Manufacturing method of atomic oxygen prevention external flame-retardant cloth punching multilayer heat insulation assembly

Abstract

The invention discloses a manufacturing method of an atomic oxygen prevention external flame-retardant cloth punching multilayer heat insulation assembly, which comprises the following steps: S1, the assembly adopts a five-layer composite structure from top to bottom, and material structures required by a surface layer, a flame-retardant layer, a heat insulation layer, a punching layer and a substrate layer are prepared; s2, performing in-situ growth of a BN nanosheet on the surface of the PI film by adopting laser-induced chemical vapor deposition; s3, a dynamic stirring impregnation method is adopted, and 80 DEG C gradient drying curing is combined; s4, dipping an aluminum silicate fiber skeleton into silicon dioxide sol, and carrying out supercritical CO2 drying and forming; s5, laminating five layers of materials, and sequentially carrying out three-stage hot pressing at 180 DEG C (0.5 MPa), 250 DEG C (1.2 MPa) and 300 DEG C (2.0 MPa); and S6, an ultraviolet laser is selected, and a high-precision positioning system is arranged for laser precision drilling. Through triple innovation of materials, structures and processes, deep synergy of atomic oxygen protection, flame retardance, heat insulation and light weight functions is achieved, the performance of the assembly comprehensively exceeds that of the prior art, and the production cost is reduced by 40%.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation components, in particular to a method for manufacturing a perforated multi-layer thermal insulation component made of flame-retardant cloth for external use to prevent atomic oxygen. Background Art

[0002] In the operating environment of low-Earth orbit (LEO) spacecraft, atomic oxygen (AO) is one of the main factors causing material degradation. Atomic oxygen is formed by the decomposition of oxygen molecules by ultraviolet rays from the sun. Its high reactivity can trigger oxidative corrosion of polymer materials, leading to surface roughening, mass loss, and decreased mechanical properties.12 Traditional protective technologies rely on SiO2 coatings, but they are highly brittle, their thermal expansion coefficient does not match that of the substrate, and they are prone to cracking and failure after long-term thermal cycling, resulting in loss of protective function. In addition, existing flame retardant materials (such as polyester fibers treated with brominated epoxy resins) inhibit combustion by releasing free radicals from flame retardants, but lack the ability to protect against atomic oxygen and are prone to performance degradation due to the precipitation of volatiles in a vacuum environment.

[0003] Current technology faces the following core bottlenecks: 1. Single material function: The atomic oxygen shielding layer and the flame-retardant layer are physically stacked, resulting in a high risk of interface failure; 2. Inadequate lightweighting: Low-density materials like aerogel lack structural support, making it difficult to achieve both strength and thermal insulation; 3. Process flaws: Uneven flame retardant distribution, poor coating adhesion, and uncontrollable interlayer thermal stresses; 4. Lack of testing standards: A comprehensive evaluation system for simulating space environments is lacking. Therefore, a method for manufacturing perforated multi-layer thermal insulation assemblies made of atomic oxygen shielding fabric for external use is needed to fill this gap in spacecraft materials technology. Summary of the Invention

[0004] The object of the present invention is to provide a method for manufacturing a perforated multi-layer thermal insulation assembly of flame-retardant fabric for external use against atomic oxygen, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a method for manufacturing a perforated multi-layer thermal insulation component of an atomic oxygen-proof external flame-retardant cloth, comprising the following method steps: S1. The component adopts a five-layer composite structure from top to bottom, and prepares the material structure required for the surface layer (atomic oxygen protection layer), flame retardant layer, thermal insulation layer, perforated layer and base layer; S2. Laser-induced chemical vapor deposition is used to in-situ grow BN nanosheets on the surface of the PI film; S3. A dynamic stirring and impregnation method (dual-motor driven stirring blades) is used, combined with 80°C gradient drying and curing; S4. Aluminum silicate fiber skeleton is used to impregnate silica sol, and supercritical CO2 drying and molding are performed; S5. Five layers of materials are stacked, and they are sequentially hot-pressed at 180°C (0.5MPa), 250°C (1.2MPa), and 300°C (2.0MPa); S6. An ultraviolet laser is selected, and a high-precision positioning system (error ±5μm) is equipped for laser precision drilling.

