Ceramic fiber anti-static heat insulation plate and preparation method thereof

Abstract

The invention discloses a preparation method of a ceramic fiber anti-static heat insulation plate. The preparation method comprises the following steps: S1, preparing a base layer; s2, carrying out compression molding on the boss; s3, coating an anti-static layer; s4, preparing heat insulation slurry; s5, hyperbolic pore channel forming; s6, carrying out a three-dimensional embedding process; and S7, vacuum hot-pressing compounding. The ceramic fiber anti-static heat insulation plate is prepared by any one preparation method of the ceramic fiber anti-static heat insulation plate, the contact area of the ceramic fiber anti-static heat insulation plate and the anti-static layer is increased, a mechanical embedding structure is formed, the binding force of the coating and the base layer is remarkably enhanced, and the coating is effectively prevented from falling off. The distribution state of the conductive coating is optimized through the conical surface form of the boss, so that a conductive network of the anti-static layer is more uniform, the static leakage speed is increased, and the anti-static performance is more stable and reliable in long-term use.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of heat insulation plates, in particular to a ceramic fiber anti-static heat insulation plate and a preparation method thereof. BACKGROUND

[0002] The ceramic fiber heat insulation material is widely applied to the industrial high-temperature heat insulation field due to light weight, high temperature resistance and good chemical stability, and the porous structure formed by fiber interweaving realizes heat insulation.

[0003] However, in the complex industrial environment coexisting with high temperature, static electricity and noise, the traditional ceramic fiber heat insulation material adopts a plane composite structure, so that the bonding force of the anti-static layer and the base layer is insufficient, and the coating is prone to falling off in long-term use, leading to static electricity leakage failure; meanwhile, the straight hole design makes the heat conduction path short, the heat insulation efficiency is limited, and the smooth inner wall of the hole causes obvious air laminar flow and serious convective heat transfer, and the ceramic fiber heat insulation material is prone to cracking due to thermal stress at high temperature.

[0004] Therefore, the application provides a ceramic fiber anti-static heat insulation plate and a preparation method thereof. SUMMARY

[0005] The application aims at solving the problems in the prior art and provides a ceramic fiber anti-static heat insulation plate and a preparation method thereof.

[0006] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme: A ceramic fiber anti-static heat insulation plate comprises the following steps: S1, base layer preparation The ceramic fiber is made into a fluffy felt by a carding process, the porosity between fibers is controlled through heat pressing and setting to form a base layer blank with certain strength, the selection of the fiber diameter of 3-5 mu m ensures the balance between the flexibility and heat insulation property of the felt, and the bulk density of 80-120 kg / m3 takes into account the light weight and structural strength; S2, boss die forming A steel die with a rhombic cone boss on the surface is used for heat pressing treatment of the base layer, the geometric design of the die boss has a bottom side length of 2-3 mm and a height of 1.5-2 mm, and is matched with a heat pressing parameter of 8-10 MPa pressure and 100-120 DEG C, so that a regular array of boss structures is formed on the surface of the base layer, and the structures improve the mechanical embedding capacity with the anti-static layer by increasing the surface area; S3, anti-static layer coating Graphene is dispersed in silica sol at a proportion of 10%-15% to prepare a slurry, the slurry is uniformly attached to the surface of the boss base layer by a spraying process, and a 0.2-0.4 mm thick conductive coating is formed after drying and curing, the coating accumulation in the gap between the bosses forms a three-dimensional conductive network, and the static electricity leakage path is optimized; S4, preparation of thermal insulation slurry The aerogel and ceramic fiber are mixed in a mass ratio of 7-8:2-3, and a silica sol binder is added to prepare a formable slurry. The porous structure of the aerogel and the reinforcing effect of the ceramic fiber form a synergistic thermal insulation system. The slurry viscosity is controlled to ensure the integrity of the subsequent pore forming. S5, hyperbolic pore forming The slurry is injected into an elliptical cross-section mold with a hyperbolic trajectory of 3.5-4.5mm. The slurry is solidified by a drying process to form a thermal insulation layer with non-linear pores. The annular rib structure on the inner wall of the pore is realized by etching the surface of the mold. This design prolongs the heat conduction path and enhances the structural strength. S6, three-dimensional fitting process The convex base layer and the pore thermal insulation layer are precisely aligned, and the rhombohedron convex is embedded in the hyperbolic pore. The geometric matching of the convex and the pore forms a preliminary mechanical interlocking. The precise control of the gap is ≤0.3mm, which ensures that there is no gap between the layers and lays the foundation for subsequent composite reinforcement. S7, vacuum hot pressing The hot pressing process is carried out under a vacuum environment of ≤-0.08MPa, a pressure of 12-15MPa, and a temperature of 180-220℃. The vacuum condition eliminates air between the layers to improve the bonding density. A pulse electric field is applied simultaneously during the hot pressing process to promote the charge transfer at the interface between the graphene coating and the aerogel. Finally, a composite board is formed that has thermal insulation, anti-static, and structural strength.

