A nozzle for an injection molding apparatus is provided. The nozzle
includes a nozzle body, a heater, a tip, a tip surrounding piece and a
seal piece. The nozzle body defines a nozzle body melt passage, which is
adapted to be in fluid communication with an upstream melt source. The
heater is thermally connected to the nozzle body for heating melt in the
nozzle body melt passage. The tip is removably connected to the nozzle
body. The tip defines a tip melt passage therethrough. The tip melt
passage is downstream from and in fluid communication with the nozzle
body melt passage, and is adapted to be upstream from and in fluid
communication with a mold cavity in a mold component. The tip surrounding
piece is removably connected with respect to the nozzle body. The tip
surrounding piece is spaced from said tip. The seal piece is positioned
between the tip and the tip surrounding piece. The seal piece forms a
seal with the tip and with the tip surrounding piece to inhibit melt
leakage between the seal piece and the tip and between the seal piece and
the tip surrounding piece, so that, in use, at least a portion of the tip
and the tip surrounding piece are separated by an air gap.