Electric heating cloth and method

An electric heating cloth which is characterized by high reliability and high flexibility comprised of:

• a first group of nonconducting threads arranged in a first direction;
• a second group of heating conducting resistive threads having outer diameters of less than 0.7 mm arranged in a second direction which is perpendicular to said first direction, each of said conducting resistive threads having a nucleus and at least one shell surrounding said nucleus, said shell being a matrix of an elastomeric, thermally stable, high temperature polymer and dispersed particles of carbon, wherein said dispersed particles of carbon in said shell of said conducting resistive thread are particles of industrial carbon made from acetylene and particles of colloidal graphite;
• and a means for connecting said resistive conducting threads of said heating cloth to a source of electrical power and the mass ratio of said polymer to said particles of industrial carbon and said particles of colloidal graphite in said shell is within a range of 1:0.3 to 1:0.6, respectively.

An electric heating cloth which is characterized by high reliability and high flexibility comprised of:

• a first group of non-conducting threads arranged in a first direction;
• a second group of heating conducting resistive threads having outer diameters of less than 0.7 mm arranged in a second direction which is perpendicular to said first direction, each of said conducting resistive threads having a nucleus and at least one shell surrounding said nucleus, said shell being a matrix of an elastomeric, thermally stable, high temperature polymer and dispersed particles of carbon, wherein said dispersed particles of carbon in said shell of said conducting resistive thread are particles of industrial carbon made from acetylene and particles of colloidal graphite;
• and a means for connecting said resistive conducting threads of said heating cloth to a source of electrical power and the mass ratio of said polymer to said particles of industrial carbon and said particles of colloidal graphite in said shell is within a range of 1:1 to 1:1.4, respectively.

An electric heating cloth which is characterized by high reliability and high flexibility comprised of:

• a first group of non-conducting threads arranged in a first direction;
• a second group of heating conducting resistive threads having outer diameters of less than 0.7 mm arranged in a second direction which is perpendicular to said first direction, each of said conducting resistive threads having a nucleus and at least one shell surrounding said nucleus, said shell being a matrix of an elastomeric, thermally stable, high temperature polymer and dispersed particles of carbon, wherein said dispersed particles of carbon in said shell of said conducting resistive thread are particles of industrial carbon made from acetylene and particles of colloidal graphite;
• and a means for connecting said resistive conducting threads of said heating cloth to a source of electrical power and the mass ratio of said polymer to said particles of industrial carbon and said particles of colloidal graphite in said shell is within a range of 0.2:1 to 0.65:1, respectively.

In a flexible electric heating cloth of the type wherein a group of flexible resistive conductive threads are provided for providing a stable elevated temperature for an environment site, the improvement comprising, flexible conductive resistive threads having outer diameters of less than 0.7, each of said conductive resistive threads having a nucleus surrounded by a shell, said shell comprised of particles of carbon dispersed in a thermally stable, elastomeric, high temperature polymer, said particles of carbon comprising particles of industrial carbon made from acetylene and particles of colloidal graphite at a mass ratio which is within a range of 1:0.3 to 1:0.6 of said polymer to said particles of said industrial carbon and said colloidal graphite.