UL 94 HB Silicone Sheeting & 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).

Need UL 94 HB  Silicone Sheeting or Slit Rolls?

We supply continuous roll stock, pre-cut solid sheets, and custom uncured compounds with low minimum order quantities, optional pressure-sensitive adhesives (PSA), and rapid turnarounds.

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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.

Frequently Asked Questions About UL 94 HB Silicone

What does the UL 94 HB flammability rating mean?

The UL 94 HB (Horizontal Burn) classification is a standard established by Underwriters Laboratories. A material with this rating is tested in a horizontal orientation and exhibits a slow burn rate or is self-extinguishing. This makes it a suitable choice for general-purpose applications where basic flame resistance is required, such as electrical housings, automotive components, and industrial enclosures.

What are the typical operating temperature and hardness ranges for ElastaPro’s UL 94 HB silicone?

ElastaPro’s UL 94 HB silicone maintains its structural integrity and elasticity across a wide temperature range of -80°F to 450°F (-62°C to 232°C). It is typically available in a hardness range of 40 to 70 Shore A, allowing users to select the appropriate durometer to meet specific gasket compression and closure force requirements.

In what forms can I order UL 94 HB silicone?

To accommodate diverse manufacturing processes, ElastaPro supplies UL 94 HB silicone in several flexible formats:

  • Solid Silicone Sheet: Available as continuous roll stock.

  • Uncured Compounds: Ready for custom molding or calendering operations.