An atomic oxygen-resistant solution coating device and coating process

Abstract

This invention relates to a coating apparatus and process for atomic oxygen resistant solutions. The coating apparatus includes an immersion tank with rollers inside, and a grid plate near the opening of the tank, with a feed inlet and a discharge outlet on the grid plate. A curing channel is located behind the immersion tank and is an arched structure composed of an ascending section and a descending section, with an air inlet and an air outlet respectively located above the ascending and descending sections. The coating process includes corona treatment, immersion, and high-temperature curing. This invention can increase the adhesion and polarity of the product surface, thereby improving the effect of atomic oxygen resistant solution coating, effectively ensuring the uniformity of the atomic oxygen resistant coating on the product surface, improving the atomic oxygen resistance performance of the product, and is suitable for mass production.

Description

Technical Field

[0001] This invention belongs to the field of oxygen-resistant atomic coating technology, specifically relating to an atomic oxygen-resistant solution coating device and coating process. Background Technology

[0002] The low Earth orbit environment is complex and highly variable, and spacecraft operating in orbit travel at extremely high speeds. Environmental effects studies include vacuum ultraviolet light and radiation, charged particle radiation, high vacuum, micrometeoroid and space debris collisions, cryogenic cycling, and the atomic oxygen effect. During high-speed operation, the average impact energy of atomic oxygen is approximately 5 eV, an energy sufficient to break chemical bonds and oxidize many materials. Flexible flat solar cables can be used on spacecraft solar panel wings, offering advantages such as small size and light weight.

[0003] In existing technologies, films made of materials such as polyimide are made resistant to atomic oxygen attack by adding modifiers. However, this method has high technical requirements and the cost of the production materials is high, making it difficult to promote widespread application. Furthermore, this method cannot change the organic structure of the material matrix, and it will still exhibit an erosion effect under the attack of atomic oxygen. Summary of the Invention

[0004] The purpose of this invention is to provide an atomic oxygen-resistant coating device and coating process to solve the problem that atomic oxygen erosion protection cannot be achieved on a large scale.

[0005] The present invention provides an atomic oxygen-resistant solution coating apparatus and coating process, which are implemented as follows:

[0006] An apparatus for coating with an atomic oxygen-resistant solution, comprising:

[0007] An impregnation tank is provided with rollers inside. A grid plate is provided inside the impregnation tank near its opening. The grid plate has a feed inlet and a discharge outlet.

[0008] The curing channel is located behind the impregnation tank and is an arched structure consisting of an ascending section and a descending section. An air inlet and an air outlet are respectively provided above the ascending section and the descending section.

[0009] Furthermore, the impregnation tank has a trapezoidal structure that is wider at the top and narrower at the bottom.

[0010] Furthermore, the feed inlet is opposite to the vertical tangent on the feed side of the roller, and the discharge outlet is located outside the vertical tangent on the discharge side of the roller.

[0011] Furthermore, the rising segment and the falling segment are symmetrically arranged, and the rising segment makes an angle of 45° with the horizontal direction.

[0012] Secondly, the present invention also provides a coating process for resisting atomic oxygen solutions, comprising the following steps:

[0013] Step 1: Corona treatment, which involves applying a corona electrode to the surface of the product;

[0014] Step 2: Impregnation. The corona-treated product is placed into an impregnation tank containing an atomic oxygen-resistant solution for impregnation.

[0015] Step 3: High-temperature curing. The impregnated product is sent into the curing channel for heating and curing.

[0016] Furthermore, in step two, the impregnation method is as follows:

[0017] The product is vertically immersed in the atomic oxygen resistant solution in the impregnation tank, and then pulled out of the impregnation tank at a constant speed in an inclined direction.

[0018] Furthermore, the rising section of the curing channel is a preheating and curing section, where the internal temperature gradually increases.

[0019] The descending section of the curing channel is the enhanced curing section, where the internal temperature gradually decreases.

