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Spraying starch on the Fourdrinier— An option between wet end starch and the size press, TAPPI Journal January 2021

ABSTRACT: Technology to apply suspensions of starch grains to the wet surface of paper, during the dewatering process, is reviewed. Though the technology is not new, it continues to attract the attention of papermakers as a means to increase bonding strength. Starch grains that are sprayed onto the wet-web of paper can be retained at levels exceeding what can be effectively added to the fiber suspension at the wet end. Unlike adding a starch solution at a size press, no additional drying capacity is required on the paper machine. To be effective, the starch needs to be able to swell and develop bonding during the paper drying process. Paperboard applications with recycled fibers appear to be a good fit. There is potential to increase bonding by processes that favor fuller gelatinization of the starch grains by the time the paper becomes dry.

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Open Access
Editorial: Agility and adaptation in a dynamic business world, TAPPI Journal January 2021

ABSTRACT: As we move into 2020, it's interesting to look back at the research topics that were covered in TAPPI Journal (TJ) the previous year. Members of the TJ editorial board organized diverse special issues on lignin, coating ,forming, and diverse papermaking and biorefinery topics, which are discussed in the following sections.

Journal articles
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Open Access
Guest Editorial: Nonwovens industry responds to COVID-19 challenge, TAPPI Journal October 2020

ABSTRACT: The COVID-19 pandemic caused by the SARS-CoV-2 coronavirus has challenged the whole world to prepare for and respond to a health crisis. While the world had previously focused on addressing challenges such as climate change, income disparity, and peace, this novel coronavirus introduced a new set of challenges not seen in 100 years.

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Open Access
Guest Editorial: Coating research addresses new product demands in response to global pandemic, TAPPI Journal November 2020

ABSTRACT: For all of us, the year 2020 has been one of significant challenge. Our communities, companies, institutions, organizations, and families have had to make many tough decisions and change our way of life as a result of the global pandemic.

Journal articles
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Open Access
Understanding the risks and rewards of using 50% vs. 10% strength peroxide in pulp bleach plants,TAPPI Journal December 2024

Authors: Alan W. Rudie and Peter W. Hart | TAPPI J. 17(11): 601(2018) - ABSTRACT: The use of 50% concentration and 10% concentration hydrogen peroxide were evaluated for chemical and mechanical pulp bleach plants at storage and at point of use. Several dangerous occurrences have been documented when the supply of 50% peroxide going into the pulping process was not stopped during a process failure. Startup conditions and leaking block valves during maintenance outages have also contributed to explosions. Although hazardous events have occurred, 50% peroxide can be stored safely with proper precautions and engineering controls.  For point of use in a chemical bleach plant, it is recommended to dilute the peroxide to 10% prior to application, because risk does not outweigh the benefit. For point of use in a mechanical bleach plant, it is recommended to use 50% peroxide going into a bleach liquor mixing system that includes the other chemicals used to maintain the brightening reaction rate. When 50% peroxide is used, it is critical that proper engineering controls are used to mitigate any risks.

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Open Access
Review of coating cracking and barrier integrity on paperboard substrates, TAPPI JournalDecember 2024

Authors: Joel C. Panek and Peter W. Hart | TAPPI J. 21(11): 589(2022) - ABSTRACT: Barrier packaging formats are major growth areas for the pulp and paper industry. It is technically challenging to maintain barrier properties during converting and end-use applications. Improved manufacturing capabilities and coating formulation knowledge will help maintain barrier integrity and enable growth of barrier products in challenging applications. These improvements will accelerate product development and commercialization, and allow faster response to product performance issues such as cracking. The literature on coating cracking provides knowledge mostly on the effects of coating formulations and to a lesser extent on substrate effects. Despite a large number of publications dedicated to coating failures, the approach to improve coating cracking remains empirical, and the transferability between studies and to real life applications has not been well established. Model development that successfully predicts commercial performance is in its infancy. However, some of these simplified models do a fairly good job predicting experimental data. The current work reviews the state of understanding as regards coating and barrier cracking and highlights the need for more research on cracking and barrier integrity.

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Open Access
Editorial: New coating grades require new tests: Barrier performance inside the package, TAPPI Journal November 2024

The TAPPI Journal special Coating issue is an annual issue that focuses on paper coating and coated papers. It is drawn from presentations at TAPPICon and from other submissions on the topic of paper coating. The TAPPICon 2024 Coating track was rich in high-quality technical content. In fact, the papers were of such significance that Coating members of the TAPPI Journal Editorial Board, which include me, Gregg Reed, and Gregory Welsch, decided that a second paper coating-related special issue would be appropriate for the TAPPI Journal editorial calendar. In addition to the current issue on Barrier Coating Testing, there will be another issue on Coating Fundamentals in early 2025.

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Wheat straw as an alternative pulp fiber, TAPPI Journal December 2024

Author: Peter W. Hart | TAPPI J. 19(1): 41(2020) - ABSTRACT: The desire to market sustainable packaging materials has led to an interest in the use of various fiber types as a raw material. It has been suggested that the use of annual crops for partial replacement of wood fiber would result in more sustainable products. Several life cycle analyses (LCA) have been performed to evaluate these claims. These LCAs provided conflicting and contradictory results because of the local conditions and the specific pulping processes investigated. Selected LCAs are reviewed and the underlying reasons for these conflicting results are analyzed.

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Open Access
Production and characterization of furanic bio-oil from Kawayan kiling (Bambusa vulgaris Schrad ex. Wendl) using molten citric acid in an open system, TAPPI Journal August 2024

ABSTRACT: The burning of fossil fuels poses many threats to the environment. These predicaments have led to a continuous search for alternative sources and production of energy, and biomass is considered the most abundant renewable energy source. In this study, the potential to produce furanic bio-oil from the cellulose of Bambusa vulgaris was explored. The proximate chemical analysis of bamboo was determined using TAPPI Standards. Cellulose was isolated through dewaxing, delignification, and alkaline treatments. The furanic bio-oil was produced by mixing cellulose and citric acid in a solvent-free environment. The effects of the digestion time (120 min, 180 min, and 240 min) on the yield and characteristics were determined. The chemical compositions were determined using Fourier transform infrared (FTIR) spectroscopy and gas chromatography-mass spectrometry (GCMS). B. vulgaris has the following chemical composition: alpha-cellulose (57.42 ± 0.40), holocellulose (78.84 ± 0.52), lig-nin (28.85 ± 0.17), hot water extractives (3.99 ± 0.08), organic extractives (0.77 ± 0.04), ash (4.67 ± 0.02), and moisture (12.98 ± 0.22). The bio-oil yield was affected by the digestion time. The highest yield was obtained at 180 min, followed by 120 min, and 240 min with 88.59%, 59.28%, and 49.96%, respectively. The peaks in the FTIR spectra corresponded to the compounds determined by the GCMS analysis. The dominant chemicals were furans (29.19%), ketones (26.31%), and carboxylic acids (19.26%). The bio-oil obtained at 180-min digestion time has the following properties: sulfur content (0.032 wt%), kinematic viscosity (1.03 mm2/s), specific gravity (0.925), copper corrosion test (No. 1a), pH (2.753), and water content (not detected). Overall, the obtained values from the properties and chemical characterization can be the basis for investigating its performance for biofuel production and utilization. This study is aligned with the Bamboo Industry’s Strategic Science and Technology Plan for the Philippines to develop other value-added products from bamboo and to achieve Sustainable Development Goal 7 (SDG 7) as determined by the United Nations.

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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.