Flame resistance and fire safety are often top priorities for companies producing consumer, residential, and commercial products. Many products require UL or Intertek testing for flame resistance and flame propagation. The prevailing flammability test for rubber materials is UL 94. There are several tests under UL 94 including horizontal burn tests and vertical burn testing, vertical being more stringent than horizontal. There are special categories for foams (HBF and HF-1) and thin materials (VTM-0, VTM-1, VTM-2).
Best UL 94 Gasket Materials and UL 94 Pad Materials
Flame Retardant Materials
| Materials | Flame Rating | Standard thickness | Firmness | Sealing | Cushioning |
|---|---|---|---|---|---|
| HT-800 Flame Rated Silicone Foam | UL 94V-0 | .031″-0.5″ (0.79mm-12.7mm) | Medium - (6-14psi to compress 25%) | Good - (UL 50E, NEMA 3, NEMA 4, IP64, IP65, IP66) | Good – moderate dampening, very good rebound |
| R10400 M Flame Rated Silicone Sponge | UL 94V-0 | .062″-0.5″ (1.59mm-12.7mm) | Medium - (9-14psi to compress 25%) | Good - (NEMA 3, NEMA 4, IP64, IP65, IP66) | Good – moderate dampening, very good rebound |
| FPC Fire Block Material | UL 94V-0 | .062″, 0.125″, 0.25″ (1.59mm, 3.18mm, 6.35mm) | Firm | N/A | Good |
| HT-6360 Flame Rated Solid Silicone | UL 94V-0 | 020″-0.125″ (0.51mm-3.18mm) | 65 durometer Shore “A” | Good - (NEMA 4, NEMA 6, IP67) | Moderate |
| EC-2130 Flame Rated EMI Gasket | 020″-0.125″ (0.51mm-3.18mm) | .062″ & 0.125″ (1.59mm & 12.7mm) | 30 durometer Shore “A” | Good - (NEMA 4, NEMA 6, IP67) | Conductive silicone |
| XIAMETER™ RBL-9591-50 Flame Rated LSR | UL 94V-0 | .031″-0.5″ (0.79mm-12.7mm) | 50 durometer Shore “A” | Good - (NEMA 4, NEMA 6, IP67) | Moderate |
Other Good UL 94 Flame Rated Materials:
- PORON® urethane foam – UL 94HBF (thickness and grade dependant)
- Neoprene sponge – UL 94HF-1 (thickness and grade dependant)
Common Industries Gasket that Require Flame Rated Materials
- Residential and commercial lighting gaskets (UL 496, UL 8750)
- Commercial signage (UL 48)
- Commercial cooking equipment and ventilation gaskets (NFPA 96)
- Enclosure gaskets (UL 60950)
- Industrial controls gasket (UL 508, UL 60947)
- Handheld electronics cushioning pad and gasket (UL 94)
- Rugged cushion pads and water seals (UL 94)
- Flame rated EMI gaskets (UL 94)
- Telecommunications base stations (UL 94)
FAR 25.853
FAR 25.853 is an FAA flame test for materials used in aircraft interiors. There are several tests including a Vertical Burn Test, 45 Degree Burn and Horizontal Burn test. FAR 25.853(a) relates to interior compartments occupied by crew or passengers. Materials must be self-extinguishing under the vertical burn test.
Flame Tested Components include:
- Interior ceiling panels
- Interior wall panels and partitions
- Galley structure
- Large cabinet walls
- Structural flooring
- Materials used in the construction of stowage compartments
Requirements for Vertical Burn:
| Flame Time: | Drip Flame Time: | Burn Length: |
|---|---|---|
| Average not to exceed 15 seconds (60 second test or 12 second test) | Average not to exceed 3 seconds for 12 second test | Average not to exceed 6″ for 60 second test |
| Average not to exceed 15 seconds (60 second test or 12 second test) | Average not to exceed 5 seconds for 60 second test | Average not to exceed 8″ for 12 second test |
UL 94V-0 Flame Retardant Silicone Sponge Burn Test Video
UL 94V-0 rated R10400 silicone sponge is exposed to a flame from a torch in this video. This is not an official UL test. Silicone foam and silicone sponge have a wide temperature range but without special chemistry they will burn. R10400 silicone sponge is formulated to meet an aggressive UL 94V-0 flame rating.
Contact Stockwell Elastomerics for Flame Retardant Gaskets and Flame Rated Gasket Materials
Contact Us for further assistance with custom UL 94 gaskets using flame rated gasket materials, including UL 94V-0, UL 94V-1, UL 94HBF, UL 94HF-1, FAR 25.853.
