The planar transient hygroexpansion of copy paper: Experiments and analysis
2004 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 19, no 2, 183-190 p.Article in journal (Refereed) Published
Experimental results for transient hygroexpansion of copy paper sheets subjected to step changes in RH were obtained. MD transient hygroexpansion strain rates (expressed in normalized forms) during adsorption were higher than the corresponding CD rates for every cycle tested. CD hygroexpansion strains were observed to be linear in the average moisture content of the sheets. MD strains however showed significantly non-linear behavior. A mathematical model for transient hygroexpansion of paper sheets was developed based on the twin mechanisms of moisture diffusion through the pore and fiber spaces. The model incorporates the effects of surface boundary layers also. Assuming the hygroexpansion to be "quasi-static" (i.e. local hygroexpansion coefficients are equivalent to the equilibrium values), traditional theory for linear thermal elasticity was applied to estimate hygroexpansion strains. The model describes different hygroexpansion strain rates in CD and MD.
Place, publisher, year, edition, pages
2004. Vol. 19, no 2, 183-190 p.
Absorption, Hygroexpansion, Moisture transport, Paper, Residual stresses, Strain, Transient
IdentifiersURN: urn:nbn:se:kth:diva-84034ISI: 000222092600008OAI: oai:DiVA.org:kth-84034DiVA: diva2:499102
QC 201202192012-02-132012-02-132012-02-19Bibliographically approved