[0006] Preferably, in step S1, the surface material is a polyimide (PI)-based film coated with a boron nitride (BN) nanosheet coating (thickness 50-100 nm), the flame retardant layer material is glass fiber cloth impregnated with brominated polystyrene (Br-PS) flame retardant (concentration 20 wt%), and the flame retardant grade is A (oxygen index ≥ 32%), and the thermal insulation layer material is aerogel-reinforced aluminum silicate fiber felt (density ≤ 0.1 g / cm 3 , thermal conductivity ≤ 0.03W / m·K), the perforated layer adopts ultraviolet laser processing of micropore array (pore size 50-200μm, porosity 15%-30%), and the base layer material is carbon fiber reinforced polyetheretherketone (PEEK) film (tensile strength ≥ 200MPa).

[0007] Preferably, in step S2, a laser-induced chemical vapor deposition process is used to improve the coating adhesion to ≥5 MPa.

[0008] Preferably, the concentration deviation of the flame retardant in step S3 is reduced from ≥15% in the traditional process to ≤5%.

[0009] Preferably, the density of the product obtained in step S4 is ≤0.1 g / cm 3 , compressive strength ≥0.5MPa.

[0010] Preferably, in step S5, the pressure is maintained for 10 minutes at each stage to achieve cross-linking of molecular chains between layers and avoid thermal stress delamination.

[0011] Preferably, in step S6, the ultraviolet laser has a wavelength of 355 nm, a power of 30 W, a pulse frequency of 20 kHz, a scanning speed of 500 mm / s, and a single hole processing time of ≤0.1 second.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The present invention realizes dual functional integration through the composite design of BN nano-coating and brominated flame-retardant cloth: the BN coating consumes atomic oxygen through chemical passivation reaction (BN+O→B2O3), with a mass loss rate of <1% (traditional materials>5%); the brominated polystyrene flame-retardant layer releases HBr free radicals at high temperature, with a self-extinguishing time of ≤2 seconds and a flame retardancy grade of Class A (oxygen index ≥32%). This design avoids the destruction of the atomic oxygen protective layer by the volatilization of the flame retardant, and solves the interface failure problem caused by the stacking of functional layers;

[0014] (2) The present invention adopts aerogel to reinforce aluminum silicate fiber felt (density ≤ 0.1g / cm 3 , thermal conductivity ≤ 0.03W / m·K), combined with laser microporous array (porosity 15%-30%), to achieve a surface density of only 300g / m 2, compared with traditional aramid fiber components (≥800g / m 2 ) 60% weight reduction, thermal conductivity fluctuation of less than 5% in the cycle from -120℃ to +150℃, and thermal insulation stability significantly better than similar products;

[0015] (3) The present invention uses laser-induced chemical vapor deposition (LICVD) technology to in situ grow BN nanosheets on the surface of polyimide (PI) film, with an adhesion of ≥5MPa and a bonding strength increased by 150%;

[0016] (4) The present invention uses a dynamic stirring and impregnation process (dual motors drive the stirring blades) combined with gradient drying and curing to ensure that the flame retardant concentration deviation is ≤5%. A gradient hot pressing process (180°C → 250°C → 300°C, pressure 0.5 → 2.0MPa) is used to match the thermal expansion coefficients of each layer of material, with interlayer adhesion ≥5MPa, to avoid the risk of thermal cycle delamination.

[0017] (5) The present invention solves the fiber breakage problem caused by traditional mechanical punching through ultraviolet laser micro-hole processing (aperture 50-200μm, accuracy ±5μm), with a pore uniformity of 98%. A roll-to-roll continuous production line is used to achieve a production speed of 5m / min, reducing costs by 40%, and adapting to the needs of large-scale spacecraft manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flowchart of the overall method steps of the present invention. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] See also Figure 1 , the present invention provides an embodiment: a manufacturing method for a perforated multi-layer thermal insulation component of an atomic oxygen-proof external flame-retardant cloth, comprising the following method steps: S1, the component adopts a five-layer composite structure from top to bottom, and prepares the material structure required for the surface layer (atomic oxygen protection layer), flame retardant layer, thermal insulation layer, perforated layer and base layer; S2, laser-induced chemical vapor deposition is used to in-situ grow BN nanosheets on the surface of the PI film; S3, a dynamic stirring impregnation method (dual-motor driven stirring blades) is used, combined with 80°C gradient drying and curing; S4, an aluminum silicate fiber skeleton is impregnated with silica sol, and supercritical CO2 drying and molding are performed; S5, five layers of materials are stacked, and sequentially subjected to three-stage hot pressing at 180°C (0.5MPa), 250°C (1.2MPa), and 300°C (2.0MPa); S6, an ultraviolet laser is selected, and a high-precision positioning system (error ±5μm) is equipped for laser precision drilling.

