A golf ball for enhancing 77 ghz millimeter wave radar reflection and a method of manufacturing the same

Abstract

This invention discloses a golf ball for enhancing the reflection performance of 77GHz millimeter-wave radar, comprising: a golf ball body; a conductive coating disposed on the surface of the golf ball body; the conductive coating is a conductive material layer formed by liquid-phase impregnation and drying, wherein the conductive material is selected from at least one of silver nanoparticles, graphene, or carbon-based conductive materials; the conductive coating is uniformly adhered to the surface of the golf ball and the pit structure on the surface, covering the pit structure, and the coating does not fill the pits; and the total weight gain of the golf ball does not exceed 0.5g. The preparation method includes the following steps: Step 1: Diluting the conductive coating with a diluent to a solid content of 1%–5% to obtain an impregnation solution; Step 2: Completely immersing the golf ball in the impregnation solution; Step 3: Removing excess liquid by centrifugation or spin-drying; Step 4: Performing a low-temperature drying treatment on the spin-dried golf ball.

Description

Technical Field

[0001] This invention relates to the fields of sports equipment and radar detection technology, and in particular to a golf ball for enhancing the reflection of 77GHz millimeter-wave radar and its manufacturing method. Background Technology

[0002] In moving target detection systems based on 77GHz millimeter-wave radar (such as TI AWR2944), golf balls, as small-sized, high-speed targets, have a low radar cross-section (RCS), resulting in weak echo signals, which affects the stability and accuracy of trajectory detection.

[0003] Golf balls are typically made of a rubber or resin core and a shell with a pitted structure. Although their surface has certain scattering characteristics, it is still insufficient to provide a stable echo signal in the millimeter wave band (wavelength of about 3.9 mm), which is especially noticeable when radar is deployed laterally.

[0004] Existing technologies often improve detection performance by adding external reflectors or improving radar algorithms, but these methods can alter the ball's structure, increase weight, or negatively impact flight performance. Therefore, there is an urgent need for a technical solution to improve the radar reflectivity of golf balls without significantly increasing weight or altering the ball's structure.

[0005] With the increasing application of millimeter-wave radar in motion trajectory detection, the demand for real-time tracking of golf ball flight trajectories is constantly growing. However, due to the small size and non-metallic surface of golf balls, their radar cross-section in the 77GHz band is relatively low, leading to: weak echo signal Limited detection distance Poor stability of multi-target tracking

[0006] Existing technologies are mainly improved in the following ways: 1. Increase radar transmission power (increase system cost); 2. Algorithm optimization (limited effectiveness); The above methods suffer from high costs or limited effectiveness. Summary of the Invention

[0007] This invention proposes a golf ball based on liquid immersion to form an ultrathin conductive layer, which improves millimeter-wave reflection performance without changing the ball's structure and aerodynamic properties.

[0008] A golf ball for enhancing the reflection performance of 77GHz millimeter-wave radar, comprising: The golf ball itself; A conductive coating is applied to the surface of the golf ball body; The conductive coating is a conductive material layer formed by liquid phase impregnation and drying, and the conductive material is selected from at least one of silver nanoparticles, graphene or carbon-based conductive materials. The conductive coating is uniformly adhered to the surface of the golf ball and the pit structure on the surface, and covers the pit structure, but the coating does not fill the pits; Furthermore, the total weight gain of the golf ball does not exceed 0.5g.

[0009] Furthermore, the conductive coating is a discontinuous conductive layer, wherein the maximum size of the discontinuous region does not exceed 0.4 mm.

[0010] Furthermore, the conductive coating is formed by diluting a water-based or alcohol-based conductive coating, wherein the solid content of the diluted coating is 1% to 5%.

[0011] Furthermore, the thickness of the conductive coating is from 0.3 micrometers to 50 micrometers.

[0012] Furthermore, the conductive coating also contains an adhesive.

[0013] Furthermore, the adhesive is polyvinyl alcohol (PVA) or an aqueous resin.

[0014] Furthermore, the conductive coating is a thickness-increasing layer formed by at least two soak-dry cycles.

[0015] Furthermore, under the action of 77GHz millimeter-wave radar, the radar cross-section (RCS) of the golf ball treated with the conductive coating is increased by at least 10dB compared with the untreated golf ball.

