Final answer:
In injection molding, narrow channels that direct molten plastic from the sprue to each mold cavity are called Runners.
Step-by-step explanation:
The narrow channels that convey the molten plastics from the sprue to each cavity in the process of injection molding are called Runners. These runners are a crucial part of the mold design and play an essential role in directing the molten plastic to the multiple cavities within a mold, ensuring that it fills evenly and efficiently. Injection moulding uses a ram or screw-type plunger to force molten plastic or rubber material into a mould cavity; this solidifies into a shape that has conformed to the contour of the mould.