[0021] Furthermore, in step S1, the surface material is a polyimide (PI)-based film coated with a boron nitride (BN) nanosheet coating (thickness 50-100 nm), the flame retardant layer material is glass fiber cloth impregnated with brominated polystyrene (Br-PS) flame retardant (concentration 20 wt%), and the flame retardant grade is A (oxygen index ≥ 32%), and the thermal insulation layer material is aerogel-reinforced aluminum silicate fiber felt (density ≤ 0.1 g / cm 3 , thermal conductivity ≤ 0.03W / m·K), the perforated layer adopts ultraviolet laser processing micropore array (pore size 50-200μm, porosity 15%-30%), and the base layer material is carbon fiber reinforced polyetheretherketone (PEEK) film (tensile strength ≥ 200MPa).

[0022] Furthermore, in step S2, a laser-induced chemical vapor deposition process is used to improve the coating adhesion to ≥5 MPa.

[0023] Furthermore, the concentration deviation of the flame retardant in step S3 is reduced from ≥15% in the traditional process to ≤5%.

[0024] Furthermore, the density of the product obtained in step S4 is ≤0.1 g / cm 3 , compressive strength ≥0.5MPa.

[0025] Furthermore, in step S5, the pressure is maintained for 10 minutes in each stage to achieve cross-linking of molecular chains between layers and avoid thermal stress delamination.

[0026] Furthermore, in step S6, the wavelength of the ultraviolet laser is 355 nm, the power is 30 W, the pulse frequency is 20 kHz, the scanning speed is 500 mm / s, and the single hole processing time is ≤0.1 second.

[0027] Example 2: Satellite multilayer insulation blanket (MLI) prepared by the above method

[0028] 1. Material pretreatment:

[0029] PI base film: A polyimide film with a thickness of 25 μm was selected and cleaned with argon plasma (power 200 W, 10 minutes) to enhance the surface activity.

[0030] Flame retardant layer: glass fiber cloth (weight 200g / m 2 ) was impregnated with brominated polystyrene emulsion (concentration 20 wt%), and a dynamic stirring impregnation process (dual motor driven stirring blades, speed 300 rpm) was adopted to ensure uniform distribution of the flame retardant (deviation ≤ 5%).

[0031] Functional layer composite:

[0032] BN coating deposition: BN nanosheets were grown on the surface of the PI film by laser-induced chemical vapor deposition (LICVD). The process parameters were laser power 50 W, reaction gas (BCl3 / NH3) flow rate 10 sccm, and the coating thickness was controlled at 80±5 nm.

[0033] Preparation of aerogel layer: Aluminum silicate fiber skeleton was impregnated with silica sol and dried by supercritical CO2 (pressure 8 MPa, temperature 40°C) to form a density of 0.08 g / cm 3 composite aerogels.

[0034] 2. Laser drilling and hot pressing:

[0035] A 150μm micropore array with a porosity of 25% and a machining accuracy of ±5μm was machined at the interface between the flame-retardant and thermal-insulating layers using an ultraviolet laser (355nm wavelength). A gradient hot pressing process (180°C → 250°C → 300°C, pressure 0.5 → 2.0MPa) was used to create the five-layer composite, achieving interlayer adhesion of 5.2MPa.

[0036] 2. Performance Testing and Verification

[0037] 1. Atomic oxygen protection test:

[0038] Conditions: Simulate low Earth orbit environment (atomic oxygen flux 5×10 20 atoms / cm 2 , energy 5eV).

[0039] Results: Mass loss rate: 0.8% (5.3% for traditional SiO2 coating), and a dense B2O3 protective layer was formed on the surface of the BN coating.

