Curl and Dimensional Stability

Mechanical and Dimensional paper properties, besides being by themselves important quality variables for paper and paperboard products, often interact in complex forms and influence other paper and paperboard quality variables (e.g. curl of paper and paperboard, that is, its deviation from a flat surface). On the other hand, these two sets of properties are partially correlated, since they both depend upon some common underlying factors, through different mechanisms. The understanding of which process variables affect mechanical and dimensional properties, and how they may be accounted for prediction purposes and for minimizing curl and other dimensional stability problems, were object of an in-depth theoretical, experimental and industrial study and resulted in a holistic and structured approach for handling curl and dimensional stability problems in paper and paper board (Reis, 2000; Reis and Saraiva, 2001).