Method and apparatus for controlling a mold melt-flow process using temperature sensors

A method for continuously characterizing the conversion of a material to a melt in a molding machine having a barrel for feeding a nozzle, where the nozzle feeds melt material to at least one mold cavity via a sprue and runner, so as to enable control of at least one element of the molding machine using a thermal sensor, including:

• monitoring the temperature of a melt material at at least one location between the barrel and the mold;
• and
• characterizing the mold cavity volume as a function of the temperature of the at least one location using only a thermal sensor;
• characterizing the barrel melt orifice flow inner flow as a function of temperature;
• characterizing the barrel melt orifice flow edge surface to mold thermal exchange rate;
• characterizing the melt center to edge differential cure rate;
• and
• characterizing the molded part inner-to-edge thermal differential during mold OPEN.

A method for continuously characterizing the conversion of a material to a melt in a molding machine having a barrel for feeding a nozzle, where the nozzle feeds melt material to at least one mold cavity via a sprue and runner, so as to enable control of at least one element of the molding machine using a thermal sensor, including the steps of:

• monitoring the temperature of a melt material at at least one location between the barrel and the mold cavity, wherein monitoring the temperature of at least one location includes placing a junction of a thermocouple within the melt flow, where the thermocouple junction is exposed directly to the melt flow, and further comprises the steps of
• reading, over a series of sequential time intervals, the temperature of the melt material at the location via a temperature signal output by a thermocouple placed at the location,
• storing the temperature signal for each time interval, and
• creating, from the series of sequential temperature signals, a temperature-time profile for the location;
• and
• characterizing the mold cavity volume as a function of the temperature of the at least one location using only the thermocouple.

A method for continuously characterizing the conversion of a material to a melt in a molding machine having a barrel for feeding a nozzle, where the nozzle feeds melt material to at least one mold cavity via a sprue and runner, so as to enable control of at least one element of the molding machine using a thermal sensor, including:

• monitoring the temperature of a melt material at at least one location between the barrel and the mold;
• characterizing the mold cavity volume as a function of the temperature of the at least one location using only a thermal sensor;
• and
• controlling the gating of at least one of a plurality of cavities in a multi-cavity mold in the molding machine, wherein the step of controlling the gating comprises
• characterizing a molding process using at least one thermocouple within each of the plurality of cavities, wherein the characterization records the temperature within the cavity as a function of time to produce a temperature-time profile,
• using the temperature-time profile to identify a control trigger-point for at least one of the plurality of cavities,
• monitoring the temperature of at least one of the plurality of cavities during a subsequent molding cycle, and
• controlling the gating of the at least one of a plurality of cavities in accordance with the control trigger-point.

An injection molding orifice temperature sensor, including:

• a melt orifice, positioned such that melt material flows past said orifice under normal injection molding parameters;
• an unsheathed thermocouple suitable for insertion into said orifice so that the thermocouple is an impinge temperature sensor, where a junction of the thermocouple is in direct contact with a melt material flowing in an injection molding system;
• and
• means for retaining the thermocouple in the orifice.