How do rail pads protect rail sleepers?
Rail pads protect sleepers by acting as elastic buffers between the steel rail and the concrete or wood sleeper, absorbing impact and vibration from trains, which prevents fatigue cracking, wear, and load concentration, ultimately extending the life of the track components by distributing forces more evenly and reducing mechanical stress. They also help seal gaps, reduce noise, and provide electrical insulation.
Key Protection Mechanisms:
- Dampens Impact & Vibration: Made from elastic materials (like polyurethane), pads absorb the sharp blows and high-frequency vibrations from passing trains, preventing them from transferring directly and damaging the sleeper.
- Reduces Wear & Abrasion: They create a cushion, stopping the metal-on-concrete or metal-on-wood rubbing that causes surface scraping and weakens sleepers.
- Distributes Load: By spreading the heavy load from the rail over a larger surface area on the sleeper, pads eliminate stress points and fatigue, preventing cracks.
- Seals Gaps: They fill uneven spaces between the rail and sleeper, preventing dirt and moisture from getting in and causing further damage or corrosion.
- Insulates Electrically: They provide electrical isolation between the rail and sleeper, which is crucial for signal systems.
Types of materials for rail pads
After years of experience in rail pad manufacturing, we have developed a range of high-performance elastic rail pads for stiffness requirements and various application areas-from trams through standard gauge railways to heavy haul lines, especially rail pads for E-clip rail fastening systems and SKL type rail fastening systems with material of HDPE/EVA/Rubber, with following properties respectively.
HDPE
| No. | Technical Parameter | Unit | Technical Requirement | Value |
|---|---|---|---|---|
| 1 | Density | g/cm3 | 0.95-0.98 | 0.95 |
| 2 | Tensile Strength | Mpa | ≥19 | 19 |
| 3 | Elongation | % | >80 | 150 |
| 4 | Melting Point | °C | 170-190 | 190 |
| 5 | Insulation Resistance | Ω | ≥1×1010 | 3.5 ×1010 |
| 6 | Hardness | A | ≥98 | 98(A) |
EVA: Polyethylene 80%, Vinyl Acetate 20%
| No. | Technical Parameter | Unit | Technical Requirement | Value |
|---|---|---|---|---|
| 1 | Density | g/cm3 | 0.95-0.98 | 0.95 |
| 2 | Tensile Strength | Mpa | ≥15 | 16 |
| 3 | Elongation | % | >500 | 550 |
| 4 | Melting Point°C | °C | 170-190 | 170 |
| 5 | Insulation Resistance | Ω | ≥1×1010 | 5.0 ×1010 |
| 6 | Hardness | A | ≥90 | 92(A) |
Rubber
| No. | Technical Parameter | Unit | Value |
|---|---|---|---|
| 1 | Stiffness | KN | 90-130 |
| 2 | Hardness Shore A°C | °C | 72-80degree |
| 3 | Electronic Resistance | Ω | ≥ 106 |
| 4 | Tensile Strength before Aging | Mpa | ≥12.5 |
| 5 | Elongation before Aging | % | ≥250 |
The Characteristics of Rail Pad
The main raw material of rail pad is rubber, which is made by using high-techs and scientific chemical composition. Rail rubber pad complies with the requirements of train speed improvement and environmental protection and is also conducive to enlarge transportation capacity.
- With strong impacting absorption, aging resistance, wear resistance, stability, high and low temperature resistance.
- Variety of rail pad raw materials, they are natural rubber, styrene butadiene rubber, butyl chloride, HDPE, EVA, high density polyethylene, etc.
- With high elasticity, hard to deform or fracture at different temperatures.
- Long service life, low cost of maintenance and replacement.
GNEE RAILWAY Rail's pad production attaches great importance to quality control and management. Our rail rubber pads are mainly made from these materials including natural rubber, synthetic rubber, styrene-butadiene rubber, chloroprene rubber, composite rubber, EVA, plastic, plastic, HDPE, high-density polyethylene and other materials. All rail rubber pads are processed according to drawings or samples. The production is completely in accordance with the material iso9001-2008 quality system, we also obtain China's railway production license. We have a full set of testing equipment to ensure the quality of all our rubber pads meet customer requirements.