Sprues connect the nozzle of the injection molding machine to the main runner or cavity. The sprue should be as short as possible to minimize material usage and cycle time. The bushing should have a smooth, tapered internal finish that has been polished in the direction of the draw to ensure clean separation of the sprue and the bushing.

An area used to pull sprue out of the bushing as the mold opens.

Sprue Puller

A space provided to trap cooled material during flow.

Cold Material Trap