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
Black liquor gasification: a combination approach, TAPPI JOURNAL, November 1999, Vol. 82(11)
Black liquor gasification: a combination approach, TAPPI JOURNAL, November 1999, Vol. 82(11)
Journal articles
Trends in sweden for closed cycle recovery of tcf bleach filtrates in integrated kraft pulp production, TAPPI JOURNAL, October 1999, Vol. 82(10)
Trends in sweden for closed cycle recovery of tcf bleach filtrates in integrated kraft pulp production, TAPPI JOURNAL, October 1999, Vol. 82(10)
Journal articles
Chlorine dioxide bleaching of single species samples of three hardwood kraft pulps: oak, maple and gum, TAPPI JOURNAL, October 1999, Vol. 82(10)
Chlorine dioxide bleaching of single species samples of three hardwood kraft pulps: oak, maple and gum, TAPPI JOURNAL, October 1999, Vol. 82(10)
Journal articles
On the 'cutting edge', TAPPI JOURNAL, October 1999, Vol. 82(10)
On the 'cutting edge', TAPPI JOURNAL, October 1999, Vol. 82(10)
Magazine articles
Paper kayaks test engineering theories, TAPPI JOURNAL, Septe
Paper kayaks test engineering theories, TAPPI JOURNAL, September 1999, Vol. 82(9)
Journal articles
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
Magazine articles
Causality of manufacturing processes with significant time
Causality of manufacturing processes with significant time delays, TAPPI JOURNAL November 2015
Journal articles
Hardwood pulping kinetics of bulk and residual phases, TAPPI JOURNAL October 2015
Hardwood pulping kinetics of bulk and residual phases, TAPPI JOURNAL October 2015
Journal articles
Magazine articles
Z-direction chemical analysis for new application methods, TAPPI Journal January 2023
ABSTRACT: In conventional wet-end chemical addition during paper production, chemical distribution through the z-direction of the sheet is usually not considered an important characteristic. With a nontraditional chemical dosing approach, such as foam-assisted additive addition, the chemistry can appear at different concentrations throughout the sheet, typically in a z-direction gradient. To fully understand the strength properties of the sheet, it is helpful to view or quantify the chemical distribution through the sheet in the z-direction. One qualitative method uses a dye technique along with confocal laser scanning microscopy to generate an image where the relative chemical concentration can be observed. A quantitative method involves compiling nitrogen analyses of layered subsections of the sheet into a composite graph of relative chemical concentration vs. the z-direction of the sheet. Chemical distribution analysis can be paired with traditional z-direction strength tests, such as Scott bond and z-direction tensile, to help one understand and improve the chemical addition process and its effects.