Partitioning Formation Into Its Components for Analysis of Paper Strength Properties, 1999 Engineering Conference Proceedings

Using non-standard procedures to vary formation, handsheets were made from commercial furnishes of linerboard, TMP and fine paper. Formation was characterized using the new method of partitioning formation nonuniformity into its components as a function of scale of formation. The different handsheet making procedures changed large scale nonuniformity selectively while leaving small scale component of formation little affected. Tear strength behaves anomalously as formation quality decreased - linerboard tear strength decreased with the other strength properties while TMP and fine paper tear strength increased. This increase in TMP and fine paper tear strength derives from the increase in formation nonuniformity over only the range of intermediate to large values of scale of formation. For the effect on tensile, burst and tear strength of the 220 g/m2 linerboard handsheets, the components of formation nonuniformity below 2-4 mm scale of formation have negligible effect but the present data are insufficient to determine the upper limit relevant scale of formation. Coupling knowledge of how some components of formation nonuniformity are affected by handsheet making parameters and how some components of formation nonuniformity selectively control specific paper properties will enable determining the limits of various handsheet making techniques to provide information concerning machine formed paper properties.