Anisotropic ablation-resistant thermal insulation material, preparation method and application

Abstract

The invention discloses an anisotropic ablation-resistant thermal insulation material, a preparation method and application, and the anisotropic ablation-resistant thermal insulation material is prepared from the following raw material components in parts by weight: 100 parts of matrix rubber, 20-50 parts of ablation-resistant filler, 5-10 parts of organic fiber, 5-10 parts of inorganic fiber and 1-5 parts of vulcanizing aid. The anisotropic ablation-resistant thermal insulation material provided by the invention is better in ablation performance, shorter in preparation period, lower in cost and higher in interface bonding reliability, the oxyacetylene line ablation rate is 0.001-0.005 mm / s, the mass ablation rate is 0.03-0.06 g / s, and when the anisotropic ablation-resistant thermal insulation material is used as an engine shell thermal insulation layer, an engine shell can be effectively protected when an engine works. According to the method, the multi-layer thermal insulation material is prepared through continuous layered co-extrusion, layered lamination, calendaring and shaping, cutting and mold pressing, layered lamination has shearing, stretching and compressing effects on a rubber material, fiber orientation in the rubber material is promoted, and finally, the layers of the prepared anisotropic ablation-resistant thermal insulation material are well attached, so that the thermal insulation performance of the material is improved, and the service life of the material is prolonged. Defects are not easy to form on an interlayer interface.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber materials, and in particular relates to an anisotropic ablation-resistant thermal insulation material, a preparation method and an application thereof. Background Art

[0002] Missile weapons are developing towards high speed, long range and high maneuverability. When missiles are performing high-speed maneuvering flight, solid rocket engines will produce a certain amount of overload in both radial and axial directions. Under overload conditions, the motion trajectory of high-temperature gas solid phase particles changes, and a high-temperature and high-speed solid phase particle aggregation area is formed locally in the combustion chamber, which aggravates the thermochemical ablation and mechanical scouring of the insulation material in the engine combustion chamber, causing the failure of the thermal protection structure, and then leading to the failure of the engine flight. At present, the method to solve the long-term overload ablation of the engine combustion chamber is to increase the thickness of the insulation layer in the severe ablation area, or to lay anti-scouring materials such as continuous fiber reinforced rubber composites and fiber reinforced hard resin composites. However, increasing the thickness of the insulation layer will increase the negative mass of the engine, which is not conducive to the range and maneuverability of the engine; the manufacturing cost of fiber reinforced rubber or resin-based composites is high, the cycle is long, the molding process is complex, and there are problems such as low interface bonding strength and poor interface deformation matching, which are difficult to adapt to the development trend of high performance, high reliability and low cost of solid rocket engines.

[0003] In summary, there is an urgent need to develop ablation-resistant and erosion-resistant insulation layer with simple manufacturing process, excellent interface performance and low cost. Summary of the invention

[0004] In view of the above-mentioned defects and shortcomings in the prior art, the present invention provides an anisotropic ablation-resistant insulation material, a preparation method and an application thereof, so as to solve the technical problems in the prior art of high manufacturing cost, long cycle and complex molding process of insulation materials for engine combustion chambers.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An anisotropic ablation-resistant thermal insulation material comprises the following raw material components by weight: 95-110 parts of base rubber, 20-50 parts of ablation-resistant filler, 5-10 parts of organic fiber, 5-10 parts of inorganic fiber and 1-5 parts of vulcanization aid.

[0007] The present invention also has the following technical features:

[0008] Specifically, the base rubber is selected from one or more of silicone rubber, EPDM rubber, and nitrile rubber.

[0009] Furthermore, the ablation-resistant filler is selected from one or more of boron phenolic resin, zirconium boride, and white carbon black.

[0010] Furthermore, the organic fiber is selected from one or more of aramid fiber, polybenzoxazole fiber and acrylonitrile fiber; the inorganic fiber is selected from one or more of carbon fiber, mullite fiber and high silica fiber; the vulcanization aid is sulfur or diisopropylbenzene peroxide.