[0016] The present invention also provides a golf ball for enhancing the reflection performance of 77GHz millimeter-wave radar, the golf ball having a multi-layer structure, comprising: A golf ball body, the golf ball body comprising a core, at least one intermediate layer, and a shell; A conductive coating or conductive film disposed on the surface of the core or any of the intermediate layers; The conductive coating or conductive film is a conductive material layer formed by liquid phase impregnation and drying, and the conductive material is selected from at least one of silver nanoparticles, graphene or carbon-based conductive materials. The conductive coating or conductive film is uniformly attached to the surface of the core or the surface of the intermediate layer; Furthermore, the total weight gain of the coated golf ball does not exceed 0.5g.

[0017] This invention also provides a method for enhancing the reflectivity of a golf ball under 77GHz millimeter-wave radar, comprising the following steps: Step 1: Dilute the conductive coating with a diluent to a solid content of 1% to 5% to obtain an immersion solution; the diluent is any one of deionized water, anhydrous ethanol or isopropanol.

[0018] Step 2: Immerse the golf ball completely in the soaking solution for 5 to 10 seconds; Step 3: Remove the soaked golf balls and remove excess liquid by centrifugation or spin-drying; Step 4: Dry the spun golf balls at a low temperature; The conductive coating contains at least one conductive material selected from silver nanoparticles, graphene, or carbon-based conductive materials, and the total weight gain of the treated golf ball does not exceed 0.5g.

[0019] Beneficial effects 1. Does not change the structure of the sphere; 2. Extremely low weight gain (<1%); 3. Significantly improves radar detection capabilities (10 to 20 dB); 4. The process is simple and can be scaled up; 5. Compatible with existing radar systems, requiring no additional hardware modifications. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 is a schematic cross-sectional view of the surface and pits of the golf ball in an embodiment of the present invention; Figure 2 is a partial enlarged cross-sectional view of the surface and pits of the golf ball in an embodiment of the present invention; Figure 3 is a schematic cross-sectional view of a golf ball in another embodiment of the present invention; Figure 4 is a schematic diagram of the process flow for preparing the conductive coating on a golf ball in an embodiment of the present invention. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0023] See Figure 1 , Figure 2 As shown. This invention provides a golf ball for enhancing the reflection performance of 77GHz millimeter-wave radar, comprising: The golf ball itself; A conductive coating is applied to the surface of the golf ball body; The conductive coating is a conductive material layer formed by liquid phase impregnation and drying, and the conductive material is selected from at least one of silver nanoparticles, graphene or carbon-based conductive materials. The conductive coating is uniformly adhered to the surface of the golf ball and the pit structure on the surface, and covers the pit structure, but the coating does not fill the pits; Furthermore, the total weight gain of the golf ball does not exceed 0.5g.

[0024] It should be noted that, Figure 1 and Figure 2 In the image, due to the thinness of the conductive coating, only its location is shown; because the conductive coating is uniformly adhered to the surface of the golf ball and its pitted structure, therefore... Figure 1 and Figure 2 The internal structure of the unreacted golf ball.

[0025] It should be noted that the conductive material layer can be: 1. Graphene (best choice, king of high-frequency reflection) Type: Few-layer graphene (1–5 layers), sheet diameter 5–20 μm, purity ≥95%; Key parameter: Conductivity ≥10 6 S / cm, sheet resistance 0.1–2Ω / □, reflectivity ≥92% at 77GHz; Applications: High-end reflective films, radome inner coatings, flexible reflective patches; Commercially available high-frequency graphene materials, such as few-layer graphene with a sheet diameter of 5–20 μm and an electrical conductivity ≥10, can be used. 6 S / cm; 2. Carbon nanotubes (CNTs) (high conductivity + easy dispersion, cost-effective) Type: Multi-walled carbon nanotubes (MWCNTs), diameter 10–30 nm, length 10–50 μm, purity ≥90%; Key parameter: Conductivity ≥10 4 S / cm, sheet resistance 1–5Ω / □, 77GHz reflectivity ≥88%; Applications: Reflective coatings, modified plastics (bumpers / radar mounts), composite films; Commercially available high-frequency conductive carbon nanotube materials can be used, such as multi-walled carbon nanotubes, with a diameter of 10–30 nm, a length of 10–50 μm, and an electrical conductivity ≥10. 4 S / cm; 3. Graphite + high conductivity carbon black compound (low cost, large-area application) Combination: Natural flake graphite (325 mesh, carbon ≥ 98%) + superconducting carbon black (acetylene black / superconducting carbon black, DBP ≥ 300); Ratio: 70% graphite + 30% carbon black (optimal conductive network); Key parameters: Sheet resistance 5–15Ω / □, 77GHz reflectivity ≥85%, lowest cost.

