How to Set Air Ejection Pressure and Timing for Thin-Wall Parts
Key Takeaway: For thin-wall parts (<1mm), use lower air pressure (3–4 bar) to prevent part distortion, and delay the air blast by 0.1–0.3 seconds after the mechanical ejection starts to break the vacuum without pushing the part.
Pressure and Timing Optimization
| Part Type | Air Pressure | Blast Duration | Timing |
|---|---|---|---|
| Thin-wall (<1mm) | 3–4 bar | 0.2–0.5 sec | 0.1–0.3 sec delay after eject start |
| Standard (1–3mm) | 4–6 bar | 0.3–0.8 sec | Simultaneous with eject |
| Deep draw (>3mm depth) | 5–7 bar | 0.5–1.0 sec | 0.1 sec before eject start |
| Textured surface | 5–8 bar | 0.5–1.0 sec | 0.2 sec before eject start |
Preventing Air Marks on Thin-Wall Parts
Excessive air pressure on thin-wall parts can cause: (1) local dimpling where the air blast pushes the part, (2) air marks (glossy spots) on the cavity-side surface, (3) part warpage from uneven air pressure distribution. Mitigate by: reducing pressure to 3–4 bar, using multiple smaller valves instead of one large valve, and adding a 0.1–0.3 second delay so the part has started to release before the air blast.