Part design: Gate location



Gates are the belly buttons of the injection molding world-every molded part has one. The big difference is that molders can control the location of the gate. The location should be selected based on an evaluation of part aesthetic requirements, mechanical loading requirements, and fill pattern.

Locating the gate for aesthetics and mechanical properties

  • The gate location on an injection molded part leaves a “witness” where the part is separated from the runner system.
  • This is considered an appearance defect and is typically hidden in an inconspicuous location on the part.  

  • Resin enters the molding cavity at high pressure and high temperatures at the gate location. 
  • ゲート部分の成形品の表面は、引張荷重や落下試験時に応力が集中し、欠陥につながる場合があります。
  • Gate locations typically exhibit inferior mechanical properties compared to the molded resin in the rest of the cavity. 
  • Gate locations should be located in areas of the part which are not subjected to externally applied high-tensile loading. 
If you have more questions about optimum gate location, talk with your Eastman technical service representative—and ask how to receive a free copy of our Injection Molding Troubleshooting Guide

 TMI TIP: Learn more about gate location and other ways to improve  manufacturability through part and mold design. Watch a recent webinar hosted by  Eastman.