SFS develops silicone sponge for rail industry seals

A new silicone sponge that meets the latest harmonised European fire/smoke and toxicity specifications for the rail industry has been developed by the SFS Manufacturing Group.

Fire retardant silicone in solid form has been used in sealing applications by the rail industry for many years, but Blackburn-based SFS says its new SP-RL grades of silicone sponge have the advantages of reduced weight and improved sealing performance.

They also require a smaller closure force than non-cellular silicones, enabling the use of thinner and lighter substrates.

"Independent testing has verified that these products meet EN45545-2 Hazard Level 3 for fire protection on railway vehicles, and UL94-V0 for electronics," said SFS Operations Manager, Tony Parker.

The new sponge can be extruded in specific shapes, which have a smooth-skinned surface. Their 100 percent closed non-interconnecting cell structure prevents the ingress of water and dust, making possible sealing ratings as high as IP67.

Extruded profiles can be fabricated into gaskets, while the sponge can also be supplied as sheeting or flat die-cut gaskets.Typical uses in the rail sector include door and roof seals, enclosure seals, HVAC seals and gaskets, anti-vibration seals and gaskets for lighting on trains, platforms and tunnels.