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Evaluation of folding effects on coating damage, TAPPI Journal November 2024

ABSTRACT: Barrier coatings on paperboard need to maintain integrity during converting and end-use for effective barrier performance. Folding is one of the most common deformations during converting; however, factors that affect damage during folding are not well defined. This is partly because methods to fold specimens and characterize damage are not standardized and the results are generally not transferable. In this work, we describe a method to fold paper specimens precisely and reproducibly. The keys to folding include using a defined geometry and controlled deformation. Multiple methods can be used to quantify damage; in this case, we use differences in permeability as a measure of how the coating becomes more open. Damage is sensitive to the degree of compression after the initial folding. Using a shim for support provides a defined amount of compression and minimizes the sensitivity to the applied pressure.

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Open Access
Soybean peroxidase treatment of ultra-high kappa softwood pulp to enhance yield and physical properties, TAPPI Journal September 2020

ABSTRACT: The working hypothesis serving as basis for this study is that pulping to a higher kappa number will produce a higher yield pulp, and then treating that pulp with a surface reactive lignin peroxidase to ablate surface lignin will increase specific bonding area. In the present case, the working hypothesis was modified so that soybean peroxidase (SBP) works like lignin peroxidase to modify surface lignin on high-kappa, high-yield softwood pulps to facilitate enhanced fiber-to-fiber bonding such that the resulting paper strength is similar to the lower kappa soft-wood pulp generally used to make linerboard. Soybean peroxidase is actually a plant peroxidase that exhibits lignin peroxidase-like activity. It is not a lignin peroxidase derived from white rot fungus. The current work did show a significant improvement in pulp yield (62.2% vs. 55.2% yield for a 103-kappa control linerboard grade sheet), while treatment with SBP showed that tensile, burst, and STFI properties of the pulp were improved, although more convincing data needs to be obtained.

Journal articles
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Open Access
Editorial: Critical literature reviews in open source journals, TAPPI Journal June 2023

ABSTRACT: We stand on the shoulders of giants” is a famous metaphor used by Sir Isaac Newton. This testifies to the fact that new information or discoveries are built on understanding and analyzing earlier information. Particularly in science, technology, engineering, and math (STEM) fields, it is important to have thorough analysis of earlier research activities in a particular field to propose a new direction of research, to evolve new ideas, and to develop new test methods and standards. It is a mandatory and required aspect of every original research paper to have a Literature Review section in the introductory part of the paper.

Journal articles
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Open Access
Dissolution of wood components during hot water extraction of spruce, TAPPI Journal May 2023

ABSTRACT: The purpose of this study was to investigate the autohydrolysis of softwood, which is the main chemical operation in both hot water extraction and steam explosion. Control of the process and monitoring its course were ensured by the careful choice of experimental setup and conditions: a milled spruce material was extracted in a small flow-through reactor to minimize degradation of the dissolved material and to enable analysis of the resulting liquors extracted at selected time points. The obtained liquid and solid fractions were analyzed for sugar composition and acetic acid concentration. The results showed that partially degraded hemicelluloses were extracted; hemicelluloses side chains were cleaved off and detected as monomers, while deacetylation was limited. Chain scissions of cellulose were observed as a result of autohydrolysis.

Journal articles
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Open Access
Investigation on the recycling of sulfuric acid from pretreatment of cellulose for nanocellulose preparation, TAPPI JOURNAL February 2020

ABSTRACT: Sulfuric acid is often used to pretreat cellulose prior to homogenization and conversion to nanocellulose. It would be economically significant to reuse the acid to close the overall value chain loop. The target of this work was to investigate the effect of recovery and recycling frequency of sulfuric acid from the pretreatments on the pretreatment yield of water-insoluble cellulose solid residue, and to explore the relationship between the nanocellulose size prepared by recovery of acid and number of cycles. The surface properties of the nanocelluloses were measured, including content of sulfate groups, absolute zeta potential, crystallinity, and thermal stability.

