The materials used in public transport applications are expected to deliver high performance in case of fire to allow people time to escape safely. Materials used in these applications are subjected by strict regulations due to the added difficulty of exiting public transportation vehicles, such as trains and aircraft.
In recent years, several standard requirements have been issued for many industries with high safety requirements. EN 45545-2 was issued in 2013 for railway applications and it became mandatory throughout Europe in 2016.
EN 45545-2 sets out the material specifications to be used in railway vehicles to protect them against fire in accordance with the test methods and criteria specified in the standard, depending on the place of use. Railway vehicles with long tunnel times or long journey times, as in sleeping cars, have additional demanding requirements, such as low smoke density and toxicity, high oxygen index and low heat release rate. These requirements become even more demanding as the hazard classes of railway vehicles increase.
Among those recently approved are PA6, PA66 and PA66/6 fire resistance grades to meet the demanding requirements for application classes R6, R22 and R23 in accordance with EN 45545-2. These products can be safely used in electrical and electronic applications for railway vehicles, such as insulators, switches, relays and connectors.
PA6 is an unfilled, flame-retardant, halogen-free and heat-stabilised material said to be suitable for HL3 duty for R22 and R23. PA6 with 30% glass fibre reinforcement is also flame-retardant, halogen-free and heat-stabilised; it is also free of red phosphorous. It is suitable for HL2 and HL3 duty for R22 and R23. PA6.6 has the same properties as PA6 and offers HL3 duty for R22 and R23. PA6.6/6 has the same properties as PA6 and PA6.6, and offers HL1 duty for R6.