[0020] Furthermore, the temperature range of the preheating and curing section is 120-155℃;

[0021] The temperature range of the reinforced curing section is 110-135℃.

[0022] Furthermore, the air intake and exhaust rates of the preheating and curing section are 30-40 L / min;

[0023] The air intake and exhaust rates of the reinforced curing section are 30-35 L / min.

[0024] Furthermore, steps two and three can be repeated multiple times.

[0025] After adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0026] (1) The present invention can effectively ensure the uniformity of the atomic oxygen resistant coating on the product surface through the arched curing channel, ensure the curing effect, and improve the atomic oxygen resistance of the product.

[0027] (2) By setting up the grid plate, the present invention can make the atomic oxygen resistant solution in the impregnation tank flush with the grid plate, thereby maintaining the flatness of the liquid surface, reducing the liquid surface agitation caused by stirring, and ensuring the impregnation effect.

[0028] (3) The present invention can effectively increase the adhesion and polarity of the product surface through corona treatment, thereby improving the effect of atomic oxygen resistance coating. In addition, combined with high temperature curing, it can effectively ensure the uniformity of the atomic oxygen resistance coating on the product surface, further improving the atomic oxygen resistance performance of the product, and is suitable for mass production. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Figure 1 This is a structural diagram of the immersion tank of the atomic oxygen-resistant solution coating apparatus according to a preferred embodiment of the present invention;

[0031] Figure 2 This is a structural diagram of the curing channel of the atomic oxygen-resistant solution coating apparatus according to a preferred embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the atomic oxygen-resistant solution coating and wetting process in a preferred embodiment of the present invention.

[0033] Figure 4 This is a schematic diagram of the formation of an atomic oxygen resistant coating in a preferred embodiment of the atomic oxygen resistant solution coating process of the present invention;

[0034] In the diagram: 1. Impregnation tank; 2. Curing channel; 2-1 rising section; 2-2 falling section; 3. Roller; 4. Grid plate; 5. Inlet; 6. Outlet; 7. Air inlet; 8. Air extraction port; 9. Film; 10. Atomic oxygen resistant solution; 11. Atomic oxygen resistant coating. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] like Figure 1-2As shown, an atomic oxygen-resistant solution coating device includes an impregnation tank 1 and a curing channel 2. Rollers 3 are installed inside the impregnation tank 1, and a grid plate 4 is installed inside the impregnation tank 1 near its opening. The grid plate 4 has a feed inlet 5 and a discharge outlet 6. The curing channel 2 is located behind the impregnation tank 1 and is an arched structure composed of an ascending section 2-1 and a descending section 2-2. An air inlet 2-3 and an air extraction port 2-4 are respectively installed above the ascending section 2-1 and the descending section 2-2.

[0038] The product in this embodiment, taking film 9 as an example, is used to coat the surface of film 9 with atomic oxygen resistant solution 10 to improve its atomic oxygen resistance.

[0039] During the impregnation process, in order to improve the uniformity of the surface of the film 9 against atomic oxygen solution 10, the feed port 5 is opposite to the vertical tangent on the feed side of the roller 3, and the discharge port 6 is located outside the vertical tangent on the discharge side of the roller 3.

[0040] This allows the film 9 to be pulled out at an angle after impregnation, which can effectively reduce the dripping of the atomic oxygen resistant solution 10 on the surface of the film 9, thereby improving the uniformity of the atomic oxygen resistant coating 11 and preparing for subsequent high-temperature curing.

[0041] In order to facilitate the placement of the discharge port 6 on the outside of the vertical tangent of the discharge side of the roller 3 and achieve the effect of inclined traction, the impregnation tank 1 is a trapezoidal tank structure that is wider at the top and narrower at the bottom.

[0042] To improve the curing effect, the rising section 2-1 and the falling section 2-2 are symmetrically arranged, and the angle between the rising section 2-1 and the horizontal direction is 45°.