[0026] In one embodiment, the conductive coating is a discontinuous conductive layer, wherein the maximum size of the discontinuous region does not exceed 0.4 mm.

[0027] A golf ball's surface has a few discontinuous gaps of 0.2–0.4 mm, which slightly reduce the reflection of 77 GHz millimeter-wave radar, but still form an effective reflection network (suitable for radar-reflecting balls, scattering points, etc.); this is because the wavelength of 77 GHz is around 4 mm. If the discontinuous gaps are greater than 0.5 mm, 77 GHz millimeter-wave radar begins to transmit in large quantities, and the reflection network becomes ineffective. It should be noted that because the surface of a golf ball is pitted and uneven, soaking it may naturally create discontinuities at the edges of these pits and uneven areas.

[0028] In one embodiment, the conductive coating is formed by diluting a water-based or alcohol-based conductive coating, wherein the solid content of the diluted coating is 1% to 5%.

[0029] Water base: deionized pure water. Alcohol group: Anhydrous ethanol / Isopropanol IPA (Isopropanol IPA is preferred due to its slower evaporation, better leveling, and more uniform film formation). Dilute only with deionized water / anhydrous ethanol / isopropanol IPA; do not add other resins or fillers arbitrarily to maintain the original conductive system of the coating.

[0030] In one embodiment, the thickness of the conductive coating is from 0.3 micrometers to 50 micrometers. At the 77 GHz millimeter-wave band, the skin depth of good conductors such as silver, copper, and nickel is approximately 0.05–0.1 μm. In engineering, when the thickness of the conductive coating reaches 2–3 times the skin depth of the metal, an equivalent continuous conductive reflective surface can be formed. This application limits the thickness of the conductive coating to 0.3 μm–50 μm, where the lower limit of 0.3 μm corresponds to 3 times the maximum skin depth of the metal, ensuring that conductive components such as silver nanoparticles can form a complete 77 GHz millimeter-wave conductive reflective interface; the upper limit of 50 μm is suitable for the skin depth characteristics of carbon-based conductive materials (a few micrometers to tens of micrometers), ensuring the full formation of the carbon-based conductive network, while also controlling the overall weight gain of the coating to no more than 0.5g, avoiding the coating from filling the pits on the surface of the golf ball, thus balancing millimeter-wave reflection performance, ball weight, and aerodynamic morphology requirements.

[0031] In one embodiment, the conductive coating further includes an adhesive. The adhesive in the conductive coating improves the interfacial adhesion between the conductive coating and the surface of the golf ball, ensuring the conductive material adheres firmly to the surface and pits of the golf ball, preventing coating detachment, maintaining the integrity of the coating structure, and ensuring stable 77GHz millimeter-wave reflection performance.

[0032] In one embodiment, the adhesive is polyvinyl alcohol (PVA) or an aqueous resin.

[0033] In one embodiment, the conductive coating is a thickness-increasing layer formed by at least two immersion-drying cycles.

[0034] This invention employs at least two immersion-drying cycles to prepare the conductive coating. Because it uses a water-based or alcohol-based conductive coating with a solid content of 1%–5%, the dry film thickness formed by a single immersion-drying cycle is relatively small, preventing the failure to reach the effective reflection critical thickness of 0.3 μm. By accumulating the film thickness layer by layer through multiple immersion-drying cycles, the total thickness of the conductive coating can be precisely controlled within the range of 0.3 μm to 50 μm. This forms an equivalent continuous conductive reflective interface. Furthermore, by controlling the number of cycles, the maximum coating thickness is limited to no more than 50 μm, preventing the coating from being too thick and filling in the pits on the golf ball's surface, thus avoiding excessive weight gain. Simultaneously, the layer-by-layer film structure ensures uniform adhesion of the coating to the ball's surface and pits.

[0035] In one embodiment, under the action of 77 GHz millimeter-wave radar, the radar cross-section (RCS) of the golf ball treated with the conductive coating is increased by at least 10 dB compared with the untreated golf ball.

[0036] Calculations and model analysis show that after a golf ball is treated with a conductive coating, its radar cross-section (RCS) in the 77 GHz band increases from approximately -43 dBsm to approximately -30 dBsm, an improvement of over 10 dB. This significantly enhances the detection capability and trajectory tracking stability of millimeter-wave radar for this target. The paper "Radar Cross-Section of Sport Balls" (2018) measured the RCS of volleyballs, soccer balls, and basketballs in the 0.8–40 GHz range and interpreted the spectral characteristics using simulations. It can serve as an analogy for a golf ball (which is smaller). The RCS of an untreated golf ball (due to medium scattering) is approximately -43 dBsm.