[0011] Furthermore, the anisotropic ablation-resistant insulation material has a width of 50 mm to 2800 mm, a thickness of 1 mm to 30 mm, an oxyacetylene line ablation rate of 0.001 to 0.005 mm / s, and a mass ablation rate of 0.03 to 0.06 g / s.

[0012] The present invention also protects a method for preparing an anisotropic ablation-resistant thermal insulation material, comprising the following steps:

[0013] Step 1, adding the base rubber, ablation-resistant filler, organic fiber, inorganic fiber and vulcanizing agent in the formula amount to a double-roll mill for mixing at room temperature to obtain a mixed rubber material;

[0014] Step 2, sending the mixed rubber material into a co-extrusion system, plasticizing it evenly, and then extruding it into a manifold having at least two flow channels to merge them, so as to obtain a multi-layer composite rubber material;

[0015] Step 3, the multi-layer composite material is cut, split and layered through a layer multiplier connected to the flow concentrator, and then widened and compacted through an extruder head mold connected to the layer multiplier to obtain a multi-layer structural rubber material;

[0016] Step 4: cutting the multilayer structure rubber material obtained in step 3 along the thickness direction at a set cutting angle and cutting interval distance to obtain a multilayer structure cut rubber material; placing a plurality of multilayer structure cut rubber materials in parallel in a mold with the cut surfaces facing upward, and performing pre-vulcanization treatment using a flat vulcanizer to obtain a preformed rubber material; and sequentially cutting, shaping, and vulcanization and compression molding the preformed rubber material to obtain;

[0017] In the step 1, by weight, the base rubber is 95-110 parts, the ablation-resistant filler is 20-50 parts, the organic fiber is 5-10 parts, the inorganic fiber is 5-10 parts and the vulcanization aid is 1-5 parts.

[0018] Furthermore, in step 4, the cutting angle is set to 0-45°, and the cutting interval is set to 1-30 mm.

[0019] Furthermore, in step 4, the temperature of the pressurized vulcanization treatment is 120-150° C. and the pressure is 1-10 MPa.

[0020] The present invention also protects the use of the above-mentioned anisotropic ablation-resistant thermal insulation material as the thermal insulation layer of an engine casing, or the use of the anisotropic ablation-resistant thermal insulation material prepared by the preparation method of the above-mentioned anisotropic ablation-resistant thermal insulation material as the thermal insulation layer of an engine casing.

[0021] The present invention also protects an engine casing, the inner wall of which is provided with an insulating layer formed by the above-mentioned anisotropic ablation-resistant thermal insulation material; or an insulating layer formed by an anisotropic ablation-resistant thermal insulation material obtained by the preparation method of the above-mentioned anisotropic ablation-resistant thermal insulation material; the anisotropic ablation-resistant thermal insulation material is molded onto the inner wall of the engine casing by a preforming-airbag vulcanization process, and the thickness of the insulating layer is 1mm to 30mm; the pre-vulcanization process parameters include a temperature of 80 to 100°C and a pressure of 10 to 12MPa; the airbag molding vulcanization process parameters include a temperature of 140 to 150°C and a pressure of 0.6 to 0.8MPa.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The anisotropic ablation-resistant thermal insulation material provided by the present invention has better ablation performance, shorter preparation cycle, lower cost, higher interface bonding reliability, oxyacetylene wire ablation rate of 0.001-0.005 mm / s, the difference between radial thermal conductivity and axial thermal conductivity of 0.04-0.08 W / m·k, and mass ablation rate of 0.03-0.06 g / s. When it can be used as an insulation layer of an engine casing, it can effectively protect the engine casing when the engine is working.

[0024] (2) The method of the present invention realizes the preparation of multilayer insulation materials through continuous layered co-extrusion, layered lamination, calendering, cutting and molding, wherein the layered lamination has shearing, stretching and compression effects on the rubber compound, thereby promoting the orientation of the fibers in the rubber compound. The layers of the anisotropic ablation-resistant insulation material finally obtained are well bonded to each other, defects are not easily formed at the interface between the layers, and the material can be prepared continuously, which has the characteristics of high production efficiency, uniform material quality and short cycle.

