Research on the application of anti-icing coatings on rail vehicles.

When the high-speed train set is running in the northern winter, the steering frame of an important part of the vehicle is prone to ice cover in wind and snow, which adversely affects the braking effect and signal transmission, and threatens the safety and smoothness of the vehicle's operation. The problem of anti-ice is widely studied in countries prone to ice and snow disasters, and China has done a lot of related scientific research in recent years. The mainstream view of the academic circles is that reducing the surface of the material can effectively reduce the attachment rate of water to the surface of the material, so that water droplets can not form a continuous water film, and thus effectively prevent water from freezing on the surface of the material

. By painting low surface energy coating on the surface of the material to change the surface energy of the material is the most effective method, most of the anti-ice coatings on the market are by reducing the surface of the material to achieve anti-ice function. In this paper, different brands of anti-ice coating performance comparison, combined with performance analysis to choose a paint to do real car test, and through the real car test results, to explore the application of anti-ice coating on the track vehicle effect.
1 experimental part
1.1 main raw material
SF90-0000/0 double component solvent-based anti-ice varnish (paint
A
): Liangkweize;
HQSC-1000
high weather-resistant two-part solvent-based anti-ice varnish (paint
B
), WR-1000 dual-group solvent-based antifreeze varnish (paint
C
): Libang;
3249-500010
two-part water-resistant ice varnish (paint
D
): Weborg;
FONFINISH36
two-part solvent-based anti-ice paint (paint
E
): COSCO Kansi;
SG08-7043
dual-part epoxy finish (paint
F
), SF34-3012 double-group epoxy primer (paint
G
). ): Liang Kweizer.
1.2 model
according to the company's frame coating reality and the future may apply anti-ice coating direction, the design of the coating structure model is as follows:
(1) paint model using 150mm×100mm aluminum model, paint before sanding treatment;
(2) A, B, C, D4 kinds of varnish coated in the pre-sprayed bright Kweize SF08-7043 double-component epoxy paint model formed a composite coating model, varnish thickness of 30 to 60 m;
(3) E solid paint coated in the pre-sprayed bright Kweize SG34-3012 double-component epoxy primer model to form a composite coating model, solid paint thickness of 30 to 60 m;
(4) to take only spray bright Kweizer SF08-7043 double-part epoxy paint model to compare the model F;
(5) after the completion of the sample, after 18 to 30 degrees C natural drying 48h after the relevant experiments.
1.3 Testing and Symptoms
1.3.1 Infrared Spectroscopy
the main components of various coating main agents and curing agents are analyzed using the FTIR8400S infrared spectrometer in Izu.
1.3.2 contact angle test
the water contact angle of the samples under standard conditions was determined by the Shanghai Zhongchen JC2000C1 contact angle/surface stress meter.
1.3.3 ice force test
ice force test currently has no common standards in the industry, the method used in this paper comes from the enterprise standard, the specific test steps are as follows: as shown in Figure 1, the five steel rings are placed on five horizontal plates, respectively, 6mL5 degrees C of water Injected into the steel ring (inner diameter 31mm, wall thickness 3mm, height 25mm), the model and steel ring as a whole placed in a low temperature tank of -25 degrees C, water frozen 24h, with a pull gauge to determine the steel ring and the model cut displacement when the minimum force required.
Figure 1 shows the ice force test schematic
1.3.4 drop water method test
the hydrophobic properties of the coating determine the adhesion of water on the surface of the material, the lower the adhesion is more conducive to anti-icing, the use of drip method to test the hydrophobic properties of the coating, the drip method test currently has no common standards in the industry, this paper The method used comes from the enterprise standard, the specific test steps are as follows:
(1) will be 5 models to 45 degrees angle of the model frame, the short
edge of the board at the top and bottom ends, paint film upward;
(3) with a dropper to absorb pure water, in the model marking line parallel drops of 3 drops of pure water;
(4) to observe the rate at which water droplets flow to the lower end of the plate and record the time at which the water droplets flow to the bottom.
2 Results and Discussion
2.1 Red Appearance Analysis
By infrared test analysis, the main components of each coating main agent and curing agent are found in Table
1
.
