What is the elasticity of rubber rail pads?
Railway rubber pad, also called rubber rail pad, rubber tie plate. It is an important part of railway structure system, which is a kind of rail pad. Railway rubber pad is installed between steel rail and sleeper. The function of the railway rubber pad is to protect the sleepers from impacting and crushing.
GNEE RAILWAY's EVA/HDPE/rubber rail pads are with high elasticity, applying to types for rails such as rail UIC54, UIC60, BS80lbs,BS100lbs, and sizes as ordered. The pads can be customized with or without grooves, in various possible designs, depending on customers' requirements.
| HDPE Rail Pad | |||
| Technical Parameter | Unit | Technical Requirement | Value |
| Density | g/cm3 | 0.95-0.98 | 0.95 |
| Tensile Strength | Mpa | ≥19 | 19 |
| Elongation | % | >80 | 150 |
| Melting Point | ℃ | 170-190 | 190 |
| Insulation Resistance | Ω | ≥1×1010 | 3.5 ×1010 |
| Hardness | A | ≥98 | 98(A) |
| EVA: Polyethylene 80%, Vinyl Acetate 20%. | |||
| Technical Parameter | Unit | Technical Requirement | Value |
| Density | g/cm3 | 0.95-0.98 | 0.95 |
| Tensile Strength | Mpa | ≥15 | 16 |
| Elongation | % | >500 | 550 |
| Melting Point | ℃ | 170-190 | 170 |
| Insulation Resistance | Ω | ≥1×1010 | 5.0 ×1010 |
| Hardness | A | ≥90 | 92(A) |
| Rubber Rail Pad | ||
| Technical Parameter | Unit | Value |
| Stiffness | KN | 90-130 |
| Hardness Shore A | ℃ | 72-80 degree |
| Electronic Resistance | Ω | ≥ 106 |
| Tensile Strength before Aging | Mpa | ≥12.5 |
| Elongation before Aging | % | ≥250 |
In professional terms, elasticity is not measured by how soft the material feels, but by its Stiffness(k). This parameter serves as the critical link between the train's dynamic forces and the track's stability. Understanding the nuances of stiffness is essential for selecting the correct component for High-Speed Rail or Heavy Haul networks.
Static Stiffness: Balancing Support and Deflection
The primary measure of elasticity is Static Stiffness, defined as the resistance of the Rail Pad to a slowly applied vertical load (measured in kN/mm). There is no single "correct" elasticity number; it depends entirely on the application.
For heavy-haul freight lines, the priority is gauge retention. Therefore, engineers specify a high-stiffness Railroad Pad (often HDPE or rigid EVA, ranging from 100−300 kN/mm) to prevent excessive rail deflection. Conversely, for High-Speed Rail, the system requires a "softer" interface to absorb impact. Here, a Rail Elastic Pad (typically grooved natural rubber) with low static stiffness (around 20-60kN/mm) is used to allow necessary vertical movement, acting as a shock absorber for the concrete sleeper.
The Dynamic-to-Static Ratio: The True Indicator of Quality
Real-world performance, however, happens when the train is moving. This is where Dynamic Stiffness comes into play. Under high-frequency vibrations caused by passing wheels, rubber materials tend to stiffen up.
A superior Rubber Track Pad is characterized by a low Dynamic-to-Static Stiffness Ratio. If this ratio is too high, the pad acts like a rigid block under speed, transmitting noise and vibration directly to the ballast. At GNEE RAILWAY RAILWAY, our premium rubber compounds are engineered to maintain a low ratio (typically <1.5), ensuring that the pad remains elastic and effective at dampening vibrations even at speeds exceeding 300 km/h.
Precision Engineering at GNEE RAILWAY RAILWAY
Achieving the exact elasticity is a matter of precise chemical compounding and geometry design. GNEE RAILWAY RAILWAY operates fully equipped testing laboratories to verify these critical parameters.
We don't just supply parts; we validate them. Whether your project requires a specific deflection curve to protect sensitive urban infrastructure or a rigid pad for industrial loads, we customize the formulation to meet exact stiffness tolerances (usually within ±10%). Contact GNEE RAILWAY RAILWAY to ensure your track system has the precise elasticity required for long-term safety.