Search

For the thermomechanical pulping (TMP) process both wood chip quality and the refining process have important effects on the resulting pulp and paper quality. Properties of wood raw material give a framework for final pulp properties. During TMP refining the specific energy consumption and refining intensity strongly impact fibre and pulp qualities. Increasing specific energy consumption benefits the development of fibres and improves their properties. However, high intensity refining tends to shorten the fibres and produces more fines content when compared with low intensity refining. This review focuses on the influence of key variables of chip qualities and the refining process on TMP pulp and paper qualities. [ABSTRACT FROM AUTHOR]

Ecosystem management requires good knowledge of preindustrial ecosystems and their dynamics. However, in most regions of Québec, the original forested landscape has been altered by human activities. To validate the ecosystem management conducted in the lower Mauricie region, the preindustrial landscape of the high hills of the lower Saint-Maurice region was characterized from the study of 18 historical forest surveys conducted by the pulp and paper industry in the early 20th century. The analysis of these surveys showed the predominance of irregular mature stands. Two-thirds of these stands were of mixedwood type, while a very small proportion was of hardwood type. Softwood volume was mainly constituted of balsam fir (Abies balsamea (L.) Mill.) and red (Picea rubens Sarg.) and black spruces (Picea mariana (Mill.) BSP). Lastly, the analysis of these inventories showed the occurrence, in the preindustrial landscape, of a mixed disturbance regime, where severe fires and insect outbreaks coexisted with gap dynamics. From a broader perspective, we can fully appreciate with this study the importance and usefulness for ecosystem management of conserving forest inventory archives, because in many cases they are the only references to the preindustrial landscape. [ABSTRACT FROM AUTHOR]

In this paper, the measurements from OpTest FQA (fiber quality analyzer) and L&W Fiber Tester were compared on 95 TMP (thermomechanical pulp) samples from a TMP-based newsprint mill in Eastern Canada that uses mixed black spruce and balsam fir as raw material. It was found that both FQA and L&W Fiber Tester provide repeatable measurements for fiber length, fines, coarseness, curl, and kink index. However, there were significant differences in the results obtained from the two instruments. Compared to FQA, the L&W Fiber Tester measurements were on average 59% higher for the arithmetic mean fiber length and arithmetic fines content, about 6% higher for the length weighted mean fiber length, approximately 44% lower for the coarseness, and about 37% lower for the kink index. [ABSTRACT FROM AUTHOR]

To date, little dendrochronological research has been conducted in western Labrador and therefore limited analysis of past tree growth patterns exists for this area. A study was undertaken to address this gap in knowledge this past summer. This paper will look at some of the first results coming from an inter-species comparison of the radial growth rates of four species from this region. Balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca), black spruce (Picea mariana) and tamarack larch (Larix laricina) are this region's dominant coniferous species, and all four were sampled at sites along a north-south latitudinal transect (55N 62W to 52N 62W). Each chronology was analyzed using standard dendrochronological procedures, with cross-dating results indicating that there is a link between all sites and between species. Each species seems to be acting in a similar nature across the spatial gradient and so we suggest that the dominant factor that links these growing environments on a regional scale across the grid is climate. [ABSTRACT FROM AUTHOR]

The predictions of properties for wood disc average are seldom reported, and they are important for sorting out logs based on their quality. The minimum near infrared (NIR) spectra required to predict wood disc average properties would also be of critical importance. In this study, calibration and prediction models for wood disc average properties were developed using NIR spectral data for balsam fir (Abies balsamea (L.) Mill.) and black spruce (Picea mariana (Mill.) B.S.P.) samples collected from 14 different sites across Newfoundland, Canada. The calibration was done against area-weighted average wood properties determined by SilviScan. NIR spectra were collected in 18 mm increments from the radial-longitudinal face of green and oven-dried samples. Results showed that using NIR spectra from three spots per wood strip was sufficient for the modeling and prediction for density and module of elasticity (MOE). The coefficients of determination ranged from 0.76 (MOE of green wood samples) to 0.88 (density of oven-dried wood samples). However, the microfibril angle (MFA) cannot be well predicted from either green wood or oven-dried wood NIR spectra. Our results further showed that the NIR spectra collected from oven-dried wood samples gave better calibration and prediction than those collected from green wood samples. Les prédictions des propriétés moyennes des disques de bois sont rarement présentées, bien qu'elles soient importantes pour trier les billes en fonction de leur qualité. Les spectres minimum dans le proche infrarouge (PIR) qui sont nécessaires pour prédire les propriétés moyennes des disques de bois ont aussi une importance cruciale. Dans cette étude, des modèles de prédiction et de calibration des propriétés moyennes des disques de bois ont été développés à partir de données spectrales PIR d'échantillons de sapin baumier (Abies balsamea (L.) Mill.) et d'épinette noire (Picea mariana (Mill.) B.S.P.) prélevés dans 14 sites différents couvrant l'ensemble de la province de Terre-Neuve, au Canada. La calibration a été effectuée à partir des propriétés moyennes du bois déterminées à l'aide de SilviScan et pondérées par la superficie. Les spectres PIR ont été obtenus à tous les 18 mm le long de la face longitudinale-radiale d'échantillons verts et anhydres. Les résultats ont démontré que l'utilisation des spectres PIR provenant de trois points par barrette de bois était suffisante pour modéliser et prédire la densité et le module d'élasticité (MOE). Les coefficients de détermination variaient de 0,76 (MOE d'échantillons de bois à l'état vert) à 0,88 (densité d'échantillons de bois à l'état anhydre). Cependant, les spectres PIR du bois vert ou anhydre ne sont pas adéquats pour prédire l'angle des microfibrilles (AMF). Nos résultats ont de plus montré que les spectres PIR des échantillons de bois à l'état anhydre permettent d'obtenir une meilleure calibration et de faire de meilleures prédictions que ceux des échantillons de bois à l'état vert. [ABSTRACT FROM AUTHOR]