[0043] The 45° tilt setting allows the atomic oxygen resistant solution 10 to gradually solidify on the surface of the film 9, thereby achieving uniformity of the atomic oxygen resistant coating 11 and enhancing the stability of the atomic oxygen resistant coating 11 structure.

[0044] During coating, a traction mechanism can be installed between the impregnation tank 1 and the curing channel 2, as well as on the rear side of the curing channel 2, for effective traction of the film 9 to ensure the progress of the processing steps.

[0045] Secondly, based on the above-mentioned atomic oxygen resistant coating device, this embodiment also provides an atomic oxygen resistant solution coating process, including the following steps:

[0046] Step 1: Corona treatment, which involves applying a corona treatment to the surface of the product, i.e., film 9.

[0047] Corona treatment is applied to the surface of film 9 to increase its surface energy, which facilitates the uniform distribution of atomic oxygen resistant solution 10 on the film surface and increases the adhesion between atomic oxygen resistant coating 11 and film 9.

[0048] Specifically, taking a 50μm thick film 9 as an example, the corona power and corona power density required to achieve a surface tension of over 50mN / m at different production speeds are shown in Table 1 below:

[0049] Table 1: Relationship between production speed and corona power

[0050]

[0051] As shown in the table above, as the production speed decreases while maintaining the same surface tension, the corona power gradually decreases, while the corona power density remains almost constant. The surface tension is not significantly affected by changes in production speed because a decrease in production speed necessitates a reduction in corona power; otherwise, the film 9 is prone to breakdown. Therefore, the surface tension of the same product after corona treatment is related to the corona power density; that is, when the corona power density remains constant, the surface tension remains relatively stable.

[0052] For a single corona treatment machine, the process can be adjusted according to the corona power density to meet the surface tension requirements of film 9. The calculation formula is as follows:

[0053]

[0054] Where ρ is the corona power density, in kJ / m³. 2 ;

[0055] P – The actual power applied to the surface of the thin film 9, in kW (the corona power applied by each corona device is different due to differences in electrodes and gaps).

[0056] v – Production speed, in m / min;

[0057] h – Corona width of the thin film, in meters.

[0058] Therefore, by performing corona treatment on a 50μm thick film 9 according to the above method, with a corona power of 0.2-1.5kW and a traction rate of 1-10m / min, the surface tension of the film 9 can be made to be above 50mN / m, which meets the requirements for subsequent impregnation with atomic oxygen solution 10.

[0059] In addition, after corona treatment, the film roll was placed in an environment under certain conditions. After removing the surface layer (1m), a sample of film 9 was tested for surface tension. It was found that when the ambient temperature exceeded 50℃, the surface tension easily decreased, reaching a non-corona treatment level. In high-temperature and high-humidity environments, the surface tension rapidly decreased. In low-temperature and low-humidity environments, it gradually decreased with storage time. Therefore, corona-treated products need to undergo impregnation treatment. If impregnation is not possible immediately, they should be stored in a low-temperature and dry environment for no more than 48 hours.

[0060] Preferably, the storage environment temperature should be below 25°C and the humidity should be below 45%RH.

[0061] Step 2: Impregnation. The corona-treated product, i.e., film 9, is placed into an impregnation tank 1 containing an atomic oxygen resistant solution 10 for impregnation.

[0062] like Figure 3 As shown, during the impregnation process, when θ < 90°, the film 9 is more affinity to the impregnation liquid, meaning that the liquid is more likely to wet the surface of the film 9. The smaller the angle θ, the better the wettability. If θ > 90°, the surface of the film 9 is hydrophobic, meaning that the impregnation liquid is less likely to wet the solid and is more likely to move on the surface.

[0063] γ SV =γ SL +γ LV ·cosθ

[0064] F = γ LV *cosθ=γ SV -γ SL

[0065] According to the above formula, the wetting tension F is affected by the interfacial tension and the wetting angle. Corona treatment increases the film surface tension, reduces θ, and is beneficial for the wetting and spreading of the impregnating solution.