[0025] (3) After the anisotropic ablation-resistant thermal insulation material provided by the present invention is used on the engine housing, the engine's ablation-resistant impact resistance is enhanced, the service life is longer, and the working reliability is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide further understanding of the present disclosure and constitute a part of the specification. They are used to explain the present disclosure together with the following detailed description, but do not constitute a limitation of the present disclosure.

[0027] Figure 1A schematic diagram of the structure of the anisotropic ablation-resistant thermal insulation material provided by the present invention, wherein a is the anisotropic thermal insulation material when the orientation angle is 15°, and b is the anisotropic thermal insulation material when the orientation angle is 0°;

[0028] Figure 2 The carbonized layer structure after ablation of the anisotropic ablation-resistant thermal insulation material prepared in Example 2;

[0029] Figure 3 This is the carbonized layer structure after ablation of the thermal insulation material prepared in Comparative Example 1.

[0030] The technical solution of the present invention is further described below in conjunction with embodiments. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments 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 any ordinary technician in the field belong to the scope of protection of the present invention.

[0032] The technical concept of the present application is: taking into account the different ablation environments faced by different positions of the engine's thermal insulation layer, a significantly anisotropic thermal insulation layer is obtained through component selection and preparation method design to maximize the utilization of the thermal insulation layer performance, thereby reducing the negative mass of the engine, specifically including: adjusting the number of layers of cut rubber in the multi-layer structure at the same thickness by changing the number of layer multipliers, thereby adjusting the degree of orientation of the fiber material in the single-layer structure; and controlling the thermal conductivity of the thermal insulation layer in different directions by adjusting the cutting angle and paving method.

[0033] The invention provides an anisotropic ablation-resistant thermal insulation material, which comprises, by weight, 95-110 parts of base rubber, 20-50 parts of ablation-resistant filler, 5-10 parts of organic fiber, 5-10 parts of inorganic fiber and 1-5 parts of vulcanization aid.

[0034] Preferably, the base rubber is selected from one or more of silicone rubber, EPDM rubber and nitrile rubber.

[0035] Preferably, the ablation-resistant filler is selected from one or more of boron phenolic resin, zirconium boride and white carbon black.

[0036] Preferably, the organic fiber is selected from one or more of aramid fiber, polybenzoxazole fiber and acrylonitrile fiber; the inorganic fiber is selected from one or more of carbon fiber, mullite fiber and high silica fiber; the vulcanization aid is sulfur or diisopropylbenzene peroxide.

[0037] Preferably, the anisotropic ablation-resistant insulation material has a width of 50 mm to 2800 mm, a thickness of 1 mm to 30 mm, an oxyacetylene line ablation rate of 0.001 to 0.005 mm / s, and a mass ablation rate of 0.03 to 0.06 g / s.

[0038] The present invention also protects a method for preparing an anisotropic ablation-resistant thermal insulation material, comprising the following steps:

[0039] Step 1, adding the base rubber, ablation-resistant filler, organic fiber, inorganic fiber and vulcanizing agent in the formula amount to a double-roll mill for mixing at room temperature to obtain a mixed rubber material;

[0040] Among them, by weight, the base rubber is 95-110 parts, the ablation-resistant filler is 20-50 parts, the organic fiber is 5-10 parts, the inorganic fiber is 5-10 parts and the vulcanization aid is 1-5 parts.

