Automated pin for gas assisted injection molding

A nozzle for an injection molding apparatus comprising:

• a nozzle housing defining a fluid passage and an outlet;
• a rod extending through said fluid passage and reciprocable therein to valve said outlet;
• an annular seal in said housing, said seal comprising a compressible elastomeric member and a resilient sleeve positioned about said rod;
• wherein compression of said elastomeric member deforms said sleeve, creating a fluid seal with said rod.

A process for pressure assisted injection molding in a molding apparatus having a mold cavity, the process comprising the steps of:

• injecting a quantity of fluent plastic into the mold cavity;
• injecting an incompressible fluid into the mold cavity via a hollow nozzle;
• pressurizing a fluid supply line connectable to the nozzle with compressible fluid;
• actuating a gas valve adjacent the nozzle to selectively connect the fluid supply line with the mold cavity via the hollow nozzle;
• injecting pressurized fluid from the supply line into the mold cavity.

A nozzle for a gas assisted injection molding apparatus having a mold cavity, the nozzle comprising:

• a nozzle body having a fluid passage;
• a rod reciprocable in the passage, the rod having a conical distal portion for valving fluid communications between said passage and the mold cavity;
• and
• an actuator for reciprocating said rod, said rod being reciprocable with either of said actuator or a fluid pressure on said conical distal portion.