Press roll cover application guidelines, Technical Information Paper TIP 0404-37 (2009) WITHDRAWN
Faster paper machine speeds and higher press loads have placed increased demand on press roll covers. These changes have resulted in development of new cover compositions and venting patterns to provide reliable operation on modern machines. The information that follows has been compiled with an objective of providing general guidelines for press roll cover application. Specific cover application for each position requires information on machine speeds, press loads, felt designs, web temperature, steam shower application, roll diameters, and other variables. This information must be developed by working with roll cover manufacturers. Guidelines for press roll applications follow. Parameters discussed include: (1) cover thickness, hardness and venting of various grades; (2) crowning; (3) cover release characteristics; (4) grinding frequency; (5) water cooling considerations; (6) polyurethane covers; (7) ceramic covers; and (8) use of steam showers.