Example No. 1 is a typical application of sleeved ejection. A fixed core pin is used to mold the internal hole in the knob. When cooled, the plastic will shrink on the core, and the knob will be ejected when the sleeve ejector is forced upward by the ejector plate assembly.
In example No. 2, the sleeve serves as a bushing for support. The sleeve can be readily replaced should wear occur.
Ejector Sleeves – Actuation
When cooled, the plastic will shrink on the stationary core pin used to form the internal hole. As the mold opens, the machine ejector rod will contact the ejector plate forcing it and the sleeve ejector forward to eject the part. When the mold closes, return pins force the ejector plate assembly back to its normal position.
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