The duty
PET blow molding inflates a heated preform against a mould at pressures well above workshop air - commonly in the 30 to 40 bar class for the machines in this family. Our high pressure range covers 22 kW to 55 kW drives with free air delivery from 3.2 to 9 m3/min, and skid-mounted configurations that pair the compressor with the high pressure treatment it needs.
| Requirement | Why |
|---|---|
| Pressure at the blowing valve | Set by the machine and the bottle type; not a round number chosen for convenience |
| Flow | Follows cavities and cycle time, not average plant demand |
| Air quality | Oil and moisture must be removed before the preform - high pressure filtration and drying are part of the package |
| Continuous duty | Blowing lines run for whole shifts; the machine must be rated for it |
| Storage | A high pressure receiver sized for the cycle keeps pressure from dipping between blows |
Separate headers
Keep blowing air separate from plant air. Raising the whole factory to 30 bar to serve one machine would cost energy on every actuator in the building, and it would put low pressure tools on a system they were never designed for. A dedicated high pressure machine and header is the normal arrangement.
What to specify
- Machine data - required pressure, consumption per cavity, cycle rate, number of cavities.
- Air quality - the dryness and oil class the process demands.
- Voltage and frequency - 380/400/415 V 50 Hz or 220/380/440 V 60 Hz builds.
- Cooling - water supply and quality if water cooled; ambient if air cooled.
- Layout - skid footprint, service access and the route into the building.
Service focus
High pressure machines run hot and run continuously, so cooling and oil condition are the two things to watch. Intercooler and aftercooler fouling shows up as rising temperature first and falling output second; oil that has degraded shows up as carryover into the high pressure filters, which then load quickly.
Browse the range on the high pressure air compressor for blow molding collection page.
Tell us the working pressure, flow and site conditions and we will propose a configuration. Contact OPPAIR.