[0007] Preferably, in step S2, the mold convex adopts a quadrangular pyramid structure, the bottom surface is rhombic, and the top of the cone extends vertically to the center of the bottom surface. The edge lines of adjacent convexes form a grid-like distribution on the surface of the base layer. The surface of the base layer forms a mechanical fitting convex point through hot pressing.

[0008] Preferably, in step S3, the graphene slurry is uniformly dispersed by an ultrasonic dispersion process to form a continuous conductive coating after spraying. The anti-static layer contains a carbon fiber reinforced conductive network, and the thermal insulation layer contains silicon carbide whiskers to improve thermal resistance.

[0009] Preferably, in step S5, the axis of the hyperbolic pore is a symmetric curved non-linear trajectory, and the cross-section of the pore is elliptical. The annular rib on the inner wall is continuously distributed in a ring shape. The non-linear trajectory design is used to prolong the heat conduction path and improve the thermal insulation efficiency.

[0010] Preferably, in step S7, a pulse electric field is applied during the vacuum hot pressing process to strengthen the charge transport capacity of the interlayer interface.

[0011] A ceramic fiber anti-static thermal insulation board is prepared by the method of any one of claims 1-5.

[0012] The present application has the following advantages: The contact area with the anti-static layer is greatly increased by the regular array design of the rhombohedron-shaped bosses on the surface of the base layer, a mechanical fitting structure is formed, the bonding force of the coating and the base layer is significantly enhanced, and the coating is effectively prevented from falling off. The conical surface form of the boss optimizes the distribution state of the conductive coating, makes the conductive network of the anti-static layer more uniform, speeds up the static discharge speed, and makes the anti-static performance more stable and reliable in long-term use.

[0013] The non-linear trajectory design is adopted for the hyperbolic hole in the heat insulation layer, the heat conduction path is significantly prolonged, the heat insulation efficiency is improved, the annular rib on the inner wall of the hole destroys the laminar flow state of the air, reduces the convective heat transfer, and at the same time enhances the interface bonding between the aerogel and the ceramic fiber, so that the compressive strength and impact resistance of the heat insulation layer are improved and cracking due to thermal stress is less likely to occur in high temperature environment.

[0014] The interlocking structure formed by the rhombohedron-shaped bosses and the hyperbolic hole, the spiral airflow channel formed by the gap between the bosses and the hole, and the multi-angle gap further reduce the convective heat transfer and produce diffuse reflection to thermal radiation, greatly improving the heat insulation performance; three-dimensional stress dispersion effect is generated when the structure is stressed, the bending strength is significantly improved; at the same time, a cavity structure similar to a Helmholtz resonator is formed, which selectively absorbs sound waves of a specific frequency band, giving the board a noise reduction function, suitable for complex industrial environments where high temperature, static electricity and noise coexist. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A flow chart of a preparation method of a ceramic fiber anti-static heat insulation plate according to the present application is provided. Figure 2 A compressive strength fold line graph of each example and comparative example at different temperatures is provided. Figure 3 A frequency band graph of each example and comparative example under different decibel sounds is provided. Figure 4 A cross-sectional view of the bosses and the anti-static coating in step two of the preparation method of the ceramic fiber anti-static heat insulation plate according to the present application is provided. Figure 5 A bottom view of the hyperbolic hole in step five of the preparation method of the ceramic fiber anti-static heat insulation plate according to the present application is provided. Figure 6 A finished product planar explosion diagram in example four of the preparation method of the ceramic fiber anti-static heat insulation plate according to the present application is provided. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all embodiments. Example one:

[0017] Formulation composition Base layer: ceramic fiber felt, fiber diameter 3-5 μm, bulk density 80 kg / m³. Specifically, the ceramic fiber raw material is processed into a fluffy felt by a carding machine, placed in a hot pressing mold, pressed at a temperature of 100 ℃ and a pressure of 5 MPa for 30 minutes to obtain a flat surface base layer.

[0018] Anti-static layer: graphene-silica sol coating, graphene ratio 10%, coating thickness 0.2 mm. When preparing, add graphene powder to silica sol, ultrasonic dispersion for 30 minutes to make uniform slurry, use air spraying equipment to spray on the surface of the base layer at a pressure of 0.4 MPa, dry in an oven at 80 ℃ for 2 hours to solidify into a film.

[0019] Thermal insulation layer: aerogel-ceramic fiber composite material, aerogel and ceramic fiber mixed in a mass ratio of 7:3. First, weigh 70 parts of aerogel powder and 30 parts of ceramic fiber chopped wire into a blender and mix for 15 minutes, then add 10 parts of silica sol binder and continue to stir until the slurry is thick.

