Elastomeric high temperature sealing material, method for its production and use

Abstract

This invention relates to an elastic high-temperature sealing material, its preparation method, and its application. The method includes: weaving a first and a second metal elastic mesh structure; preparing a coating on the surface of a fiber cloth to obtain a coated fiber cloth; sequentially stacking the first, coated, and second metal elastic mesh structures, then repeatedly folding them to form a W-shaped strip structure, followed by shaping with a pressure roller to obtain an elastic component; and finally, covering the elastic component with a fiber fabric and sewing it together to obtain the elastic high-temperature sealing material. The elastic high-temperature sealing material of this invention maintains excellent elasticity at high temperatures, possesses adaptive adjustment capability to match thermal expansion of gaps in external thermal protection systems, exhibits excellent thermal sealing performance, and can be used for thermal insulation sealing of gaps in external thermal protection systems of spacecraft. It has application value in wide-range high and low temperature applications and elastic adaptive sealing of gaps.

Description

Technical Field

[0001] This invention belongs to the field of sealing material technology, and particularly relates to an elastic high-temperature sealing material, its preparation method, and its application. Background Technology

[0002] The external thermal protection system of a spacecraft consists of a number of thermal insulation material components spliced ​​and laid on the surface of the load-bearing structure. These thermal insulation materials are then filled with insulating material in the gaps between them, collectively forming the external thermal protection system. The gaps in the external thermal protection system are typically sealed with materials such as fiber cloth wrapped with cotton strips, fiber sleeve wrapped with cotton strips, fiber braided tape, and fiber-reinforced aerogel insulation sheets. Different thermal insulation material systems, component dimensions, and thermal environments subjected to by the external thermal protection system result in different gap dimensions and requirements for gap insulation and sealing. Existing single gap sealing materials are insufficient to meet the sealing requirements of external thermal protection systems under complex environments. Therefore, there is an urgent need to develop elastic high-temperature sealing materials for the gaps in external thermal protection systems to meet the elastic sealing requirements of these gaps, improve the thermal insulation and sealing effect of the external thermal protection system, and ensure the reliability of the thermal protection system.

[0003] Therefore, it is essential to provide an elastic high-temperature sealing material, its preparation method, and its application. Summary of the Invention

[0004] To address one or more technical problems existing in the prior art, this invention provides an elastic high-temperature sealing material, its preparation method, and its application.

[0005] In a first aspect, the present invention provides a method for preparing an elastic high-temperature sealing material, the method comprising the following steps:

[0006] (1) Weaving a first metal elastic mesh structure and a second metal elastic mesh structure;

[0007] (2) A coating is prepared on the surface of the fiber cloth to obtain a coated fiber cloth;

[0008] (3) The first metal elastic mesh structure, the coated fiber cloth and the second metal elastic mesh structure are stacked in sequence, and then folded repeatedly to form a strip structure with a W-shaped cross section. The strip structure is then shaped by a pressure roller to obtain an elastic component.

[0009] (4) The elastic component is covered with fiber fabric and then sewn together to obtain an elastic high-temperature sealing material.

[0010] Preferably, the first and second metal elastic mesh structures are woven with metal wires; the metal wires used in the first and / or second metal elastic mesh structures are one or more of stainless steel wire, nickel-based alloy wire, copper-based alloy wire, and titanium alloy wire; the wire diameter is 0.05-0.15 mm; the first and / or second metal elastic mesh structures are plain weave structures or 2.5D braided structures.

[0011] Preferably, the fiber cloth is one or more of quartz fiber cloth, mullite fiber cloth, and aluminum silicate fiber cloth; the thickness of the fiber cloth is 0.05-0.15 mm; and / or the coating is one or more of polytetrafluoroethylene coating, silicone rubber coating, and fluororubber coating.

[0012] Preferably, in step (2): a coating is applied to the surface of the fiber cloth and then cured to complete the preparation of the coating; preferably, the curing temperature is 25 to 150°C and the curing time is 0.5 to 24 hours.

[0013] Preferably, the number of reciprocating folds is 3 or more; and / or the width of the reciprocating folds is 8 to 50 mm.

[0014] Preferably, the thickness of the pressure roller is 0.5 to 5 mm.

[0015] Preferably, the fiber fabric is one or more of plain weave fiber cloth, twill weave fiber cloth, 2.5D fiber sleeve, and two-dimensional three-phase fiber sleeve; the fibers in the fiber fabric are one or more of quartz fiber, aluminum silicate fiber, alumina fiber, mullite fiber, and silicon carbide fiber.

