Polyurethane Resins for Roll Covers

Coldwater Resins polyurethane roll covers provide distinct advantages over bone-hard rubber covers. In the wet end of the paper machine, from the breast roll to the wire return roll, these special polyurethanes never have to be "dried out." They are hydrophobic (water repellant), making them suitable for wet end applications. Roll covers made of this material are softer than bone-hard rubber. Less hardness means less slippage between the wires and the roll, which promotes longer life.

Because these polyurethanes have very low internal stresses, there is never any "edge lifting" as with rubber. Also, they can be easily applied over the end of the roll, all the way out onto the journals, guaranteeing no water penetration around the ends. Doctoring, grooving, and even drilling for suction couch or suction pickup applications are no problem for these covers.

The material is also suitable for use on wet felt rolls, offering the same extended fabric life as with wires on press felts. One of the polyurethane resins is suitable for reel spools. These covers provide tighter turn-ups and more usable paper per spool.

Coldwater Resins, Inc., 311 Wilson Willingham Rd., Oxford, AL 36203. Tel: 256-835-1035. Fax: 256-831-9611.