Search
Use the search bar or filters below to find any TAPPI product or publication.
Filters
Content Type
Publications
Level of Knowledge
Committees
Collections
Journal articles
Editorial: Advancing the Digital Twin paradigm — From network mechanics to functional paper physics, TAPPI Journal March 2026
This Special Paper Physics Issue of TAPPI Journal serves as a critical bridge between the phenomenological observations shared at the last International Paper Physics Conference in Wuppertal, Germany, and the rigorous quantification required to realize the “Digital Twin” paradigm. This paradigm involves the creation of a virtual dynamic representation of a process that acts as a real-time counterpart of the actual one. We are particularly indebted to Jaan-Willem Simon of the University of Wuppertal, whose leadership was pivotal in translating the conference’s academic rigor into this scholarly collection.
Journal articles
Estimating dose and interaction of X-rays with cellulose-based fibrous materials using micro-computed tomography, TAPPI Journal March 2026
ABSTRACT: Micro-computed tomography (ìCT) has a reputation as a nondestructive analysis method. Unfortunately, this leads to the common misconception that radiation damage of the sample does not play a role. With the increased use of ìCT in laboratory-based machines, more and more cellulose-based materials are studied. In this paper, we show with three examples that radiation damage is important in dry and wet paper and in viscose fibers. In an attempt to quantify radiation damage, we came up with a workflow that enables researchers to predict the X-ray dose within a laboratory-based ìCT machine. This gives researchers the possibility to quantitatively judge the influence of radiation damage on each measured sample. While one cannot extend the measured doses from one machine to another, one can still apply the work flow presented in this study to any ìCT setup. In this way, it is possible to minimize radiation damage by choosing the best parameters in a ìCT for obtaining perfect data with no or little radiation damage.
Journal articles
Point load measurements on paperboard packages and bulging, TAPPI Journal March 2026
ABSTRACT: Paperboard packaging is made by processing board materials into sheets or rolls and shaping them through creasing, cutting, folding, and erecting. The conversion process generates residual moments at the folds that cause panel bulging. This study experimentally investigates how the bulging introduced during the converting processes influence the mechanical response of paperboard packages during point load testing within the elastic deformation range. The study shows that panel bulging may significantly affect packaging performance as-perceived strength and stiffness. Bulging, influenced by the board’s basis weight, can affect the package performance even more than packaging stiffness. Point load tests in the elastic region were performed on empty packages (78 mm × 50 mm × 110 mm) with force applied at specific points along their long sides. The packages evaluated in this study were made of two identically processed materials of different grammages. The heavier material showed more pronounced bulging than the lighter one, leading to overlapping force-displacement curves for the packages, and to that, a lower force and stiffness may be measured at a certain indentation depth for the package of heavier material. This complicates material choice according to functional requirements. The results show that a highly bulged package might resemble one with less bulging of another material. According to the results, it is not certain that a higher grammage package shows a higher indentation force and stiffness than a lower grammage package when measured at a certain indentation. This indicates that optimizing the creasing and folding processes can be a way to enhance performance rather than simply increasing board weight. The study underscores the importance of controlling converting parameters, especially creasing and folding behavior. Well-performed creasing and folding gives a low residual momentum, little bulging, and a high stiffness and compression strength at point loading in the elastic region. Proper optimization can improve packaging performance and manual handling user-friendliness.
Journal articles
Understanding coating strength at the molecular and microscopic level, TAPPI JOURNAL June 2015
Understanding coating strength at the molecular and microscopic level, TAPPI JOURNAL June 2015
Journal articles
Characterization of refined papermaking pulps using hydrodynamic parameters from filtration analysis, TAPPI JOURNAL May 2015
Characterization of refined papermaking pulps using hydrodynamic parameters from filtration analysis, TAPPI JOURNAL May 2015
Journal articles
Examination of the potential to reduce water application rates in pine wet decks, TAPPI JOURNAL October 2015
Examination of the potential to reduce water application rates in pine wet decks, TAPPI JOURNAL October 2015
Polyvinylamine as a wet-end additive: Effects of pH and anionic contamination, TAPPI Journal May 2024
ABSTRACT: The effects of polyvinylamine (PVAm) on papermaking process attributes and handsheet quality were evaluated for a recycled copy paper furnish in a near neutral-to-alkaline pH range. The degree of protonation of primary amine groups, such as those in PVAm, is known to decrease with increasing pH. Streaming potential tests surprisingly showed that a high treatment level of PVAm on the copy paper furnish was able to maintain a net positive zeta potential up to pH of about 11, whereas charge demand titrations indicated that PVAm maintained its positive charge character up to about pH 10. Favorable dewatering was observed when the furnish had been pretreated with 1% polyacrylate dispersant prior to treatment with PVAm at the 0.5% level, and the mass of filtrate increased slightly with increasing pH. First-pass retention tests showed poor retention efficiency in systems where the furnish had been treated with the dispersant, then PVAm, in an unfavorable pH range of about 9 to 9.5. Higher retention was achieved both at pH 8.2 and at pH 10 or higher. Handsheets showed superior breaking length results in the systems where the stock had been pretreated with the dispersant, though strength decreased strongly with increasing pH. Differences in filler content, as indicated by ash analysis, were not large enough to account for the observed strength differences. Formation uniformity was substantially increased by the pretreatment with dispersant, even in the presence of PVAm and throughout the studied pH range.