[0020] Preparation steps: S1, base layer preparation The ceramic fiber raw material is carded into a fluffy felt by a carding machine, placed in a hot pressing mold, hot pressed at 100 ℃ and 5 MPa for 30 minutes to obtain a flat surface base layer.

[0021] S3, anti-static layer coating Add graphene to silica sol in proportion, ultrasonic dispersion for 30 minutes to make slurry, use air spraying equipment to spray on the surface of the base layer at a pressure of 0.4 MPa, dry in an oven at 80 ℃ for 2 hours to solidify.

[0022] S4, thermal insulation layer slurry preparation Weigh 70 parts of aerogel and 30 parts of ceramic fiber, pour into a blender and mix for 15 minutes, then add silica sol binder and continue to stir until the slurry is thick.

[0023] S7, vacuum hot pressing Align and stack the base layer and thermal insulation layer slurry in the vacuum hot pressing equipment, vacuum to -0.08 MPa, hot press at 180 ℃ and 10 MPa for 1 hour to solidify the slurry and bond with the base layer into a whole. Example two:

[0024] Formulation composition Base layer: Ceramic fiber felt with a fiber diameter of 3-5μm and a bulk density of 100kg / m³. Diamond-shaped pyramidal bosses are formed on the surface through molding. A flat base layer is first produced. A steel mold with diamond-shaped pyramidal bosses on the surface is then used. The bosses have a bottom side length of 2.5mm and a height of 1.8mm. The mold is hot-pressed at 110°C and 8MPa for 5 minutes to form an array of bosses on the base layer. The bosses are spaced 4mm apart.

[0025] Antistatic layer: Graphene-silica sol coating, with graphene accounting for 15% and a coating thickness of 0.35mm. Graphene is added to silica sol in appropriate proportions, ultrasonically dispersed after adding a dispersant, and sprayed onto the surface of the boss base. After drying, a three-dimensional conductive network is formed between the bosses.

[0026] Thermal insulation layer: aerogel-ceramic fiber composite material, aerogel and ceramic fiber are mixed in a ratio of 7:3, and the amount of silica sol binder added is 12%.

[0027] Preparation steps S1. Base preparation A flat ceramic fiber felt was prepared according to the steps of Example 1.

[0028] S2, boss molding Replace the mold with a diamond-shaped conical boss with a bottom side length of 2.5mm and a height of 1.8mm. Place the flat base layer into the mold and hot press it at 110℃ and 8MPa for 5 minutes to form regularly arranged bosses on the surface of the base layer.

[0029] S3, antistatic layer coating First, a silica sol slurry with a 15% graphene content was sprayed onto the surface of the boss base layer. After the slurry penetrated into the boss gap, it was dried and cured at 80°C for 3 hours to form a 0.35mm thick coating.

[0030] S4. Preparation of thermal insulation slurry Same as in Example 1, the amount of silica sol added was adjusted to 12%.

[0031] S7. Vacuum hot pressing composite: Lay the boss side of the boss base layer with the insulation layer slurry, put it into the vacuum hot pressing equipment, and hot press it for 40 minutes at a vacuum degree of -0.08MPa, a temperature of 190℃ and a pressure of 12MPa to solidify the slurry and embed the top of the boss into the solidified insulation layer by about 0.5mm. Example 3:

[0032] Formula composition Base layer: ceramic fiber felt, fiber diameter 3-5 μm, volume density 90 kg / m³, surface is a planar structure, preparation method is the same as Example 1.

[0033] Antistatic layer: graphene-silica sol coating, graphene accounts for 12%, the coating thickness is 0.3mm, and a coupling agent is added to enhance the bonding strength.

[0034] Thermal insulation layer: Aerogel-ceramic fiber composite material, with aerogel accounting for 80%, ceramic fiber accounting for 20%, 5% silicon carbide whiskers added, and silica sol binder added in an amount of 15%. It is formed into a thermal insulation layer with non-linear channels through a hyperbolic mold.

[0035] Preparation steps S1. Base preparation A flat ceramic fiber felt was obtained in the same manner as in Example 1.

[0036] S3, antistatic layer coating Graphene was added to silica sol at a ratio of 12%, ultrasonically dispersed after adding a coupling agent, sprayed on the surface of the base layer, dried at 80°C for 2.5 hours, and solidified into a 0.3 mm thick coating.

[0037] S4. Preparation of thermal insulation slurry Weigh 80 parts of aerogel, 20 parts of ceramic fiber and 5 parts of silicon carbide whiskers, dry mix them for 15 minutes, then add 15% silica sol binder and stir for 20 minutes until the slurry is uniform.

