Abstract: The mixing nozzle of the present invention generally includes a casing and mixer. The mixer fits within the casing and includes alternating elongated helical flow directing lands and notched barrier lands. The flow directing lands extend from the body and seal against the inside wall of the casing. The barrier lands also extend from the body but are offset from said inside wall of the casing. The flow directing lands and the barrier lands have differing helix angles and thus define alternating converging inlet channels and diverging outlet channels. Mixing of molten plastic is accomplished when the molten plastic is received from the inlet end of the mixing portion primarily by the inlet channels, passes over the barrier lands and through the notches in the barrier lands and passes primarily via the outlet channels through the outlet end of the mixer.