Butyl compounds are one of the key materials used in modern railway rolling stock. Thanks to exceptionally low gas permeability, high resistance to ageing, and very good vibration damping properties, butyl rubber (IIR) is widely used in railcar sealing systems, acoustic insulation, and vibration isolation systems in rail vehicles.
Products made from butyl compounds are used in both passenger and freight wagons, as well as in metro vehicles and low-floor trams. Their application has a direct impact on structural durability, travel comfort, and rolling stock maintenance costs.
Butyl Rubber IIR – Key Properties for Railway Rolling Stock
In the operating environment of railway cars, elastomeric materials must meet requirements related to tightness, chemical resistance, temperature stability, and vibration damping capability.
Compared to other elastomers, butyl compounds stand out due to the following properties:
- very low permeability to gases and water vapour
- high resistance to UV radiation and ozone
- very good vibration isolation properties
- resistance to acids, alkalis, and atmospheric factors
- flexibility at low temperatures
- stability of performance parameters over long service life
The closed molecular structure of butyl rubber makes it possible to maintain the tightness of structural joints in railway cars for many years of operation, even under conditions of intensive vibration and large temperature fluctuations.
Products Made from Butyl Compounds Used in Railway Cars
The production of rubber components for the railway industry includes a wide range of sealing and vibration isolation elements made from IIR compounds.
Butyl cords
Butyl cords manufactured by extrusion are used in sealing welded joints of railcar body panels, installing glazing in gasket-free systems, and protecting bolted joints in the underframe.
Uncured butyl cords allow compensation of assembly tolerances and filling of surface micro-irregularities. Vulcanized butyl cords are used in dynamic applications requiring long-term elasticity.
Butyl tapes
Sealing tapes made from butyl compounds are used for sealing roof sheet joints, side wall panels, cable penetrations, and external equipment elements of railway cars.
Butyl tapes with an aluminium foil backing provide an additional vapour barrier and improved thermal insulation. Expanding versions are used in locations requiring automatic filling of structural gaps.
Butyl sealing profiles
Extruded profiles made from IIR compounds are used in sealing railway car doors and windows. Properly selected profile geometry and compound hardness enable sealing performance to be maintained even after many millions of door opening and closing cycles.
Vibration isolation mats and sheets
Butyl mats are used in acoustic insulation systems in passenger wagons. Installed under floors, along side walls, and in underframe areas, they effectively reduce vibration and noise generated by wheel-rail contact and the operation of drive systems.
Anti-vibration pads and silent blocks
Vibration isolation elements made from butyl compounds are used in mountings for air-conditioning units, compressors, and traction converters. Thanks to the high material loss factor, transmission of vibrations to the railcar body structure can be significantly reduced.
Vibration Isolation of Railway Cars Using Butyl Compounds
Noise and vibration in railway cars are among the main factors affecting passenger comfort.
The use of butyl mats, sealing profiles, and silent block components helps reduce impact noise and vibrations over a wide frequency range. Isolation systems based on butyl compounds can reduce interior noise levels by even several decibels.
In practice, this means improved travel conditions, reduced passenger fatigue, and lower noise emissions to the external environment.
Railcar Tightness and Thermal & Energy Comfort
Sealing systems made from butyl compounds play an important role in maintaining the thermal tightness of passenger cars. Eliminating thermal bridges in window and door areas helps reduce energy losses and increases the efficiency of heating and air-conditioning systems.
Additionally, butyl materials maintain sealing performance during pressure washing of railcars and during long-term exposure to moisture and de-icing salts.
Railway Standards for Butyl Compound Products
Materials used in railway rolling stock must meet requirements related to fire safety, smoke emissions, and operational durability.
The most important standards include:
- EN 45545-2 – fire performance requirements for railway materials
- EN 682 – requirements for elastomeric technical seals
- DIN 7863 – sealing profiles for rail vehicles
- UIC 564-2 – technical requirements for passenger wagons
Compliance with these standards is a fundamental condition for approving butyl products for use in railway rolling stock.
Durability of Butyl Seals in Railway Cars
Seals and vibration isolation elements made from butyl compounds can achieve service lives of 15 to 25 years. Their durability results from high resistance to atmospheric ageing and stable mechanical properties over a wide temperature range.
The use of high-quality IIR compounds contributes to extending overhaul intervals for railway cars and reducing service costs.
Butyl Compounds as a Material Standard in Modern Railways
Butyl compounds are currently one of the most important elastomer materials used in the construction of railway cars.
Their application in sealing, acoustic insulation, and vibration isolation systems helps increase rolling stock durability, improve passenger comfort, and reduce operating costs for railway operators.
Proper selection of product geometry, compound parameters, and installation technology is crucial for achieving long-term tightness and effective vibration reduction in rail vehicles.