[0038] S5, Hyperbolic channel forming The slurry is injected into a mold with a hyperbolic channel inside. The channel cross-section is elliptical with a major axis of 4mm and a minor axis of 3mm. The mold is vibrated during injection to remove bubbles. The slurry is cured in a drying oven at 60°C for 48 hours to form an insulating layer with non-linear channels.

[0039] S7, vacuum hot pressing composite Align the flat base layer with the pore insulation layer, with the long axis of the pore perpendicular to the fiber arrangement direction of the base layer. Place it in a vacuum hot pressing device, evacuate to -0.08MPa, and hot press at 200℃ and 13MPa pressure for 30 minutes. Example 4:

[0040] Formula composition Base layer: ceramic fiber felt, with diamond-shaped pyramidal bosses formed on the surface, with a bottom side length of 2.8 mm, a height of 1.9 mm, and a cone angle of 55°. The preparation method is the same as in Example 2, but the mold size is adjusted.

[0041] Antistatic layer: graphene-silica sol coating, graphene accounts for 12%, 10% carbon fiber is added to enhance the conductive network, and the coating thickness is 0.3mm.

[0042] Thermal insulation layer: Aerogel-ceramic fiber composite material, aerogel accounts for 75%, ceramic fiber accounts for 25%, 5% silicon carbide whiskers are added, and silica sol binder is 15%. It is formed by a hyperbolic mold and the inner wall of the channel has annular ribs.

[0043] Preparation steps S1. Grassroots system The ceramic fiber raw material is combed into a fluffy felt shape by a carding machine, placed in a hot pressing mold, and hot pressed at 100°C and 5MPa for 30 minutes to obtain a flat base layer.

[0044] S2, boss molding A diamond-shaped cone mold with a bottom side length of 2.8 mm and a height of 1.9 mm was used to place the flat base layer into the mold. The mold was hot-pressed at 120°C and 9 MPa for 6 minutes to form a boss array on the surface of the base layer.

[0045] S3, antistatic layer coating Graphene and carbon fiber were mixed in a ratio of 9:1, added to silica sol and ultrasonically dispersed for 1.5 hours, sprayed on the surface of the boss base using an air spraying device at a pressure of 0.6 MPa, and dried at 90°C for 3 hours to solidify.

[0046] S4. Preparation of thermal insulation slurry Weigh 75 parts of aerogel, 25 parts of ceramic fiber and 5 parts of silicon carbide whiskers, dry mix them for 15 minutes, then add 15% silica sol binder and stir for 20 minutes until the slurry is uniform.

[0047] S5, Hyperbolic channel forming The slurry was injected into a hyperbolic mold (the long axis of the channel was 4.2 mm and the short axis was 3.2 mm) with 0.2 mm deep rectangular ribs etched on the inner wall. The mold was vibrated during injection to remove bubbles. The slurry was cured in a drying oven at 70°C for 36 hours to form a thermal insulation layer with ribbed channels.

[0048] S6, three-dimensional mosaic process The boss base layer and the channel insulation layer are precisely aligned using a laser positioning device so that each boss is embedded in the hyperbolic channel, the fitting clearance is controlled to be ≤0.2mm, and the position is fixed by a mechanical fixture.

[0049] S7, vacuum hot pressing composite The interlocked plates were placed in a vacuum hot pressing device, evacuated to -0.09 MPa, and hot pressed at 220°C and 15 MPa pressure for 30 minutes. At the same time, a pulsed electric field of 12 kV and 80 Hz was applied to promote interfacial charge migration and form a three-dimensional interlocking structure.

[0050] It should be noted that, in comparison with the various embodiments, Comparative Example 1 is a commercially available ordinary insulation board, which adopts a traditional ceramic fiber pressing process, has no aerogel filling and anti-static structural design, and its basic performance meets general insulation requirements; Comparative Example 2 is a flat composite board introduced with aerogel and graphene coating on the basis of Comparative Example 1, and the base layer and the insulation layer are both flatly laminated; the details are shown in Table 1: Table 1: Comparison of performance parameters of thermal insulation panels based on structural innovation Comparison items Surface resistance (Ω / sq) Thermal conductivity / (mW / (m·K)) Bulk density (kg / m³) Compression rebound rate (%) Example 1 9.35 x 10 5 ]]> 32.7 119.5 81.6 Example 2 8.47×10³ 29.6 124.3 87.9 Example 3 4.82 x 10 5 ]] 25.9 114.7 90.7 Example 4 7.18×10³ 22.8 121.4 94.6 Comparative Example 1 1.15 x 10 8 ]] 46.3 152.3 67.5 Comparative Example 2 4.72 x 10 6 ]] 35.8 127.6 74.8 Specifically, from the surface resistance, example one as the basic structure, through the basic graphene coating to achieve 9.35 x 10 5 Ω / sq surface resistance, single-layer coating forms a basic conductive network, but the planar structure limits the contact area; example two relies on the convex structure to increase the contact area by 40%, and the coating is stacked between the convex gaps to form a three-dimensional conductive path, so that the resistance is suddenly reduced to 8.47 x 10 4 Ω / sq critical value; example three, although not using convex, but optimizing the coating process makes the graphene distribution more uniform, and the resistance is maintained at 4.82 x 10 5 Ω / sq; example four cooperates with carbon fibers through convex, and the carbon fibers like a bridge penetrate the graphene layers, eliminating the interface resistance, and finally the resistance is as low as 7.18 x 10 8 Ω / sq; the comparative example two uses graphene, but the planar lamination leads to uneven coating thickness, and the resistance stays at 4.72 x 10 6 Ω / sq, which fully shows that the structural innovation of the present application can fundamentally improve the continuity of the conductive network.

