CAN THE EFFECT OF FURNISH BE DETECTED IN THE ROUGHNESS OF HANDSHEETS

Optical surface profilometry yields an accurate image of the surface s tructure of paper. Even so, measuremenets of handsheets are often comp licated by large variations in the surface height. In this article we show that the effect of furnish composition on paper surface propertie s can still be determined if the roughness measurements on handsheets are combined with a numerical KCL-PAKKA simulation model. Uncoated TMP and SW kraft handsheets were compared in this study. The TMP sheets w ere rougher than the kraft sheets. The correlation length of the surfa ce increases with increasing RMS roughness when the furnishes are comp ared. Hence the peaks and valleys in a rough paper surface have large area - a rough surface seems to be ''coarse''.