Patent ID: 8525084

Claim:
A parallel resistance heating cable comprising: a heating element; a longitudinal axis extending along the cable; and two power supply conductors extending parallel to the longitudinal axis, the two power supply conductors defining a plane, the heating element extending along the cable and between the power supply conductors, and connected in parallel between the power supply conductors; the heating element comprising a compound material, the compound material comprising a mixture of an electrically conductive material and an electrically insulative material, the electrically conductive material comprising a plurality of agglomerates or particles; wherein the agglomerates or particles are orientated or distributed within a first portion of the heating element extending between the two power supply conductors such that the resistivity of the first portion of the heating element in a first direction parallel to the longitudinal axis is lower than the resistivity of the first portion of the heating element in a second direction substantially perpendicular to the longitudinal axis and substantially perpendicular to the plane of the two power supply conductors; wherein the agglomerates or particles are orientated or distributed within the first portion of the heating element extending between the two power supply conductors by the application of a predetermined pressure to the first portion of heating element in the second direction.