Mfr. of electrical conductor with linear polyester insulation - with preliminary treatment with release agent

摘要

Prodn. of an electrical conductor with impact-resistant and temp, -resistant insulation of linear polyester comprises first treating the surface of the conductor with a release agent. The insulation is then applied by extrusion, and after leaving the extruder the conductor is subjected to directed temp. treatment at temps. above freezing point of the polyester. The polyester may be polyethylene terephthalate which is extruded at 250-350 degrees C, or polybutylene terephthalate which is extruded at 220-290 degrees C. The conductor is pref. sprayed with silicone oil prior to introduction into the extruder. Process is effected in a single stage, with very thin insulation.