Anti-icing method for spraying super-hydrophobic material on pantograph of locomotive and motor train unit

Abstract

The invention provides an anti-icing method for spraying a super-hydrophobic material on pantographs of locomotives and motor train units, and belongs to the technical field of rail transit equipment protection. By selecting the high-performance super-hydrophobic coating and combining the surface pretreatment and spraying process, a uniform coating is formed, the adhesive force of an ice layer is remarkably reduced, and the icing problem of the pantograph in a freezing rain environment is solved, so that the accident risks of pantograph catenary arcing, contact failure and the like caused by icing are reduced. The anti-icing device has the characteristics of excellent anti-icing performance, high economy and good safety, and is suitable for the field of rail transit equipment protection.

Description

[0001] This application claims priority to Chinese Patent Application No. 202520572116.6, filed on March 28, 2025, entitled "A Method for Preventing Icing by Spraying Superhydrophobic Material onto the Pantograph of Locomotives and EMUs", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of rail transit equipment protection technology, and in particular to a method for preventing icing by spraying superhydrophobic materials onto the pantographs of locomotives and EMUs. Background Technology

[0003] Currently, railway locomotives and EMU pantographs lack effective anti-icing designs. In extreme low-temperature freezing rain, ice easily forms on the pantograph surface, causing it to become unable to rise due to increased weight from the ice buildup, or even if it manages to rise, the pantograph-catenary contact fails, leading to arcing damage. For example, during the cold wave in southern China in February 2024, the lower arm, upper frame, and pantograph head support of the pantograph were generally covered with about 10mm of ice, causing the pantograph lifting pressure to drop to zero. The pantograph's sliding plate broke due to arcing, resulting in locomotive malfunctions and severely disrupting transportation (see [reference]). Figure 1 , Figure 2 Existing anti-icing technologies have the following drawbacks: 1. Electric heating method: High energy consumption, requires modification of the power supply system, and increases operating costs; 2. Mechanical de-icing method: This method is complex to operate and can easily damage the surface of the pantograph's carbon sliding plate. 3. Chemical de-icing agents: pose environmental pollution risks and require frequent re-application.

[0004] Therefore, there is an urgent need to develop a maintenance-free, low-cost passive anti-icing solution. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preventing pantograph icing by spraying superhydrophobic materials on locomotives and EMUs. This superhydrophobic coating anti-icing technology is based on the biomimetic principle of the "lotus effect" (the phenomenon that the surface of a lotus leaf does not attract water). By inhibiting the formation of ice nuclei and reducing the adhesion of ice layers, it solves the problem of pantograph icing in freezing rain environments, ensures that the pantograph can be raised normally, and ensures reliable pantograph-catenary contact, thus avoiding pantograph failure to receive current, loss of train power, and arcing and ablation accidents due to poor pantograph-catenary contact.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preventing icing by spraying superhydrophobic materials onto the pantographs of locomotives and EMUs, comprising the following steps: a) Coating selection: Superhydrophobic coatings with fluorinated polymers as the matrix and nano-silica as the reinforcing phase are adopted; b) Surface pretreatment: Grinding or sandblasting, solvent degreasing and plasma activation treatment of the receiving bow body; c) Spraying process: High-pressure airless spraying equipment is used to form a uniform coating by cross-spraying; d) Performance verification: The anti-icing effectiveness was confirmed by using a contact angle measuring instrument and ice shear strength test.

[0007] Furthermore, the performance indicators of the superhydrophobic coating include: contact angle ≥150°, roll-off angle ≤10°, temperature resistance range -30℃~70℃, and abrasion resistance grade ≥H.

[0008] Furthermore, the surface pretreatment includes grinding or sandblasting to Sa2.5 grade, solvent degreasing, and plasma activation treatment to ensure that the surface energy of the substrate is ≤25mN / m.

[0009] Furthermore, the spraying process uses high-pressure airless spraying equipment with a working pressure of 0.4~0.6MPa and a spraying distance of 30 cm, and is sprayed in three cross-coating stages to a total thickness of 10~50μm.

[0010] Furthermore, the curing conditions are 60°C hot air circulation for 1 hour followed by room temperature curing for 8 hours or room temperature self-crosslinking for 24 hours.

