In most paper mills, roll replacement is driven by cumulative roll diameter loss due to wear and corrective grinds. Profile distortion and uneven wear during operation require increasingly aggressive corrective grinds pushing rolls toward an early end-of-life. Once minimum diameter, chill depth, or shell thickness limits are reached, replacement becomes inevitable.

A paper mill partnered with Precision Roll Grinders to evaluate the long-term relationship between tight roll tolerances grinds and calender stack roll diameter reduction. The focus of the study was to understand how profile grind quality influenced wear behavior and cumulative stock removal over the roll’s full service life.

The study revealed that rolls entering service with tighter, more accurate profiles exhibited more uniform loading in operation. This reduced localized wear and minimized profile distortion between each grind. As a result, subsequent regrinds required less corrective stock removal to restore geometry, slowing the roll’s progression toward its end-of-life diameter.

Additionally, incoming roll profile deviations improved with subsequent grinds, indicating that the rolls were not only starting in better condition, but also wearing more evenly while in service. Lower corrective stock removal per grind allowed for additional regrinds before replacement limits were reached. This, coupled with longer run time between corrective grinds, could more than double the expected lifespan of the roll.

Precision grinding changes the wear trajectory of a roll, not just its immediate condition. By slowing the progression towards end of life, mills can extract more total value from each roll and lower their long-term capital expenses.

Contact PRG today to be connected with your local Account Manager.