Extrusion Line Pressure Control for High-Speed Production

Back pressure in extrusion refers to the resistance the molten plastic encounters as it is pushed through the screw and die. It affects melt homogeneity and output consistency. In tubing extrusion, internal air pressure — regulated by devices like OLC's MicroAir — is a separate, critical parameter that controls tubing diameter and dimensional stability downstream of the die.

Pressure inside an extruder typically ranges from hundreds to thousands of psi at the screw and die, depending on material and output rate. However, the internal air support pressure used to size free-extruded plastic tubing is ultra-low — often below 1 inch of water — which is precisely what OLC's MicroAir regulators are engineered to control with exceptional accuracy.

OLC MicroAir regulators cover ultra-low to low pressure ranges, from as little as 0–2 inches of water up to 0–5 psi. Multiple range options are available for each unit, and a range change service is offered so the same unit can be reconfigured for different production requirements without purchasing a new regulator.

OLC offers three control interface options: manual control via a 30-turn precision adjustment knob (MicroAir I), contact closure input from diameter gauges or external controllers (MicroAir II), and 0–10 volt analog or PLC input for high-speed programmable switching (MicroAir IV). This allows seamless integration into manual, semi-automated, or fully automated extrusion lines.

Yes. OLC's multi-channel MicroAir units — available in dual, 3-channel, and 4-channel configurations — provide independent air pressure control for each lumen. Each channel can have a different pressure range and its own display, making them ideal for complex multi-lumen medical and catheter tubing manufacturing where precise, independent lumen sizing is critical.

The MicroAir IV series achieves a response time of less than 0.1 second — typically around 20 milliseconds for a 50% full-scale step change. This high-speed capability is essential for bump and taper tubing applications where rapid, programmable pressure switching is required to produce tubing with intentional diameter variations along its length.