Foamed Insulation Semi-Finished Coaxial Cable
1. Basic Structure
Inner Conductor (Copper or CCA)
+
Foamed Insulation Layer (PE or FEP)
2. Purpose of Foamed Insulation
Reduces dielectric constant for better signal transmission and lower attenuation.
Improves high-frequency performance, suitable for RF, CATV, and broadband signals.
Lightweight & cost-effective compared to solid insulation.
3. Key Manufacturing Process
1) . Conductor Preparation
Copper rod drawing & annealing.
Stranding (for multi-strand conductors).
Surface cleaning for optimal insulation adhesion.
2) . Foamed Insulation Extrusion
Raw material: Foaming-grade PE or FEP with foaming agents.
Physical foaming: Injecting gas (e.g., nitrogen) into the melted polymer.
Chemical foaming: Using chemical blowing agents that release gas during heating.
Control of:
Foam cell size and density.
Insulation diameter uniformity.
Surface smoothness.
Cooling & Sizing: Solidifies insulation and maintains dimensional stability.
Online Testing: Continuous monitoring of insulation thickness and concentricity.
4. Next Processing Stages
Once foamed insulation is completed, the semi-finished product will undergo:
Aluminum foil or copper tape wrapping (shielding).
Braiding: Copper/CCA wire braiding for enhanced shielding.
Jacket Extrusion: PVC, PE, or LSZH outer sheath for protection.
Marking & Coiling
5. Applications
RG Coaxial Cables (e.g., RG6, RG59)
CATV cables
Satellite TV
Broadband internet cables
RF signal transmission
