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Magazine articles
Kraft pulp viscosity as a predictor of paper strength: Its uses and abuses, TAPPI Journal October 2023
ABSTRACT: 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.
Journal articles
Magazine articles
Filtration efficiency and breathability of selected face masks, TAPPI Journal September 2023
ABSTRACT: Face masks have been used as physical barriers to stop respiratory infections for many years. Due to insufficient and low supply of certified masks, alternative face covers such as face shields, neck gaiters, and fabric reusable masks gained attention during the COVID-19 pandemic. However, for these alternate face masks to fulfill their intended function, they must be effective. Additionally, the level of breathability provided by the makeshift masks must be at a certain level. The work reported in this paper was carried out to determine the relationship between filtration efficiency (FE), breathability, and important physical characteristics of mask substrates. The fiber diameter of the core filter layer was determined using a scanning electron microscope. Five types of face masks (two types of N95, two types of surgical masks, and a 100% knitted cotton fabric) were tested for their FE and breathability using moisture vapor transmission rate (MVTR). The cotton knitted mask had the lowest FE (5.10%•26.47%), while the National Institute for Occupational Safety and Health (NIOSH)-certified N95 mask had the highest FE values (92.10%•99.65%). However, the cotton mask outperformed the N95 in terms of the pressure drop, meaning higher comfort. In general, the N95 face mask provided the best protection against aerosolized particles. According to the regression analysis, the fiber diameter of the mask filter substrate serves as an important predictor of FE of mask substrates. In this study, it was confirmed that fiber diameter is inversely related to the filtration ability. Results show that compact structure with finer fibers will enable higher filtration efficiency. The study lends itself to developing layered face masks to obtain optimum filters with good filtration, better fit, and acceptable comfort for the wearer.
Journal articles
Solid-State Structure Comparison Between Standard LLDPE and
Solid-State Structure Comparison Between Standard LLDPE and Enhanced Performance LLDPE, 1995 Polymers, Laminations & Coatings Conference Proceedings
Journal articles
Steambox Comparator Experiments: Apparatus Validation and In
Steambox Comparator Experiments: Apparatus Validation and Investigation of Steambox Performance, 1999 Engineering Conference Proceedings
Journal articles
Diffusion of Flavors in Polymers: Effect of Permeant Size an
Diffusion of Flavors in Polymers: Effect of Permeant Size and Shape, 1991 Polymers, Laminations & Coatings Conference Proceedings
Journal articles
Shop talk: Manufacturing a high-quality slit roll, TAPPI JOURNAL, September 1997, Vol. 80(9)
Shop talk: manufacturing a high-quality slit roll, TAPPI JOURNAL, September 1997, Vol. 80(9)
Journal articles
Laboratory high-consistency dispersion studies of laser-printed office copy paper, part ii, TAPPI JOURNAL, April 1998, Vol. 81(4)
Laboratory high-consistency dispersion studies of laser-printed office copy paper, part ii, TAPPI JOURNAL, April 1998, Vol. 81(4)
Journal articles
Improved fibers for hot-gas filtration, TAPPI JOURNAL, April 1998, Vol. 81(4)
Improved fibers for hot-gas filtration, TAPPI JOURNAL, April 1998, Vol. 81(4)
Journal articles
Biofiltration of a-pinene and its application to the treatment of pulp and paper air emissions, TAPPI JOURNAL, August 1998, Vol. 81(8)
Biofiltration of a-pinene and its application to the treatment of pulp and paper air emissions, TAPPI JOURNAL, August 1998, Vol. 81(8)
Journal articles
Speed: its effect on coating equipment and formulations, TAPPI JOURNAL, August 1998, Vol. 81(8)
Speed: its effect on coating equipment and formulations, TAPPI JOURNAL, August 1998, Vol. 81(8)