UL 94 HB Silicone Sheet and Uncured Compound

UL 94HB silicone meets the UL 94 HB horizontal burn flammability standard established by Underwriters Laboratories. Formulated for general-purpose electrical, automotive, and industrial enclosure applications, UL 94HB solid silicone rubber offers controlled flame resistance under horizontal burn conditions while delivering the superior environmental sealing, ozone resistance, and thermal flexibility characteristic of high-grade silicone elastomers across a temperature range of -80°F to 450°F (-62°C to 232°C).

UL 94HB Silicone Properties

Key characteristics of UL 94HB silicone rubber:

  • Flammability Rating: Certified or tested to meet the UL 94 HB horizontal burn classification (slow burn rate or self-extinguishing in horizontal orientation).

  • Hardness Range: Available in multiple durometer options (typically 40 to 70 Shore A) to accommodate varying gasket compression and closure force requirements.

  • Temperature Resistance: Maintains elasticity and structural integrity across broad operating temperatures, from -80°F to 450°F (-62°C to 232°C).

  • Environmental & Weathering Resistance: Exceptional resistance to UV radiation, ozone, moisture, and extreme outdoor weather conditions, making it ideal for environmental sealing.

  • Material: Solid silicone rubber (VMQ elastomer).

  • Forms: Supplied in solid sheets, continuous roll stock, uncured compounds, precision die-cut gaskets, and custom extrusions.

ElastaPro makes UL 94 silicone in solid sheets and uncured compounds. Contact us for more information.