SOLIMIDE® AC-550H
SOLIMIDE® AC-550H is a lightweight, non-wicking polyimide foam with a density of 0.50 lb/ft³ (8.0 kg/m³) — slightly denser than AC-550 for improved thermal properties — designed for aircraft, aerospace, and space applications where low fire, toxicity, and smoke generation are critical. It passes FAA Radiant Panel testing per FAR 25.856(a), is rated for continuous use up to 400°F (200°C), and provides outgassing performance of TMI < 1.0% and CVCM < 0.1% per ASTM E595.
Key Properties
- Density: 0.50 (8.0) lb/ft³ (kg/m³) (ASTM D3574 Test A, ISO 845)
- Thermal Conductivity @ 75°F (24°C): 0.30 (0.043) BTU·in/hr·ft²·°F (W/mK) (ASTM C518)
- Max Continuous Use Temperature: 400 (200) °F (°C)
- FAA Radiant Panel FAR 25.856(a): Pass (FAR 25.856(a))
- Smoke Developed Index — Flaming & Non-flaming Modes: < 5 (ASTM E662)
- Offgassing / Outgassing TMI: < 1.0% (ASTM E595)
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Density | 0.50 (8.0) lb/ft³ (kg/m³) | ASTM D3574 Test A, ISO 845 |
| Max Continuous Use Temperature | 400 (200) °F (°C) | — |
Thermal Properties
| Property | Value | Test Method |
| Thermal Conductivity @ 75°F (24°C) | 0.30 (0.043) BTU·in/hr·ft²·°F (W/mK) | ASTM C518 |
Flame & Fire Performance
| Property | Value | Test Method |
| FAA Radiant Panel FAR 25.856(a) | Pass | FAR 25.856(a) |
| Smoke Developed Index — Flaming & Non-flaming Modes | < 5 | ASTM E662 |
Outgassing
| Property | Value | Test Method |
| Offgassing / Outgassing TMI | < 1.0% | ASTM E595 |
| Offgassing / Outgassing CVCM | < 0.1% | ASTM E595 |
Compliance
- Airbus AIMS 04-14-006 — Compliant
- Embraer MEP-17-010 — Compliant
- Hughes HMS 17-1186 — Compliant
- Lockheed Martin (formerly General Dynamics) 5-06147 — Compliant
- Sikorsky SS9232 — Compliant
- ASTM C 1482 — Compliant
- Aircraft sidewalls and ECS system insulation requiring the lowest thermal conductivity in the SOLIMIDE® aerospace range
- Space vehicle cushioning and thermal protection where low outgassing and non-wicking construction are required
- Vibration damping in space applications demanding lightweight, stable insulation materials
- Aerospace thermal and acoustic insulation approved to rotorcraft and fixed-wing OEM specifications
- Aircraft interior assemblies requiring FAR 25.856(a) flame compliance and formaldehyde-free construction
Common industries: Aerospace, Aviation, Defense, Space.
SOLIMIDE® AC-550H is the highest-density grade in the SOLIMIDE® aerospace polyimide foam range at 0.50 lb/ft³ (8.0 kg/m³). It is used in aircraft and aerospace markets as a lightweight, non-wicking thermal and acoustic insulation where low fire, toxicity, and smoke generation are critical, and is specifically noted as a variant of AC-550 formulated with slightly higher density to deliver improved thermal properties. Applications include aircraft sidewalls, ECS systems, and space vehicle cushioning, thermal protection, and vibration damping.
AC-550H achieves a thermal conductivity of 0.30 (0.043) BTU·in/hr·ft²·°F (W/mK) at 75°F (24°C) per ASTM C518 — the lowest in the SOLIMIDE® aerospace range — and passes the FAA Radiant Panel test per FAR 25.856(a). Smoke developed index is less than 5 in both flaming and non-flaming modes per ASTM E662. Outgassing is characterized per ASTM E595, with TMI less than 1.0% and CVCM less than 0.1%.
The material is formaldehyde-free and demonstrates excellent long-term stability under humid conditions and after temperature cycling. It is compatible with facings, coatings, and adhesives.
Compliant with Airbus AIMS 04-14-006, Embraer MEP-17-010, Hughes HMS 17-1186, Lockheed Martin (formerly General Dynamics) 5-06147, Sikorsky SS9232, and ASTM C 1482.
What differentiates AC-550 (H) from AC-550 in the SOLIMIDE® aerospace foam range?
AC-550H is specifically formulated to be slightly denser than AC-550 — 0.50 lb/ft³ (8.0 kg/m³) versus 0.44 lb/ft³ (7.1 kg/m³) — to deliver improved thermal properties. Its thermal conductivity of 0.30 (0.043) BTU·in/hr·ft²·°F (W/mK) is lower than AC-550's 0.32 (0.046), making it the best-insulating grade in the SOLIMIDE® aerospace range. It also holds a distinct OEM approval set including Airbus, Embraer, Sikorsky, and Lockheed Martin specifications.
Why does thermal conductivity matter for polyimide foam selection?
Thermal conductivity determines how effectively the foam reduces heat transfer at a given thickness and density. For aircraft sidewall panels, ECS systems, and space applications, lower thermal conductivity means better insulating efficiency — allowing thinner or lighter insulation to meet the same thermal performance requirement. AC-550H achieves the lowest thermal conductivity in the SOLIMIDE® aerospace range at 0.30 (0.043) BTU·in/hr·ft²·°F (W/mK).
What is the maximum continuous use temperature for AC-550H?
AC-550H is rated for continuous use up to 400°F (200°C).
Is AC-550H suitable for aerospace flame-rated or space environments?
Yes. AC-550H passes the FAA Radiant Panel test per FAR 25.856(a) and produces a smoke developed index of less than 5 in both flaming and non-flaming modes per ASTM E662. Outgassing per ASTM E595 is TMI < 1.0% and CVCM < 0.1%, supporting suitability for space applications where outgassing control is critical.
How should AC-550H be specified?
Specify grade (AC-550H), thickness, facing or coating requirements if applicable, compliance specifications required (e.g., Airbus AIMS 04-14-006, Sikorsky SS9232), dimensional tolerances, and finished format.
