A novel approach to study the hydroexpansion mechanisms of paper using spray technique
2009 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 24, no 4, 371-380 p.Article in journal (Refereed) Published
A new method has been developed to measure the dimensional stability of printing paper by measuring the impact of liquid water on the in-plane dimensional change, i.e. the hydroexpansion, without any simultaneous mechanical interference that can occur when water is pressed into the sheet. This was achieved by using a specially developed spray technique and using electronic speckle photography to continuously measure the dimensional change as water is applied.
The in-plane expansion for a given change in moisture content was found to be lower in the case of hydroexpansion than for earlier reported hygroexpansion. After the initial expansion following the water application, it was found that sheets rapidly start to contract again already 10-20 seconds after being wetted, i.e. despite still having a fairly constant and significantly higher moisture content than the initial moisture content before water application. These effects suggest that there are different mechanisms behind hydroexpansion than hygroexpansion of paper, and that hygroexpansion measurements should be extrapolated with caution when evaluating papers with respect to printability.
Place, publisher, year, edition, pages
2009. Vol. 24, no 4, 371-380 p.
Dimensional stability, Hydroexpansion, Electronic speckle photography, Controlled spraying, RELATIVE HUMIDITY CHANGES, CREEP
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-12170ISI: 000273724200001ScopusID: 2-s2.0-76349113333OAI: oai:DiVA.org:kth-12170DiVA: diva2:305243