Patent ID: 7438551

Claim:
An injection molding apparatus, comprising: an injection molding manifold heated by a manifold heater; a mold plate having a well, wherein the mold plate is separated from the manifold by an air space; a mold gate communicating with a mold cavity; an injection nozzle seated in the well and located between the manifold and the mold gate, the injection nozzle having a nozzle body with a nozzle melt bore having a longitudinal axis; a first electrical resistive heater fixed to the nozzle body and having a first wire element wrapped around the nozzle body, the first wire element being electrically insulated from the nozzle body; and a second electrical resistive heater fixed to the nozzle body and having a second wire element wrapped around the nozzle body, the second wire element being electrically insulated from the nozzle body, wherein the first electrical resistive heater and the second electrical resistive heater are positioned from substantially one end of the nozzle body to another end of the nozzle body and wherein the second electrical resistive heater provides redundancy in operation for the first electrical resistive heater.