Electric cables of reduced micro-voids in the extruded insulation

摘要

A product by process for reducing micro-voids in cross-linked cable insulation without reducing the voltage breakdown strength thereof in which process the insulation, after cross-linking, is heated at a temperature in the range from about 120 DEG C. to about 150 DEG C. and under a pressure less than 10 mm. Hg for a period from about 8 hours to 48 hours. Also, a cable having such insulation which has micro-voids less than about 102 per mm3 and a perforation gradient greater than the perforation gradient of a cable which has not been so treated.