The gating system is responsible for delivering molten plastic from the injection molding machine into the mold cavity smoothly and evenly; acting as the "blood vessels" of the mold, it comprises three main components:
Sprue: The primary channel connecting the injection molding machine nozzle to the mold. It is typically designed with a conical shape (1°–3° taper) to facilitate melt flow and the removal of waste material during demolding;
Runner: Distributes plastic from the sprue to multiple cavities (in multi-cavity molds). It requires a balanced layout based on the number of cavities to ensure consistent filling speed and pressure across all cavities;
Gate: The "final entry point" for plastic entering the cavity. Its location and dimensions must be determined based on the product's structural design-for instance, submarine gates are commonly used for cosmetic parts (to avoid visible marks), while fan gates are often used for thin-walled parts (to accelerate filling).