THE EFFECT OF DRYER FABRIC CHARACTERISTICS ON PAPER DRYING - A LABORATORY STUDY

Using a felted laboratory dryer cylinder, the relative importance of fabric permeability, effective contact area, and tension on the drying rate of paper was determined. Models were developed using regression analysis to assist in verifying the performance of the drying system. The test results indicate that permeability influences drying rate more than does effective contact area in both the constant-rate and falling-rate drying zones. In the falling-rate zone, increasing effective contact area significantly increases drying rate as sheet moisture diminishes. Increasing fabric tension increases drying rates at all levels of sheet moisture content. For all tests except those involving tension, ambient temperature, humidity, and atmospheric pressure were incorporated into the regression models to account for their influence on the drying rate.