aviation cable factory

Aviation Cable Manufacturing Process Explained: From Raw Material to High-Flying Safety

Aviation cables are the lifelines of aircraft, carrying critical power, signals, and data. Their manufacturing demands extreme precision and adherence to rigorous standards (like MIL-specs or AS standards). Understanding the key steps highlights why quality is paramount:

1. ​Raw Material Selection & Preparation:
   • ​Conductor: High-conductivity copper (often oxygen-free) or aluminum is chosen. Stranded wire is standard for flexibility.
   • ​Insulation/Jacket: Specialized thermoset (e.g., Teflon®, ETFE, Silicone Rubber) or high-performance thermoplastic materials resist harsh aviation conditions (temperature extremes, fluids, abrasion).
   • ​Shielding: Often needed for signal integrity. Braided tinned copper or aluminum foil with drain wire are common.
2. ​Wire Drawing (Conductor Preparation):
   • Metal rods are pulled through progressively smaller dies to achieve the precise diameter needed for individual strands.
   • Ensures consistent size, surface finish, and conductivity.
3. ​Annealing:
   • After drawing, strands go through heat treatment (annealing). This relieves internal stresses, softens the metal, and restores flexibility crucial for stranded cable performance.
4. ​Stranding:
   • Multiple annealed strands (7, 19, 37 etc.) are twisted together concentrically around a core to form the final conductor. Precision machinery controls the lay length (twist rate).
   • Why it matters: Balanced stranding ensures flexibility, fatigue resistance, and consistent electrical performance throughout the cable’s bend cycles.
5. ​Insulation/Jacket Extrusion:
   • ​Primary Insulation: The stranded conductor passes through an extruder, where melted insulation material is applied uniformly around each conductor in a multi-conductor cable. For coaxial or triaxial cables, dielectrics are applied.
   • ​Shield Application: Shielding layers (braid or foil) are applied over the insulated conductors.
   • ​Outer Jacket: A final extrusion layer provides overall environmental protection, marking, and abrasion resistance. Tight tolerances on thickness are critical.
   • Key Control: Temperature profiles, extrusion speed, and cooling must be meticulously controlled to prevent voids, ensure adhesion, and achieve specified material properties.
6. ​Curing (for Thermoset Materials):
   • Cables using thermoset insulation/jackets (like most Teflon® types) pass through continuous vulcanization tubes (CV tubes) under heat and pressure. This permanently cross-links the polymer, creating its final, durable, temperature-resistant form.
7. ​Printing & Marking:
   • Essential information (part number, manufacturer ID, date codes, rating info) is printed continuously along the jacket using hot foil stamping, ink jet, or laser etching. Legibility and durability are vital for traceability and maintenance.
8. ​Rigorous Testing (Throughout & Final):
   • ​In-Line: Continuous checks for conductor resistance, insulation thickness, concentricity, diameter, spark testing (for pin-holes) during extrusion.
   • ​Final QA: Includes:
     • ​Electrical: Conductor resistance, insulation resistance, hi-pot (dielectric withstand voltage), capacitance, impedance (for coax).
     • ​Physical: Dimensions (OD, insulation thickness), mechanical properties (tensile strength, elongation), weight, marking permanence, flexing tests, visual inspection.
     • ​Environmental: Often subjected to tests simulating temperature extremes, fluid immersion, flammability resistance (e.g., FAR 25.853), smoke density, and toxicity.
9. ​Packaging & Traceability:
   • Cable is carefully reeled or coiled to prevent kinking or damage.
   • Packaging protects against environmental contamination during storage and shipping.
   • Strict traceability is maintained from raw material batches through every manufacturing step to the final reel, linking back to test certifications.

Key Considerations for Solution Selection

Understanding this process helps when sourcing or specifying aviation cable:

• ​Material Matters: Insulation/jacket material defines resistance to temperature, fluids, smoke, and abrasion. Match it precisely to the application environment (e.g., engine bay vs. cabin).
• ​Standards are Safety: Certifications to MIL-specs (e.g., MIL-W-22759), SAE AS (e.g., AS22759), or FAA TSOs are non-negotiable evidence of compliance. Always verify.
• ​Traceability is Critical: Full material and process traceability is essential for maintenance, repairs, and safety investigations.
• ​Supplier Expertise: Choose manufacturers with proven expertise in aviation-grade cable production and stringent quality systems like AS9100. Process consistency is key to reliability.

The aviation cable manufacturing process is a blend of advanced materials science, precision engineering, and relentless quality control. This meticulous attention to detail ensures the lightweight wires woven throughout an aircraft can withstand decades of punishing conditions and keep critical systems operating safely and reliably.