[0041] Step 2, sending the mixed rubber material into a co-extrusion system, plasticizing it evenly, and then extruding it into a manifold provided with at least two flow channels for superposition, so as to obtain a multi-layer composite rubber material;

[0042] Step 3, the multi-layer composite material is cut, split and layered through a layer multiplier connected to the flow concentrator, and then widened and compacted through an extruder head mold connected to the layer multiplier to obtain a multi-layer structural rubber material;

[0043] Step 4: cutting the multilayer structure rubber material obtained in step 3 along the thickness direction at a set cutting angle and cutting interval distance to obtain a multilayer structure cut rubber material; placing a plurality of multilayer structure cut rubber materials in parallel in a mold with the cut surfaces facing upward, and performing pre-vulcanization treatment using a flat vulcanizer to obtain a preformed rubber material; and sequentially cutting, shaping, and vulcanization and compression molding the preformed rubber material to obtain;

[0044] Preferably, the cutting angle is set to 0-45°, and the cutting interval is set to 1-30 mm.

[0045] Preferably, the temperature of the pressurized vulcanization treatment is 120-150° C. and the pressure is 1-10 MPa.

[0046] Unless otherwise specified, the raw materials used in the present invention are commercially available.

[0047] The extruder used in the present invention is commercially available, and the confluence device, layer multiplier and molding die are all existing equipment. The co-extrusion system composed of the above devices can realize the pressing of the rubber into sheets, layered compounding and widening compaction in one go, and the cutting is carried out by automatically and continuously cutting the film along the thickness direction through a cutting machine.

[0048] The oxyacetylene wire ablation rate test is carried out in accordance with the standard GJB 323B-2018. The oxyacetylene wire ablation rate and mass ablation rate are calculated according to the standard. The thermal conductivity test is carried out in accordance with ISO22007-2: Determination of thermal conductivity and thermal diffusivity of plastics Part 2: Instantaneous planar heat source (heating plate) method. The scanning electron microscope image is tested using the S4800 scanning electron microscope of Hitachi, Japan.

[0049] Example 1

[0050] Following the above technical solution, Figure 1 As shown, this embodiment provides an anisotropic ablation-resistant thermal insulation material, which is prepared by the following method:

[0051] Step 1, by weight, 100 parts of EPDM rubber as a base rubber, 10 parts of white carbon black, 15 parts of boron phenolic resin, 7 parts of aramid fiber, 10 parts of carbon fiber and 5 parts of sulfur are added to a double-roll mill and mixed at room temperature for 15 minutes to obtain a mixed rubber material;

[0052] Step 2, the mixed rubber is divided into two parts, and the two parts are added into the co-extrusion system at the same time, and after being plasticized evenly, they are extruded into a manifold provided with two flow channels to be overlapped to obtain a double-layer composite rubber material;

[0053] Step 3, the double-layer composite rubber material is cut, split and layered by a layer multiplier connected to the flow combiner, and then widened and compacted in an extruder head mold connected to the multi-layer multiplier to obtain a four-layer structural rubber material;

[0054] Step 4, cutting the 4-layer structure rubber material along the thickness direction at a set cutting angle and cutting interval distance to obtain a plurality of 4-layer structure cut rubber materials; wherein the cutting angle is selected to be 0° and the cutting interval distance is 10 mm; placing the plurality of 4-layer structure cut rubber materials in a flat plate mold in sequence with the cut surfaces facing upward, and molding them for 30 minutes using a flat plate vulcanizer at 150° C. and 10 MPa to obtain the obtained material;

[0055] The anisotropic ablation-resistant thermal insulation material prepared in this embodiment has a thickness of 10 mm and a structure as shown in FIG. Figure 1 As shown in b, the width can be controlled by cutting.

[0056] The performance of the ablation-resistant thermal insulation material prepared in this embodiment was tested, and the results showed that the oxyacetylene wire ablation rate was 0.005 mm / s, the mass ablation rate was 0.06 g / s, the radial thermal conductivity was 0.26 W / m·k, and the axial thermal conductivity was 0.22 W / m·k. There was a significant difference between the radial thermal conductivity and the axial thermal conductivity, which proved the anisotropy of the internal structure of the ablation-resistant thermal insulation material prepared in this embodiment.

