Views: 0 Author: Site Editor Publish Time: 2025-07-07 Origin: Site
A slider is a movable component in an injection mold that forms features not aligned with the main demolding direction. It moves laterally (sideways) during mold opening to release undercuts before the part is ejected.
Example:
A plastic housing with side clips requires a slider to form and release the clips smoothly.
A slider system consists of:
Slider Core – Forms the undercut feature (made of hardened steel like H13).
Slider Body – Supports the core and slides along guides.
Angle Pin (Oblique Pin) – Drives the slider’s movement as the mold opens.
Locking Wedge – Secures the slider during injection to prevent deflection.
Guide Rails – Ensure smooth sliding motion.
Return Mechanism – Springs or hydraulic cylinders reset the slider after ejection.
Mold Closes – The slider is pushed into position by the angle pin, and the locking wedge holds it firmly.
Plastic Injection – Resin fills the cavity, including the undercut area formed by the slider.
Mold Opens – The angle pin forces the slider to retract sideways, clearing the undercut.
Part Ejection – Once the slider is fully retracted, ejector pins push the part out.
| Type | Description | Best For |
|---|---|---|
| Standard Slider | Driven by an angle pin, cost-effective | Simple side holes & undercuts |
| Hydraulic Slider | Uses a hydraulic cylinder for movement | Large undercuts, high precision |
| Lifter (Angle Lifter) | Combines ejection & side action | Shallow undercuts inside parts |
| Internal Slider | Collapses inward to release undercuts | Internal threads, grooves |
✔ Travel Distance = Undercut depth + safety margin (1–3mm).
✔ Angle Pin Selection – Typically 15°–25°; steeper angles increase friction.
✔ Cooling Channels – Sliders must be cooled to prevent overheating.
✔ Wear Resistance – Hardened steel or coatings (e.g., TiN) extend lifespan.
Sticking/Jamming → Check lubrication, guide rail alignment, or angle pin wear.
Part Damage → Polish slider surfaces or increase draft angles.
Flash (Leakage) → Tighten locking wedge fit or increase clamping force.
Automotive – Door handles, dashboard clips.
Electronics – Connector housings with side snaps.
Consumer Goods – Bottle caps with threads.
Sliders expand the possibilities of injection molding by enabling complex part geometries. Proper design—considering movement, cooling, and material—ensures smooth operation and high-quality parts. For challenging undercuts, advanced solutions like hydraulic sliders or lifters can be employed.
Pro Tip: Always simulate slider motion (e.g., using Moldflow) before machining the mold!
