| 摘要 |
PURPOSE: To prevent contact between element wires and an external conductor by producing a cable by forming an insulating body of a prescribed polyolefine material on an inner conductive wires composed of stranded wires, the external conductor, and a sheath. CONSTITUTION: An insulator 2 of a polymer with cross-linking degree as high as 70% or more, e.g. polyethylene, an external conductor 3 with a mesh structure of a soft wire, and a sheath 4 of a flame resistant vinyl chloride resin are successively formed on an inner conductor 1 consisting of stranded wires to give a heat resistant coaxial cable. Consequently, even in the case the cable is heated at 420 deg.C for 30 minutes, the cable is prevented from twisting and the element wires and the external conductor are prevented from contacting mutually and the prescribed property can be kept and the cable can be used as a communication cable with high reliability against fires in underground towns, etc., for prevention of disasters. |
