Rail pads are elastic polyurethane mats which are interposed between steel rails and railway sleepers to protect the sleeper top from wearing and impacting.
What is the difference between a Rail Rubber Pad and an HDPE railway pad?
Rail Rubber Pads and HDPE Railway Pads both cushion the rail from sleepers, but HDPE (High-Density Polyethylene) pads are a type of plastic pad, often stiffer and durable for heavy loads, while "Rubber Pads" usually imply blends of natural/synthetic rubber (like SBR, neoprene) for higher elasticity, shock absorption, and vibration damping, though modern pads frequently combine HDPE with rubber or EVA for optimal stiffness/resilience, creating composite materials with varied performance.
Rail Rubber Pads (Traditional/Composite)
- Material: Natural Rubber, SBR (Styrene-Butadiene Rubber), Chloroprene (Neoprene), often mixed with EVA or HDPE.
- Properties: High elasticity, excellent shock absorption, superior vibration dampening, good insulation, and abrasion resistance.
- Best For: General applications, reducing concrete sleeper cracking, providing resilience.
- Design: Often feature grooves for specific load-deflection curves, ensuring constant contact.
| 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 |
HDPE Railway Pads
- Material: High-Density Polyethylene (HDPE), sometimes with recycled crumb rubber.
- Properties: High stiffness (around 800 kN/mm), good wear resistance, corrosion resistance, weather resistance, and excellent electrical insulation.
- Best For: Heavy haul lines, preventing sleeper crushing, where high stiffness is needed to avoid rail rollover.
- Design: Can be plain or grooved; softer versions with rubber can improve durability over pure HDPE.
| 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) |
Key Differences & Choice
- Stiffness vs. Elasticity: HDPE is generally stiffer, ideal for high loads; Rubber offers more elastic deformation and shock absorption.
- Application: HDPE excels where high load capacity and preventing sleeper damage are key; Rubber shines in damping vibrations.
- Modern Trend: The lines blur with composites (HDPE/Rubber/EVA) that blend properties, offering tailored solutions for various rail systems (e.g., E-type, SKL).
How are railroad pads manufactured?
Railroad pads are manufactured by first preparing and mixing rubber compounds with additives, then molding them into shape using hot-press or injection molding, followed by vulcanization (curing) under heat and pressure, and finally trimming and quality checking to create durable, shock-absorbing pads from materials like rubber, polyurethane, or composites.
- Rubber compound preparation
- Mixed by an internal mixer or a two-roll mill. In terms of the internal mixer, the raw materials are processed by single or double stage, during which the masterbatch prepared ahead of time is finalized by adding curing agents to the twin roll mill.
- Shaping and curing
- Compression or Injection molding
- End products trimming
- Ready for use
GNEE RAIL is equipped with rail pad production lines for 130sets of machines, for the whole process of injection, refining rubber, sulfuration, moulding and inspection, etc. We own the most engineers for rail pad development, design, production and inspection, with annual production capacity reaching up to 2000, 000 pieces.