Web tension in a flotation dryer

In a flotation dryer, the web rides on a cushion of air and typically takes a "sine wave" path over the air bars. The non-straight path and the elastic effect of the air cushion interact with the normal tensioning of the web in the dryer zone. Equations were developed to describe the geometry of the web path, air pressure effect and the tensioning of the web in the zone. Computer simulation was used to solve the Equations simultaneously. It was found that the air cushion and pressure have no effect on the steady state tension. On the other hand, the dynamic response showed that the air cushion increased the time constant for the zone. Thus, the dryer zone appears to be much longer than the actual web length. Results also predict how riding height decreases as tension increases in time. Several cases were run at different air cushion pressures