PRESS SECTION GRINDS: UNDERSTANDING
THE IMPACT OF AXIAL CONCENTRICITY
Author: Matthew Harris1 1Precision Roll Grinders, United States
O PAPEL vol. 84, N.o 6, pp. 82 – 85 – JUN 2023
Energy efficiency has become a top priority for paper mills
when process decisions are made. The goal of this study was to
determine if steam usage would be reduced, or if paper machine
speed increased, by improving the geometric tolerances of the
press roll section. This was achieved by improvement in axleto-roll face concentricity, roundness, shape, and profile.
An analysis of data over 17 months produced three key findings.
Cross-direction moisture two-sigma variation was reduced by
19.08% over seven months when the bottom crown-controlled
press roll was installed. Machine speed increased 18 feet-perminute, however, the lack of system controls made it difficult to
determine if the press roll was the direct cause of the machine speed
increase. An unexpected result was a 25.10% decrease in vacuum
required in the pick-up felt uhle box. This indicates a reduced need
for water removal. Future studies will examine how reducing the
vacuum needed in the press section impacts felt life.
Keywords: Press Section, Concentric Grinding, Uhle Box
Corresponding Author: Matthew Harris. Precision Roll Grinders. 6356 Chapmans Rd. Allentown, PA, 18018. United States: +1-610-395-6966. [email protected]