HOT RUNNER: Understanding Hot Tip Design

摘要

While sampling a hot-to-cold-runner mold, a particular shop was fighting variations that appeared to be related to steel imbalances. It was difficult to show any variations in the actual steel that related to the data collected, but during a color change, operators noticed a few colored streaks in the runner following the hot tip. These streaks were very specific in location and consistency. Around the same time, another shop was experiencing variations in filling and part quality. After evaluating its data, this shop also looked at the mold steel for variations, but again no glaring evidence pointing to the culprits was found. However, similar streaking was noticed in the hot sprue.