Infrared stealth polytetrafluoroethylene radome film coating and preparation method

Abstract

The application discloses a kind of polytetrafluoroethylene radome film coating with infrared stealth and preparation method, coating is coated on the single-color infrared stealth film coating of glass fiber plain cloth polymer film, single-color infrared stealth film coating is polytetrafluoroethylene coating with superfine flaky low-emissivity particle and pigment in multiple passes, the color of single-color infrared stealth film coating is adapted to the environment.The application coats polytetrafluoroethylene radome film coating with infrared stealth function on glass fiber plain cloth polymer film, for building large radar antenna cover and other facilities, effectively realizes the thermal infrared stealth of radome, and gives consideration to visible light band camouflage protection.

Description

Technical Field

[0001] This invention relates to the field of camouflage and protection technology, specifically to a thin film coating of polytetrafluoroethylene (PTFE) radar dome with infrared stealth and its preparation method. Background Technology

[0002] With the rapid development of modern detection technology, the survivability of important targets has been greatly threatened. Therefore, improving the counter-detection capabilities of these important targets is particularly important. Utilizing stealth and camouflage protection technology to protect ground targets has become an important means to improve their survivability in the future. Stealth and camouflage technology, also known as target signature control technology, makes targets difficult to detect and identify by controlling or reducing their signature signals.

[0003] In recent years, polytetrafluoroethylene (PTFE) film materials have been gradually applied to the protection of ground radar radomes. This material is a white or brightly colored thin-film polymer composite material, but it lacks ground camouflage capabilities. Its main characteristics are: 1) White film structures used in radar radomes have obvious visible light characteristics, making them easily detectable by aerospace reconnaissance, posing a significant challenge to radar survivability; 2) Brightly colored PTFE film polymer composite materials blend poorly with the background earth-toned or green background, and their dielectric properties affect radar wave transmittance.

[0004] Therefore, it is of great significance to innovate polytetrafluoroethylene (PTFE) radome film materials to reduce the radiation difference between target and background features based on low infrared radiation characteristics, and to achieve the purpose of preventing infrared detection without affecting the transmission of radar waves in the operating band by using gradient design and color control of low emissivity particle filler. Summary of the Invention

[0005] To address the problem that existing polytetrafluoroethylene (PTFE) radome film materials lack infrared stealth capabilities, leading to a decrease in their survivability and protection, this invention provides an infrared stealth polytetrafluoroethylene (PTFE) radome film coating and its preparation method.

[0006] This invention discloses an infrared stealth polytetrafluoroethylene (PTFE) radome thin film coating. The coating is a monochromatic infrared stealth thin film coating applied to a glass fiber plain weave polymer film, and the coated glass fiber plain weave composite film directly serves as the radome. The monochromatic infrared stealth thin film coating consists of multiple layers of PTFE coating containing ultrafine flake-shaped low emissivity particles and pigments, and the color of the monochromatic infrared stealth thin film coating is adapted to the surrounding environment.

[0007] As a further improvement of the present invention, the monochromatic infrared stealth film coating is applied to one or both sides of the glass fiber plain weave polymer film.

[0008] As a further improvement of the present invention, the ultrafine flake-shaped low emissivity particles include one or more of aluminum powder, copper powder, ATO, graphene or MXene two-dimensional materials, and the pigment includes one or more of carbon black, titanium dioxide, cadmium yellow and cobalt blue.

[0009] As a further improvement of the present invention, the particle size of the ultrafine flake-shaped low emissivity particles and the pigment is no greater than 10 μm.

[0010] As a further improvement of the present invention, the content of ultrafine flake-shaped low emissivity particles in the monochromatic infrared stealth film coating decreases in a gradient of 25-10 wt% from the outer layer to the inner layer.

[0011] As a further improvement of the present invention, the thickness of the monochromatic infrared stealth film coating is 51-63 μm. Preferably, the monochromatic infrared stealth film coating is coated in three layers, each layer having a thickness of 17-21 μm. The content of ultrafine flake-like low emissivity particles in the outermost monochromatic infrared stealth film coating to the innermost monochromatic infrared stealth film coating decreases in a gradient of 25-10 wt%.

[0012] As a further improvement of the present invention, the infrared countermeasure band of the monochromatic infrared stealth film coating is 3-5μm and 8-14μm, and the visible light countermeasure band is 0.3-0.78μm; the single-pass transmittance (power transmission coefficient) of the monochromatic infrared stealth film coating in the radar operating band is not less than 85%.

[0013] This invention also discloses a method for preparing an infrared stealth polytetrafluoroethylene radome thin film coating, comprising: Step 1: Add the polytetrafluoroethylene film coating solvent, ultrafine flake low emissivity particles, pigments and fillers to the mixing tank in sequence, stir and mix well, and then disperse by sand milling until the fineness is no greater than 10μm; Step 2: Gradually coat the glass fiber plain weave polymer film with a polytetrafluoroethylene film coating solvent containing low emissivity particles and pigments at a mass fraction of not less than 90%. The coating thickness is adjustable. Step 3: Place the product into a tunnel kiln for heating and curing, gradually increasing the temperature to between 370-410℃, with a curing time of 2-8 minutes.

