BISCO MF1 Bun silicone is a lightweight cellular silicone foam cast into block form. This high quality material is designed for a wide range of cushioning applications such as passenger rail car seating. MF1 silicone’s proven durability and fire resistance means reliable comfort, longevity and safety. MF1 is available in three firmness ranges, allowing engineers to optimize seat designs and maximize passenger comfort while reducing weight and size.


  • Available in blocks up to 8 in. thick
  • Tested for a UL94 V-0 and HF-1 rating
  • Low compression set
  • Used most often as cushion foam in passenger rail car seating


  • Exceptional flame, smoke and toxicity (FST) resistance performance
  • Superior weather and UV resistance
  • Outperforms competitive cushion foams in durability
  • Ensures safety, long cushion life and lasting passenger comfort

Please see below for a sampling of data for this material formulation. For detailed material information and to use advanced features such as filtering, visit the BISCO® Product Properties Guide.

MF1-35 MF1-55 MF1-75
Minimum Thickness (mm) 6.35 6.35 6.35
Maximum Thickness (mm) 178.0 178.0 152.0
Density (kg/m3) 80 96 112
Compression Force Deflection (kPa) 5.5 6.2 6.9
Compression Set (%) 1.5 1.5 1.5
Water Absorption (%) NA NA NA
UL94 V-0 (Pass/Fail) N/A N/A N/A
UL94 HF-1 (Pass/Fail) N/A N/A N/A
Min Operating Temp (°C) N/A N/A N/A
Max Operating Temp (°C) 200° 200° 200°



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