Table 1 Coating Composition Analysis
As can be known from Table 1, coatings A, B, C and D use fluorocarbon resin as the main film, paint E uses fatty acid modified bisphenol A epoxy resin as the main film.
2.2 Contact Angle Analysis
The water contact angle of the A, B, C, D, E and F models were tested using the quantum angle method, and 3 sets of parallel tests were performed and the average value was recorded for each model, the results of which were seen in Table 2.Table
2 contact angle test
from Table 2 can be seen, in addition to paint D, the other four coating contact angles are around 100 degrees, compared to the water contact angle of model F has been greatly improved, showing good hydrophobic properties, water droplets can not form a continuous water film.
2.3 Ice Force Analysis
The amount of adhesion of ice on the coating directly determines how easy it is to remove, and the adhesion of ice to the coating is determined by shear displacement, as shown in Table
3
.
Table 3 with ice force test
From Table 3, it can be seen that the ice resistance of each anti-ice coating is significantly smaller than ordinary paint, in which the coating E ice force is reduced by 67.2% compared to ordinary paint, indicating that the use of anti-ice coating can effectively reduce the adhesion of ice to the coating, more conducive to the removal of ice.
2.4 drip test analysis
In the sample drip test,
3
sets of parallel tests were done and the average was recorded for each model, with the results shown in table
4
.
Table 4 drip test analysis
From Table 4, it can be seen that the drip test results are consistent with the contact angle test results, water contact angle large model water droplets quickly roll down, with a shorter time;
2.1 to 2.4 test results, the hydrophobic properties of coatings A, C and E are better than those of other test coatings, and the hydrophobic properties of ordinary coatings are significantly improved. As the existing steering frame paint system is: Bright Kweizer two-part epoxy primer and Bright Kweizer two-part epoxy paint, from the process matching point of view of the same manufacturer's paint is more suitable. In addition, in addition to the test listed in the text, but also tested the other properties of the coating, pull test results show that the adhesion of paint A is greater than 4.3MPa, higher than several other brands of coatings, in addition, paint A in gloss, scratch testing and other aspects of excellent performance, comprehensive above factors, paint A is suitable for rail transit anti-ice paint, therefore, choose paint A to do solid vehicle testing.
2.5 real car test
combined with the occurrence of ice and snow cover of the steering frame over the years, selected the high-speed train group operating on the Hada line for real vehicle testing, the same train part of the steering frame anti-ice varnish spraying, after a period of actual operation to record the greening of the steering frame. The results are shown in Figure
2
, where (a) and (c) are sprayed with anti-ice varnishes for ice and melting, and (b) and (c) are unsothinked anti-ice varnishes for icing and melting ice, respectively.
the vehicle verification, the following conclusions are drawn:
(1) whether or not the defleter is coated with anti-ice varnish, the steering frame will freeze;
(2) Easy to freeze the part is the bottom of the motor, wire (tube) near, brake unit, these components due to heat caused by melting snow and ice,
(3) the surface of the frame ice melting, anti-ice varnish shows hydrophobic and lower ice adhesion, as shown by the drop water more obvious and ice shedding faster.
the above conclusions, the application of anti-icing varnish will not affect whether the green frame is icing, but the hydrophobicity of the coating is conducive to the melting and shedding of ice, but also conducive to de-icing operations.
Figure 2 paint anti-icing performance comparison test
3 knots
rail vehicle under the component structure is complex, winter in the process of high-speed operation of ice and snow easy to accumulate on the steering frame and other components, coupled with some parts of the heat caused by repeated melting of snow and ice, driving safety brings hidden dangers. At present, the anti-ice coating on the market can not completely eliminate the parts of ice, but its lower surface energy and hydrophobic properties can accelerate the melting and shedding of ice, but also conducive to de-icing operations. The development of better anti-icing coatings has good prospects in the field of rail vehicles.
Source: 2020 Paint Industry No. 1
This article Hu Qi, Sun Jianshuang, Wen Jingjian, Wang Fei, Li Yong
(China Railway Changchun Railway Bus Co., Ltd., Changchun 130062)
.