[0051] Specifically, in terms of thermal conductivity, example one preliminarily reduces the thermal conductivity to 32.7 mW / (m·K) by filling aerogel, and the nanopores of aerogel block part of the heat conduction; the convex of example two forms a micro air sandwich inside the material, and the heat flow needs to bypass the convex to propagate, so that the thermal conductivity is further reduced to 29.6 mW / (m·K); the hyperbolic channel of example three prolongs the heat conduction path by 35%, and the inner wall rib increases the heat reflection interface, so that the thermal conductivity is directly 25.9 mW / (m·K); example four realizes "double blocking", and the convex and the channel interlock to form a multi-stage heat insulation unit, so that the heat flow not only has to pass through the air layer of the channel, but also has to bypass the three-dimensional structure of the convex, and finally the thermal conductivity is as low as 22.8 mW / (m·K). While the comparative example one does not use aerogel, and the fibers are tightly packed, so the thermal conductivity is as high as 46.3 mW / (m·K); the comparative example two adds aerogel, but the planar structure leads to uneven distribution of aerogel, so the thermal conductivity is only reduced to 35.8 mW / (m·K), which proves that the three-dimensional structure is far superior to the planar optimization in regulating the heat conduction path.

[0052] Specifically, the bulk density reflects the lightweight design effect. The density of Example One is reduced to 119.5 kg / m3 by replacing part of the ceramic fiber with aerogel; the density of Example Two is slightly increased to 124.3 kg / m3 due to the increase in local material usage caused by the boss structure; the density of Example Three is as low as 114.7 kg / m3 due to the reduction of 22% of the solid material proportion caused by the hyperbolic channel; and the density of Example Four is controlled at 121.4 kg / m3 by balancing the structure of the boss and the channel. Comparative Example One adopts a traditional pressing process, and the material is densely stacked, with a density as high as 152.3 kg / m3; Comparative Example Two optimizes the formula, but the planar structure cannot reduce the material usage, with a density of 127.6 kg / m3. Obviously, the contribution of the channel structure and other structural innovations of the present application to lightweight is much higher than that of material replacement.

[0053] Specifically, the compression resilience reflects the durability of the material. Example One achieves a resilience of 81.6% through a flexible binder; the boss of Example Two acts as an elastic node, storing energy during compression, and the resilience is increased to 87.9%; the channel wall of Example Three has elastic deformation capability, like a honeycomb, absorbing pressure, and the resilience is 90.7%; and Example Four has a "spring matrix" structure of the boss and the channel, combined with shape memory resin, with a resilience of 94.6%, and the attenuation is less than 1% after 500 cycles. Comparative Example One has a high cross-linking degree and a large material rigidity, with a resilience of only 67.5%; Comparative Example Two increases the elastic additive, but the planar structure lacks support points, with a resilience of 74.8%, indicating that the three-dimensional structure of the present application can improve the fatigue resistance of the material from the mechanical aspect. In summary, the performance improvement of each example corresponds to a specific structural innovation, and the limitations of the comparative examples prove the bottleneck of the traditional planar structure. The present application combines the three-dimensional structure of the boss, the channel, and the material formula to achieve multi-performance collaborative optimization, and the technical path of structural innovation has significant advancement.

[0054] As shown in Figure 2 , the line chart presents the performance trend of each example and comparative example under temperature change. The multiple curves in the figure respectively represent the thermal insulation plates of Examples One to Four and the two comparative materials, the horizontal axis is the temperature change interval, and the vertical axis is the corresponding performance index. The overall trend of the example curves is flat, and they exhibit stable or unique performance response characteristics at different temperature stages, while the comparative curves show a significant decay trend.

[0055] Further, as a basis aerogel plate, the compressive strength of Example One slowly decays from 2.50 MPa to 2.15 MPa in the temperature range of 50-300°C, with an overall decay rate of only 14.0%. This data shows that the aerogel base material itself has good high-temperature structural stability, and its nanoporous network is not prone to collapse at high temperatures, and can maintain basic mechanical properties. Compared with the decay rate of 34.1% of Comparative Example One traditional ceramic fiber plate and the decay rate of 30.5% of Comparative Example Two plane composite plate, the basic performance of Example One is significantly superior, providing a reliable material substrate for subsequent structural optimization.

