COATED WIRE AND METHOD OF MANUFACTURING THE SAME

1 . A coated wire, comprising:

a core wire;

one or more grooved insulation layer coating the core wire, the grooved insulation layer comprising a silane-crosslinked insulating resin composition and a groove on an outer surface thereof; and

a sheath layer coating an outermost layer of the grooved insulation layer.

2 . The coated wire according to claim 1 , wherein the groove on the grooved insulation layer is formed along an axial direction of the core wire.

3 . The coated wire according to claim 1 , further comprising:

one or more non-grooved insulation layer comprising a silane-crosslinked insulating resin composition, the non-grooved insulation layer being formed between the grooved insulation layer and the sheath layer or between the core wire and the grooved insulation layer and having no groove on an outer surface thereof.

4 . The coated wire according to claim 1 , wherein the insulating resin composition composing the grooved insulation layer or the non-grooved insulation layer comprises a halogen-free flame-retardant thermoplastic composition.

5 . A method of manufacturing a coated wire, comprising:

extruding an insulating resin composition from an extruder having a die with a convex portion on an inner surface thereof and located at an outlet port to coat a core wire with the insulating resin composition and adhering water to the insulating resin composition, the extrusion and the water adhesion being performed once or more than once, thereby forming one or more than one grooved insulation layers that coats the core wire and has a groove on an outer periphery thereof along an axial direction of the core wire; and

forming a sheath layer for coating the outermost periphery of the grooved insulation layer.

6 . The method according to claim 5 , further comprising:

extruding an insulating resin composition from an extruder on the fed core wire or on an outer periphery of a layer coating the core wire before or after forming the grooved insulation layer to coat the core wire or the grooved insulation layer with the insulating resin composition and adhering water to the insulating resin composition, the extrusion and the water adhesion performed once or more than once, thereby forming a non-grooved insulation layer that coats the core wire or the grooved insulation layer and does not have a groove on an outer periphery thereof.

7 . The method according to claim 5 , wherein a silane cross-linking reaction of the grooved insulation layer or the non-grooved insulation layer is enhanced by adhering water to a layer inside or outside of the grooved insulation layer or the non-grooved insulation layer.

8 . The method according to claim 5 , wherein the water is adhered by dipping in water in a cooling water pool.