On Line Controls Celebrates 40 Years

On Line Controls Inc. has achieved the milestone of 40 years in the extrusion tubing equipment business, selling a niche product for high-precision, ultra-low air pressure regulation.

The company’s air pressure regulators and controllers are used by some of the most well-known and niche medical tubing manufacturers to make small, complex tubes with the tightest tolerances. The precision is needed to be capable of controlling even the slightest pressure variations when making complex medical tubing. For many years, the industry would choose between making medical tubing with vacuum or air regulation, but as the tubing changed (e.g., differing plastic properties and smaller OD, ID, and wall thickness demands), many now require the use of both vacuum (used to minimize water drool at the tank entrance) and air to hold the dimensions. Single-lumen, multi-lumen, medical, catheter, bump, taper, co-extrusion, profile, balloon, multi-layer, custom, micro-tubing, and thinner wall tube extrusion are some of the products where a MicroAir unit can be used during the extrusion process.

“Less air is best as air is compressible” explained Bob Bessemer of Novatec. Over the years, customers have ordered lower ranges of air pressure. Many now use air pressure below 0.036 psi. Each MicroAir unit has a customized range chosen by the customer.

Changes to the MicroAir ultra-low air pressure regulators and controllers over the last 40 years have included adding a model MicroAir II, which can be controlled by contact closures with up/down signals usually from an OD Gauge. Also, the MicroAir IV was initially designed with high speed switching for bump and taper tubing (now also used for 0-10 volt input control from the PLC or other controller). The MicroAir III was a 1980s version that was retired when the MicroAir IV came out. Digital Display and output options of voltage or current for closed-loop control were added to the MicroAir II and MicroAir IV models in the 1990s. Also added to the line was a remote control unit for the MicroAir II with 100 feet of cable to control the unit from the end of line, and more recently, a stand with rollers. Multilumen tubing can require the 2-, 3-, or 4-channel units to supply air to each lumen.

Kay DeWolfe, president of On Line Controls said, “The most important changes to our MicroAir units have been internally. While the outside stainless-steel box and the controls have not changed, smaller, tighter tolerances on the internal parts have made for higher precision, stability, and reliability.”

The company’s name, while sounding like it has something to do with computers, was established well before the internet was in the public’s purview. It stands for equipment used on an extrusion line to control the internal air pressure (MicroAir).

In addition, On Line Controls was the first manufacturer of ultrasonic wall thickness measurement equipment (known as the UltraGage). This technology is now used on almost every extrusion line and has become a necessity when extruding tubing and pipe. The UltraGage line was sold off in 2007 when the former owner, who was one of the original design engineers of the ultrasonic wall thickness technology and software, retired.

The MicroAir, ultra-low air pressure regulators, and controllers, as well as motorized potentiometers (which were used to control speed on an extrusion line) are the main products now. DeWolfe said, “On Line Controls continues to improve the precision and accuracy of our products.”

For more information, visit the company’s website at www.onlinecontrols.com.