[0066] The impregnation method is as follows:

[0067] The product is vertically immersed in the atomic oxygen resistant solution 10 in the impregnation tank 1, and then pulled out of the impregnation tank 1 at a constant speed in an inclined direction.

[0068] Specifically, the atomic oxygen resistant solution 10 is placed in a trapezoidal impregnation tank 1, with the liquid level level with the height of the grid plate 4. Rollers 3 are installed at the bottom. The membrane 9 is vertically immersed into the atomic oxygen resistant solution 10 from the feed port 5, and after passing around the rollers 3, it is pulled out of the liquid surface at an angle. The membrane 9 avoids touching the grid plate 4 during the entry and exit process.

[0069] The main function of the grid plate 4 is to maintain the flatness of the liquid surface and reduce the fluctuation of the liquid surface caused by agitation. Tilting the plate to pull out the impregnation liquid surface can reduce the dripping phenomenon of the atomic oxygen resistant solution 10 on the surface of the film 9, thereby improving the uniformity of the atomic oxygen resistant coating 11 on the film 9, and also preparing for the subsequent high-temperature curing.

[0070] Step 3: High-temperature curing. The impregnated product, i.e., film 9, is sent into the curing channel 2 for heating and curing.

[0071] The curing channel 2 can be heated using, but is not limited to, thermocouples.

[0072] The inclined curing channel 2 ensures the uniformity of the atomic oxygen resistant coating 11 on the surface of the film 9. The rising section 2-1 of the curing channel 2 is a preheating and curing section, in which the internal temperature gradually increases and the temperature range is 120-155℃.

[0073] Specifically, the preheating and curing section is a high-temperature preheating and curing process of atomic oxygen resistant solution 10, which can be divided into three increasing temperature zones from bottom to top: T1 is the 120-125℃ preheating zone, T2 is the 130-135℃ preheating and curing zone one, corresponding to the curing temperature of silazane resin in atomic oxygen resistant solution 10, and T3 is the 150-155℃ preheating and curing zone two, corresponding to the curing temperature of silicone resin in atomic oxygen resistant solution 10.

[0074] The descending section 2-2 of curing channel 2 is the enhanced curing section, where the internal temperature gradually decreases and the temperature range is 110-135℃.

[0075] Specifically, the enhanced curing section is a further curing process after the atomic oxygen resistant coating 11 has been cured. This process strengthens the structure of the atomic oxygen resistant coating 11 and enhances its compactness. Simultaneously, the high temperature allows residual solvents in the atomic oxygen resistant coating 11 to evaporate, reducing surface defects. The enhanced curing section is divided into three decreasing temperature zones from top to bottom: T4 is 135-130℃, T5 is 125-120℃, and T6 is 115-110℃. The temperature should not decrease too rapidly, as this can easily lead to uneven shrinkage and cracking of the atomic oxygen resistant coating 11. Preferably, the total length of the curing channel 2 is 5.5 meters, the film traction rate of 9 is 1-1.5 m / min, the length of the preheating curing section is 2.75 meters, and the gelation time of the atomic oxygen resistant solution 10 is adjusted to within 2 minutes.

[0076] Too short a gel time can lead to uneven surface of the atomic oxygen resistant coating 11, while too long a gel time can result in insufficient curing of the atomic oxygen resistant coating 11, reducing structural stability. The traction rate of the film 9 must be strictly maintained at a constant speed, without excessive fluctuations. A decrease in the rate can lead to a reduction in the traction tension of the film 9, causing wrinkles on the surface of the film 9 and affecting the film formation effect of the atomic oxygen resistant coating 11. An increase in the rate can lead to a sudden increase in the traction tension of the product, making the traction connection device and the film 9 prone to breakage.

[0077] The air intake and exhaust rates for the preheating and curing section are 30-40 L / min, and the air intake and exhaust rates for the enhanced curing section are 30-35 L / min.

