Radial fin thermal transfer element and method of manufacturing same

An electrical resistance heating element for heating a fluid medium, comprising:

• a solid central polymer core having an interface end, an inactive end and an outer surface with a channel spirally extending around said outer surface between said interface end and said inactive end;
• first and second terminal leads mounted to said interface end of said central core;
• a resistance wire having a first end and a second end, disposed within said channel in said outer surface of said central core wherein said first and second ends are respectively connected to said first and second terminal leads;
• and
• a thermally conductive elastomeric composition having an outer thermal interface surface, said composition being positioned about said resistance wire and said outer surface of said central core, thereby encapsulating and electrically insulating said resistance wire from said fluid medium;
• said polymer coating including an elastomeric polymer base matrix and a thermally conductive filler loaded therein;
• said outer thermal interface surface having an array of integrally formed thermal transfer fins to increase its surface area.

A method of manufacturing an electrical resistance heating element for heating a fluid medium, comprising:

• providing a solid central core having an outer surface and an interface end;
• mounting first and second terminal leads to said interface end of said central core;
• winding a resistance wire having a first end and a second end, in a spiral fashion onto said outer surface of said central core;
• respectively connecting said first and second ends of said resistance wire to said first and second terminal leads;
• injection molding a thermally conductive elastomeric composition, having an outer thermal interface surface, over and about said resistance wire and said outer surface of said central core, thereby encapsulating and electrically insulating said resistance wire from said fluid medium;
• said polymer coating including an elastomeric base matrix and a thermally conductive filler loaded therein;
• and
• providing integrally molded thermal transfer fins in said outer thermal interface surface.