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Journal articles
Open Access
An instrument to assess the biaxial stress during paper drying, TAPPI JOURNAL, May 1994, Vol. 77(5)

An instrument to assess the biaxial stress during paper drying, TAPPI JOURNAL, May 1994, Vol. 77(5)

Journal articles
Open Access
Activated sludge treatment of tmp mill effluents part 1: effluent characterization and treatability study, TAPPI JOURNAL, November 1994, Vol. 77(11)

Activated sludge treatment of tmp mill effluents part 1: effluent characterization and treatability study, TAPPI JOURNAL, November 1994, Vol. 77(11)

Journal articles
Open Access
Activated sludge treatment of tmp mill effluents part 2: biokinetic parameters and effluent treatment strategies, TAPPI JOURNAL, November 1994, Vol. 77(11)

Activated sludge treatment of tmp mill effluents part 2: biokinetic parameters and effluent treatment strategies, TAPPI JOURNAL, November 1994, Vol. 77(11)

Journal articles
Open Access
Effect of printer roll-quality requirements on winding technology, TAPPI JOURNAL, October 1994, Vol. 77(10)

Effect of printer roll-quality requirements on winding technology, TAPPI JOURNAL, October 1994, Vol. 77(10)

Journal articles
Open Access
Accurate determination of six common fillers in fine papers, newsprint, and recycled stock by x-ray fluorescence spectrometry, TAPPI JOURNAL, April 1995, Vol. 78(4)

Accurate determination of six common fillers in fine papers, newsprint, and recycled stock by x-ray fluorescence spectrometry, TAPPI JOURNAL, April 1995, Vol. 78(4)

Journal articles
Open Access
X-ray diffraction for quantifying calcium carbonate fillers in printing and writing papers, TAPPI JOURNAL, April 1995, Vol. 78(4)

X-ray diffraction for quantifying calcium carbonate fillers in printing and writing papers, TAPPI JOURNAL, April 1995, Vol. 78(4)

Journal articles
Magazine articles
Open Access
Colloid chemical aspects of paper formation in the presence of nanofibrillated cellulose and cationic starch, TAPPI Journal September 2024

ABSTRACT: A series of experimental tests were carried out to examine colloidal-scale consequences of optionally treating nanofibrillated cellulose (NFC) with cationic starches of different charge density and dosage (0.5% or 2.0% by weight), adding that material to a furnish prepared from 100% recycled copy paper, and then subjecting the mixture to very different levels of hydrodynamic shear. Tests included optical microscopy, sediment volume tests, sediment velocity tests, and “percent fines” assessment by means of a fiber quality analyzer (FQA). In addition, the zeta potential and charge demand of the studied materials were evaluated. Optical imaging revealed that cationic starch treatment of the NFC tended to agglomerate it into multiparticle clusters, which sometimes could be mostly redispersed by hydrodynamic shear. Subsequent addition of the starch-treated NFC to the default furnish resulted in much of the colloidal material becoming attached to fibers. Subsequent shearing of the mixtures was at least partly effective in separating the clusters of NFC from the fiber surface, resulting in essentially a two-component mixture. Multiparticle NFC clusters coexisted with the fiber suspension, sometimes attached and sometimes not, depending on the details of treatments. Sediment volume tests showed that systems containing cationic starch-treated NFC tended to have a higher density after settling in comparison to untreated NFC; these findings are consistent with the cationic starch acting as a stabilizer on the solid surfaces, allowing them to slide past each other during the settling process. Application of intense hydrodynamic shear tended to result in denser sediment. Results of tests with the sediment velocity messurement and the FQA percent fines assessment did not correlate well with changes in test conditions considered in this study.