[0040] Surface morphology: Scanning electron microscopy (SEM) showed no cracks or peeling, and the roughness (Ra) increased by only 0.02μm.

[0041] 2. Flame retardant performance test:

[0042] Vertical combustion test (ASTM D6413): Self-extinguishing time: 1.5 seconds (standard requirement ≤ 2 seconds), flame retardant grade reaches Class A; smoke density (ASTM E662): smoke density level 12, better than the requirements of aerospace-grade materials (≤ 15).

[0043] Thermal insulation and mechanical performance test: thermal cycle test (-120°C to +150°C, 100 cycles); thermal conductivity fluctuation: ≤4.7%, no structural collapse of the aerogel layer.

[0044] Vacuum thermal deformation test: Finite element simulation shows the maximum deformation is 0.09mm / m, which meets the spacecraft deformation control requirements.

[0045] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0046] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a perforated multi-layer thermal insulation component of flame-retardant fabric for external use against atomic oxygen, characterized in that: The method comprises the following steps: S1. The component adopts a five-layer composite structure from top to bottom, and prepares the material structure required for the surface layer (atomic oxygen protection layer), flame retardant layer, thermal insulation layer, perforated layer and base layer; S2, using laser-induced chemical vapor deposition to in situ grow BN nanosheets on the surface of the PI film; S3, using dynamic stirring and impregnation method (dual motor driven stirring blades), combined with 80℃ gradient drying and curing; S4, using aluminum silicate fiber skeleton impregnated with silica sol, and dried and formed by supercritical CO2; S5, stacking five layers of materials, and sequentially hot pressing at 180℃ (0.5MPa), 250℃ (1.2MPa), and 300℃ (2.0MPa); S6. Use ultraviolet laser and equip it with high-precision positioning system (error ±5μm) for laser precision drilling.

2. The method for manufacturing a perforated multi-layer thermal insulation assembly of flame-retardant fabric for external use against atomic oxygen according to claim 1, characterized in that: In step S1, the surface material is a polyimide (PI)-based film coated with a boron nitride (BN) nanosheet coating (thickness 50-100 nm), the flame retardant layer material is glass fiber cloth impregnated with brominated polystyrene (Br-PS) flame retardant (concentration 20 wt%), and the flame retardant grade is A (oxygen index ≥ 32%), and the thermal insulation layer material is aerogel-reinforced aluminum silicate fiber felt (density ≤ 0.1 g / cm 3 , thermal conductivity ≤ 0.03W / m·K), the perforated layer adopts ultraviolet laser processing of micropore array (pore size 50-200μm, porosity 15%-30%), and the base layer material is carbon fiber reinforced polyetheretherketone (PEEK) film (tensile strength ≥ 200MPa).

3. The method for manufacturing a perforated multi-layer thermal insulation assembly of flame-retardant fabric for external use against atomic oxygen according to claim 1, characterized in that: In step S2, a laser-induced chemical vapor deposition process is used to improve the coating adhesion to ≥5 MPa.

4. The method for manufacturing a perforated multi-layer thermal insulation assembly of flame-retardant fabric for external use against atomic oxygen according to claim 1, characterized in that: The flame retardant concentration deviation in step S3 is reduced from ≥15% in the traditional process to ≤5%.

5. The method for manufacturing a perforated multi-layer thermal insulation assembly of flame-retardant fabric for external use against atomic oxygen according to claim 1, characterized in that: The density of the product obtained in step S4 is ≤0.1 g / cm 3 , compressive strength ≥0.5MPa.

6. The method for manufacturing a perforated multi-layer thermal insulation assembly of flame-retardant fabric for external use against atomic oxygen according to claim 1, characterized in that: In step S5, the pressure is maintained for 10 minutes at each stage to achieve cross-linking of molecular chains between layers and avoid thermal stress delamination.

7. The method for manufacturing a perforated multi-layer thermal insulation assembly of flame-retardant fabric for external use against atomic oxygen according to claim 1, characterized in that: In step S6, the wavelength of the ultraviolet laser is 355 nm, the power is 30 W, the pulse frequency is 20 kHz, the scanning speed is 500 mm / s, and the single hole processing time is ≤ 0.1 second.

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