[0056] Further, Example Two adopts a boss structure design, with a compressive strength of 2.65 MPa at 50°C, an increase of 6.0% over Example One. At 150°C, its strength reaches 2.55 MPa, exceeding the 2.48 MPa of Example Three at the same time. This is because the boss structure forms a mechanical interlocking effect in the medium temperature zone, and the air layer in the boss gap effectively buffers the stress generated by thermal expansion, delaying the decay of material strength. Although the boss interface coating softens at high temperatures, causing accelerated decay after 200°C, the decay is 0.15 MPa from 200°C to 250°C, but the overall decay amplitude is still less than that of the comparative example, proving that the boss structure can specifically enhance the material's resistance to thermal stress in a medium temperature environment, and embodies the strengthening effect of structural optimization on the performance of the base material.

[0057] Further, the hyperbolic channel structure of Example Three exhibits unique temperature response characteristics: the strength is 2.70 MPa at 50°C, and the self-tightening effect due to channel thermal expansion causes the strength to decrease slightly to 2.68 MPa at 100°C, an increase of 2.1% over the 2.57 MPa of Example Two at the same time. At 150°C, the strength drops to 2.48 MPa, which may be due to lattice distortion of the channel inner wall material in this temperature range. At 250°C, the channel rib structure reflects the thermal stress, keeping the strength almost flat at 2.39 MPa compared to 2.41 MPa at 200°C. This dynamic response mechanism of thermal expansion self-tightening, lattice adjustment, and stress reflection makes the material exhibit non-uniform decay characteristics in the medium and high temperature range of 100-250°C, with a strength retention capability significantly better than the plane structure of the comparative example, which cannot achieve active dissipation of thermal stress through structural design, confirming the innovative value of the channel structure in high-temperature mechanical stability.

[0058] Furthermore, the three-dimensional interlocking structure of Example 4 achieves optimal performance over the entire temperature range: the strength reaches 2.90MPa at 50°C and remains at 2.40MPa at 300°C, with a decay rate of only 17.2%, and the strength at each temperature point is higher than that of other examples and comparative examples. Its attenuation fluctuates irregularly, such as a decay of 0.05MPa from 100°C to 150°C and a decay of 0.15MPa from 200°C to 250°C. This is due to the reversible phase change of the shape memory resin at the interlocking node. When the temperature rises, the resin phase changes to fill the gap and enhance support; when the temperature continues to rise, the phase change lag causes strength attenuation fluctuations. This synergistic mechanism of adaptive phase change and structural interlocking enables the material to maintain high strength over a wide temperature range, with the strength at 300°C being 1.67 times that of Comparative Example 2, and to alleviate thermal damage accumulation through dynamic response, fully demonstrating the breakthrough advantages of the present invention in structural design.

[0059] Furthermore, the traditional ceramic fiberboard of comparative example 1 decays from 1.67MPa at 50°C to 1.10MPa at 300°C, with a decay rate of up to 34.1%. After 200°C, the structure becomes loose due to the loss of fiber crystallization water, and the slope of the curve increases significantly, indicating that its high-temperature stability is extremely poor. The flat composite board of comparative example 2 decays from 2.23MPa at 50°C to 1.43MPa at 300°C due to the mismatch of the interface thermal expansion coefficient. The interface debonding problem is aggravated after 150°C, and the strength at 300°C is only 59.6% of that of Example 4. The common defect of the two is that they adopt a flat or single structure design, which cannot effectively cope with the thermal stress concentration caused by temperature changes, resulting in rapid strength decay. This is in sharp contrast to the technical solution of the embodiment that achieves thermal stress dispersion and dynamic buffering through three-dimensional structural bosses, channels, and interlocking.

[0060] like Figure 3 As shown, it covers Examples 1 to 4 and two comparative examples. Example 1 is a basic ceramic fiber structure, Example 2 optimizes low-frequency absorption through a boss design, Example 3 uses hyperbolic channels to enhance mid- and high-frequency scattering, and Example 4 achieves full-band synergistic noise reduction with a three-dimensional interlocking structure. The comparative examples are traditional disordered fiberboard and flat composite board, respectively, to highlight the significant advantages of the structured design of the present invention in breaking through frequency response limitations and improving broadband noise reduction efficiency.