[0016] Preferably, the covering is a wrapping or nesting type; the yarn used for sewing has the same fiber type as the fiber fabric; and / or the spacing of the sewing is 10-25 mm.

[0017] In a second aspect, the present invention provides an elastic high-temperature sealing material prepared by the preparation method described in the first aspect of the present invention.

[0018] In a third aspect, the present invention provides the application of an elastic high-temperature sealing material prepared by the preparation method described in the first aspect of the present invention in gaps of an external heat protection system.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] (1) This invention innovatively uses a two-layer metal elastic mesh structure laminated coated fiber cloth (isolation layer) to form a W-shaped multi-layer repeating sealing elastic structure with a "1+1+1" sandwich by molding. It has very good high-temperature elastic performance, which can solve the technical problem of elastic adaptive sealing of gaps in high-temperature thermal protection systems, improve the reliability of thermal protection gap sealing in external thermal protection systems, and the prepared elastic high-temperature sealing material is an elastic adaptive high-temperature sealing material for gaps in external thermal protection systems.

[0021] (2) This invention innovatively designs a structure in which a metal mesh elastic structure forms an elastic layer and ceramic fibers form an isolation layer. The isolation layer effectively blocks the heat transfer of the metal mesh elastic layer and also reduces the interlocking of the two metal elastic mesh structures, maintaining the elastic mechanical properties of the multilayer. Through reciprocating folding, a multilayer reciprocating W-shaped strip structure is formed. This layered arrangement maintains the excellent elasticity of the gap sealing material at high temperatures, has the ability to adapt to the thermal expansion matching of the gaps in the external heat protection system, and has excellent thermal sealing performance. It can be used for thermal insulation sealing between gaps in the external heat protection system of spacecraft, and has the application value of wide-range use in high and low temperatures and elastic adaptive sealing of gaps.

[0022] (3) The elastic high-temperature sealing material (elastic adaptive high-temperature sealing material for gaps in external heat protection system) of the present invention has a simple molding process, strong product design performance, and is suitable for customization of heat sealing materials with different gap widths and gap depths. The process is flexible and it is an excellent high-temperature sealing material with universal promotion value. Attached Figure Description

[0023] The accompanying drawings are provided for illustrative purposes only, and the proportions, dimensions, etc. of the parts in the drawings may not be consistent with the actual product.

[0024] Figure 1 This is a flowchart illustrating the preparation of elastic high-temperature sealing materials in some specific embodiments of the present invention;

[0025] Figure 2 These are schematic diagrams of the cross-sectional structure of the strip structure in some specific embodiments of the present invention; Figure 2 The arrow in the image indicates the direction of the pressure roller shaping process. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] In a first aspect, this invention provides a method for preparing an elastic high-temperature sealing material, including a flowchart of the preparation process, for example, as shown below. Figure 1 As shown; the method includes the following steps:

[0028] (1) Weaving a first metal elastic mesh structure and a second metal elastic mesh structure; specifically, for example, a metal braiding machine can be used to weave metal wires of different or the same diameter into a first metal elastic mesh structure and a second metal elastic mesh structure in sequence;

[0029] (2) Prepare a coating on the surface of the fiber cloth to obtain a coated fiber cloth; specifically, for example, a coating can be applied to the surface of a thin fiber cloth and cured to obtain a coated fiber cloth, i.e., an isolation layer;

[0030] (3) The first metal elastic mesh structure, the coated fiber cloth, and the second metal elastic mesh structure are stacked sequentially, and then folded repeatedly to form a strip structure with a W-shaped cross-section. This is then shaped by a pressure roller to obtain an elastic component (also referred to as an adaptive elastic component). In this invention, for example, the first metal elastic mesh structure, the coated fiber cloth, and the second metal elastic mesh structure are stacked sequentially, and folded repeatedly at a certain width to form a strip structure with a W-shaped cross-section. A pressure roller is then used to shape this strip structure to a certain thickness, resulting in an adaptive elastic component containing an isolation layer. In this invention, the repeated folding forms a strip structure with a W-shaped cross-section; in other words, the strip structure is formed by repeated W-shaped folding, similar to the repeated folding of a folding fan. In this invention, after repeated folding, the strip structure has a certain degree of fluffiness. It is then shaped by a pressure roller to a preset thickness, making the adaptive elastic component compact. After the pressure roller shaping, the width of the adaptive elastic component is the same as the width of each fold, i.e., for example... Figure 2 The pressure roller is shaped in the direction indicated by the middle arrow.

