| In this research we investigated the interrelationship between fiber properties and the effects of fiber properties on paper properties. The Fiber Kappa Analyzer (FKA) was modified for this project to measure fiber geometric properties such as fiber length, curl index, kink index, and cell wall thickness in addition to kappa number. Meaningful measurements can be made by the FKA, but sampling problems need to be resolved before it can be used for routine analysis. Unique homogeneous pulps were prepared for this work such that they differ with regard to kappa number, cell wall thickness (earlywood/latewood), and fiber length. Handsheets were made from these pulps. They were pressed to different densities, then tested for paper properties.; The interrelationship between fiber properties was investigated both at the pulp level and at the fiber level. The results showed a dependence of fiber curl on fiber length and kappa number, and a dependence of kink on fiber length. Curl index and kink index were found to be inversely correlated. For the study of fiber property-paper property relationships, apparent density was used as a controlled intermediate variable. The scattering coefficient of handsheets was found to be affected by fiber length, kink index, and kappa number. Tensile strength was driven by bonding and densification, but the effect of fiber properties could be seen under the density effects. Tear strength, in contrast, was found to be driven by intrinsic fiber strength and fiber length. Kink adversely affects all strength properties. Percentage of earlywood fibers was found to be better correlated with paper sheet properties than coarseness. In general, correlations between fiber properties and paper sheet properties can be determined but the relationships are complex and depend highly on the path used to go from fiber to the paper. |
