Mold Concerns
Except for special cases, such as sprue-gated systems which have no runner sections, gates connect the runner to the part. Gates perform two major functions, both of which require the thickness to be less than the runner and part wall. First, gates freeze-off and prevent pressurized material in the cavity from backing through the gate after the packing and holding phases of injection. Applied pressure from the press injection unit can stop earlier in the cycle, before the part or runner system solidifies, saving energy and press wear-and-tear. Secondly, gates provide a reduced-thickness area for easier separation of the part from the runner system. Refer to our Mold Design Guide for more information. |