[0031] (4) The elastic component is covered with fiber fabric and then sewn together to obtain an elastic high-temperature sealing material; In this invention, the elastic high-temperature sealing material is also referred to as an elastic adaptive high-temperature sealing material for gaps in external heat protection system or an elastic adaptive high-temperature sealing material; In this invention, specifically, for example, the adaptive elastic component containing the isolation layer is covered with fiber fabric, and then sewn together to form a protective layer, thereby obtaining the elastic adaptive high-temperature sealing material for gaps in external heat protection system.

[0032] In this invention, the elastic high-temperature sealing material is made by covering a fiber fabric with an adaptive elastic component and then sewing it together. The adaptive elastic component is formed by stacking the first metal elastic mesh structure, the coated fiber cloth and the second metal elastic mesh structure in sequence, folding them in a W-shape and then shaping them with a pressure roller, forming a strip-shaped structure. It is suitable for high-temperature sealing of various gaps in external heat protection system components.

[0033] In this invention, the coated fiber cloth, acting as an isolation layer, effectively separates the first and second metal elastic mesh structures, preventing direct contact between them and reducing heat conduction and radiation. This isolation helps improve the overall thermal insulation performance of the elastic high-temperature sealing material. Furthermore, after coating and curing, the coated fiber cloth forms a relatively stable and high-temperature resistant coating, giving the entire elastic high-temperature sealing material good resistance to high temperatures and preventing performance loss due to heat. The presence of the coated fiber cloth also creates a more stable structure between the metal elastic mesh structure of the adaptive elastic component and the fiber cloth, further improving the durability and service life of the overall elastic high-temperature sealing material. In this invention, after covering the elastic component with fiber fabric, the coated fiber cloth and the covering fiber fabric form a composite protective layer. This composite protective layer has good flexibility and elasticity, better adapting to complex surface shapes and structures, thus sealing gaps more effectively during use and ensuring the material retains excellent elasticity at high temperatures.

[0034] In this invention, the first metal elastic mesh structure, the coated fiber cloth, and the second metal elastic mesh structure are stacked sequentially, then folded repeatedly to form a W-shaped strip structure, and then shaped by a pressure roller. This process allows the adaptive elastic component to have more elastic energy, which helps the sealing material to adaptively fit under different surface shapes, ensuring a more reliable sealing effect. The pressure roller shaping process gives the adaptive elastic component the required shape and stability, ensuring that it is not easily deformed during installation and use, maintaining sealing performance, and ensuring that the material exhibits excellent performance in high-temperature environments, suitable for the sealing requirements of external heat protection system gaps. Compared with existing technologies such as the heat sealing material disclosed in CN115556425A, this invention, by repeatedly folding to form a W-shaped strip structure and then shaping it by a pressure roller, allows the material to adapt and rebound well during use, exhibiting excellent resilience, thus maintaining good sealing performance under different surface shapes and structures, ensuring a tight seal of gaps.

[0035] This invention innovatively utilizes a two-layer metal elastic mesh structure laminated coated fiber cloth (isolation layer) to form a "1+1+1" sandwich W-shaped multi-layered repetitive sealing elastic structure. This structure exhibits excellent high-temperature elastic performance, solving the technical challenge of elastic adaptive sealing of gaps in high-temperature thermal protection systems and improving the reliability of thermal protection gap sealing in external thermal protection systems. The resulting elastic high-temperature sealing material is an elastic adaptive high-temperature sealing material for gaps in external thermal protection systems. This invention innovatively designs a structure with a metal mesh elastic structure forming the elastic layer and ceramic fibers forming the isolation layer. The isolation layer effectively blocks heat transfer from the metal mesh elastic layer and reduces the interlocking of the two metal elastic mesh structures, maintaining the multi-layered elastic mechanical properties. Through reciprocating folding, a multi-layered W-shaped strip structure is formed. This layered configuration maintains the excellent high-temperature elasticity of the gap sealing material, possessing the ability to adaptively adjust to the thermal expansion of gaps in external thermal protection systems. It exhibits excellent thermal sealing performance and can be used for thermal insulation sealing between gaps in external thermal protection systems of spacecraft. It has application value in high and low temperature wide-range use and elastic adaptive sealing of gaps.

[0036] According to some preferred embodiments, the first and second metal elastic mesh structures are woven with metal wires; the metal wires used in the first and / or second metal elastic mesh structures are one or more of stainless steel wire, nickel-based alloy wire, copper-based alloy wire, and titanium alloy wire; the present invention does not specifically limit the stainless steel wire, nickel-based alloy wire, copper-based alloy wire, and titanium alloy wire, and products that can be directly purchased from the market or products made by existing methods can be used; the metal wires used in the first and second metal elastic mesh structures may be the same or different; the wire diameter is 0.05-0.15 mm; the first and / or second metal elastic mesh structures are plain weave structures (also referred to as plain weave structures) or 2.5D weave structures.

