crosslinked polyethylene insulated cable mfr - by crosslinking operation after enclosure of insulation in metal sheath

摘要

A cable with a thermoplastic insulation is produced by extruding around a core a not yet crosslinked polyethylene insulation. The extrusion can be done in three stages, with a smoothing layer, an insulating layer proper and a conductive outer layer. A metal sheath is applied to this by spraying or by welding a spiralling metal tape. The originally a little larger inside dia. of the metal sheath is reduced to the outside dia. of the insulation by a drawing operation. After cooling the insulation to give it a higher mechanical strength, the polyethylene is crosslinked in the closed metal sheath, by conventional heating in a steam tube. The insulation cover is thus protected all the time against the ingress of moisture. The result is a very high-class crosslinked polyethylene insulation.