Drawing of Insulated Sodium Conductor

The preparation of high strength, small diameter sodium wire is discussed. A new production method consisting of simultaneous extrusion of conductor and insulation followed by high speed drawing and annealing of the composite is described. The influence of polyethylene properties and process conditions on the characteristics of the wire is shown. Resistance to damage through crushing is of particular note because the soft conductor does not act as an anvil to cut the insulation. The wire has high tensile strength, especially in the smaller sizes. Permeability to water vapor is a problem but practical means of combating it already are in use in other services. Development of reliable long life connectors is required for future applications.