Thermal process device with non-uniform insulation

A thermal process device for heat treating a product or plurality of products, the device comprising:

• a thermal processing chamber having opposed distal ends and at least one controllable heating zone;
• at least one buffer zone disposed at each of the distal ends, the buffer zones and at least one heating zone of the thermal processing chamber forming a heating element assembly having an inner surface and an outer surface;
• an outer shell disposed about the outer surface of the heating element assembly;
• at least one inner layer of an insulation material disposed along the at least one buffer and heating zones of the thermal processing chamber and forming part of the heating element assembly, the at least one inner layer of insulation material having an insulation efficiency that varies non-uniformly across an axial length of the heating element assembly;
• and
• an outer layer of insulation material extending along the at least one buffer and heating zones of the thermal processing chamber,
• wherein the least one inner layer of an insulation material forms a layer that is located between an outer surface of the thermal processing chamber and an inner surface of the outer layer of insulation, and
• wherein a portion of the at least one layer of insulation material located at the at least one buffer zone has an insulation efficiency that is greater than the insulation efficiency of a portion of the at least one layer of insulation material at the at least one heating zone.