@article{brogdon_lucia_2023, title={Kraft pulp viscosity as a predictor of paper strength: Its uses and abuses}, volume={22}, ISSN={["0734-1415"]}, DOI={10.32964/TJ22.10.631}, abstractNote={For bleached kraft pulps, two factors govern paper strength: the individual fiber strength, and the bond strength that adheres the individual fibers together in the paper matrix. Inherent fiber strength is related to the length of the carbohydrate polymers, also known as the degree of polymerization (DP). Average DP (DP) is inferred by performing pulp viscosity measurements. Under certain circumstances during kraft pulping and bleaching, the average polymer lengths can be shortened, resulting in lower pulp viscosity, and may indicate fiber damage. Fiber damage typically manifests itself as a reduction in tear strength for well-bonded handsheets. This paper will review the literature on how pulp viscosity can predict paper/fiber strength and how it can be used as a diagnostic tool. It can be a means to monitor pulp quality during pulping and bleaching, as well as to alert when such operations approach a critical threshold. However, viscosity losses must be carefully and judiciously analyzed. Like most diagnostic tools, viscosity measurements can be misused and abused, which can lead to incorrect inferences about intrinsic fiber strength. This review will also cover these misuses. The overall goal is to provide the papermaker a better understanding of what pulp viscosity is, how it correlates to potential sheet strength, and what its limitations are. It will be illustrated that when pulp viscosity drops below a critical value, it will indicate an appreciable deterioration in the paper’s tear and tensile strength.}, number={10}, journal={TAPPI JOURNAL}, author={Brogdon, Brian N. and Lucia, Lucian A.}, year={2023}, month={Oct}, pages={631–643} }
 @article{brogdon_lucia_2021, title={Extension of a steady-state chlorine dioxide brightening model for Z-ECF bleaching of softwood kraft pulps}, volume={20}, ISSN={["0734-1415"]}, DOI={10.32964/TJ20.3.186}, abstractNote={Earlier studies developed a steady-state model to predict the brightness and/or bleach consumption during the chlorine dioxide brightening (D1) of softwood pulps produced by conventional elemental-chlorine-free (ECF) sequences. This model relates the chlorine dioxide consumed to the brightness gains predicated upon an asymptotic D1 brightness limit, an incoming D1 pulp brightness, and an equation parameter (β11). The current investigation examines the application of this model to ECF sequences that use ozone delignification (Z-ECF). Literature D1 data from various Z-ECF bleaching studies, which investigated OZ, OD0/Z, and OZ/D0 delignification, were fitted to the model. The β11 parameter was found to be linearly correlated to the entering kappa number. Interestingly, this linear relationship was found to be identical to the relationships observed when modeling the D1 stage for conventional ECF and chlorine-based bleach sequences. Subtle differences in D1 brightening response in the model among the various bleach sequences are reflected by incoming pulp brightness (at the same kappa number). The current model is used to illustrate how alterations to Z-ECF delignification affect D1 brightening and chlorine dioxide consumption.}, number={3}, journal={TAPPI JOURNAL}, author={Brogdon, Brian N. and Lucia, Lucian A.}, year={2021}, month={Mar}, pages={186–197} }
 @article{brogdon_lucia_2018, title={Using multistage models to evaluate how pulp washing after the first extraction stage impacts elemental chlorine-free bleach demand}, volume={17}, ISSN={["0734-1415"]}, DOI={10.32964/TJ17.11.621}, abstractNote={Steady-state models were constructed to predict the response of a southern U.S. softwood brown¬stock to three- and five-stage elemental chlorine-free (ECF) bleach sequences. The models provided insight into how typical (EO) washing efficiencies from a vacuum drum unit affected pulp brightening and total chlorine dioxide con¬sumption. When (EO) carryover was between 15% and 30%, the chlorine dioxide needed to reach target brightness increased by 8% to 15% for the D0(EO)D1(EP)D2 sequence (89% ISO) and by 15% to 23% for the D0(EO)D1 sequence (86% ISO) versus perfect washing. Use of (EO) filtrate as D0 shower water, such as in split-flow countercurrent wash¬ing, caused the bleach uptake to increase by 1.5 to 3.0 kg chlorine dioxide (ClO2)/ton pulp when compared to using cleaner D0 shower water sources. The ClO2 consumed by 15% to 30% (EO) washer carryover is comparable to that consumed by typical carryover levels from brownstock washing (~10 kg Na2SO4/ton pulp). High (EO) carryover made ECF bleaching to higher brightness targets more difficult.}, number={11}, journal={TAPPI JOURNAL}, author={Brogdon, Brian N. and Lucia, Lucian A.}, year={2018}, month={Nov}, pages={621–630} }