Effect of conductivity on paper and board machine performance— a review and new experiences

Abstract

The current trend to further reuse water within paper mills has resulted in more accumulated salts, as reflected by increased conductivity values. Although conductivity measurement is widely used in paper mills, its fundamental principles and interpretation are not often fully understood. This keeps papermakers from reaching the full benefits of using conductivity measurements to help manage the wet end chemistry of paper or board machines. High and variable conductivity affects the intrinsic properties of pulps, the performance of chemical additives, and the interaction between them. This paper reviews principles of conductivity; its measurement; its effect on important aspects of papermaking operations, such as retention, drainage, sizing, strength development and deposit control; and the fundamentals behind the effects of conductivity on the papermaking process. Specific mill examples are also provided. Potential solutions for operating a mill under high and variable conductivity conditions are discussed.