[0061] Further, example one is based on the porous network of ceramic fiber itself. The noise reduction amount of 18.5 at 125Hz low frequency band is due to the frictional dissipation of the initial pores between the fibers to low-frequency sound waves; 20.8 from 250Hz, indicating that the pore resonance starts to take effect, but the increment 2.3 is small, reflecting the insufficient matching of the basic pore size and the low-frequency wavelength. The noise reduction amount of 26.3 to 34.7 from 500 to 4000Hz in the medium and high frequency band reflects the multiple reflection advantage of the porous structure to high-frequency waves, but the increment of 4000Hz is only 1.6, exposing the absorption bottleneck of the basic structure to very high frequency waves. This example verifies the noise reduction potential of ceramic fiber substrate, and its nonlinear increment characteristics such as 5.5 at 500Hz are significantly higher than 3.2 at 1000Hz, indicating that pure reliance on the material itself cannot achieve balanced noise reduction in the full frequency band, providing a benchmark for subsequent structure optimization.

[0062] Further, example two realizes a noise reduction amount of 20.3 at 125Hz low frequency band through the boss structure design, which is 9.7% higher than example one, because the air layer formed by the boss gap is equivalent to a Helmholtz resonator, which produces targeted absorption to low-frequency waves; but the increment of 250Hz is only 0.9, because the mechanical fitting of the boss limits the deformation of the air layer, resulting in a weakening of the resonance effect. The noise reduction amount of 25.9 at 500Hz medium frequency is lower than example one, revealing that the boss interface coating produces sound wave reflection in the medium frequency region, and the 1000Hz rises to 31.8, benefiting from the new resonance cavity formed by the boss gap in the medium and high frequency band. The noise reduction amount of 32.5 at 2000Hz high frequency band reflects the diffraction effect of the boss edge to high-frequency waves, but the coating softening also leads to fluctuations in absorption efficiency. This example proves that the boss structure can improve the noise reduction ability of specific frequency bands through the composite mechanism of low-frequency resonance and medium-high frequency diffraction, but its fluctuation characteristics such as 500Hz decrease and 1000Hz increase also reflect the limitations of the flat boss design that cannot achieve full-band collaborative optimization.

[0063] Further, the hyperbolic channel structure of Example Three exhibits a unique frequency response: the noise reduction of 19.7 at 125Hz is slightly lower than Example Two, but 22.5 at 250Hz increases by 2.8, resulting from the variable cross-section structure formed by the thermal expansion of the channel, which resonates and absorbs 250Hz sound waves; the noise reduction of 28.7 at 500Hz is 10.8% higher than Example Two, thanks to the multi-stage reflection of the channel inner wall ribs to sound waves. The noise reduction of 30.2 at 1000Hz is due to the lattice resonance of the channel material at this frequency, resulting in a decrease in absorption efficiency, while the noise reduction of 35.8 at 2000Hz increases by 5.6, indicating that the multi-stage structure of the channel significantly scatters high-frequency waves. The core advantage of this example is that the variable cross-section resonance and rib scattering mechanism of the channel structure achieves efficient absorption of mid-to-high frequency sound waves, especially at 2000Hz, which is 47.3% higher than Example Two, verifying the breakthrough role of the three-dimensional channel design in high-frequency noise reduction.

[0064] Further, the three-dimensional interlocking structure of Example Four achieves optimal performance in the full frequency band: the noise reduction of 22.1 at 125Hz is due to the matching absorption of low-frequency waves by micron-sized pores formed by interlocking nodes; the noise reduction of 23.8 at 250Hz increases, and the flexibility of the interlocking structure avoids excessive attenuation of low-frequency resonance. The noise reduction of 29.4 to 33.7 in the 500 to 1000Hz mid-frequency range increases, benefiting from the hierarchical size of the interlocking pores, i.e., the millimeter-level main pores and nanometer-level secondary pores, which precisely match the wavelength of the mid-frequency band; the noise reduction of 34.9 at 2000Hz, through the shape memory resin phase change to fill the gap between the pores, reduces sound wave transmission; the noise reduction of 39.8 at 4000Hz, the three-dimensional architecture of the interlocking network forms reflection, diffraction, and dissipation effects on extremely high-frequency waves, which is 69.4% higher than Example One. This example achieves irregular increments in the full frequency band through multi-scale design of hierarchical pores, phase change materials, and three-dimensional interlocking, such as the fluctuations of 1.2 at 2000Hz and 4.9 at 4000Hz. This non-linear response proves that the material can adapt to different frequency sound waves, breaking through the limitations of traditional structure frequency and performance linear correspondence.

[0065] Further, the comparative example one, the traditional ceramic fiber board, because of the disordered accumulation of fibers, the low frequency noise reduction at 125Hz is only 12.3, and at 4000Hz is only 23.5, and the linear increment characteristics of each frequency band is 1.8 on average, which exposes that the structure cannot produce resonance absorption for specific frequency sound waves, and can only rely on passive dissipation of fiber friction; the comparative example two, the plane composite board, although achieves a noise reduction of 15.6 at 125Hz, but only 26.4 at 4000Hz, and the thermal expansion mismatch of the plane interface leads to serious sound wave reflection, especially in the frequency band above 2000Hz, the noise reduction is more than 30% lower than that of the fourth embodiment. The common defects of the two are that the structure design is single, and cannot achieve active dissipation of wide frequency sound waves through multi-stage interfaces or three-dimensional pores, which contrasts the significant advantages of the application in the full frequency band noise reduction performance through the three-dimensional structure innovation of bosses, channels, interlocking and the like.

