In spring 2007, the newly designed couch roll was put into field test operation on the PM 2 in Frastanz, Austria. During the observation period until the end of 2009, there had been no unplanned standstills caused by a failure or regrinding, thus meeting one of the major requirements - high operational reliability.
The peculiarity of this product is that the wire clothing has been replaced: EvoRun C runs with the BlackStone rubber cover instead. The crucial benefit of this change is the considerably longer lifetime compared to earlier solutions with wire clothing. In Frastanz, service life increased from six to more than 24 months and the first regrinding of the BlackStone rubber cover was required after more than two years. Since lifetime was four times longer than usual, operating costs went down considerably for the paper mill. A service life of eight years is expected for the cover.
"Every six months, the wire clothing of the old couch roll had to be replaced with a new one. This has cost us a lot of time and money," reports Maik Willig, Mill Manager of Frastanz Paper Mill of Rondo Ganahl. In addition, the new couch roll design has had a positive influence on top wire life.
After the successful start-up in Frastanz, a technology comparison before/after the rebuild was made. Most importantly, all technological parameters (such as SCT orbreaking length) remained as good as they were. After hardly a year of operating experience, Rondo Ganahl was convinced and decided to order a second couch roll of the new design.