With the controllability of synthetic materials, polyurethane rail pads have shown multi-dimensional performance advantages in the rail system and have become the core choice for high-speed, heavy-load and other high-end rail scenarios.
Its dynamic stiffness stability is particularly outstanding. Through molecular structure design, the dynamic-static stiffness ratio can be stably controlled below 1.3, and the stiffness change rate after 3 million fatigue cycles is ≤15%, which is much better than the fluctuation range of more than 20% of rubber pads.
Weather resistance and environmental adaptability are its significant highlights. The product made of aromatic isocyanate has a temperature resistance range of -40℃ to 70℃. In the freeze-thaw cycle test in cold areas, after 50 cycles from -40℃ to 20℃, the elasticity retention rate is still 82%, while the ordinary rubber pad drops to 65% during the same period. In high temperature and high humidity environments, the hydrolysis stability of polyester polyurethane makes its service life more than 1 times longer than that of rubber pads.
Precise control of mechanical properties meets differentiated needs. By adjusting the molecular weight of polyether polyol, the static stiffness of 40-120kN/mm can be continuously adjusted, which is suitable for the low stiffness requirements of 350km/h high-speed rail and the high load requirements of heavy-duty railway with an axle load of 30t. Its compression permanent deformation is ≤2% (70℃×22h condition), which is much lower than the 25% limit of rubber pads, and it can still maintain the designed thickness after long-term use.
Structural integrity and safety are more guaranteed. After adding nano-calcium carbonate reinforcement, the shear strength is increased to 8MPa, which can resist the shear stress generated by lateral forces in small radius curve sections. The flame-retardant polyurethane pad has an oxygen index of ≥32, passes the TB/T 3560 rail material fire test, and can delay the spread of fire in closed environments such as tunnels. At the same time, its insulation resistance is >10⁸Ω, which fully meets the insulation requirements of track circuits.
The combination of these performance advantages enables polyurethane rail pads to form comprehensive competitiveness in terms of track stiffness uniformity, life cycle cost, and extreme environmental adaptability, becoming a key material support for the upgrade of modern rail technology.
GNEE RAILWAY RAILWAY is a professional trading company focusing on the export of railway fasteners, committed to providing reliable rail connection products for global railway construction projects. The main products include a full range of railway fasteners such as various spring clip fastener systems, sleeper bolts, anti-loosening washers and insulating components, which are suitable for various application scenarios such as conventional railways, heavy-duty railways and urban rail transit.