Customer case:

GPI’s West Monroe mill benefits from digester optimization

Mar 6, 2020

Valmet and Graphic Packaging International (GPI) collaborated on continuous digester optimization projects that included three digesters in West Monroe, Louisiana. Graphic Packaging is one of the world’s largest manufacturers of folding cartons, unbleached paperboard, coated recycled board, microwave packaging, and machinery. The West Monroe facility manufactures combined folding cartons for use in beverage and other product packaging.

GPI_Blow kappa level_570x277.jpg


Location West Monroe, Louisiana
Customer challenge The goal of the optimization project was to tackle the mill’s high degree of Kappa variability and a lower than optimum average Kappa from the mill’s three kraft pulp digesters.

Valmet Cooking Liquor Analyzer (Valmet Alkali C) online alkali titrator for white liquor and black liquor residual alkali

Valmet Kappa Analyzer (Valmet Kappa QC)

Valmet Continuous Cooking Optimizer

Continuous application performance management

  • Overall Kappa standard deviation decreased by 40 %
  • With steadier blow line Kappa, the digester Kappa target could be increased by 7 units
  • Increased Kappa target means higher yield and increased production.
  • The figure shows the results have been getting better after the actual project due to continuous application performance management (APM)
Keywords Kraft pulp, Digester optimization, Automation, North America

This reference is based on a technical presentation prepared by Graphic Packaging International and Valmet to the TAPPI Peers Conference in St. Louis, MO, on October 28, 2019.