Extrusion Foam Coating of Coaxial Cables using Chemical Blowing Agent

This paper presents an experimental study on manufacture and characterization of an insulating foam coating in the coaxial cables. Coaxial cables with foam insulator are widely used in the communication industries; low loss attenuation coaxial cable is used in the feeders of base stations for mobile phones. The insulating foam plays a principle role in the attenuation characteristics of the cable. In this research work, an extrusion setup was prepared to produce foam insulated coaxial cable where a chemical blowing agent was used as the foaming agent. The effects of blowing agent and die outlet diameter on foam density and loss-attenuation were investigated. The results show that an acceptable loss-attenuation is achievable via adjusting processing parameters.