[0037] A standard golf ball has a diameter of 42.7 mm, and its equivalent radius r = 21.35 mm = 0.02135 m. Substituting these values ​​into the calculation, we get σ as the radar cross section and r as the equivalent radius of the golf ball.

[0038] Converted to dBsm, the standard decibel form commonly used in radar:

[0039] The actual conductive silver coating is a thin conductive layer, not an ideal perfect conductor. Therefore, a reflection efficiency coefficient of 0.5 to 0.9 is introduced, and a conservative value of α = 0.7 is used for correction.

[0040] See Figure 3 As shown, the present invention also provides a golf ball for enhancing the reflection performance of 77GHz millimeter-wave radar, the golf ball having a multi-layer structure, comprising: A golf ball body, the golf ball body comprising a core, at least one intermediate layer, and a shell; A conductive coating or conductive film disposed on the surface of the core or any of the intermediate layers; The conductive coating or conductive film is a conductive material layer formed by liquid phase impregnation and drying, and the conductive material is selected from at least one of silver nanoparticles, graphene or carbon-based conductive materials. The conductive coating or conductive film is uniformly attached to the surface of the core or the surface of the intermediate layer; Furthermore, the total weight gain of the coated golf ball does not exceed 0.5g.

[0041] The conductive coating is first applied to the outer surface of the golf ball's core. After drying, the middle layer of the golf ball is made, and the conductive coating is applied to the outer surface of the middle layer. After drying, the outer shell of the golf ball is finally made, but the outer shell of the golf ball is not coated with a conductive coating.

[0042] It should be noted that, Figure 3 In the figure, due to the thinness of the conductive coating, only the location of the conductive coating is shown.

[0043] See Figure 4 As shown, the present invention also provides a method for enhancing the reflectivity of a golf ball under 77GHz millimeter-wave radar, comprising the following steps: Step 1: Dilute the conductive coating with a diluent to a solid content of 1% to 5% to obtain an immersion solution; the diluent is any one of deionized water, anhydrous ethanol or isopropanol.

[0044] The main component of the soaking solution is a diluent: deionized water, anhydrous ethanol, or isopropanol, selected from at least one of silver nanoparticles, graphene, or carbon-based conductive materials. Optional trace additives can enhance the effect.

[0045] Trace additives: Wetting and leveling agent (0.05%~0.1%): Prevents pinholes and exposed substrate on the surface of the sphere.

[0046] A small amount of dispersant: to prevent the agglomeration and sedimentation of carbon fillers with low solids content.

[0047] Conductive coating with 1% solid content: extremely thin coating, strong transparency, and best uniformity; Conductive coating with 3% solid content: balanced and recommended, continuous conductivity, no dripping, suitable for 77GHz reflection; Conductive coating with 5% solid content: thicker coating, better conductivity, prone to slight dripping, soaking time needs to be controlled.

[0048] Step 2: Immerse the golf ball completely in the soaking solution for 5 to 10 seconds.

[0049] After dilution, stir at low speed for 5-10 minutes, let stand to defoam for 15 minutes, and then soak. Completely immerse the spheres, soak for 5-10 seconds, and then slowly lift them vertically, dripping at a uniform speed to avoid localized liquid accumulation and dripping.

[0050] Immersion solution ambient temperature: Optimal temperature: 20-25℃, constant room temperature; below 15℃: viscosity increases, wetting is poor, spheres are prone to showing through, coating is uneven; above 30℃: alcohol / water evaporates too quickly, liquid surface forms skin, coating is uneven in thickness, and bubbles are also easy to form.

[0051] Temperature of the sphere substrate: It should be the same as the temperature of the soaking solution. Avoid large temperature differences. The soaking solution should be at room temperature (25℃). Do not soak cold spheres directly in hot solution or hot spheres in cold solution, as this will cause the conductive coating to peel, shrink, and crack.

[0052] Step 3: Remove the soaked golf balls and remove excess liquid by centrifugation or spin-drying; Step 4: Dry the spun golf balls at a low temperature; The conductive coating contains at least one conductive material selected from silver nanoparticles, graphene, or carbon-based conductive materials, and the total weight gain of the treated golf ball does not exceed 0.5g.

[0053] When drying, if water-based drying is used, first allow it to surface dry at room temperature for 10-15 minutes, then bake it at 60-80℃ for 30-60 minutes;

[0054] If an alcohol-based product is used, it will basically air dry after standing at room temperature for 20-30 minutes due to its rapid evaporation, or it can be dried at a low temperature of 50-60℃.

