Individual cavity shut-off valve for an injection molding apparatus

An edge-gated injection molding nozzle for delivering molding material from a manifold to a plurality of mold cavities, comprising:

• a nozzle body;
• a heater connected to the nozzle body;
• a nozzle melt channel defined in the nozzle body and in fluid communication with a manifold melt channel;
• a plurality of outwardly extending melt passages defined in the nozzle body and in fluid communication with the nozzle melt channel;
• a plurality of gate seals coupled to the nozzle body, the plurality of gate seals for delivering melt from the plurality of outwardly extending melt passages to a plurality of mold cavities through respective mold gates;
• and
• a plurality of shut-off valves, each shut-off valve disposed within the nozzle body and associated with an outwardly extending melt passage, the shut-off valves each independently switchable between an open position and a closed position.

A method of shutting off an individual cavity in an injection molding apparatus, comprising:

• providing a plurality of shut-off valves, each shut-off valve disposed within an edge-gated nozzle of the injection molding apparatus and associated with an outwardly extending melt passage of a plurality of outwardly extending melt passages for delivering melt to a plurality of mold cavities through respective mold gates, the shut-off valves each independently switchable between an open position and a closed position, shut-off valves initially provided in the open position;
• operating the injection molding apparatus to deliver melt to the plurality of mold cavities;
• interrupting operation of the injection molding apparatus and then switching at least one of the shut-off valves to the closed position;
• and
• after shutting off the at least one of the shut-off valves, resuming operation of the injection molding apparatus.