[0078] The air intake and exhaust configuration promotes the curing of the atomic oxygen resistant coating 11 and enhances the curing strength. Specifically, the height of the air intake 2-3 in the preheating curing section is lower than the height of its exhaust 2-4, and the height of the air intake 2-3 in the reinforced curing section is also lower than the height of its exhaust 2-4.

[0079] The preheating and curing section's air intake provides moisture from the air to participate in the curing process of the atomic oxygen resistant coating 11, while the exhaust system removes byproducts generated during the atomic oxygen resistant curing process, as well as solvents from the solution. The reinforcing and curing section's air intake is dry air, and the exhaust system removes byproducts generated during the atomic oxygen resistant curing process, as well as solvents from the solution.

[0080]

[0081] Where c is the concentration of the solute, which is actually the activity value when the activity coefficient is 1, and is a dimensionless quantity; σ is the surface tension of the solution; Γ is the relative surface adsorption amount of the solute (also known as surface excess), which represents the difference between the amount of solute contained in the surface layer per unit area and the amount of solute contained in the bulk solution with the same amount of solvent.

[0082] Based on the Gibbs adsorption isotherm above, the saturated adsorption capacity Γ can be calculated. The higher the solute concentration, the lower the saturated adsorption capacity; the higher the temperature, the lower the saturated adsorption capacity. To increase the absorption rate of water vapor from the air by the coated film 9 in this process, the solute concentration in the solution must be controlled to avoid being too high. Simultaneously, under the condition of satisfying curing requirements, a slightly lower temperature should be selected to promote the absorption of water vapor by the solution.

[0083] The aforementioned corona treatment, impregnation, and high-temperature curing are all single-layer process steps for atomic oxygen resistant coating. This process can be used to coat multiple layers of atomic oxygen resistant coating 11 according to the requirements of atomic oxygen erosion resistance level.

[0084] Steps two and three can be repeated multiple times.

[0085] Generally, a single-layer atomic oxygen resistant coating 11 needs to be thicker than 100 nm to effectively protect against atomic oxygen corrosion. However, single-layer coating technology carries certain technical risks, namely, uneven coating can lead to localized thinning or even complete absence of the atomic oxygen resistant coating 11, posing significant risks and failing to meet the requirements of aerospace equipment. The atomic oxygen resistant solution 10 coating technology described in this paper enables multi-layer coating; while meeting the thickness requirements, the number of atomic oxygen resistant solution 10 coatings can range from 3 to 10 layers. Considering a single-layer coating risk rate of 1%, the risk of a 4-layer coating can be reduced to 10%. -8 This significantly reduces the risks associated with coating technology and enhances product safety and reliability. Furthermore, the multi-layer coating process allows for flexible adjustment of the protective layer thickness, meeting the requirements for different levels of resistance to atomic oxygen erosion.

[0086] The atomic oxygen resistant coating apparatus and coating process disclosed in this invention have the following characteristics:

[0087] (1) The corona treatment can ensure the adhesion of the atomic oxygen-resistant solution 10 to the surface of the film 9 and increase the polarity of the surface of the film 9.

[0088] (2) The slanted traction process of impregnation with atomic oxygen resistant solution 10 reduces the phenomenon of impregnation liquid sagging, improves the uniformity of atomic oxygen resistant coating 11 on film 9, and prepares for subsequent high temperature curing.

[0089] (3) Figure 4 As shown, during the high-temperature curing process, the film 9 is pulled at a 45° angle. Under high-temperature conditions, the atomic oxygen resistant solution 10 gradually cures on the surface of the film 9. The 45° tilt angle enables the atomic oxygen resistant coating 11 to gradually cure. As the solvent evaporates, the functional components in the atomic oxygen resistant solution 10 gradually precipitate and gradually cure, thereby achieving uniformity of the atomic oxygen resistant coating 11 on the film 9 and enhancing the stability of the atomic oxygen resistant coating 11 structure.