Journal articles
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Open Access
On increasing wet-web strength with adhesive polymers, TAPPI JOURNAL February 2020

ABSTRACT: Fiber-fiber adhesion, called “bonding” in the old paper physics literature, is a critical component of the overall strength of dry paper. With freshly formed very wet pulp fiber webs, all evidence suggests there are no fiber-fiber crossings with significant adhesive joint strength. With water removal, a point will be reached where fiber-fiber adhesion starts to contribute to the overall wet-web strength.The literature reveals very few examples of polymers that increase fiber-fiber joint strength in freshly formed webs. Here, we summarize the literature and explain why it is so difficult to promote fiber-fiber wet adhesion with polymers. Nevertheless, ongoing research in areas as diverse as tissue engineering scaffolds and biomimetic adhesives gives clues to future developments. Advances in paper machine engineering have lessened the importance of wet-web strength. By contrast, a critical issue in many of the evolving nanocellulose technologies is the strength of objects first formed by aqueous processing, the green strength—the strength of wet bodies before drying. For exam-ple, 3-D printed nanocellulose objects and ultralow density cellulosic aerogels can be destroyed by capillary forces during drying. There is a need for adhesives that strengthen freshly formed, wet lignocellulosic joints.

Journal articles
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Open Access
Research on improving the basis weight measurement accuracy of tissue paper based on PSO-BP neural network, TAPPI Journal October 2022

ABSTRACT: The near-infrared (NIR) sensor can be used for measuring the basis weight and moisture of tissue paper, but the measurement accuracy is not ideal for this paper grade. The weight range of the tissue is 10~30 g/m2, indicating that it is a low gram weight paper. The temperature and humidity of the production environment significantly impact an NIR sensor. This paper focuses on improving the measurement accuracy of tissue paper basis weight. In order to reduce the influences of temperature and humidity, a mathematical model based on a particle swarm optimization back propagation (PSO-BP) neural network is proposed. In comparison with multiple linear regression measurement models, the basis weight measurement error with the PSO-BP model is within ± 0.5 g/m2. This model can effectively improve the measurement accuracy and has a good effect on overcoming the basis weight nonlinear effect caused by the changes in ambient temperature and humidity.

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Open Access
PEERS 2023 Poster Session: a competition for students and young professionals, TAPPI Journal April 2023

ABTRACT: Originating in the field of scientific research and academia, poster sessions at conferences may date back to the mid-20th century, although the origins aren’t quite clear. Some sources have said as early as the 1950s and others later, while the term “poster session” itself may not have been coined until the 1975 American Physics Conference. The original concept behind poster sessions was to provide a platform for researchers to share their work in a more visual and interactive format as compared to the traditional long-form oral presentation.

Journal articles
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Open Access
Tetraethyl orthosilicate-containing dispersion coating — water vapor and liquid water barrier properties, TAPPI Journal September 2021

ABSTRACT: An aqueous styrene-butadiene latex dispersion coating containing in-situ processed tetraethyl orthosilicate (TEOS) applied on paperboard demonstrated improved water barrier performance. Coatings containing TEOS equivalent to 0.8% silicon dioxide (SiO2; dry basis) exhibited water vapor performance of < 25 g/m2/day (23°C, 50% relative humidity [RH]) and liquid water barrier performance Cobb 1800 s of < 6 g/m2, when applied as a single-layer 18 g/m2 coating. Cobb 1800 s barrier performance was still good (< 11 g/m2) at coat weights of 7–10 g/m2. The use of filler materials such as kaolin improved the vapor barrier properties of the coating, but this was not critical to the liquid water barrier properties.

Journal articles
Open Access
Low-temperature precausticizing — a hopeful approach for green liquor desilication, TAPPI JOURNAL February 2017

Low-temperature precausticizing —  a hopeful approach for  green liquor desilication, TAPPI JOURNAL February 2017