Patent ID: 8800136
Filing Date: 2014-08-12
Classification: D01D,H01B,Y10T

Abstract:
1. A method for making an insulated microwire comprising an electrically conductive metallic core and an insulative polymer sheath, comprising the steps of: selecting a metal of suitably high electrical conductivity and of relatively low melting point; selecting a polymer of relatively high melting point; forming an assembly of at least one elongated solid member of said metal in one or more bores in an elongated solid member of said polymer; supporting the assembly of said solid member of said polymer and said at least one solid member of said metal such that the axes of elongation thereof are oriented vertically; forming a weakened portion of said solid member of said polymer above a lower extremity of said assembly; heating said metal and said polymer such that said metal is substantially liquefied while said polymer is softened; and codrawing said polymer and said metal simultaneously by applying downward force to said lower extremity of said assembly, such that the assembly of said solid member of said polymer and said at least one solid member of said metal commences elongation at said weakened portion of said solid member of said polymer, and so that said polymer forms an elongated tube sheathing a continuous filament of said metal; connecting said elongated tube of polymer sheathing an elongated filament of said metal to a take-up reel; and employing said take-up reel to further elongate and reel up said elongated tube of polymer sheathing an elongated filament of said metal; whereby a microwire comprising a metal core in a polymer sheath is formed.