Appts. for mfg. plastics coated HT cables - has extruder head associated with ceramic chamber with calibrating duct and connectable to UHF energy source

摘要

Appts. for mfg. elongate profiles from crosslinked plastics material and/or rubber and having a worm screw extruder head with an adjacent UHF treatment section, has the head or section (10) associated with a chamber (14) formed by temp. and heat resistant material of low dielectric loss. Material is enclosed by metallic walls and the chamber which has a channel (13) for the profile is supplied with UHF energy. Used in high tension cables whose plastics or rubber outer surface is coated with carbon black filled semi-conductor layers. Mfr. of conductors can be effected without the use of protective gas screens whilst oxidation of and pore formation in the surfaces is prevented.