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Magazine articles
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
Magazine articles
Paper bending stiffness and web tension measurement from a running web using a vacuum and computer imaging, TAPPI Journal May 2023
ABSTRACT: A novel method for measuring the bending stiffness of paper online during manufacturing is introduced. The method uses photometric stereo imaging to detect the shape of the deflection surface caused by a controllable pressure difference over the paper’s surfaces. The hardware for the measurement is based on a combination of two existing sensors, which has accelerated and facilitated the development of the implementation. The deflection and loads are tied together by the governing differential equation for the bending of an orthotropic elastic plate with selected simplifications. An approach to resolve material parameters and in-plane loads without knowledge of traditional boundary conditions is suggested. The presented method was tested in a paper mill during manufacturing. For bending stiffnesses measured online, correlation coefficients 0.88 and 0.92 were obtained compared to state-of-the-art laboratory measurements. However, the results gained from a moving web are noisy and the data requires correction of the slope and an off-set. Although several issues remain to be resolved before the method can be considered as an accurate measurement for industrial use, the theoretical background, the performance of online implementation, and the results are promising. Possible causes for the observed discrepancies and the future development of the method are discussed.
Magazine articles
Treatment efficiency of eucalypt kraft pulp bleaching effluents: influence of dissolved organic matter, SOLUTIONS! & TAPPI JOURNAL, April 2002 (128KB)
Treatment efficiency of eucalypt kraft pulp bleaching effluents: influence of dissolved organic matter, SOLUTIONS! & TAPPI JOURNAL, April 2002 (128KB)
Magazine articles
Barbara Dalpke: insights from a recent graduate, TAPPI JOURN
Barbara Dalpke: insights from a recent graduate, TAPPI JOURNAL, August 2002, Vol. 1(6) (144KB)
Magazine articles
Using climate change policies for u.s. pulp and paper industry efficiency, TAPPI JOURNAL, July 2000, Vol. 83(7)
Using climate change policies for u.s. pulp and paper industry efficiency, TAPPI JOURNAL, July 2000, Vol. 83(7)
Magazine articles
Calcium based sulfur recovery process for kraft black liquor gasification - proof of concept', TAPPI JOURNAL, July 2000, Vol. 83(7)
Calcium based sulfur recovery process for kraft black liquor gasification - proof of concept', TAPPI JOURNAL, July 2000, Vol. 83(7)
Magazine articles
Shop talk: concerning coefficient of friction, TAPPI JOURNAL, June 2000, Vol. 83(6)
Shop talk: concerning coefficient of friction, TAPPI JOURNAL, June 2000, Vol. 83(6)
Magazine articles
The use of oxidized white liquor as a caustic replacement in o, eo, eop, and e2 bleaching stages of kraft hardwood and softwood pulp, TAPPI JOURNAL, June 2000, Vol. 83(6)
The use of oxidized white liquor as a caustic replacement in o, eo, eop, and e2 bleaching stages of kraft hardwood and softwood pulp, TAPPI JOURNAL, June 2000, Vol. 83(6)
Magazine articles
Deinking difficulties related to ink formulation, printing process, and type of paper, TAPPI JOURNAL, June 2000, Vol. 83(6)
Deinking difficulties related to ink formulation, printing process, and type of paper, TAPPI JOURNAL, June 2000, Vol. 83(6)
Magazine articles
A volunteer honored: David J. Bentley Jr., TAPPI JOURNAL, March 2000, Vol. 83(3)
A volunteer honored: David J. Bentley Jr., TAPPI JOURNAL, March 2000, Vol. 83(3)