Central vacuum system for an injection moulding facility
The customer
An automotive interior parts supplier running twelve injection moulding presses producing dashboard trim. Each press uses vacuum for mould evacuation (purging air from the cavity before injection) and parts handling on the take-out robot.
The challenge
The original setup used venturi vacuum generators at each press — simple, but each generator continuously consumes 40 Nm³/h of compressed air. Across 12 presses, that's 480 Nm³/h of compressed air just for vacuum. With electricity at 4.5 THB/kWh, the compressor was costing a small fortune.
The solution
A centralised vacuum system built around:
- 3× V0301 single-stage rotary vane (300 m³/h each), N+1 redundancy
- 100 mm stainless ring main looped around the press hall
- Local accumulator tank at each press
- PLC-controlled lead/lag/standby rotation to balance pump-hours
The result
| Metric | Venturi (before) | Central V0301 (after) |
|---|---|---|
| Compressed air for vacuum | 480 Nm³/h | 0 |
| Energy cost (vacuum) | 720,000 THB/yr | 290,000 THB/yr |
| Cycle-time variability | ±0.4 s | ±0.1 s (stable supply) |
| Maintenance | 12 venturis | 3 pumps |
ROI: 18 months on energy savings alone.