The Benefits of Combining Seal Technologies for Pulper Leakage Discussed in Industry Publication

Do you work in a paper mill? Do you experience frequent pulper leakage or gearbox failures? Perhaps combining sealing technologies should be your solution.

According to a recent Pump & Systems article, an Upstate New York paper mill experienced an ongoing problem: a leaking pulper.

“Like many pulpers, it had major shaft runout,” the article said. “It was caused by the uneven distribution and weight of the bales of paper dumped into it. In addition to a messy housekeeping issue, personnel safety was at risk and additional equipment failed …”

Paper Pulper Leakage Causes Multiple Problems

According to the article, mixers, agitators and pulpers frequently experience shaft leaks. The sheer weight of the product in the bowls and any other motion results in packing movement, contamination, and premature failure.

paper pulper leakage
A pulper (in a different paper mill) with leakage similar to that experienced in the Upstate New York paper mill

Even if your paper mill team uses mechanical seals in these applications, the movement and abrasive stock mixture may cause even more damage to the seal.

“Contamination, movement and shock can foul and damage the seal faces, causing premature failure,” the article said.

In the New York pulper system, packing was the technology used for sealing. Some of the issues encountered included:

  • Paper stock losses, housekeeping, and disposal
  • Packing replacement
  • Safety issues
  • Gearbox oil contamination
  • Belt and shaft wear
  • Gearbox and shaft replacement
  • Downtime with lost production

Combining Proven Seal Technologies Solved These Pulper Leakage Issues

Here’s the thing …

In the past, a paper mill’s solutions to paper pulper leakage was to tediously replace one technology at a time. However, in this application, the team consulted a seal manufacturer. They opted to seal the pulp process and protect the lubricant with a three-pronged approach.

“A shaft-stabilizing bushing, noncontact air seal, and vertical labyrinth bearing isolator eliminated excessive leakage from a pulper, ended repeat failure of a gearbox, and minimized shaft movement.” — Pumps & Systems article

paper pulper leakage
An air seal installed on a pulper that is similar to the one in the New York mill

According to the article, these three solutions solved the plant’s problems. The time consumed by personnel maintaining the equipment, cleaning the floor around the system, and disposing of waste stock was eliminated.

“All … the associated costs were eliminated as well,” the article said. “The mill recently celebrated three years of leak- and maintenance-free pulper operation.”

Read the full article on to learn more.

About the Author
Anna Claire Howard is a contributing writer, editor, and content marketing specialist for Sealing Equipment Products Co. Inc. (SEPCO) and has been since Spring 2019. Before those two big life changes, she was the content marketing specialist for Fluke Accelix; assistant editor for Grand View Outdoors, publisher of Bowhunting World, Predator Xtreme, Whitetail Journal, Tactical Retailer, and Shooting Sports Retailer; managing editor for Media Solutions, Inc., publisher of Gear Solutions, Wind Systems, and Thermal Processing magazines; assistant editor for MSI; and the editorial intern for B.A.S.S., LLC, publisher of Bassmaster Magazine and In these B2B/B2C roles, Anna Claire developed an appreciation for the industrial sector, as well as the operators and technicians who make up the workforce. You can find her on LinkedIn at