Directional emittance of dry and moist paper
2014 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 29, no 2, 294-303 p.Article in journal (Refereed) Published
The directional emittance of dry and moist paper and board samples was measured in two wavelength ranges; the mid-wavelength infrared (MWIR) range and the long-wavelength infrared (LWIR) range. The influence of pulp type, pulp drying, pulp refining, fibre orientation, additives, coating, and observation angle on the emittance of dry paper was examined. The influence of sample moisture and observation angle on the emittance of moist samples was also investigated. The emittance in the LWIR range was higher than the MWIR emittance. The emittance varied with pulp type, especially for TMP, which had a significantly lower emittance compared to the samples made of chemical pulp. The impact of different properties, such as pulp type, refining or coating, was much smaller in the LWIR range than in the MWIR range. Observation angle was found to significantly impact the emittance at angles larger than 60 degrees from the normal direction in the MWIR range, and angles larger than 70 degrees in the LWIR range. The emittance increased with increasing moisture ratio. This increase was most pronounced at low absolute moisture ratios, where an addition of an already small amount of water could impart a large change in emittance. It was found that the emittance and sample moisture could be correlated well using a linear combination of the emittance of dry paper and pure water.
Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University , 2014. Vol. 29, no 2, 294-303 p.
Paper, Board, Moisture, Infrared, Thermography, Emittance, Emissivity, Directional, MWIR, LWIR
Paper, Pulp and Fiber Technology
Research subject Production Engineering; Physics; Fibre and Polymer Science
IdentifiersURN: urn:nbn:se:kth:diva-141776DOI: 10.3183/NPPRJ-2014-29-02-p294-303ISI: 000338336400014ScopusID: 2-s2.0-84901785653OAI: oai:DiVA.org:kth-141776DiVA: diva2:698384
FunderSwedish Energy Agency, 2011-0054422
QC 201402252014-02-212014-02-212016-01-22Bibliographically approved