[0057] The anisotropic ablation-resistant insulation material provided in this embodiment can be used to prepare the insulation layer of the engine casing, specifically including: according to the distribution of ablation inside the engine combustion chamber, the anisotropic insulation material is used to obtain the convergent section insulation layer component and the head section component through a pre-vulcanization process and compression molding, the processing temperature is 90°C, and the pressure is 10MPa, and then the convergent section insulation layer component, the head section component and the cylindrical section insulation layer are molded onto the inner wall of the engine casing by means of an airbag vulcanization process, and the molding process parameters include a molding temperature of 150°C and a molding pressure of 0.8MPa. Finally, an insulation layer with a thickness of 2mm to 20mm is formed on the engine casing, and the thickness can be adjusted as needed.

[0058] Engine test:

[0059] The anisotropic insulation layer of the engine casing provided in this embodiment was subjected to an engine ground test and the remaining casing was found to be intact.

[0060] Example 2

[0061] In accordance with the above technical scheme, this embodiment provides an anisotropic ablation-resistant insulation material. The raw materials and preparation methods used are basically the same as those in Example 1. The only difference is that after merging into two layers of composite rubber in the confluence, it is cut, diverted and layered by two layer multipliers to obtain an 8-layer structural extrudate, and then an 8-layer structural rubber is obtained; the obtained 8-layer structural rubber is cut along the thickness direction at a cutting angle of 15° and a cutting interval of 10mm, and the cut surfaces are placed side by side in a mold for pre-vulcanization treatment, and a flat-plate vulcanizer is used to press at 150°C and 10MPa for 30 minutes to obtain the obtained material.

[0062] The anisotropic ablation-resistant thermal insulation material prepared in this embodiment has a thickness of 10 mm and a structure as shown in FIG. Figure 1 As shown in a, it can be regulated by the cutting width.

[0063] The SEM image of the anisotropic ablation-resistant thermal insulation material prepared in this embodiment is as follows: Figure 1 As shown in the figure, it can be seen that after the ablation experiment, there is an obvious parallel strip skeleton structure in the carbonized layer of the anisotropic insulation material, indicating that the fiber carbonization forms a skeleton structure under high temperature conditions.

[0064] The performance of the ablation-resistant thermal insulation material prepared in this embodiment was tested, and the results showed that the oxyacetylene wire ablation rate was 0.001 mm / s, the mass ablation rate was 0.03 g / s, the radial thermal conductivity of the material was 0.31 W / m·k, and the axial thermal conductivity was 0.24 W / m·k. There was a significant difference between the radial thermal conductivity and the axial thermal conductivity, which proves the anisotropy of the internal structure of the ablation-resistant thermal insulation material prepared in this embodiment.

[0065] The anisotropic ablation-resistant insulation material provided in this embodiment can be used to prepare the insulation layer of the engine casing. The usage is the same as that of Example 1. After the engine ground test, the remaining casing is intact.

[0066] Comparative Example 1

[0067] This comparative example provides an insulating material, and its preparation raw materials and steps 1 to 4 of the preparation method are the same as those in Example 1, with the only difference being that in step 4, the four layers of structural rubber are not cut, but the structural rubber is directly placed in a mold and then subjected to a pressurized vulcanization treatment under the same conditions as in Example 1 to obtain the insulating material.

[0068] The thickness of the anisotropic ablation-resistant thermal insulation material prepared in this comparative example is 10 mm.

[0069] The performance of the thermal insulation material prepared in this comparative example was tested by the testing method used in Example 1. The test results were as follows: the oxyacetylene line ablation rate was 0.14 mm / s, the mass ablation rate was 0.1 g / s, the radial thermal conductivity of the material was 0.21 W / m·k, and the axial thermal conductivity was 0.26 W / m·k.

[0070] It can be seen from Example 1, Example 2 and Comparative Example 1 that there are obvious differences between the radial thermal conductivity and axial thermal conductivity of the anisotropic ablation-resistant insulation materials prepared in Example 1, Example 2 and Comparative Example 1, which is due to the different orientation directions of the ablation-resistant functional filler fibers inside the material.