[0055] High-temperature baking is not allowed, as the thin coating with low solids content is prone to cracking and breakage of the conductive network, affecting 77GHz reflection.

[0056] It should be noted that if a golf ball is controlled or selected with an initial weight of 45g, and then the weight is increased by 0.5g to 45.5g, it meets the USGA / R&A rule: golf balls must not exceed 45.93g.

[0057] The weight of a standard golf ball is between 45g and 45.5g. After the above selection, the weight gain is still within the standard weight range.

[0058] Impact on actual hitting performance: 1. Weight inertia +0.0g relative weight gain percentage: Approximately 0% weight gain; The swing feels almost imperceptible; At the same clubhead speed: the initial ball velocity and flight distance remain unchanged, so neither professional nor amateur players can feel the difference.

[0059] 2. Rotation and Spin An additional conductive coating layer less than 50μm was added to the surface, resulting in slight changes to the spherical surface roughness and coefficient of friction. The inversion will change slightly; The ball's landing point and grip on the turf are slightly affected, but these changes are negligible for everyday use.

[0060] 3. Center of gravity and roundness As long as you soak it and then centrifuge it at a constant speed to ensure even coating: It will not be biased or deformed; The flight trajectory and lateral rotation will not deviate.

[0061] This is why the process of soaking-uniform centrifugation-low temperature drying is adopted.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A golf ball for enhancing the reflection performance of 77GHz millimeter-wave radar, characterized in that, include: The golf ball itself; A conductive coating is applied to the surface of the golf ball body; The conductive coating is a conductive material layer formed by liquid phase impregnation and drying, and the conductive material is selected from at least one of silver nanoparticles, graphene or carbon-based conductive materials. The conductive coating is uniformly adhered to the surface of the golf ball and the pit structure on the surface, and covers the pit structure, but the coating does not fill the pits; Furthermore, the total weight gain of the golf ball does not exceed 0.5g.

2. The golf ball according to claim 1, characterized in that: The conductive coating is a discontinuous conductive layer, wherein the maximum size of the discontinuous region does not exceed 0.4 mm.

3. The golf ball according to claim 1, characterized in that: The conductive coating is formed by diluting a water-based or alcohol-based conductive coating, wherein the solid content of the diluted coating is 1% to 5%.

4. The golf ball according to claim 1, characterized in that: The thickness of the conductive coating is from 0.3 micrometers to 50 micrometers.

5. The golf ball according to claim 1, characterized in that: The conductive coating also contains an adhesive.

6. The golf ball according to claim 5, characterized in that: The adhesive is polyvinyl alcohol (PVA) or a water-based resin.

7. The golf ball according to claim 1, characterized in that: The conductive coating is a thickness-increasing layer formed by at least two soak-dry cycles.

8. The golf ball according to claim 1, characterized in that: Under the action of 77GHz millimeter-wave radar, the radar cross-section (RCS) of the golf ball treated with the conductive coating is increased by at least 10dB compared with the untreated golf ball.

9. A golf ball for enhancing the reflection performance of 77GHz millimeter-wave radar, said golf ball having a multi-layered structure, characterized in that, include: A golf ball body, the golf ball body comprising a core, at least one intermediate layer, and a shell; A conductive coating or conductive film disposed on the surface of the core or any of the intermediate layers; The conductive coating or conductive film is a conductive material layer formed by liquid phase impregnation and drying, and the conductive material is selected from at least one of silver nanoparticles, graphene or carbon-based conductive materials. The conductive coating or conductive film is uniformly attached to the surface of the core or the surface of the intermediate layer; Furthermore, the total weight gain of the coated golf ball does not exceed 0.5g.

10. A method for preparing a golf ball with enhanced reflectivity under 77GHz millimeter-wave radar, characterized in that, Includes the following steps: Step 1: Dilute the conductive coating with a thinner to a solid content of 1% to 5% to obtain an immersion solution; the thinner is any one of deionized water, anhydrous ethanol, or isopropanol; Step 2: Immerse the golf ball completely in the soaking solution for 5 to 10 seconds; Step 3: Remove the soaked golf balls and remove excess liquid by centrifugation or spin-drying; Step 4: Dry the spun golf balls at a low temperature; The conductive coating contains at least one conductive material selected from silver nanoparticles, graphene, or carbon-based conductive materials, and the total weight gain of the treated golf ball does not exceed 0.5g.

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