The present application describes injection molding machines and, more particularly, a removable nozzle tip and nozzle assembly for use with an injection molding machine and an engagement tool and methods for replacing a nozzle tip. In an aspect, an injection molding machine may include a nozzle. The nozzle may include a nozzle housing and a nozzle tip threadably attached to the nozzle housing. At least a portion of an exterior wall of the nozzle housing and at least a portion of an exterior wall of the nozzle tip may align to provide a cylindrical surface. The injection molding machine may further include a tubular heater enclosing at least a portion of the continuous cylindrical surface. The nozzle tip does not include a torque feature in any location that is downstream of the tubular heater and upstream of a mold gate of the nozzle.

An injection molding system is disclosed. The injection molding system includes: a mold; a hot runner including: a manifold; one or more injection nozzles coupled to the manifold; a plurality of heaters in thermal contact with the manifold and the one or more injection nozzles, the heaters being arranged into one or more defined heating zones within the hot runner; and at least one temperature sensor associated with each heating zone, and a system controller coupled to the plurality of heaters, the system controller being configured to: for each heating zone: determine a setpoint temperature associated with the heating zone; obtain, via a temperature sensor, measurement of a current local temperature of the heating zone; determine a control gain value associated with the heating zone; and compute a predicted heating time for the heating zone based on the setpoint temperature, the current local temperature, and the control gain value, determine a heating schedule for the hot runner based on the predicted heating times for the heating zones; and operate the plurality of heaters in accordance with the heating schedule.

Disclosed herein is apparatus and methods for separating plastic runners in a cold runner system between injection cycles of an injection molding process. In one exemplary embodiment, the apparatus is a heated runner separator that includes a heated melt disc with a central aperture, a heating band positioned around the heated melt disc, a first insulator ring positioned proximate to a first end of the central aperture of the heated melt disc, and a second insulator ring positioned proximate to a second and opposite end of the central aperture of the heated melt disc. The heated runner separator further includes a first terminal and second terminal extending from the heating band and arranged to couple to a heating source to heat the heating band. The heated runner separator further includes a thermocouple in contact with the heated melt disc and arranged to measure the temperature of the heated melt disc.