[0071] However, the radial thermal conductivity of the materials prepared in Examples 1 and 2 is significantly higher than that of the material prepared in Comparative Example 1, which indicates that the radial orientation of ablation-resistant fillers such as fibers is more obvious in the examples, which is beneficial for the carbonized layer formed during the ablation process to form a continuous and dense structure in the radial direction, thereby more effectively resisting erosion in the direction of heat flow. This shows that Example 1 significantly changed the anisotropic performance of the material through the cutting and paving operation.

[0072] Comparative Example 2

[0073] This comparative example provides an insulating material, the raw materials and step 1 of the preparation method of which are the same as those in Example 2, and then the obtained mixed rubber material is directly placed in a mold, and subjected to a pressure vulcanization treatment under the same conditions as in Example 2 to obtain an isotropic insulating material.

[0074] The thickness of the anisotropic ablation-resistant thermal insulation material prepared in this comparative example is 10 mm.

[0075] The performance of the thermal insulation material prepared in this comparative example was tested by the testing method used in Example 1. The test results were as follows: the oxyacetylene line ablation rate was 0.09 mm / s, the mass ablation rate was 0.08 g / s, the radial and axial thermal conductivities were 0.25 W / m·k and 0.26 W / m·k, and the thermal conductivities in different directions were similar.

[0076] It can be seen from Example 1, Example 2 and Comparative Example 2 that:

[0077] The materials prepared in Example 1 and Example 2 have a more significant difference in radial thermal conductivity and axial thermal conductivity, while the radial thermal conductivity and axial thermal conductivity of the material prepared in Comparative Example 2 are similar, indicating that compared with the traditional mixing process, the ablation-resistant thermal insulation material prepared in the present invention has more obvious anisotropy through orientation treatment and anisotropic design of the thermal insulation material, and ultimately achieves a significant improvement in ablation performance.

[0078] from Figure 2 and Figure 3 It can also be seen that the carbonized layer formed by the material prepared in Example 2 after the ablation test has good structural integrity and a dense overall structure, while the carbonized layer structure formed by the material prepared in Comparative Example 2 after ablation has obvious defects such as continuous holes, resulting in a significant decrease in the strength of the carbonized layer, which is not conducive to resisting heat flow shock.

[0079] Comparative Example 3

[0080] This comparative example provides an insulating material, and its raw materials for preparation are the same as those in Example 2. After the mixed rubber material is prepared, it is not laminated by a co-extrusion system, but is laminated by manual layers. It is then pressed again by a double-roll mill to form a composite rubber material with the same thickness as in Example 2. Then, it is cut, laid and pressurized and vulcanized under the same conditions as in Example 2 to obtain the obtained material.

[0081] The thickness of the anisotropic ablation-resistant thermal insulation material prepared in this comparative example is 10 mm.

[0082] The performance of the thermal insulation material prepared in this comparative example was tested by the testing method used in Example 1. The test results were as follows: the oxyacetylene line ablation rate was 0.07 mm / s, the mass ablation rate was 0.08 g / s, the axial thermal conductivity was 0.26 W / m·k, and the radial thermal conductivity was 0.28 W / m·k.

[0083] It can be seen from Example 1, Example 2 and Comparative Example 3 that the materials prepared in Example 1 and Example 2 have more significant differences in radial thermal conductivity and axial thermal conductivity, while the radial thermal conductivity and axial thermal conductivity of the material prepared in Comparative Example 3 are similar, indicating that the anisotropy of the material prepared by manual layering and lamination is not obvious.

[0084] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0085] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An anisotropic ablation-resistant thermal insulation material, characterized in that: The raw material components include, by weight: 95-110 parts of base rubber, 20-50 parts of ablation-resistant filler, 5-10 parts of organic fiber, 5-10 parts of inorganic fiber and 1-5 parts of vulcanization aid.

