Plastic Injection Molding Process

Collapsible core checking by Upmold

A telescopic core in injection molding (IM) is a multi-stage, sliding core system used to mold deep internal features that cannot be ejected with a single straight core. A telescopic core is used when: The part has a very deep hole There are internal undercuts A normal core would lock the part and prevent ejection How it works Mold closes → telescopic core extends fully Plastic is injected around the core Mold opens Core retracts in stages (one section at a time) Part is safely ejected Typical a