The Dancer Cushion
Superior tension control. That's what you'd like to expect and that's the difference between Dynaweb dancer tension control solutions and typical load cell and conventional dancer systems on the market.
Ability to Respond
When a roll is not round it lopes when it turns, and, as it comes around on the high side, it feeds too much material out and then it doesn't feed enough. This snaps the web back and forth. A load cell can't do anything about this. But a dancer can smooth things out with its ability to store and give up web, responding quickly to rapidly changing tensions caused by out-of-round rolls and flying splices.
And under rapid running conditions, a load cell has a high probability of breaking the web. Nobody else's tension control system, in fact, can compare with Dynaweb's capability to maintain web tensions at high running speeds.
The Dancer Cushion
With pulsating feeds like sheeters with rotating knives grabbing the web, pulling it - stopping, feeding, stopping - the dancer cushions the web to keep it from breaking.
For other kinds of transients causing big jolts - flying splices, for instance, when running speeds are not perfectly matched - the Dynaweb dancer control systems provide an unmatched ability to maintain proper tension and prevent breaks in the web.
Both a load cell and dancer control the brake, but the load cell does not have the mechanical ability to take up web and give up web. The dancer has a swinging roller which the load cell doesn't have. This air loaded, floating roller creates web tension by pushing into the web path. So even if the process line is stopped, it's still possible to set or change web tension.
The roller usually moves through some physical arc as it controls the web tension by taking up or giving out web‹moving the web in and out of "storage" - much like the suspension on a car. When the tires hit a pothole, the springs "store" or absorb the movement so that the car is not jolted. The dancer control does the same thing for the web: keeps the tension constant and because of its web storage capability, absorbs shocks in the web.
Accommodate Process Line
A load cell controller has only a tiny amount of movement capacity - essentially zero, one could say. It works more like a scale. It measures the pull against it without really moving. In fact, it moves only a few thousandths of an inch but not enough to really be able to provide "storage."
The load cell control does half of what the dancer can do. Since it has only a small movement capability, it can only measure the tension in the web sheet and adjust the brake. But it cannot "smooth out" tension variables in the process line by taking up excess material or giving out more material and adjust the brake as a dancer can.
Simple Operator Controls
All Dynaweb dancer systems are simple to operate and incorporate full PID control so that stability can be handled entirely within the electronics. No external hydraulic or pneumatic damping is required.