In injection molding, what is the sprue?

The sprue in injection molding is the channel through which the molten material enters the mold cavity. Its design is crucial because it directly influences the flow of the material and the quality of the final product. The sprue connects the injection unit, where the material is heated and liquefied, to the mold itself. Properly sized and designed, the sprue allows for an efficient and uniform distribution of the material, ensuring that the mold fills correctly without defects such as air bubbles or incomplete filling.

This distinguishes the sprue from other components and measurements associated with the injection molding process. The final product refers to the completed item removed from the mold, whereas a measurement for the mold's thickness relates to the structural characteristics of the mold itself but does not describe any channel for material. The part that holds the mold together pertains to the clamping mechanism or mold plates, which serve a different function in the injection process. Thus, understanding the specific role of the sprue is vital for those working in the field of tool and die making.