MANUFACTURE OF ELECTRICALLY INSULATED WIRE

PURPOSE:To provide a method for manufacture of an electrically insulated wire wherein an electrically insulated layer of at least a specific value in layer thickness can excellently be formed on a conductor of a thin diameter. CONSTITUTION:A method is provided wherein an electrically insulated wire having an electrically insulated layer of at most 0.05mm layer thickness is manufactured by covering a continuously fed conductor with molten thermoplastic resin. A screw shaft for an extruder 10 used when this method is applied has a feed zone 12, a compression zone 14, and a metalling zone 16 successively toward a tip, and equipped with a continuous spiral groove 20 on them. A diameter of the screw shaft is within a range of 10mm-25mm a groove width of the feed zone is within a range of 0.1 times-0.9 times the groove width of the metalling zone, and a groove depth of the feed zone is respectively within a range of 1.1 times-10.0 times the groove depth of the metalling zone.