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Weight scaling

methods to determine the quantity of pulpwood

Hultnäs, Mikael (2012). Weight scaling. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2012:34
ISBN 978-91-576-7670-2
[Doctoral thesis]

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Scaling pulpwood according to its weight for payment purposes is done in many places
around the world. In North America, pulpwood is commonly scaled according to its green weight, while in Central Europe the wood is commonly scaled according to its dry weight. In Sweden pulpwood is measured according to its volume.

This doctoral thesis aims to study the prerequisites for Sweden to weight scale its pulpwood. Historical observations of the green density plus meteorological data were used to create a model that predicted the green density of Norway spruce pulpwood that arrived at Braviken pulp and paper mill. By obtaining the weight of the wood and the prediction of green density, the volume could be obtained. To study the prerequisites for scaling wood according to its dry weight, the variation in moisture content was described within and between logs of Norway spruce. Further, dual energy X-ray absorptiometry was recognized and studied with respect to its potential to quickly and accurately determine the moisture content in wood samples. Different techniques for sampling roundwood to determine the moisture content were also studied.

The results of this thesis showed that the green density could be determined with similar precision as the volume measurement performed today. Moreover, it was shown that there was a large variation in the moisture content both within single discs and between logs of Norway spruce. It was shown that with dual energy X-ray absorptiometry, it was possible to determine the moisture content in chips of Scots pineand Norway spruce in good concurrence with the gravimetric method. The different techniques to sample roundwood showed similar results for a regular chainsaw and a modified chain sampler, but none of them worked totally satisfactorily and they both contained systemic errors.

The main benefits of weight scaling are that it is faster compared to volume measurement, it has potential to be less laborious while the new technique using X-ray absorptiometry to determine the moisture content in the wood provides the opportunity to sort arriving wood dependent on its moisture content.

Authors/Creators:Hultnäs, Mikael
Title:Weight scaling
Subtitle:methods to determine the quantity of pulpwood
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :18 May 2012
Number of Pages:64
IMikael Hultnäs, Mats Nylinder, Anders Ågren. Predicting the green density as a means to achieve the volume of Norway spruce (Picea abies) (submitted).
IIMikael Hultnäs, Maria Jonsson. Variation in moisture content of Norway spruce and its consequences for sampling to determine the dry matter content (submitted).
IIIMikael Hultnäs. (2011). Methods to determine the dry matter content of roundwood deliveries. TAPPI Journal (June), 33-37.
IVMikael Hultnäs, Ragnar Kullenberg, Erik Persson, Mats Nylinder. (2009). Determination of moisture content in spruce woodchips by dual energy Xray absorptiometry. Proceedings of the International Mechanical Pulping Conference, Sundsvall, May 31 to June 4, 2009. 213-219.
VMikael Hultnäs, Victor Fernandez-Cano. Determination of the moisture content in wood chips of Scots pine and Norway spruce using Mantex Desktop Device, based on dual energy X-ray absorptiometry (accepted for publication in Journal of Wood Science).
Place of Publication:Uppsala
Publisher:Institutionen för skogens produkter, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-7670-2
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:K Forestry > K50 Processing of forest products
Subjects:(A) Swedish standard research categories 2011 > 2 Engineering and Technology > 205 Materials Engineering > Paper, Pulp and Fiber Technology
Agrovoc terms:pulpwood, picea abies, pinus sylvestris, pulp, moisture content, weight, x rays
Keywords:pulpwood , Norway spruce , Scots pine
Permanent URL:
ID Code:8822
Department:(S) > Dept. of Forest Products (until 180101)
Deposited By: Mikael Hultnäs
Deposited On:08 May 2012 07:59
Metadata Last Modified:02 Dec 2014 10:50

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