SOLIMIDE® AC-550
SOLIMIDE® AC-550 is a lightweight, non-wicking polyimide foam with a density of 0.44 lb/ft³ (7.1 kg/m³), designed for aircraft and aerospace thermal and acoustic insulation where low fire, toxicity, and smoke generation are critical. It passes FAA Radiant Panel testing per FAR 25.856(a) and is rated for continuous use up to 400°F (200°C). The material is formaldehyde-free and demonstrates excellent long-term stability under humid conditions and after temperature cycling.
Key Properties
- Density: 0.44 (7.1) lb/ft³ (kg/m³) (ASTM D3574 Test A, ISO 845)
- Thermal Conductivity @ 75°F (24°C): 0.32 (0.046) 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)
- Noise Reduction Coefficient (NRC), 1 in (25mm): 0.75 (ASTM C423 & E795, Mounting A)
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Density | 0.44 (7.1) 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) | 0.32 (0.046) 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 |
Acoustic Properties
| Property | Value | Test Method |
| Noise Reduction Coefficient (NRC), 1 in (25mm) | 0.75 | ASTM C423 & E795, Mounting A |
Outgassing
| Property | Value | Test Method |
| Offgassing / Outgassing TMI | < 1.0% | ASTM E595 |
| Offgassing / Outgassing CVCM | < 0.1% | ASTM E595 |
Compliance
- Boeing BMS 8-300 — Compliant
- Bombardier BAMS 544-006 — Compliant
- Boeing (Douglas) DMS 2330 — Compliant
- ASTM C 1482 — Compliant
- Hamilton Sundstrand HS 14190 — Compliant
- Lockheed Martin LAC 23-4831 — Compliant
- Aircraft fuselage thermal and acoustic insulation requiring FAR 25.856(a) flame compliance and low outgassing
- Under-floor and ECS duct insulation in commercial and military aircraft
- Aircraft interior insulation compatible with facings, coatings, and adhesives
- Aerospace thermal and acoustic insulation requiring Boeing, Bombardier, and Lockheed Martin material specifications
- Non-wicking insulation assemblies where humidity resistance and thermal cycling stability are required
Common industries: Aerospace, Aviation, Defense.
SOLIMIDE® AC-550 is the standard aircraft-grade polyimide foam in the SOLIMIDE® aerospace range, with a density of 0.44 lb/ft³ (7.1 kg/m³). It is utilized in aircraft and aerospace markets as a lightweight, non-wicking thermal and acoustic insulation material where low fire, toxicity, and smoke generation are critical. Primary applications include aircraft fuselage insulation, under-floor and ECS duct insulation, and aircraft interior assemblies.
The foam can be cut into numerous shapes and sizes and is compatible with a wide range of facings, coatings, and adhesives.
AC-550 achieves a thermal conductivity of 0.32 (0.046) BTU·in/hr·ft²·°F (W/mK) at 75°F (24°C) per ASTM C518 — improved over the lower-density AC-530 — 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. Noise reduction coefficient is 0.75 at 1 in (25mm) thickness per ASTM C423 & E795, Mounting A.
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 stability under humid conditions and after temperature cycling.
Compliant with Boeing BMS 8-300, Bombardier BAMS 544-006, Boeing (Douglas) DMS 2330, ASTM C 1482, Hamilton Sundstrand HS 14190, and Lockheed Martin LAC 23-4831.
What differentiates AC-550 from AC-530 and AC-550 (H) in the SOLIMIDE® aerospace foam range?
AC-550 is the standard aircraft-grade foam in the range at 0.44 lb/ft³ (7.1 kg/m³), sitting between the lighter AC-530 (0.37 lb/ft³ max) and the denser AC-550 (H) (0.50 lb/ft³). Its thermal conductivity of 0.32 (0.046) BTU·in/hr·ft²·°F (W/mK) is lower than AC-530, reflecting the performance benefit of higher density. AC-550 holds the broadest OEM approval portfolio in the range, including Boeing, Bombardier, and Lockheed Martin specifications.
Why does thermal conductivity matter for polyimide foam selection?
Thermal conductivity determines the insulating effectiveness of the foam at a given thickness. Lower thermal conductivity means less heat transfer through the insulation, which is critical for aircraft fuselage, ECS, and under-floor applications where maintaining stable thermal environments and meeting weight budgets are simultaneous constraints. AC-550's thermal conductivity of 0.32 (0.046) BTU·in/hr·ft²·°F (W/mK) is improved relative to the lower-density AC-530.
What is the maximum continuous use temperature for AC-550?
AC-550 is rated for continuous use up to 400°F (200°C).
Is AC-550 suitable for aerospace flame-rated environments?
Yes. AC-550 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. It is also approved to Boeing BMS 8-300, Bombardier BAMS 544-006, Boeing (Douglas) DMS 2330, Hamilton Sundstrand HS 14190, and Lockheed Martin LAC 23-4831.
How should AC-550 be specified?
Specify grade (AC-550), thickness, facing or coating requirements if applicable, compliance specifications required (e.g., Boeing BMS 8-300, Bombardier BAMS 544-006), dimensional tolerances, and finished format.
