Flame-retardant thermoplastic elastomers (TPE) are increasingly being specified for railway applications.
This is so that, if a fire should break out, the amount of disorientating smoke is reduced and the products of combustion are less toxic.
In addition, flame retardants that are free of chlorine and bromine minimise the risk of damage from the corrosive gases that normally develop when halogen-containing compounds are burnt.
To meet this demand, German manufacturer Kraiburg TPE is expanding its flame-retardant product portfolio with innovative materials which, in addition to complying with UL 94 V0, the plastics flammability standard released by Underwriters Laboratories of the United States, also meet DIN 45545-2 for railway applications.
Kraiburg TPE has extensive experience in the development of TPEs with halogen-free flame-retardant properties. A second product series, with a V-0 nonflammability classification at wall thicknesses of 1.5mm in accordance with UL standard 94 V-0, has recently been introduced for multi-component applications with polypropylene.
These materials are self-extinguishing in case of fire, do not form into burning droplets and meet this requirement without the use of halogen-containing flame retardants.
This series is the only TPE material on the market that meets DIN EN 45545-2 for railway applications. These specially developed materials, which meet the requirements of R22 and R23 for hazard levels HL1-3 with a wall thickness of up to 3 mm, make it possible to seal the interior and exterior of trains, regardless of their design and operating class.
The first railway applications have already been introduced – TPE compounds from the FR2 series are being used as sealing materials in cable glands and bushings.
The new flame-retardant materials are produced at all three Kraiburg TPE production sites – in Germany, Malaysia and the USA.