A Complete Guide to Flame Retardant Silicone Rubber (Rail Specification)
What is Rail Specification Flame Retardant Silicone Rubber?
Rail specification flame retardant silicone rubber is a formulated to meet the stringent fire safety and performance standards required for rail and mass transit applications. This specialised material provides exceptional thermal stability, mechanical durability and resistance to extreme environmental conditions to ensure the safety and reliability of rail systems.
Our rail specification silicone has been formulated to meet the following global standards associated with rail and mass transit usage. This includes:
- BS6853: 1999 (Category 1A conformity) BS EN ISO 4589 – 3 1996
- NFX70-100
- NF F 16-101 & NF F 16-102 Classification: F0
- EN 45545-2 R1, R7H. L1, HL2
- EN45545-2 R22, R23. HL1, HL2, HL3
- UL94-V0
These certifications ensure compliance with fire resistance, smoke emission and toxicity requirements. This makes silicone rubber an optimal solution for railway infrastructure and rolling stock applications.
Appearance
Off-white so accepts limited pigmentation.
Tear Strength
Resistance
to tearing of 22kN/m.
Density
Formulated
for a density of 1.29 g/cm3 at 25°C.
Hardness
Available with a 69ᵒ Shore A hardness.
Tensile Strength
Tensile strength of 9.3MPA.
Elongation at Break
Flexibility of 300% without breaking.
Temperature Range
Operates effectively between -50°C and 220°C.
Properties
Excellent
fire resistance and non-toxic.
Learn how rail specification silicone is formulated, how it differs from other specialist grades and common applications within the industry.
How is Rail Flame Retardant Silicone Rubber Made?
The production of rail-grade flame retardant silicone rubber starts with high-purity polydimethylsiloxane (PDMS) as the base polymer. To meet stringent fire safety regulations, the formulation is reinforced with halogen-free flame retardant additives. These additives ensure the material meets global safety standards while maintaining flexibility and resilience.
The curing process is carried out using platinum-based catalysts to achieve a cross-linked polymer structure. This results in an elastomer that combines superior flame resistance, mechanical strength and long-term environmental stability. The material undergoes extensive testing to validate its compliance with international standards and ensure it meets flammability, smoke emission and toxic gas release thresholds.
Custom formulations can be tailored to meet specific operational needs, with variations in hardness, colour and mechanical properties available. This enables us to integrate the material seamlessly into various rail applications while ensuring regulatory compliance and performance optimisation.
Advantages of Rail Flame Retardant Silicone Rubber
Rail specification silicone rubber offers several key advantages that make it a suitable material in rail and mass transit applications. The most significant benefit is its ability to meet stringent fire safety regulations and ensure that it does not contribute to flame spread or emit harmful smoke and toxic gases in case of a fire. This property is important for protecting passengers and crew in enclosed rail environments.
The material also provides outstanding resistance to extreme temperatures, typically functioning reliably in environments ranging from -50°C to 220°C. This ensures its effectiveness in both high-heat applications, such as engine compartments, and cold-weather conditions, where flexibility must be maintained.
Additionally, its exceptional durability and resistance to environmental degradation, including UV exposure, ozone and railway-specific pollutants, make it a long-lasting solution that reduces maintenance and replacement costs over time. Its mechanical integrity allows it to perform under continuous vibration and movement, common in rail transportation systems.
Common Applications and Uses
Rail-grade flame retardant silicone is widely used across railway and mass transit systems due to its superior safety and performance properties. Below are three key application areas:
Industries
Rolling Stock Interiors
In rolling stock interiors, this material is used in seat cushions, wall panels and insulation systems. Its flame-retardant properties ensure compliance with stringent safety regulations, while its flexibility and resilience contribute to passenger comfort and durability. The materials ability to withstand continuous mechanical stress and varying temperature conditions makes it ideal for long-term use in train cabins.
Electrical and Cable Insulation
In electrical and cable insulation, flame retardant silicone rubber plays an important role in protecting wiring systems and electrical enclosures. It acts as an insulating barrier that prevents short circuits and enhances fire safety by reducing the risk of ignition. Its resistance to moisture and pollutants ensures the reliability of rail electronics, even in demanding environments.
Seals and Gaskets
In seals and gaskets for rail infrastructure, this material is used in door seals, window gaskets and other critical sealing components that must maintain airtight and watertight integrity. Its long-term resistance to environmental factors, combined with its ability to retain flexibility over extended periods, ensures continued performance and safety in railway applications.
Material Compound Datasheets
Flame retardant silicone can be extruded in a range of different hardnesses, each suitable for different applications. The properties and characteristics of these hardnesses may differ. Please see the downloadable PDF material compound datasheets for this information.
Looking for a different grade of Silicone?
As well as rail specification silicone, we are also able to manufacture rubber sealing products in a selection of other specialised Silicone compounds. This includes general purpose silicone, metal detectable silicone, high temperature silicone and aerospace flame retardant silicone.
Contact Us
With over 50 years' experience in the rubber sealing industry, our team has extensive experience in finding sealing solutions for our customers. Contact our experts via phone or email for sealing advice or bespoke quotations.
Email:
sales@sealsplusdirect.co.uk
Telephone:
01425 617722