow rate was 600 kg / h (see schematic diagram of the melting equipment). Figure 2 (As shown).

[0043] The molten material is spun into fibers. The fiber-forming distance during the fiber-forming process is 1m. The cooling water inlet flow rate in the spun roller is 35L / h. The temperature at the fiber-forming point is controlled at 1500~1650℃. The temperature fluctuation range during the spun process is 1570~1600℃, and the fiber-forming temperature fluctuation range is 1.90%. The linear speed of the spun roller during the fiber-forming process is 170m / s.

[0044] The fibers, after being formed, are needle-punched to form a needle-punched blanket, resulting in a soluble ceramic fiber product. The needle-punching density during the process is 13 needles / cm. 2 .

[0045] The solubility of the needle-punched blanket prepared in Example 1 of this invention was tested according to the method in GB / T3003-2017 "Refractory Fibers and Products"; the tensile strength, thermal conductivity and non-fibrous material content of the needle-punched blanket prepared in Example 1 of this invention were tested according to GB / T17911-2018 "Test Methods for Refractory Fiber Products" (unlike slag balls, slag balls are >212μm, and the non-fibrous material does not need to be sieved after separation from the fiber).

[0046] The test results show that the solubility of the needled blanket prepared in Example 1 of this invention is 220 mg / L, the tensile strength is 75 kPa, the thermal conductivity is 0.089 W / mk, the content of non-fibrous material <45 μm is 4.1 wt%, and the content of non-fibrous material >45 μm is 25 wt%.

[0047] Example 2

[0048] The raw materials, containing 29.3 wt% calcium oxide, 5.25 wt% magnesium oxide, and 65.45 wt% silicon oxide, were melted. During the melting process, the internal furnace temperature was maintained at 1870–1920°C, the outlet current was controlled at 350 A, the furnace outlet temperature was 1670–1780°C, and the melt flow rate was 560 kg / h. (A schematic diagram of the melting equipment is shown below.) Figure 2 (As shown).

[0049] The molten material is spun into fibers. The fiber-forming distance is 1.1m, the temperature at the fiber-forming point is 1620-1680℃, the cooling water inlet flow rate in the spun roller is 30L / h, the temperature fluctuation range during the spun process is 1590-1610℃, and the fiber-forming temperature fluctuation range is 1.24%. The linear speed of the spun roller during the fiber-forming process is 160m / s.

[0050] The fibers, after being formed, are needle-punched to form a needle-punched blanket, resulting in a soluble fiber product; the needle-punching density during the needle-punching process is 13 needles / cm. 2 .

[0051] The performance of the needled blanket prepared in Example 2 of the present invention was tested according to the method of Example 1. The test results are as follows: the solubility of the needled blanket prepared in Example 2 of the present invention is 219 mg / L, the tensile strength is 78 kPa, the thermal conductivity is 0.090 W / mk, the content of non-fibrous material <45 μm is 3.8 wt%, and the content of non-fibrous material >45 μm is 20 wt%.

[0052] Comparative Example 1

[0053] The raw materials contain 29.5 wt% calcium oxide, 5.12 wt% magnesium oxide, and 65.38 wt% silicon oxide. During the melting process, the internal temperature of the furnace is 1870–1920 °C, the outlet current is controlled at 0 A, the furnace outlet temperature is 1640–1700 °C, and the melt outflow rate is 600 kg / h.

[0054] The molten material is spun into fibers. The fiber forming distance during the fiber forming process is 1m. The cooling water inlet flow rate in the spun roller is 35L / h. The temperature fluctuation range during the spun process is 1500~1580℃, and the fiber forming temperature fluctuation range is 5.06%. The linear speed of the spun roller during the fiber forming process is 170m / s.

[0055] The fibers, after being spun into fibers, are needle-punched to form a needle-punched blanket, thus obtaining a soluble ceramic fiber product; the needle-punching density during the needle-punching process is 13 needles / cm. 2 .

[0056] The performance of the needled blanket prepared in Comparative Example 1 of the present invention was tested according to the method of Example 1. The test results were as follows: the solubility of the needled blanket prepared in Comparative Example 1 of the present invention was 220 mg / L, the tensile strength was 38 kPa, the thermal conductivity was 0.126 W / mk, the content of non-fibrous material <45 μm was 4.4 wt%, and the content of non-fibrous material >45 μm was 45 wt%.

