Glossary

The shaped void in a mold where molten plastic forms each part during the injection cycle.

The tonnage required to keep an injection mold closed against melt pressure during fill, pack, and hold.

Unwanted thin plastic that leaks past the mold parting line during fill or pack.

The narrow entry point where melt flows from the runner into the cavity.

Post-fill pressure that packs the cavity and compensates for shrinkage as the part solidifies.

One-time tooling price driven by steel, cavities, precision, and finish — the figure buyers use to compare mold quotations.

A lab measurement of polymer flow rate that indicates how easily a resin fills thin or long mold features.

Simulation of fill, pack, cool, and shrink before steel is cut — used to catch gate, vent, and warp issues early.

Rated shot count before rebuild or replacement — set by steel, geometry, resin, and maintenance.

Who holds legal title to the tool — set in the contract, separate from who stores the mold.

T0–T2 sampling rounds that prove a new tool — build them into lead time and the purchase order.

The interface where mold halves meet; projected area here drives clamp-force requirements.

Channels that carry melt from the machine nozzle to each gate: cold, hot, or insulated designs.

How much a molded part contracts after fill: drives cavity oversize and hold-pressure settings.

Shallow channels or gaps that let trapped air exit the cavity during fill.

The junction where separate melt fronts merge, often weaker and more visible than surrounding material.