Pulp & Paper
Regulating Pressure, Thickness and Volume for Pulp & Paper Industry
Closed loop circuits are often used in the manufacturing of pulp and paper products.
Proportion-Air’s custom-designed systems can regulate pressure, thickness, volume and other variables. Our products:
- Control the volume of powder being sprayed on paper based on line speed
- Regulate the deceleration of cylinders when using pneumatic presses
- Control pressure on a pneumatic brake on the position of an unwind station dancer arm
- Regulate thickness of paper
- Add pressure to press rolls to squeeze moisture from wood pulp
- Control air pressure going to the cylinders that apply force to the press rollers
- Maintain pressure on steam showers
Our system is used to control tension on press rollers. These are large, fixed rollers, with one or two having the ability to move up and down to maintain proper tension so the product doesn’t bind up. Our system controls the fill in a pressure cylinder to control that properly. As the rolls push the paper through, there must be tension control – and not the application of a single tension, but rather a control valve that can continually react, exhausting or adding pressure as necessary to maintain consistent tension. There is consistency in output, which means less scrap and more bottom line.
Wind/Unwind Tension Control
When big rolls of paper (e.g. ten feet tall, twenty feet long) are put on slitting machines, the rolls need to unwind at a very smooth pace. If there’s too little tension, the paper becomes unwieldy. If there’s too much tension, it can bind up the machine.
Here, the application of Proportion-Air’s ultrasonic tension controller (UTC), which provides consistent control of the tension on the brake, is based on a signal from an ultrasonic sensor. The sensor constantly measures the roll diameter, and as it shrinks, our UTC releases the right amount of tension to allow smoother flow. Without this control, you must continually adjust pressures, and change equipment for different size rolls.
Once installed, our UTC accommodates for everything and you can switch rolls freely without having to change programming or equipment.