[0037] According to some preferred embodiments, the fiber cloth is one or more of quartz fiber cloth, mullite fiber cloth, and aluminum silicate fiber cloth; the thickness of the fiber cloth is 0.05-0.15 mm, which is a thin fiber cloth; and / or the coating is one or more of polytetrafluoroethylene coating, silicone rubber coating, and fluororubber coating.

[0038] According to some preferred embodiments, in step (2): a coating is applied to the surface of the fiber cloth and then cured to complete the preparation of the coating; preferably, the curing temperature is room temperature to 150°C, preferably 25 to 150°C (e.g., 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C), and the curing time is 0.5 to 24 hours (e.g., 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24 hours).

[0039] According to some preferred embodiments, the number of reciprocating folds is more than 3 times; and / or the width of the reciprocating folds is 8 to 50 mm (e.g., 8, 10, 15, 20, 25, 30, 35, 40, 45 or 50 mm), that is, the width of each fold is 8 to 50 mm.

[0040] According to some preferred embodiments, the thickness of the pressure roller is 0.5 to 5 mm (e.g., 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5 mm).

[0041] According to some preferred embodiments, the fiber fabric is one or more of plain weave fiber cloth, twill weave fiber cloth, 2.5D fiber sleeve, and two-dimensional three-phase fiber sleeve; the fibers in the fiber fabric are one or more of quartz fiber, aluminosilicate fiber, alumina fiber, mullite fiber, and silicon carbide fiber.

[0042] According to some preferred embodiments, the covering is a wrapping or nesting covering; in this invention, for example, two layers of fiber fabric can be used for wrapping; the type of fiber used for sewing is the same as that of the fiber fabric, that is, the sewing uses the same type of fiber yarn as the fiber fabric; and / or the spacing of the sewing is 10-25 mm; in this invention, for example, a fixed stitch spacing can be made along the center line of the width, and the fixed stitch spacing is 10-25 mm.

[0043] In a second aspect, the present invention provides an elastic high-temperature sealing material prepared by the preparation method described in the first aspect of the present invention.

[0044] In a third aspect, the present invention provides the application of an elastic high-temperature sealing material prepared by the preparation method described in the first aspect of the present invention in gaps of an external heat protection system.

[0045] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments.

[0046] Example 1

[0047] This embodiment provides a method for preparing an elastic adaptive high-temperature sealing material (elastic high-temperature sealing material) for gaps in an external heat protection system, which is prepared according to the following method:

[0048] Using 0.08mm diameter stainless steel wire and 0.08mm diameter nickel-based alloy wire, a first metal elastic mesh structure and a second metal elastic mesh structure are woven separately using a metal braiding machine. Both are plain weave structures. A polytetrafluoroethylene coating is applied to the surface of a 0.05mm thick quartz fiber cloth and cured at 130℃ for 6 hours to obtain a coated fiber cloth, which serves as the isolation layer. The first metal elastic mesh structure, the isolation layer (coated fiber cloth), and the second metal elastic mesh structure are stacked sequentially, and the fabric is folded back and forth 4 times with each fold being 8mm wide. A W-shaped strip structure is formed and shaped with a 0.5mm thick pressure roller to obtain an adaptive elastic component with an isolation layer. The cross-sectional dimensions of the adaptive elastic component are 0.5mm (thickness) × 8mm (width). The adaptive elastic component with the isolation layer is wrapped with two layers of quartz plain weave fiber cloth (fiber fabric) and sewn along the center line of the width with the same type of fiber yarn (quartz fiber yarn) as the fiber fabric at a fixed stitch spacing of 10mm to make an elastic adaptive high-temperature sealing material for the gaps of the external heat protection system.

[0049] The elastic adaptive high-temperature sealing material for gaps in external heat protection systems prepared by the above method has a rebound rate of 100% after 30% compression at room temperature and a rebound rate of 95% after 30% compression at 900℃.

[0050] Examples 2-6

[0051] Examples 2 to 6 are basically the same as Example 1, with the differences shown in Table 1.