[0014] As a further improvement of the present invention, in step 1, a polytetrafluoroethylene thin film coating solvent containing low emissivity particles and pigments is prepared by ball milling.

[0015] As a further improvement of the present invention, in step 2, the polytetrafluoroethylene film coating solvent containing low emissivity particles and pigments is coated by a roller coating method.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention coats a polytetrafluoroethylene (PTFE) radome thin film coating with infrared stealth function onto a glass fiber plain weave polymer film for constructing large radar antenna radomes and other facilities, effectively achieving thermal infrared stealth of the radome while also providing camouflage and protection in the visible light band. In addition, this invention enables the roll coating of glass fiber polymer composite stealth film materials, saving subsequent coating time and tedious auxiliary work, improving work efficiency, and meeting the high-tech needs of the rapidly developing defense industry. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The present invention will now be described in further detail: This invention provides an infrared stealth polytetrafluoroethylene (PTFE) radome thin film coating. The coating is a monochromatic infrared stealth thin film coating applied to a glass fiber plain weave polymer film, with the coated glass fiber plain weave film directly serving as the radome. The monochromatic infrared stealth thin film coating consists of multiple layers of PTFE coating containing ultrafine flake-shaped low emissivity particles and pigments, and the color of the monochromatic infrared stealth thin film coating is adapted to the surrounding environment.

[0019] Specifically: The camouflage pattern of the monochrome infrared stealth film coating of the present invention is determined by the following method: 1) Conduct background investigation; 2) Select a monochrome camouflage design, choosing the dominant color in the background that is closest to the average brightness as the monochrome camouflage color; 3) Modulate a monochrome infrared stealth film coating according to the monochrome compatible infrared low emissivity modulation.

[0020] The monochromatic infrared stealth film coating of the present invention is coated on one or both sides of a glass fiber plain weave polymer film. The ultrafine flake-shaped low emissivity particles include one or more of aluminum powder, copper powder, ATO, graphene or MXene two-dimensional materials. The pigment includes one or more of carbon black, titanium dioxide, cadmium yellow and cobalt blue. The particle size of the ultrafine flake-shaped low emissivity particles and the pigment is not greater than 10 μm.

[0021] The content of ultrafine flake-like low emissivity particles in the monochromatic infrared stealth film coating of the present invention decreases in a gradient of 25-10 wt% from the outer layer to the inner layer. The thickness of the monochromatic infrared stealth film coating is 51-63 μm. Preferably, the monochromatic infrared stealth film coating is coated in three layers, each layer having a thickness of 17-21 μm. The content of ultrafine flake-like low emissivity particles in the monochromatic infrared stealth film coating from the outermost layer to the innermost layer decreases in a gradient of 25-10 wt%.

[0022] The monochromatic infrared stealth film coating of the present invention has infrared countermeasure bands of 3-5μm and 8-14μm, and also has visible light countermeasure bands of 0.3-0.78μm; the monochromatic infrared stealth film coating has a single-pass transmittance (power transmission coefficient) of not less than 85% in the radar operating band.

[0023] The aforementioned infrared stealth coating is composed of resin (polytetrafluoroethylene resin), ultrafine flake-shaped low emissivity particles, pigments, fillers (thickeners, etc.), and additives. By selecting ultrafine flake-shaped low emissivity particles, pigments, and fillers, the low emissivity reduces infrared energy radiation while simulating different background colors.

[0024] This invention provides a method for preparing a thin film coating of infrared stealth polytetrafluoroethylene radome, comprising: Step 1: Add the polytetrafluoroethylene film coating solvent, ultrafine flake low emissivity particles, pigments and fillers to the mixing tank in sequence, stir and mix well, and then disperse them by ball milling to a fineness of no more than 10μm; to prevent the ultrafine flake low emissivity particles and pigment particles from being too coarse and causing roller scratching. Step 2: Gradually coat a polytetrafluoroethylene (PTFE) film coating solvent containing low emissivity particles and pigments with a mass fraction of not less than 90% onto a glass fiber plain weave polymer film. The coating thickness is adjustable. The PTFE film coating solvent containing low emissivity particles and pigments is coated using a roller coating method. Step 3: Place the product into a tunnel kiln for heating and curing, gradually increasing the temperature to between 370-410℃, with a curing time of 2-8 minutes. Example 1

