Injection molding system with flanged insulating gate seal

In an injection molding apparatus having an elongated heated nozzle with a forward end and a rear end, said heated nozzle seated in a well of surrounding cooled cavity plate, an insulative air space extending between the heated nozzle and the surrounding cooled cavity plate, the heated nozzle having a melt passage extending therethrough to convey pressurized melt to a gate extending through the cavity plate to a cavity, the improvement comprising:

• a hollow seal having a central bore extending therethrough from an inner end of the seal to an outer end of the seal, the outer end having a central portion surrounded by a flange portion which projects outwardly a predetermined distance past the central portion and is substantially larger in diameter than said gate, the inner end of the seal being seated in the nozzle in a position wherein the seal bridges the insulative air space wherein the central bore through the seal is in alignment with at least a portion of the melt passage and said gate, and the flange portion extends into contact against an inner surface of the well around said gate whereby a predetermined insulation space is provided between the central portion of the outer end of the seal and the inner surface of the well.