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Journal articles
Open Access
Barrier properties created by dispersion coating, TAPPI JOURNAL April 2013

Barrier properties created by dispersion coating, TAPPI JOURNAL April 2013

Journal articles
Open Access
Ozone bleaching of South African Eucalyptus grandis kraft pulps containing high levels of hexenuronic acids, TAPPI JOURNAL August 2013

Ozone bleaching of South African Eucalyptus grandis kraft pulps containing high levels of hexenuronic acids, TAPPI JOURNAL August 2013

Journal articles
Open Access
Allocation of carbon dioxide emissions from key production steps in high-grade paper mills, TAPPI JOURNAL August 2013

Allocation of carbon dioxide emissions from key production steps in high-grade paper mills, TAPPI JOURNAL August 2013

Journal articles
Open Access
Characterization of the pore structure and clay orientation in curtain coating layers using SEM and image analysis, TAPPI JOURNAL August 2013

Characterization of the pore structure and clay orientation in curtain coating layers using SEM and image analysis, TAPPI JOURNAL August 2013

Journal articles
Open Access
Acid methanolysis: An analytical tool for estimating the proportions of different pulp types in deinked pulp or recovered paper, TAPPI JOURNAL August 2013

Acid methanolysis: An analytical tool for estimating the proportions of different pulp types in deinked pulp or recovered paper, TAPPI JOURNAL August 2013

Journal articles
Magazine articles
Open Access
Editorial: Explore the experience of this year’s virtual PEERS Conference, TAPPI Journal September 2020

ABSTRACT: Since impacts from the pandemic took hold this past March, we’ve all begun to truly ap-preciate safe in-person interaction with others. Whether it’s a trip to the grocery, visiting elderly parents, instructing students, or networking with colleagues, no direct contact is simple, so we’ve learned to negotiate virtual gatherings in a way we never dreamed would be important at the start of 2020.

Journal articles
Magazine articles
Open Access
Repulping of wet strength paper towel with potassium monopersulfate, TAPPI Journal September 2020

ABSTRACT: Potassium monopersulfate (KMPS) was used in repulping of polyamide-epichlorohydrin (PAE)-containing paper towel. The effectiveness of the repulping aid was compared with that of sodium hypochlorite. Addition of a 2.4% KMPS repulping aid achieved complete repulping of the paper towel, resulting in 88% screen yield and about 5% rejects. To reach a similar pulping result, two times the oxidative equivalent amount of sodium hypochlorite had to be used. Compared to the pulp fibers obtained from sodium hypochlorite repulping, those obtained from KMPS repulping had higher physical strength, longer fiber length, and lower fines content. This study demonstrated that KMPS was superior to sodium hypochlorite in repulping of PAE-containing paper towel in terms of effectiveness and pulp quality.

Journal articles
Magazine articles
Open Access
Mechanistic aspects of nanocellulose•cationic starch•colloidal silica systems for papermaking, TAPPI Journal February 2023

ABSTRACT: Optimization of a chemical additive program for a paper machine can require attention to both colloidal charges and kinetic effects. This work considered an additive program with two negatively charged substances (nanofibrillated cellulose [NFC] and colloidal silica) and two positively charged items (cationic starch and cationic acrylamide copolymer retention aid). Results were shown to depend on charge interactions; however, that clearly was not the whole story. Some findings related to cationic demand, dewatering, fine-particle retention, and flocculation among fibers were best explained in terms of at least partly irreversible complexation interactions between the charged entities. Adjustments in ratios between oppositely charged additives, their sequences of addition, and effects of hydrodynamic shear levels all affected the results. In general, the most promising results were obtained at a cationic starch level of 0.25% to 0.5% based on sheet solids in systems where the cationic starch was used as a pretreatment for NFC.

Journal articles
Magazine articles
Open Access
Setting priorities in CNF particle size measurement: What is needed vs. what is feasible, TAPPI Journal February 2023

ABSTRACT: Measuring the size of cellulose nanomaterials can be challenging, especially in the case of branched and entangled cellulose nanofibrils (CNFs). The International Organization for Standardization, Technical Committee 6, Task Group 1—Cellulosic Nanomaterials, is exploring opportunities to develop standard methods for the measurement of CNF particle size and particle size distribution. This paper presents a summary of the available measuring techniques, responses from a survey on the measurement needs of CNF companies and researchers, and outcomes from an international workshop on cellulose nanofibril measurement and standardization. Standardization needs differed among groups, with Japanese companies mostly requiring measurements for product specification and production control, and other companies mostly needing measurements for safety/regulatory purposes and for grade definitions in patents. Among all the companies, average length and width with percen-tiles (D(10), D(50), D(90)) were the most desired measurands. Workshop participants concurred that defining the location(s) on the CNF at which to measure the width and the length is an urgent and complex question. They also agreed that methods are needed for rapid particle size measurement at the nanoscale. Our recommendation within ISO is to start work to revise the definition of CNFs and develop sample preparation and measurement guidelines. It was also recommended that further research be done to reproducibly prepare hierarchical branched CNF structures and characterize them, develop automated image analysis for hierarchical branched CNF structures, and develop a classification system encompassing measurements at multiple size ranges from micro- to nanoscale to fully characterize and distinguish CNF samples.

Journal articles
Magazine articles
Open Access
An analytical method to quantitatively determine the amount of polyamide epichlorohydrin (PAE) in paperboard and white water, TAPPI Journal February 2023,

ABSTRACT: Polyamide epichlorohydrin (PAE) is a permanent wet strength resin. When applied to paperboard, some amount of resin is retained in the sheet, and some is lost to the white water. An analytical method for quantifying the amount of PAE retained in the sheet and lost into the white water has been developed. This method hydrolyzes the PAE to adipic acid, which in turn is derivatized to diethyl adipate and quantified by pyrolysis gas chromatography•mass spectrometry (pyGCMS). In addition, the hydrolysis conditions of the PAE were studied by the Taguchi approach, and PAE material balances around the dry sheet and white water for 3 and 6 lb/ton PAE applications have been performed. The PAE resin recovery was 95.4% with 65.0% in the sheet for the 3 lb/ton PAE-charged paper-board, and the recovery was 96.7% with 36.1% in the sheet for the 6 lb/ton PAE-charged paperboard.