Self repairing cable with layer of self repairing material surrounding inner conductor

摘要

A power cable includes a layer 4 of self-repairing material 4. This layer is intended to automatically form a seal if the layer is ruptured by an external force. The self repairing layer is formed as an inclusion in insulation layer 6. The layer 4 is not continuous in cross section, but is interrupted by ridges 5 in the insulation layer (Fig 1). Alternatively the self-repairing layer may be completely encapsulated in the insulating layer (Fig 2). The self repairing layer may consist of solid polymeric materials dispersed in an oily phase. An apparatus for applying the self-repairing layer by extruding it onto the outside of a conductor is also described.