2. The anisotropic ablation-resistant thermal insulation material according to claim 1, characterized in that: The base rubber is selected from one or more of silicone rubber, EPDM rubber and nitrile rubber.

3. The anisotropic ablation-resistant thermal insulation material according to claim 1, characterized in that: The ablation-resistant filler is selected from one or more of boron phenolic resin, zirconium boride and white carbon black.

4. The anisotropic ablation-resistant thermal insulation material according to claim 1, characterized in that: The organic fiber is selected from one or more of aramid fiber, polybenzoxazole fiber and acrylonitrile fiber; the inorganic fiber is selected from one or more of carbon fiber, mullite fiber and high silica fiber; the vulcanization aid is sulfur or diisopropylbenzene peroxide.

5. The anisotropic ablation-resistant thermal insulation material according to claim 1, characterized in that: The anisotropic ablation-resistant thermal insulation material has a width of 50 mm to 2800 mm, a thickness of 1 mm to 30 mm, an oxyacetylene line ablation rate of 0.001 to 0.005 mm / s, and a mass ablation rate of 0.03 to 0.06 g / s.

6. The method for preparing an anisotropic ablation-resistant thermal insulation material according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1, adding the base rubber, ablation-resistant filler, organic fiber, inorganic fiber and vulcanizing agent in the formula amount to a double-roll mill for mixing at room temperature to obtain a mixed rubber material; Step 2, sending the mixed rubber material into a co-extrusion system, plasticizing it evenly, and then extruding it into a manifold having at least two flow channels to merge them, so as to obtain a multi-layer composite rubber material; Step 3, the multi-layer composite material is cut, split and layered through a layer multiplier connected to the flow concentrator, and then widened and compacted through an extruder head mold connected to the layer multiplier to obtain a multi-layer structural rubber material; Step 4, cutting the multilayer structure rubber material obtained in step 3 along the thickness direction at a set cutting angle and cutting interval distance to obtain a multilayer structure cut rubber material; placing a plurality of multilayer structure cut rubber materials in a mold in parallel with the cut surfaces facing upward, and performing pressure vulcanization treatment using a flat plate vulcanizer to obtain the obtained multilayer structure cut rubber material; In the step 1, by weight, 95 to 110 parts of base rubber, 20 to 50 parts of ablation-resistant filler, 5 to 10 parts of organic fiber, 5 to 10 parts of inorganic fiber and 1 to 5 parts of vulcanization aid are included.

7. The method for preparing the anisotropic ablation-resistant thermal insulation material according to claim 6, characterized in that: In step 4, the cutting angle is set to 0-45°, and the cutting interval is set to 1-30 mm.

8. The method for preparing the anisotropic ablation-resistant thermal insulation material according to claim 6, characterized in that: In step 4, the temperature of the pressurized vulcanization treatment is 120-150° C. and the pressure is 1-10 MPa.

9. Use of the anisotropic ablation-resistant thermal insulation material as described in any one of claims 1 to 5 as a thermal insulation layer of an engine casing, or use of the anisotropic ablation-resistant thermal insulation material prepared by the preparation method of the anisotropic ablation-resistant thermal insulation material as described in any one of claims 6 to 8 as a thermal insulation layer of an engine casing.

10. An engine housing, characterized in that: The inner wall of the engine casing is provided with an insulating layer formed by the anisotropic ablation-resistant insulating material as described in any one of claims 1 to 5; or an insulating layer formed by the anisotropic ablation-resistant insulating material prepared by the preparation method of the anisotropic ablation-resistant insulating material as described in any one of claims 6 to 8; the anisotropic ablation-resistant insulating material is formed on the inner wall of the engine casing by a pre-vulcanization-airbag molding vulcanization process, and the thickness of the insulating layer is 1 mm to 30 mm; the pre-vulcanization process parameters include a temperature of 80 to 100°C and a pressure of 10 to 12 MPa; the airbag molding vulcanization process parameters include a temperature of 140 to 150°C and a pressure of 0.6 to 0.8 MPa.

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