[0052]

[0053]

[0054]

[0055]

[0056] Comparative Example 1

[0057] This comparative example provides a method for preparing an elastic sealing material, which is prepared according to the following method:

[0058] Using stainless steel wire with a diameter of 0.08mm and nickel-based alloy wire with a diameter of 0.08mm, a first metal elastic mesh structure and a second metal elastic mesh structure are woven separately using a metal braiding machine. Both are plain weave interwoven structures. The first and second metal elastic mesh structures are stacked in sequence and folded back and forth 4 times with a fold width of 8mm each time to form a W-shaped strip structure. The strip structure is then shaped with a pressure roller with a thickness of 0.5mm to obtain a component unit with a cross-sectional size of 0.5mm × 8mm. The component unit is wrapped with two layers of quartz plain weave fiber cloth (fiber fabric) and sewn with the same type of fiber yarn (quartz fiber yarn) along the width center line with a fixed stitch spacing of 10mm to make an elastic sealing material.

[0059] The elastic sealing material prepared by the above method has a rebound rate of 85% after 30% compression at room temperature and 72% after 30% compression at 900℃.

[0060] Comparative Example 2

[0061] This comparative example provides a method for preparing an elastic sealing material, which is prepared according to the following method:

[0062] Using stainless steel wire with a diameter of 0.08mm and nickel-based alloy wire with a diameter of 0.08mm, a first metal elastic mesh structure and a second metal elastic mesh structure are woven respectively using a metal braiding machine. Both are plain weave structures. A polytetrafluoroethylene coating is applied to the surface of a 0.05mm thick quartz fiber cloth and cured at 130℃ for 6 hours to obtain a coated fiber cloth, which serves as the isolation layer. The first metal elastic mesh structure, the isolation layer (coated fiber cloth), and the second metal elastic mesh structure are stacked in sequence to obtain a component unit. The component unit is wrapped with two layers of quartz plain weave fiber cloth (fiber fabric) and sewn with the same type of fiber yarn (quartz fiber yarn) along the width centerline at a fixed stitch spacing of 10mm to create an elastic sealing material.

[0063] The elastic sealing material prepared by the above method has a rebound rate of 46% after being compressed by 30% at room temperature.

[0064] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing an elastic high temperature sealing material, characterized by, The method comprises the following steps: (1) weaving a first metal elastic net structure and a second metal elastic net structure; (2) preparing a coating layer on the surface of a fiber cloth to obtain a coated fiber cloth; (3) sequentially stacking the first metal elastic net structure, the coated fiber cloth and the second metal elastic net structure, then folding back and forth to form a strip structure with a W-shaped cross section, and then shaping by a pressing roller to obtain an elastic assembly; (4) covering the elastic assembly with a fiber fabric and then sewing to obtain an elastic high-temperature sealing material.

2. The preparation method according to claim 1, characterized in that: the first metal elastic net structure and the second metal elastic net structure are woven by metal wires; the metal wires used in the first metal elastic net structure and / or the second metal elastic net structure are one or more of stainless steel wires, nickel-based alloy wires, copper-based alloy wires and titanium alloy wires; the diameter of the metal wires is 0.05-0.15 mm; the first metal elastic net structure and / or the second metal elastic net structure is a plain weave structure or a 2.5D woven structure.

3. The preparation method according to claim 1, characterized in that: the fiber cloth is one or more of quartz fiber cloth, mullite fiber cloth and aluminum silicate fiber cloth; the thickness of the fiber cloth is 0.05-0.15 mm; and / or the coating layer is one or more of a polytetrafluoroethylene coating layer, a silicone rubber coating layer and a fluororubber coating layer.

4. The method of claim 1, wherein, In step (2): the coating layer is prepared by coating a coating layer on the surface of the fiber cloth and then curing.

5. The preparation method according to claim 4, characterized in that: the curing temperature is 25-150°C, and the curing time is 0.5-24 h.

6. The preparation method according to claim 1, characterized in that: the number of times of folding back and forth is more than 3; and / or the width of the folding back and forth is 8-50 mm.

7. The preparation method according to claim 1, characterized in that: the thickness of the shaping by the pressing roller is 0.5-5 mm.

8. The preparation method according to claim 1, characterized in that: the fiber fabric is one or more of a plain weave fiber cloth, a twill fiber cloth and a 2.5D fiber sleeve; the fibers in the fiber fabric are one or more of quartz fibers, aluminum silicate fibers, alumina fibers, mullite fibers and silicon carbide fibers.

9. The preparation method according to claim 1, characterized in that: the covering is winding covering or nesting covering; the fiber type of the yarn used in the sewing is the same as that of the fibers in the fiber fabric; and / or the interval of the sewing is 10-25 mm.

10. An elastic high-temperature sealing material prepared by the preparation method according to any one of claims 1 to 9.

11. Application of the elastic high-temperature sealing material prepared by the preparation method according to any one of claims 1 to 9 to a gap in an outer thermal protection system.

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