Journal articles
Magazine articles
Z-directional testing of paperboard in combined tensile and compression loading, TAPPI Journal May 2024
ABSTRACT: The out-of-plane properties of paperboard are important in several converting applications such as printing, sealing, creasing, and calendering. A juxtaposed tensile and compression curve in the z direction (ZD) will, however, appear to have a kink or discontinuity at 0 stress. The purpose of the present work is to capture the continuous transition between tension and compression and to increase the understanding of the complex ZD properties of paperboard by cyclic testing. In this attempt to unify the ZD tensile and compressive behavior of paperboard, samples were laminated to the testing platens using heat seal laminate film. The method for adhering the samples was compared to samples that were laminated and glued to the testing platens. The edge effects of the cutting method were evaluated in compression testing with samples not attached to the testing platens. The flat slope seen in the initial part of the pure compression curve disappeared when the samples were laminated to the testing platens. The flat slope was instead replaced by a continuous response in the transition across 0 N. The stiffness in the transition region resembled the response in tensile testing. When the testing is cycled, the material exhibits a history dependence. Starting the cycle in either compression or tensile will show an effect on the stiffness at the transition, as well as the compressive stiffness. However, the ultimate tensile strength is unaffected.
Journal articles
Magazine articles
Orifice geometry as a tool for evaluating extensional flow resistance of barrier coating colors, TAPPI Journal November 2024
ABSTRACT: Knowledge of extensional flow behavior of coating colors can be beneficial for improving runnability and eliminating defects in various coating processes. The current work evaluates the use of an orifice geometry attached to a commercial capillary viscometer as a tool to obtain extensional flow properties of barrier coating dispersions. By measuring the pressure drop across the orifice as a function of flow velocity, the method presents the flow resistance as Euler number at industrially relevant high deformation rates. The results agree with the earlier results obtained with a capillary entrance pressure loss technique. The type of polymer additive is shown to control the extensional flow resistance, with high molecular weight linear flexible polymers such as polyethylene oxide (PEO) and polyvinyl alcohol (PVOH) having highest impact. The orifice method offers advantages over other approaches, including the need for only a small sample amount, ease of measurement, and access to high deformation rates.
Journal articles
Magazine articles
Experimental investigations into fold cracking of double coated barrier dispersion coatings, TAPPI Journal November 2024
ABSTRACT: The trend for replacing single-use plastics with fiber-based barrier coated board packaging has prompted a significant amount of research. There are many proposed ways of providing suitable packaging for applications like food service. Among these are dispersion coated barriers on board, as well as laminated boards that can be produced using conventional polyethylene (PE) or new biodegradable plastics. Minerals have also been shown to be suitable additives to these coatings for improving barrier performance through surface chemistry and by increasing the tortuosity of the pathway through the barrier layer. They also improve the cost effectiveness of the layer by lowering the material cost and raising the solids content, and by improving hold out of the functional layers, leading to a reduction in the amount of barrier coating needed to meet a given performance requirement. Minerals can also aid in the barrier handling in terms of rheology and reduced “stickiness,” as well as blocking of the films. When incorporated as fillers into extruded films, improved adhesion of the film to the board has been reported. One of the remaining challenges is the potential for cracking at the fold during converting and the loss of barrier performance that this can lead to. In this work, we systematically looked at the impact of mineral type and level in a dispersion coating. We assessed the differences in performance resulting from different coating application methods for the precoat layer by looking at the cracking tendency and loss of barrier functionality after folding for both the precoat alone and the final double coated sheets. Barrier results include moisture vapor transmission rate (MVTR), viscous vegetable oil, and the fluid blue stain in industrial methylated spirits (IMS) and Cobb water absorption, both before and after folding.