| In this study, the effect of non-uniformity of grammage on the fracture toughness and strength properties of unbleached Kraft and TMP handsheets was investigated.;The mechanical properties of the TMP sheets were inferior to those of the Kraft sheets for all levels of formation studied. Except for the fracture toughness and tensile stiffness in TMP handsheets, the mean of all material properties decreased as formation worsened. An increase in the tensile stiffness in TMP handsheets was observed and was attributed to increasing fines retention with increasing settling time. (Abstract shortened by UMI.);The formation of paper, defined in this study as the coefficient of variation of grammage (C.V.) over zones of selected size, was measured from calibrated soft X-ray radiographs of the handsheets. The relative increase in the C.V. over the range of settling times studied was more significant in the Kraft handsheets than in those made from TMP. |