[0057] Comparative Example 2

[0058] The raw materials contain 29.5 wt% calcium oxide, 5.12 wt% magnesium oxide, and 65.38 wt% silicon oxide. During the melting process, the internal temperature of the furnace is 1870–1920℃, the outlet current is controlled at 200A, the furnace outlet temperature is 1660–1710℃, and the melt outflow rate is 600 kg / h.

[0059] The molten material is spun into fibers. The fiber forming distance during the fiber forming process is 1m. The cooling water inlet flow rate in the spun roller is 45L / h. The temperature fluctuation range during the spun process is 1450~1520℃, and the fiber forming temperature fluctuation range is 4.61%. The linear speed of the spun roller during the fiber forming process is 170m / s.

[0060] The fibers, after being spun, are needle-punched to form a needle-punched blanket, resulting in a soluble ceramic fiber product; the needle-punching density during the needle-punching process is 13 needles / cm. 2 .

[0061] The performance of the needled blanket prepared in Comparative Example 2 of the present invention was tested according to the method of Example 1. The test results showed that the solubility of the needled blanket prepared in Comparative Example 2 of the present invention was 219 mg / L, the tensile strength was 35 kPa, the thermal conductivity was 0.128 W / mk, the content of non-fibrous material <45 μm was 5.2 wt%, and the content of non-fibrous material >45 μm was 46 wt%.

[0062] As can be seen from the above embodiments, the present invention improves the material channel of the melt outflow heating equipment, thereby controlling the temperature fluctuation range of the outflowing melt to not exceed 150°C; by controlling the process parameters during the fiber formation process, the temperature fluctuation range of the melt dripping onto the spinning roller is ensured to be 100-200°C; by controlling the cooling water flow rate in the spinning roller during the fiber formation process, the temperature fluctuation range of the fiber formation process is kept to not exceed 2%; the soluble ceramic fiber product prepared by the method provided by the present invention has a dust content of <5wt% with an average particle size <45μm.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a soluble ceramic fiber product, comprising: Melt the raw materials; During the melting process, the internal temperature of the furnace body is 1800~2000℃; the furnace body discharge temperature is 1650~1800℃; the melt outflow rate is 460~780kg / h; the melting is carried out in a melting device; the melting device includes a flow port body, which includes a flow port body and an intermediate channel for fluid outflow. The flow port body is externally connected to a circuit that can conduct electricity. The conductive flow port body is connected to the high-temperature molten liquid to form a closed circuit loop. By controlling the current I of the flow port body, the temperature of the molten liquid outflow is controlled, and the temperature of the material channel outflowing the melt is regulated to keep the temperature fluctuation range of the outflowing melt not exceeding 150℃. The molten material is then processed into fibers. The fibers are needle-punched to form a fiber blanket, resulting in soluble ceramic fiber products. The fiber-forming method is spun fiber formation; During the fiber spinning process, the flow rate of cooling water in the spinning roller is adjusted to 30~40L / h so that the temperature fluctuation range during the spinning process does not exceed 2%, and the final fiber forming temperature is 1570~1620℃. The dust content in the soluble ceramic fiber product with an average particle size of <45μm is <5wt%.

2. The method according to claim 1, characterized in that, The raw materials include: calcium oxide, magnesium oxide and silicon oxide.

3. The method according to claim 2, characterized in that, The calcium oxide content in the raw material is 28-30% by mass; The magnesium oxide content in the raw material is 4.5-6% by mass; The silicon dioxide content in the raw material is 64-66% by mass.

4. The method according to claim 1, characterized in that, The current I is 100~500A.

5. The method according to claim 4, characterized in that, The fiber-forming distance during the spinning process is 1~1.5m; the spinning process uses lifting spinning rollers to control the temperature at the fiber-forming point to be 100~150℃ lower than the fluid outlet temperature.

6. The method according to claim 4, characterized in that, The linear speed of the spinning roller during the fiber spinning process is 120~180m / s.

7. A soluble ceramic fiber product prepared by the method of claim 1.

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