CNT/Carbon Black Masterbatch for Drone EMI Shielding
A high-loading carbon nanotube (CNT) and conductive carbon black (CCB) dual-filler masterbatch for compounding into engineering thermoplastics to provide electromagnetic interference (EMI) shielding and electrostatic dissipation (ESD) in drone electronics enclosures, flight controller housings, and RF-sensitive payload boxes.
Key Features
- ✓Dual MWCNT + CCB filler — EMI shielding >30 dB at lower total carbon content vs single-filler CCB systems
- ✓Surface resistivity tunable 10²–10⁶ Ω/sq — one system covers both ESD dissipative and EMI shielding requirements
- ✓CNT aspect ratio >100 — percolation network at <5 vol% minimizes density and viscosity impact
- ✓Carrier-resin matched for PA6, PA12, ABS, PC/ABS — no inter-resin compatibility issues
- ✓30 dB shielding effectiveness prevents motor switching harmonics from corrupting drone sensor signals
- ✓Stable to 300°C — compatible with PA6 and PA12 compounding and injection molding temperatures
Specifications
| Parameter | Value |
|---|---|
| CNT type | Multi-wall CNT (MWCNT), aspect ratio >100 |
| Carbon black type | Conductive grade, structure >150 mL/100g (DBP) |
| Compatible base resins | PA6, PA12, ABS, PC/ABS |
| Masterbatch composition | 3–5 wt% MWCNT + 15–20 wt% CCB in carrier resin |
| Addition level in base resin | 5–20 wt% masterbatch |
| Particle size (CNT diameter) | 8–15 nm diameter, 5–30 μm length |
| Percolation threshold in PA6 | <5 vol% total carbon |
| Processing temperature stability | Stable to 300°C |
| EMI shielding effectiveness (30 dB target) | >30 dB at 100 MHz–3 GHz (ASTM D4935) |
| Surface resistivity range (adjustable by dilution) | 10²–10⁶ Ω/sq |
FAQ
For 30 dB shielding effectiveness in a 2.5 mm wall thickness PA6 housing, the required surface resistivity is approximately 10²–10³ Ω/sq. With this CNT/CCB masterbatch, this resistivity is reached at 12–18 wt% masterbatch addition in PA6. The exact dosage must be calibrated by measuring resistivity on a molded test plaque since dispersion quality (mixing temperature, screw speed, residence time) significantly affects percolation network formation. A compounding trial with resistivity measurement at 10%, 15%, and 20% addition levels is recommended to map the specific resistivity curve for your compounding conditions.