[0066] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method for preparing a ceramic fiber antistatic heat insulation board, characterized in that: The method comprises the following preparation steps: S1. Base preparation The ceramic fibers are made into a fluffy felt through a carding process. The porosity between the fibers is controlled through hot pressing to form a base body with a certain strength. The fiber diameter of 3-5μm ensures a balance between the flexibility and thermal insulation of the felt. The volume density of 80-120kg / m³ takes into account both lightweight and structural strength. S2, boss molding The base layer is hot-pressed using a steel mold with diamond-shaped pyramidal bosses on its surface. The geometric design of the mold bosses has a bottom side length of 2-3mm and a height of 1.5-2mm. Combined with the hot-pressing parameters of 8-10MPa pressure and 100-120°C, a regular array of bosses is formed on the surface of the base layer. This structure improves the mechanical interlocking ability with the antistatic layer by increasing the surface area. S3, antistatic layer coating Graphene is dispersed in silica sol at a ratio of 10%-15% to prepare a slurry. The slurry is evenly adhered to the surface of the boss base using a spraying process. After drying and curing, a 0.2-0.4mm thick conductive coating is formed. The coating accumulates in the gaps between the bosses to form a three-dimensional conductive network, optimizing the static leakage path. S4. Preparation of thermal insulation slurry Aerogel and ceramic fiber are mixed in a mass ratio of 7-8:2-3, and silica sol binder is added to form a moldable slurry. The porous structure of the aerogel and the reinforcement of the ceramic fiber form a synergistic thermal insulation system. The slurry viscosity is controlled to ensure the integrity of the subsequent channel forming. S5, Hyperbolic channel forming The slurry is injected into an elliptical cross-section mold with a hyperbolic trajectory and a long axis of 3.5-4.5mm. The slurry is shaped into a thermal insulation layer with non-linear channels through a drying and curing process. The annular rib structure on the inner wall of the channel is achieved by etching the mold surface. This design extends the heat conduction path and enhances structural strength. S6, three-dimensional mosaic process The boss base layer is precisely aligned with the channel insulation layer, so that the diamond-shaped cone boss is embedded in the hyperbolic channel. The geometric matching of the boss and the channel forms a preliminary mechanical interlocking, and the precise control of the clearance is ≤0.3mm to ensure that there is no gap between the layers, laying the foundation for subsequent composite strengthening. S7, vacuum hot pressing composite Hot pressing treatment is carried out in a vacuum environment of ≤-0.08MPa at a pressure of 12-15MPa and a temperature of 180-220°C. The air between the layers is removed under vacuum conditions to improve the bonding density. A pulsed electric field is applied simultaneously during the hot pressing process to promote charge migration at the interface between the graphene coating and the aerogel, ultimately forming a composite board with thermal insulation, anti-static properties and structural strength.

2. The method for preparing a ceramic fiber antistatic heat insulation board according to claim 1, characterized in that: In step S2, the mold boss adopts a quadrangular pyramid structure with a diamond-shaped bottom surface and the top of the cone extending vertically toward the center of the bottom surface. The ridges of adjacent bosses form a grid-like distribution on the surface of the base layer, and mechanical interlocking convex points are formed on the surface of the base layer through hot pressing.

3. The method for preparing a ceramic fiber antistatic heat insulation board according to claim 1, characterized in that: In step S3, the graphene slurry is dispersed by ultrasonic technology to ensure uniformity, and a continuous conductive coating is formed after spraying. The antistatic layer contains a carbon fiber reinforced conductive network, and the thermal insulation layer contains silicon carbide whiskers to improve thermal resistance.

4. The method for preparing a ceramic fiber antistatic heat insulation board according to claim 1, characterized in that: In step S5, the axis of the hyperbolic channel is a symmetrically curved non-linear trajectory, the channel cross-section is elliptical, and the annular ribs on the inner wall are distributed in a continuous ring shape. The non-linear trajectory is designed to extend the heat conduction path and improve the thermal insulation efficiency.

5. The method for preparing a ceramic fiber antistatic heat insulation board according to claim 1, characterized in that: In step S7, a pulse electric field is applied during the vacuum hot pressing process to enhance the charge transfer capability of the interlayer interface.

6. A ceramic fiber antistatic heat insulation board, characterized in that: Prepared by the method according to any one of claims 1 to 5.

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