[0090] (4) The dual-temperature curing section is adopted, which corresponds to the dual curing components in the atomic oxygen resistant solution 10. This can reduce the defects on the surface of the cured film 9 and improve the resistance to atomic erosion.

[0091] (5) The extraction and intake settings can accelerate the evaporation of the solvent in the atomic oxygen resistant solution 10, while the moisture in the air introduced by the intake can promote the curing of the atomic oxygen resistant coating 11. Controlling the extraction and intake rates can be coordinated with the curing rate of the atomic oxygen resistant coating 11 to achieve uniform stability of the film 9 surface;

[0092] (6) The performance requirements can be met by multi-layer coating process according to the requirements of atomic oxygen erosion resistance level. This atomic oxygen erosion resistance coating process is applicable to batch continuous operation and ensures the stability of product quality.

[0093] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A coating device for atomic oxygen-resistant solutions, characterized in that, include An impregnation tank (1) is provided with rollers (3) inside. A grid plate (4) is provided inside the impregnation tank (1) near its opening. The grid plate (4) has a feed inlet (5) and a discharge outlet (6). The curing channel (2) is located on the rear side of the impregnation tank (1), and the curing channel (2) is an arched structure composed of an ascending section (2-1) and a descending section (2-2). An air inlet (7) and an air extraction port (8) are respectively provided above the ascending section (2-1) and the descending section (2-2). The atomic oxygen resistant solution (10) is placed in a trapezoidal impregnation tank (1), with the liquid level being level with the height of the grid plate (4), and rollers (3) are installed at the bottom. The rising section (2-1) of the curing channel (2) is the preheating and curing section, and its internal temperature gradually increases; The descending section (2-2) of the curing channel (2) is the enhanced curing section, and its internal temperature gradually decreases; The feed inlet (5) is opposite to the vertical tangent on the feed side of the roller (3), and the discharge outlet (6) is located outside the vertical tangent on the discharge side of the roller (3).

2. The atomic oxygen-resistant solution coating apparatus according to claim 1, characterized in that, The impregnation tank (1) is a trapezoidal tank structure that is wider at the top and narrower at the bottom.

3. The atomic oxygen-resistant solution coating apparatus according to claim 1, characterized in that, The ascending segment (2-1) and descending segment (2-2) are symmetrically arranged, and the ascending segment (2-1) makes an angle of 45° with the horizontal direction.

4. A coating process for a solution resistant to atomic oxygen, characterized in that, Includes the following steps: Step 1: Corona treatment, which involves applying a corona electrode to the surface of the product; Step 2: Impregnation. The corona-treated product is placed into an impregnation tank (1) containing an atomic oxygen resistant solution for impregnation. Step 3: High-temperature curing. The impregnated product is sent into the curing channel (2) for heating and curing. The solidification channel (2) is an arched structure consisting of an ascending section (2-1) and a descending section (2-2); The rising section (2-1) of the curing channel (2) is the preheating and curing section, and its internal temperature gradually increases; The descending section (2-2) of the curing channel (2) is the enhanced curing section, and its internal temperature gradually decreases; In step two, the impregnation method is as follows: The product is vertically immersed in the atomic oxygen resistant solution (10) in the impregnation tank (1), and then pulled out of the impregnation tank (1) at a constant speed in an inclined direction.

5. The atomic oxygen-resistant solution coating process according to claim 4, characterized in that, The temperature range of the preheating and curing section is 120-155℃; The temperature range of the reinforced curing section is 110-135℃.

6. The atomic oxygen-resistant solution coating process according to claim 4, characterized in that, The air intake and exhaust rates of the preheating and curing section are 30-40 L / min; The air intake and exhaust rates of the reinforced curing section are 30-35 L / min.

7. The atomic oxygen-resistant solution coating process according to claim 4, characterized in that, Steps two and three can be repeated multiple times.

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