Injection molding hot tip seal

A method of manufacturing an integral injection molding nozzle seal having a body portion and a central pin portion, the body portion having a generally cylindrical outer portion and a plurality of spaced ribs which extend radially inward from the outer portion to join the pin portion which extends centrally through the outer portion in alignment therewith, the central pin portion having a tip portion extending in one direction and a head portion extending in the opposite direction, the central pin portion being formed of a highly conductive inner portion and an abrasion and corrosion resistant outer portion, comprising the steps of:

• (a) forming the body portion having the outer portion with the plurality of ribs extending radially inward therefrom, the ribs having inward ends which define a central channel therebetween,
• (b) forming a hollow elongated pin casing out of an abrasion and corrosion resistant material, the pin casing having a closed lower tip and an open upper mouth,
• (c) inserting a predetermined quantity of highly conductive material into the hollow pin casing through the open mouth,
• (d) heating the pin casing in an upright position in a vacuum furnace until the highly conductive material melts and runs downward to integrally fill a lower portion of the casing leaving an empty upper portion of the casing,
• (e) cutting off an upper portion of the casing to form an integral filled casing portion of a predetermined length,
• (f) locating the filled casing portion in a predetermined position in the central channel between the ribs, and locating a cap formed of an abrasion and corrosion resistant material on the filled casing portion, and
• (g) joining the cap to the filled casing portion to form the central pin portion, and the central pin portion to the outer portion to form the integral nozzle seal by applying a brazing material to the joints between them and brazing in a vacuum furnace.