[0011] The beneficial effects of this invention are: 1. Anti-icing performance: Ice adhesion ≤0.1MPa (compared to 0.8MPa for untreated surfaces), which can significantly reduce de-icing energy consumption; 2. Economic efficiency: Single construction life > 2 years, saving more than 60% of operation and maintenance costs compared with electric heating method; 3. Safety: Eliminates the risk of arcing during pantograph-catenary circuit repair; contact resistance fluctuation rate ≤5% (EN 50367 standard). Attached Figure Description

[0012] Figure 1 Photographs of an example of pantograph icing; Figure 2 Photographs of an example of arc ablation at the contact of an icing bow wire mesh; Figure 3 This is a schematic diagram of the contact angle and roll-off angle of the superhydrophobic coating surface; Figure 4 The image shows a comparison between the superhydrophobic coating and the uncoated version. Figure 5 This is a structural diagram of the TSG15B pantograph of the HXD1C locomotive; where 1-underframe; 2-lower boom; 3-upper frame; 4-tie rod; 5-airbag assembly; 6-balance bar; 7-pantograph head; 8-damper; 9-air circuit and ADD; 10-valve plate; 11-insulator assembly; 12-insulating hose; 13-pantograph head current connection assembly; 14-underframe current assembly; 15-elbow joint current connection assembly. Figure 6 This is a diagram showing the state of the pantograph surface before pretreatment. Figure 7 This is a diagram showing the state of the pantograph surface after pretreatment. Figure 8 Example of the effect of spraying superhydrophobic material onto TSG15B pantograph (water droplets rolling off the superhydrophobic coating). Figure 9 Example of the effect of spraying superhydrophobic material onto TSG15B pantograph (no water adhering to the superhydrophobic coating). Detailed Implementation

[0013] This invention provides a method for preventing icing by spraying superhydrophobic materials onto the pantographs of locomotives and EMUs, comprising the following steps: a) Coating selection: Superhydrophobic coatings with fluorinated polymers as the matrix and nano-silica as the reinforcing phase are adopted; b) Surface pretreatment: Grinding or sandblasting, solvent degreasing and plasma activation treatment of the receiving bow body; c) Spraying process: High-pressure airless spraying equipment is used to form a uniform coating by cross-spraying; d) Performance verification: The anti-icing effectiveness was confirmed by using a contact angle measuring instrument and ice shear strength test.

[0014] In this invention, the performance indicators of the superhydrophobic coating include: contact angle ≥150°, roll-off angle ≤10° (ASTM D7334 standard) (see...). Figure 3 (Schematic diagram of contact angle and roll-off angle of superhydrophobic coating surface), temperature range -30℃~70℃ (GB / T1735 test), abrasion resistance grade ≥H (ISO 7784-2:2016).

[0015] In this invention, the surface pretreatment includes grinding or sandblasting to Sa2.5 grade, solvent degreasing, and plasma activation treatment to ensure that the surface energy of the substrate is ≤25mN / m.

[0016] In this invention, the solvent degreasing is performed using acetone cleaning.

[0017] In this invention, the spraying process uses a high-pressure airless spraying device with a working pressure of 0.4~0.6MPa, preferably 0.5MPa; the spraying distance is 30 cm, and the spraying is done in three cross-spraying stages to a total thickness of 10~50μm, preferably 20~40μm.

[0018] In this invention, the curing conditions are 60°C hot air circulation for 1 hour followed by room temperature curing for 8 hours or room temperature self-crosslinking for 24 hours.

[0019] In this invention, performance verification was conducted by using a contact angle measuring instrument (OCA20, Dataphysics) and an ice shear strength test (ASTM D7338) to confirm the anti-icing effectiveness.

