Scheduled maintenance outages are a necessary part of paper production. For calender rolls, mills plan roll change intervals conservatively, pulling rolls before quality or operational problems can develop. Those intervals are only as reliable as the rolls themselves. When rolls are not ground to tight tolerances, unpredictable wear behavior forces mills to adhere to more conservative schedules. Rolls ground to tighter tolerances wear more evenly and predictably, giving operators the confidence to make well-informed decisions about their equipment. This allows them to  take advantage when conditions support extending a run interval.

A paper partnered with Precision Roll Grinders (PRG) to grind their calender stack rolls. The rolls were ground for improved profile, journal concentricity to roll face, and roundness. When an unrelated situation in the mill required delaying an outage and planned roll change, the mill was forced to consider extending their traditional 9-month interval to 12 months. This was not standard practice and would normally carry significant risk.  Considering that the PRG ground rolls still looked good, and paper quality off the calender reflected that, mill management was confident in their decision to extend the run.

The PRG ground rolls completed the full 12-month run with no issues. Paper quality remained consistent throughout, and no degradation in roll condition was observed at the end of the 12 month run. The results gave the mill the confidence to make 12 months their new standard run interval. This change saved them nearly $18,000 annually in maintenance costs.
 
PRG’s precision grinding gives mills the quality and consistency to make smarter operational decisions. Contact your local Account Manager to discover how Precision Roll Grinders can work with you.