What are the components of injection molding?

Injection mold components are specialized, high-precision parts designed to shape molten plastic into finished products. The core, cavity, and mold base form the structure, while the feeding (sprue, runner, gate), cooling, and ejection systems ensure efficient, precise production. These essential components are typically categorized into mold structure, molding systems, and ejection systems.

Core Mold Structure Components
Mold Base: The main structural frame (A-side/cavity and B-side/core) that holds the mold together and provides rigidity.
Cavity Plate (A-side): The cavity shapes the external surface of the part.
Core Plate (B-side): The core forms the internal shape.
Support Plates & Pillar: Support the core and cavity plates against injection pressure.
Leader Pins & Bushings: Ensure precise alignment of the mold halves.

Molding and Feeding System
Sprue Bushing: Receives molten plastic from the nozzle and directs it into the mold.
Runner System: Channels that guide the molten plastic from the sprue to the gates.
Gate: Small openings that allow plastic to enter the cavity.

Ejection and Cooling System
Ejector Pins: Rods that push the solidified part out of the mold upon opening.
Ejector Plates/Retainer Plates: Hold and actuate the ejector pins.
Cooling Channels: Internal channels (usually water) that remove heat to solidify the plastic.
Ejector Box: Houses the ejection assembly.

Auxiliary and Precision Components
Locating Ring: Positions the mold properly on the machine's platen.
Insulation Board: Limits thermal transfer to the machine.
Side Actions/Lifters/Slides: Mechanisms for creating undercuts, holes, or detailed features that cannot be formed by simple opening.
Date/Recycle Inserts: Small, removable inserts for tracking manufacturing dates or material types.

The essential components are often categorized as either part of the mold structure, feeding system, or ejection system.