[0020] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0021] Example 1

[0022] The HXD1C locomotive uses a TSG15B pantograph (see...) Figure 5 For the object, implement the following steps: 1. Coating Selection: A technologically mature superhydrophobic coating is selected. Specifically, NeverWet® SC-100 superhydrophobic coating (a fluorinated polyurethane / nano-SiO2 composite system with strong hydrophobic properties, a contact angle greater than 150°, suitable for various substrates such as metals, plastics, and fabrics; applications include self-cleaning surfaces, corrosion protection, and anti-icing) is chosen. 2. Coating equipment: Graco Ultra Max II 695 equipment was selected; 3. Surface Pretreatment: Use #0 sandpaper to sand the surfaces of the pantograph's lower boom, upper frame, and head support. Clean the surfaces with alcohol to remove oxide layers and dirt, ensuring they are free of oil and dust (see...). Figure 6 , Figure 7 (Comparison before and after preprocessing) 4. Coating mixing: Premix SC-100 coating at a volume ratio of 4:1 (base material: hardener) and allow to mature for 20 minutes; 5. Spraying process: A Graco Ultra Max II 695 sprayer was used with a pressure of 25 MPa, a nozzle diameter of 0.017 inches, and a spraying distance of 30 cm. The spraying was done in three cross-spraying stages to achieve a total thickness of 35±5μm to form a uniform coating. 6. Curing and Testing: After spraying, the sprayed surface is first pre-cured using a hot air gun at approximately 60°C for 1 hour, followed by natural curing for 8 hours. The coating performance is then tested using a contact angle meter, yielding a contact angle of 162° and a roll-off angle of 6°. Comparative test: In a simulated freezing rain environment at -15℃, the pantograph in the treatment group showed no visible ice layer within 24 hours, while the control group (pantograph not treated by this invention) showed complete icing within 2 hours.

[0023] Quality control: Use a wet film thickness gauge (such as Elcometer 323) to check the thickness every 10 minutes; Defect handling: Local touch-up spraying must be completed within 10 minutes (if the curing window is exceeded, it must be sanded and resprayed). Figure 8 , Figure 9 Example of the effect of spraying superhydrophobic material on TSG15B pantograph.

[0024] Effects of implementing the technical solution of this invention: Spraying according to the process flow, such as... Figure 4 As shown, the superhydrophobic coating and the uncoated metal surfaces exhibit very obvious hydrophilic and hydrophobic effects.

[0025] As shown in the above embodiments, this invention provides a method for preventing icing of pantographs on locomotives and EMUs by spraying superhydrophobic materials. By selecting high-performance superhydrophobic coatings, combined with surface pretreatment and spraying processes, a uniform coating is formed, significantly reducing ice adhesion and solving the problem of pantograph icing in freezing rain environments. This reduces the risk of accidents such as pantograph-catenary arcing and contact failure caused by icing. This invention features excellent anti-icing performance, high economy, and good safety, and is suitable for the field of rail transit equipment protection.

[0026] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preventing icing by spraying superhydrophobic material onto the pantograph of a locomotive or EMU, characterized in that, Includes the following steps: a) Coating selection: Superhydrophobic coatings with fluorinated polymers as the matrix and nano-silica as the reinforcing phase are adopted; b) Surface pretreatment: Grinding or sandblasting, solvent degreasing and plasma activation treatment of the receiving bow body; c) Spraying process: High-pressure airless spraying equipment is used to form a uniform coating by cross-spraying; d) Performance verification: The anti-icing effectiveness was confirmed by using a contact angle measuring instrument and ice shear strength test.

2. The method for preventing icing by spraying superhydrophobic material onto the pantograph of locomotives and EMUs according to claim 1, characterized in that, The performance indicators of the superhydrophobic coating include: contact angle ≥150°, roll-off angle ≤10°, temperature resistance range -30℃~70℃, and abrasion resistance grade ≥H.

3. The method for preventing icing by spraying superhydrophobic material onto the pantograph of locomotives and EMUs according to claim 1, characterized in that, The surface pretreatment includes grinding or sandblasting to Sa2.5 grade, solvent degreasing, and plasma activation treatment to ensure that the surface energy of the substrate is ≤25mN / m.

4. The method for preventing icing by spraying superhydrophobic material onto the pantograph of locomotives and EMUs according to claim 1, characterized in that, The spraying process uses high-pressure airless spraying equipment with a working pressure of 0.4~0.6MPa and a spraying distance of 30 cm. The spraying is done in three cross-spraying stages to achieve a total thickness of 10~50μm.

5. The method for preventing icing by spraying superhydrophobic material onto the pantograph of locomotives and EMUs according to claim 1, characterized in that, The curing conditions are 60℃ hot air circulation for 1 hour followed by room temperature curing for 8 hours or room temperature curing for 24 hours for self-crosslinking.

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