| 摘要 |
PURPOSE:To prevent crack initiation at the inner surface of a vinyl sheath caused by the edge of the overlapped part of a plastic laminate metal tape by forming the inner layer sheath fusion welded to the plastic laminate metal tape from cold resistance soft vinyl. CONSTITUTION:On a conductor 1 as the core are put one over another an internal semiconductive layer 2, electric insulating substance 3, external semiconductive layer 4, metal shield layer 5, holding tape 6, plastic laminate metal tape 7, and a cold resistant soft vinyl sheath 8A as inner layer sheathing, and further a semi-hard vinyl sheath 8B as outer layer sheathing. These vinyl sheaths 8A, 8B are extruded simultaneously to constitute covering for the power cable concerned, wherein the inner layer shall consist of soft vinyl having a larger cold resistance than the outer 8B while the outer layer consists of semi- hard vinyl. This prevents crack initiation in the vinyl sheaths 8A, 8B caused by the edge of the plastic laminate metal tape 7. |
