Nick Parker⚡ Need High-Performance EMI/RFI Shielding or Custom Conductive Profiles?
Sourcing specialized conductive elastomers for aerospace enclosures, military hardware, or medical diagnostics? Accuseal Rubber extrudes custom electrically conductive silicone tubing and hollow O-cords in-house at our New Jersey facility—meeting stringent MIL-SPEC standards with low closure force.
➔ Upload Your CAD Drawing (.STEP / .DWG / PDF) or Shielding Specs for a 24-Hr Engineering Quote
What Is Electrically Conductive Silicone Rubber Tubing?
Direct Answer: Electrically conductive silicone rubber tubing is an elastomeric composite extrusion filled with microscopic conductive metal particles (such as nickel-coated graphite, silver-plated aluminum, or carbon). It provides simultaneous dual-function performance: reliable electromagnetic interference (EMI) and radio frequency interference (RFI) shielding across wide frequency bands, coupled with environmental ingress protection (IP65 to IP68) against dust, moisture, and extreme temperatures (-55°C to +160°C+).
Standard silicone acts as an electrical insulator; by compounding high-grade silicone base polymers with precisely dispersed metallic and metallized glass fillers, the material achieves ultra-low volume resistivity while preserving elastic memory and compressibility.
Conductive Filler Options: Cost vs. Shielding Effectiveness
The mechanical flexibility, corrosion resistance, and shielding performance of conductive tubing depend directly on the conductive particle system selected:
| Conductive Filler System | Shielding Effectiveness (20 MHz – 10 GHz) | Volume Resistivity (Ω⋅cm) | Galvanic Corrosion Risk | Best Application Fit |
| Nickel-Coated Graphite (Ni/C) | 90 dB – 105 dB | $0.050 – 0.100$ | Low (Mates well with aluminum) | Commercial aerospace, telecom cabinets, industrial electronics (Best cost/performance ratio) |
| Silver-Plated Aluminum (Ag/Al) | 100 dB – 120+ dB | $0.008 – 0.012$ | Very Low (Engineered for aerospace alloys) | High-reliability defense, airborne radar, tactical communications |
| Silver-Plated Copper (Ag/Cu) | 110 dB – 120+ dB | $0.004 – 0.010$ | Moderate | Maximum attenuation, EMP hardening, military test racks |
| Conductive Carbon Black | 30 dB – 50 dB | $1.0 – 10.0$ | None | Electrostatic discharge (ESD), static dissipation, grounding lines |
Solid Cords vs. Hollow Conductive Tubing: Low Closure Force Advantage
Direct Answer: In electronic enclosures and cast aluminum housings, excessive gasket compression force can warp thin covers or strip thread inserts. Hollow conductive silicone tubing is specifically engineered to resolve this: the hollow cross-section permits high deflection (up to 40%–50%) under minimal latching force while maintaining continuous, low-resistance electrical contact across flange joints.
Structural Comparison
Hollow Extruded Tubing: Recommended for sheet-metal enclosures, lightweight avionics boxes, optical access doors, and portable electronics requiring tight weather and EMI sealing with light fastener torque.
Solid Conductive Cords: Specified for heavy machined grooves, marine bulkhead hatches, and high-pressure military chambers where rigid clamping force is available.
Material Compounds & Operating Specifications
Accuseal Rubber extrudes conductive elastomers compounded to meet strict MIL-DTL-83528 requirements:
| Engineering Specification | Typical Range / Value |
| Elastomer Base | High-grade Silicone or Fluorosilicone (for fuel/solvent resistance) |
| Durometer Hardness | 50 to 75 Shore A ($\pm 5$) |
| Operating Temperature Range | -55°C to +160°C (Silicone) / -55°C to +150°C (Fluorosilicone) |
| Elongation at Break | 100% to 300% (dependent on filler loading) |
| Compression Set Resistance | <30% to 35% after 70 hrs @ 100°C |
| Volume Resistivity | As low as $0.004\ \Omega\cdot\text{cm}$ (Ag/Cu grades) |
| Dimensional Tolerances | RMA Class 1 (High Precision) Extrusions |
In-House Tooling & Secondary Fabrication Services
Conductive elastomers are dense, abrasive to process, and exhibit unique die swell behavior. Accuseal Rubber manufactures conductive extrusions with complete in-house control:
Custom Die Tooling: Fast wire EDM die fabrication in New Jersey for custom hollow profiles, D-tubing, and P-strips within 1 to 2 weeks.
Conductive Splicing & Endless O-Rings: Hot-vulcanized joints utilizing matched conductive adhesive compounds to ensure uninterrupted electrical continuity across spliced gasket loops.
Conductive PSA Backing: Application of electrically conductive pressure-sensitive adhesive tape for solderless, peel-and-stick flange mounting.
Precision Cut Pieces: Tight linear tolerance cutting to eliminate field assembly trimming and reduce component assembly time.
Frequently Asked Questions (FAQ)
How does conductive silicone tubing prevent galvanic corrosion?
When mounted against structural metals (such as aluminum alloy enclosures), dissimilar metals can create galvanic reactions. Selecting Nickel-Graphite (Ni/C) or Silver-Aluminum (Ag/Al) filled silicone dramatically reduces electrochemical potential mismatch, preventing oxidation in harsh salt-spray and humid environments.
What is the maximum deflection recommended for hollow conductive tubing?
Optimal performance is achieved between 20% and 35% nominal deflection. Exceeding 50% deflection can cause over-compression fatigue, cracking of the inner lumen, or loss of long-term elastic recovery.
Can conductive silicone tubing be co-extruded with non-conductive rubber?
Yes. We can manufacture dual-durometer and dual-compound profiles featuring an electrically conductive outer jacket or contact bead supported by a non-conductive, ultra-soft silicone sponge core for maximum compliance and lower raw-material costs.
Request an Engineering Review & Conductive Extrusion Quote
Ensure your electronic enclosures achieve certified electromagnetic compliance and moisture ingress defense. Connect directly with Accuseal Rubber’s technical manufacturing team:
Email Specifications & Drawings: info@accusealrubber.com
Manufacturing Facility: 18-F Home News Row, New Brunswick, NJ 08901, USA
Submit Your Drawing: Send your CAD file (.STEP / .DWG / PDF), target volume resistivity, and housing dimensions for a complete engineering assessment and rapid quotation within 24 hours.