ANS:A - runner

In injection molding, the runner refers to the system of channels or passages within the mold that distribute the molten plastic material from the sprue to the various cavities where the final parts are formed. Once the molten plastic enters the mold through the sprue, it flows through the runner system, which directs the material to each individual cavity in the mold. The runner system can have various configurations, including a single runner that branches off into multiple sub-runners or a multi-cavity mold with a complex network of runners. The design of the runner system is crucial for ensuring uniform filling of all cavities in the mold and achieving consistent part quality. Factors such as runner size, shape, length, and gating location are carefully considered to optimize the injection molding process. Additionally, the runner system may include features such as gates, vents, and cooling channels to control the flow of molten material and facilitate the molding process. Once the molding process is complete, the runner and any associated gating components are typically removed from the final molded parts during the demolding process. However, in some cases, the runner system may be designed to incorporate features that allow it to be reused or recycled, depending on the specific requirements of the injection molding application.