Rigid PU Foam for UAV Sandwich Core
A two-component rigid polyurethane (PU) foam system designed as lightweight sandwich core material for drone wings, fuselage panels, and payload bay structures.
Key Features
- ✓15–20× free-rise expansion fills complex UAV cavities without manual cutting or laminating
- ✓Density tunable 40–80 kg/m³ by mold temperature and A:B ratio — weight-strength trade-off by zone
- ✓Closed-cell structure limits water absorption to <2 vol% — moisture-stable in rain and fog deployment
- ✓Direct epoxy and PU resin bond — no separate core adhesive layer required
- ✓1:1 volume mix ratio compatible with standard 2-component dispensing equipment
- ✓Halogen-free FR grade available (UL 94 HF-1) for battery bay and electronics compartment applications
Specifications
| Parameter | Value |
|---|---|
| Tack-free time | 3–5 min |
| Free-rise density | 35–45 kg/m³ (40 kg/m³ target) |
| Rise time (25°C) | 90–120 s |
| Cream time (25°C) | 15–25 s |
| Molded density range | 40–80 kg/m³ |
| Foam-skin peel strength | 3.5–5.0 N/mm (T-peel) |
| Mix ratio (A:B by volume) | 1:1 |
| Shear strength (60 kg/m³) | 0.3 MPa (ASTM C273) |
| Water absorption (ASTM D2842) | <2.0 vol% |
| Compressive strength (60 kg/m³) | 0.5 MPa (ASTM C365) |
FAQ
Free-rise density is approximately 40 kg/m³ at 25°C with a 1:1 A:B volume mix. To achieve 60 kg/m³ molded density, fill approximately 65–70% of the mold cavity volume with mixed foam before closing the mold (overpack factor 1.5). The compressed foam fills the cavity under back-pressure, increasing density to the target range. Preheat the mold to 40–50°C for faster demold and better skin adhesion. For densities above 70 kg/m³, use an overpack factor of 1.8–2.0. Always perform a small-scale trial pour to calibrate the exact overpack factor for your specific mold geometry.