Internal Air Pressure Control for Plastic Tubing Extrusion

Extruded tubing is produced by feeding plastic pellets or resin into an extruder, where it is melted and pushed through a tube die. The emerging hot tube is then sized using internal air pressure and cooled in a water trough. The internal air pressure regulator maintains precise bore size and diameter control throughout the extrusion line, resulting in finished tubing that meets tight dimensional tolerances.

OLC MicroAir regulators are available in multiple pressure ranges to suit different extrusion requirements. Options include ultra-low ranges from 0–2" or 0–3" of water, through 0–5", 0–10", 0–15", and 0–30" of water, up to 0–3 psi and 0–5 psi. Range change services are also available for existing units.

OLC offers several control interface options. MicroAir I models use manual-only control via a 30-turn precision knob. MicroAir II models add contact closure inputs compatible with O.D. gauges or other controllers. MicroAir IV models feature a 0–10V analog input for direct PLC integration and high-speed switching, including dual-state and linear operating modes.

MicroAir IV regulators use a precision voice-coil linear motor with viscostatic damping, achieving a response time of less than 0.1 second — typically around 20 milliseconds for 50% of full scale. Standard MicroAir I and II models use a spring-balanced design with a response time of approximately 2 minutes to full scale, which is suitable for most steady-state extrusion processes.

The number of channels needed corresponds to the number of lumens in your tubing. OLC offers single-channel, dual-channel, 3-channel, and 4-channel MicroAir configurations. Each channel can independently control a separate lumen, and in MultiAir units each channel can be set to a different pressure range with its own digital display, providing complete flexibility for complex multi-lumen catheter and medical tubing production.

Yes. OLC MicroAir regulators are widely used in the manufacture of medical tubing, catheter tubing, and multi-lumen tubing. Their ultra-low pressure capability, hysteresis-free operation, and high accuracy — better than 0.1 inch of water resolution — make them ideal for the tight dimensional tolerances required in medical device manufacturing. All units are CE compliant for international shipping.