Skogar® VHT & UHT — High-Temperature Thermal Barriers for Aerospace & Defense
Two grades for the hottest zones — silica fiber up to 1400 °C (VHT) or ceramic fiber up to 1700 °C (UHT). FAR 25.853 certified semi-rigid thermal barriers engineered for extreme aerospace, space, and defense environments.
1400 — 1700 °C
Short-time flame exposure
0.012–0.018 W/(m·K)
Thermal conductivity at 20 °C
2 substrate fibers
Silica · Ceramic
FAR 25.853
+ UL94 V-0 certified
Product family
Two variants for extreme temperature environments.
VHT and UHT extend the Skogar® range into the temperature regimes where ST (1100 °C) and HT (1300 °C) reach their limits. Both are semi-rigid silica aerogel composites with the same FAR 25.853 Appendix F aerospace fire certification — only the substrate fiber, thickness range, and temperature ceiling differ.
Skogar® VHT uses a silica fiber substrate, rated up to 1400 °C, available in 2.0 and 3.0 mm — the thinner option, suited to aerospace high-temperature zones where every millimetre counts.
Skogar® UHT uses a ceramic fiber substrate for greater thermal stability, rated up to 1700 °C, available in 4.5 and 6.5 mm — the grade for atmospheric re-entry, solid rocket propulsion, and the hottest exhaust zones.
Typical applications
- Space — atmospheric re-entry thermal protection systems, launcher exhaust zones, upper-stage propulsion insulation
- Defense — solid rocket motor casings, missile propulsion zones, hypersonic platform internal protection
- Aerospace — turbine surrounds, engine exhaust zones, APU thermal zones exceeding 1300 °C
- Custom programmes — extreme thermal environments, sensitive defense applications, advanced R&D projects
Choose your grade
VHT and UHT cover overlapping but distinct ranges. The decision usually comes down to peak temperature and integration thickness.
Skogar® VHT — Silica fiber
Up to 1400 °C · 2.0 / 3.0 mm
The thinner option in the high-temperature family. Silica fiber provides excellent thermal stability and mechanical integrity up to 1400 °C in a 2 to 3 mm semi-rigid sheet. Well suited for engine bays, turbine surrounds, and aerospace fire zones where ST and HT reach their thermal limits.
- Thermal conductivity: 0.012–0.017 W/(m·K)
- Density: 145–165 kg/m³
- Compression deformation @ 0.2 MPa: ≤ 45%
- UL94 V-0 + FAR 25.853 Appendix F
- Hydrophobic surface chemistry
Skogar® UHT — Ceramic fiber
Up to 1700 °C · 4.5 / 6.5 mm
The thicker option, for the most extreme thermal environments. Ceramic fiber substrate maintains structural and thermal integrity up to 1700 °C — the grade for atmospheric re-entry, solid rocket motor zones, and exhaust sections where 1400 °C is exceeded.
- Thermal conductivity: 0.012–0.018 W/(m·K)
- Density: 170–190 kg/m³
- Compression deformation @ 0.2 MPa: ≤ 45%
- UL94 V-0 + FAR 25.853 Appendix F
- Hydrophobic surface chemistry
Side-by-side specifications
| Property | Skogar® VHT | Skogar® UHT |
|---|---|---|
| Substrate | Silica fiber | Ceramic fiber |
| Short-time flame exposure | Up to 1400 °C | Up to 1700 °C |
| Thermal conductivity (20 °C) | 0.012–0.017 W/(m·K) | 0.012–0.018 W/(m·K) |
| Available thicknesses | 2.0 / 3.0 mm | 4.5 / 6.5 mm |
| Thickness tolerance | ± 0.3 mm | ± 0.3 mm |
| Density | 145–165 kg/m³ | 170–190 kg/m³ |
| Stiffness | Semi-rigid | Semi-rigid |
| Compression deformation @ 0.2 MPa | ≤ 45% | ≤ 45% |
| Dielectric strength | > 2.5 kV/mm | > 2.5 kV/mm |
| Surface chemistry | Hydrophobic | Hydrophobic |
| Flammability | UL94 V-0 + FAR 25.853 Appendix F | UL94 V-0 + FAR 25.853 Appendix F |
Below 1300 °C? Consider HT or ST.
VHT and UHT are reserved for environments above 1300 °C. For lower-temperature applications, the rest of the Skogar® range offers broader thickness options, lighter density, and shorter lead times.
Skogar® HT
Flexible, preox-fiber based. Up to 1300 °C. FAR 25.853 certified. 2.0 to 6.0 mm. The reference grade for aerospace and defense fire protection on complex geometries.
Skogar® ST
Rigid, glass-fiber based. Up to 1100 °C. UL94 V-0. From 0.5 mm. The grade for tight spaces, ultra-thin profiles, and rigid integration.
Full range comparison
Side-by-side specs for the full Skogar® range — ST, HT, VHT, UHT. Thermal conductivity, thickness, temperature range, certifications.
Designing for re-entry, propulsion, or extreme thermal zones?
VHT and UHT projects start with a technical conversation. Share your thermal profile, geometry, and qualification needs — our engineering team will tell you which grade fits, what’s achievable, and how to get there.