| 摘要 |
The method involves extruding a two-layer pipe having an electrically insulating inner layer (1) and an electrically conductive layer (2) over the inner layer. Two current leads are spirally wound around the electrically conductive layer. The conductive layer comprises thickness of 0.1-1.5 mm of an electrically conductive molding composition by extrusion over the spirally wound current leads to obtain a surface having wave peaks formed by current leads (5, 6). An outer cladding of electrically insulating plastic material is applied over the electrically conductive layer. |
