Silicone Sheets: The "Multifunctional Guardian" in Rail Transit Systems​

Silicone Sheets: The "Multifunctional Guardian" in Rail Transit Systems

In the field of rail transit, from high-speed trains operating at 350 km/h to urban subways, safe, stable and comfortable operation relies on the support of key materials. With comprehensive properties such as temperature resistance, shock absorption, sealing and insulation, silicone sheets have become "invisible heroes" in rail transit vehicles and supporting systems. Their core application scenarios are as follows:

First, sealing and environmental protection is a core scenario. Areas such as gaps around train doors and windows, connections between carriages, air conditioning duct interfaces and cable penetration holes need to block external dust, rainwater, hot/cold air and noise. Silicone sheets fit irregular surfaces tightly with excellent flexibility and elasticity, forming a long-lasting sealing barrier.

Second, they play a prominent role in shock absorption and noise reduction. During the operation of rail transit, friction between wheels and tracks as well as equipment operation generate vibration and noise, which not only affect passenger comfort but also accelerate component aging. Silicone sheets can be used as shock-absorbing gaskets, installed at the connection points between bogies and carriages, motor bases, seat brackets and other parts.

Third, electrical insulation ensures train safety. The electrical system of rail transit vehicles is complex. Power distribution cabinets, traction converters, cable lines and other components require reliable insulation to prevent leakage and short circuits. Silicone sheets not only have high insulation resistance and dielectric strength, but also are resistant to high and low temperatures and aging.

The data of CRRC Qingdao Sifang in the application of silicone sheets have all undergone rigorous testing and verification:

In terms of sealing, the "alpine version" Fuxing EMU uses silicone rubber materials with a brittle temperature lower than -60℃. Relying on the National Engineering Research Center for High-Speed EMU Assembly, the enterprise simulates -40℃ and even lower temperature environments in the laboratory, conducts brittleness tests on various sealing strips, and verifies the low-temperature performance stability of silicone rubber. At the same time, continuous monitoring is carried out on the operation lines in cold regions such as Northeast China. Long-term tracking has confirmed that this material can prevent air and water leakage, ensuring the safe operation of trains.

In terms of shock absorption, the data of the silicone shock-absorbing pads between the axle boxes and frames of the bogies of CR400 series EMUs come from multiple rounds of tests. CRRC Qingdao Sifang uses a first-class test and verification platform in the industry. Through bench tests, it simulates the friction and vibration between wheels and tracks at a speed of 350 km/h, and uses high-precision sensors to measure the energy absorption effect of the shock-absorbing pads and the change of vibration transmission to the carriage. It also conducts long-term monitoring of operating trains on lines such as the Beijing-Shanghai High-Speed Railway. After comprehensive analysis of a large number of test and operation data, it is concluded that the vibration amplitude is reduced by 30%-40%.

In terms of electrical insulation, the silicone insulation sheets used in key parts of the train electrical system have undergone strict testing by the national-level enterprise technology center. In the complex electromagnetic environment simulation laboratory, it simulates the electromagnetic interference that the train may face during actual operation; at the same time, combined with the high-low temperature alternating test chamber, it tests the insulation performance of the sheets in the temperature range of -60℃ to 120℃. After multiple rounds of verification, this material can effectively prevent leakage and short-circuit faults, ensuring the reliable operation of the electrical system, and the relevant data have also been confirmed in the long-term operation of the train.

In the manufacturing process, the data on the efficiency improvement of silicone suction cups used in car body assembly can be traced. After the introduction of this process, the workshop uses a digital management system to accurately record the assembly time of each vehicle, the number of welding quality defects and other data. Comparative statistics with traditional positioning methods show that when silicone suction cups are used to assist the positioning and welding of aluminum alloy car body components, not only the welding quality and consistency are significantly improved, but also the production efficiency is increased by about 20%.

The above data show that silicone sheets are widely used in rail transit. Like a "guardian", they have been silently protecting the safety of the rail transit system.