[0025] A gray, infrared-stealth-functional polytetrafluoroethylene (PTFE) radome thin-film coating was prepared using a ball milling method. The PTFE thin-film coating solvent contained ultrafine flake aluminum powder, low-emissivity MXene two-dimensional material particles, and pigments such as titanium dioxide and carbon black. The PTFE thin-film coating solvent, low-emissivity particles, pigments, and fillers were sequentially added to a mixing tank and stirred at high speed to prepare ultrafine camouflage pigment particles. The prepared slurry was then dispersed by sand milling to a fineness of no more than 6 μm. Using a roller coating method, three layers of 17 μm low-emissivity particles and pigments were progressively coated onto a glass fiber plain weave PTFE thin film. The content of ultrafine flake low-emissivity particles in the coating decreased gradually from 25 wt% in the outer layer, 18 wt% in the middle layer, to 10 wt% in the inner layer. The total thickness of the infrared stealth coating was 51 μm. The coating was then heated and cured in a tunnel kiln, with the temperature increased to 390℃ in three stages and a curing time of 8 minutes. Example 2

[0026] A green, infrared-stealth polytetrafluoroethylene (PTFE) radome thin-film coating was prepared using a ball milling method. The PTFE thin-film coating solvent contained ultrafine flake aluminum powder, low-emissivity graphene particles, and ultrafine cobalt blue pigment particles. The PTFE thin-film coating solvent, low-emissivity particles, pigment, and fillers were sequentially added to a mixing tank and stirred at high speed to prepare ultrafine camouflage pigment particles. The prepared slurry was then dispersed by sand milling to a fineness of no more than 6 μm. Using a roller coating method, three layers of 20 μm low-emissivity particles and pigment were progressively coated onto a glass fiber plain weave PTFE thin film. The content of ultrafine flake low-emissivity particles in the coating decreased gradually from 25 wt% in the outer layer, 15 wt% in the middle layer, to 10 wt% in the inner layer. The total thickness of the infrared stealth coating was 60 μm. The coating was then heated and cured in a tunnel kiln, with the temperature increased to 400℃ in three stages and a curing time of 7 minutes. Example 3

[0027] A brownish-brown PTFE radome thin-film coating with infrared stealth capabilities was prepared using a ball milling method. The PTFE thin-film coating solvent contained ultrafine flake copper powder, ATO low-emissivity particles, and ultrafine carbon black and titanium dioxide pigment particles. The PTFE thin-film coating solvent, low-emissivity particles, pigments, and fillers were sequentially added to a mixing tank and stirred at high speed to prepare ultrafine camouflage pigment particles. The prepared slurry was then dispersed by sand milling to a fineness of no more than 7μm. Using a roller coating method, three layers of 21μm low-emissivity particles and pigments were progressively coated onto a glass fiber plain weave PTFE thin film. The content of ultrafine flake low-emissivity particles decreased gradually from 25wt% in the outer layer, 20wt% in the middle layer, to 10wt% in the inner layer. The total thickness of the infrared stealth coating was 63μm. The coating was then heated and cured in a tunnel kiln, with the temperature increased to 410℃ in three stages and a curing time of 5 minutes.

[0028] The advantages of this invention are: This invention coats a polytetrafluoroethylene (PTFE) radome thin film coating with infrared stealth function onto a glass fiber plain weave polymer film for constructing large radar antenna radomes and other facilities, effectively achieving thermal infrared stealth of the radome while also providing camouflage and protection in the visible light band. In addition, this invention enables the roll coating of glass fiber polymer composite stealth film materials, saving subsequent coating time and tedious auxiliary work, improving work efficiency, and meeting the high-tech needs of the rapidly developing defense industry.

[0029] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A radar dome film with infrared stealth function, characterized in that, The radome film is a glass fiber plain weave polymer film; wherein, a monochromatic infrared stealth film coating is coated on the glass fiber plain weave polymer film, the monochromatic infrared stealth film coating is a polytetrafluoroethylene coating containing ultrafine flake-shaped low emissivity particles and pigments, and the color of the monochromatic infrared stealth film coating is adapted to the environment. The content of ultrafine, low-emissivity flake particles in the monochromatic infrared stealth film coating decreases gradually from 25 wt% to 10 wt% from the outermost layer to the innermost layer. The monochromatic infrared stealth film coating has infrared countermeasures in the 3-5μm and 8-14μm bands, and also has visible light countermeasures in the 0.3-0.78μm band; the monochromatic infrared stealth film coating has a single-pass transmittance of not less than 85% in the radar operating band.

2. The radome film as described in claim 1, characterized in that, The monochrome infrared stealth film coating is applied to one or both sides of the glass fiber plain weave polymer film.

3. The radome film as described in claim 1, characterized in that, The ultrafine flake-shaped low emissivity particles include one or more of aluminum powder, copper powder, ATO, graphene, or MXene two-dimensional materials, and the pigments include one or more of carbon black, titanium dioxide, cadmium yellow, and cobalt blue.

4. The radome film as described in claim 1 or 3, characterized in that, The particle size of the ultrafine flake-shaped low emissivity particles and pigments is no greater than 10 μm.

5. The radome film as described in claim 1, characterized in that, The thickness of the monochrome infrared stealth film coating is 51-63 μm.