Compact cartridge hot runner nozzle

An injection molding nozzle comprising:

• (a) a nozzle body having an outer surface and at least one melt channel through said body;
• (b) a first insulating layer having a chemical composition, said first insulating layer disposed on said nozzle body outer surface so as to substantially cover at least a portion of said nozzle body;
• (c) at least one wire element disposed exterior to and in contact with said first insulating layer, said at least one wire element being connectable to a power supply capable of heating said wire element;
• and
• (d) a second insulating layer having a chemical composition, said second insulating layer disposed over said first insulating layer and said at least one wire element, said second insulating layer substantially covering said at least one wire element and at least a portion of said first insulating layer,
• wherein said chemical compositions of said first and second insulating layers remain substantially unchanged once said layers are disposed on said nozzle body, and wherein said second insulating layer is a self-supporting sleeve.

An injection molding nozzle comprising:

• (a) a nozzle body having an outer surface and at least one melt channel through said body;
• (b) a fist insulating layer disposed on said nozzle body outer surface so as to substantially cover at least a portion of said nozzle body;
• (c) at least one wire element disposed exterior to and in contact with said first insulating layer, said at least one wire element being connectable to a power supply capable of heating said wire element;
• and
• (d) a second insulating layer disposed over said first insulating layer and said at least one wire element, said second insulating layer substantially covering said at least one wire element and at least a portion of said first insulating layer,
• said wire element comprising a coiled wire with a series of coils wound on said nozzle body,
• and wherein the density of winding of said coils is greater adjacent each end of said nozzle body and comparatively less dense adjacent the central region of said nozzle body so that said wire element may supply relatively more heat adjacent the ends of said nozzle body and relatively less heat in the central region of said nozzle body.