Journal articles
Open Access
A targeted approach to produce energy-efficient packaging materials from high-yield pulp, TAPPI Journal August 2025

ABSTRACT: Unlike fossil-based plastics, wood-based packaging materials can be produced in an ecofriendly manner using wood chip residuals from sawmills and pulpwood. To produce high-yield pulp like chemithermomechanical pulps (CTMPs) for paperboard and liquid packaging, it is crucial to reduce the electric energy consumption during fiber separation. The ultimate objective is to revolutionize paperboard production by achieving a middle-layer CTMP process that consumes less than 200 kilowatt-hours per metric ton (kWh/t), significantly improving from the current 500•600 kWh/t energy demand. Optimizing the CTMP impregnation process of sodium sulfite (Na2SO3) in wood chips is crucial for achieving uniform softening, ideally at the fiber level. The properties of the fibers are significantly affected by the content of lignin sulfonates within the walls of the fiber and the middle lamellae. In this study, we employed in-house developed X-ray fluorescence (XRF) techniques, validated by beamline measurements, to map the distribution of sulfonated lignin within fibers. It also seemed possible to enhance the surface area of lignin-rich pulp fibers while losing minimal bulk by refining them with well-optimized low consistency (LC) refining. We aimed to achieve a highly efficient separation of coniferous wood fibers by co-optimizing the sulfonation and the temperature in the preheater and chip refiner. Additionally, we explored how lignin’s softening behavior and potential crosslinking influence subsequent unit operations, including pressing, peroxide bleaching, and drying, following the defibration process. In defibration during chip refining, the maximum softening of wood fibers is preferred to maximize fiber preservation and minimize energy consumption. However, optimizing the stiffness of finished pulp fibers is preferable to reduce bulk loss during paperboard production. It can strive to optimize processes to develop stronger, lighter, and more sustainable composite packaging materials. Reducing environmental impact and electric energy can help create a more sustainable future.

Journal articles
Open Access
On the design of corrugated boards: A new FEM modeling and experimental validation, TAPPI Journal August 2025

ABSTRACT: This study presents a simplified finite element modeling (FEM) approach suitable for large structures made of corrugated boards, such as customized packages, based on a homogenization method, which is combined with correction factors for internal mechanisms. The homogenization process reduces computational time by transforming flute geometries into equivalent elastic models. In large deformations and in the presence of contact for a given geometry, the effective elastic modulus in the thickness direction, as well as the effective thickness of the structure, are corrected by two statistical Weibull distributions representing the contact and buckling mechanisms in a corrugated board. The Weibull parameters are obtained via experimental analysis, and such a process is then validated. The results demonstrate that the statistical parameters (â1 = 0.14, â2 = 1.31) can be used for the simplistic representation of corrugated boards, being computationally efficient. This research contributes to the optimization of corrugated packaging design, specifically by simplifying FEM models for faster, yet equally accurate, simulations.

Journal articles
Reinforcing folding boxboard ply stock with refined pulp and its effect on dewatering potential, TAPPI Journal February 2025

ABSTRACT: The folding boxboard (FBB) filler ply typically contains a significant amount of mechanical pulp such as bleached thermomechanical pulp (BTMP), bleached chemi-thermomechanical pulp (BCTMP), and chemi-thermomechanical pulp (CTMP), etc. It is usually reinforced with either refined broke from the same paper machine line and converting process or by utilizing traditional bleached kraft pulp (BKP). In response to the drive for improved/increased ply bond (to avoid undesired delamination), increased bulk, reduced basis weight, and minimized energy consumption, papermakers have experimented with various options and strategies. In between the common approaches, choices have been made between reducing the refining of the mechanical pulp, increasing the broke refining (more frequently practiced on the production scale), or increasing the BKP refining (a potentially superior choice). This study focused on a simplified approach to assess the impact of three reinforcement pulps with different refining levels on the dewatering of the filler ply. The reinforcement pulp was added to the core stock for the FBB filler ply — a mechanical pulp, BCTMP, with a drainability of 25 °SR. The proportions of the reinforcement pulp, hardwood bleached kraft pulp (HWBKP), were 20% of 30-35 °SR, 10% of HWBKP 50-55 °SR, and 5% of HWBKP 70-75 °SR. The intention behind using varying percentages of reinforcement pulp was to attain a controlled internal bond while enhancing bulk through increased mechanical pulp content. The dewatering potential of the stock mixtures was assessed at three vacuum levels — 4, 10, and 25 kPa — that can be found in progressive stages within production- scale forming sections. Our goal was to find an optimal reinforcement strategy for filler ply that would minimize the use of the reinforcement pulp, give better strength, retain bulk, and lower basis weight. The success of this strategy was verified with an actual FBB machine.