Fibre properties of Norway spruce of different growth rates grown under birch shelterwoods of two densities

2000 ◽  
Vol 30 (3) ◽  
pp. 487-494 ◽  
Author(s):  
Göran Bergqvist ◽  
Urban Bergsten ◽  
Bo Ahlqvist
Keyword(s):  
Growth Rate ◽  
Norway Spruce ◽  
Kraft Pulp ◽  
Coniferous Forest ◽  
Fibre Length ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Strong Negative Correlation ◽  
Fibre Properties ◽  
The Difference

The effects of birch shelterwood density (0, 300, and 600 trees/ha) and growth rate on fibre and pulp properties of Norway spruce (Picea abies (L.) Karst.) understorey (growing at 1500 trees/ha) were evaluated for a trial in the boreal coniferous forest, 58 years after establishment of the stand and 21 years after establishment of the trial. Microdensitometry was used to record variations in wood density, whereas fibre properties and kraft pulp strength properties were measured on laboratory-made batches of unbleached kraft pulp. The main conclusion of the investigation is that a birch shelterwood has only a minor influence on the wood and fibre properties of sheltered Norway spruce and that the resulting consequences for kraft pulping are moderate. Length-weighted mean fibre length was significantly affected only by growth rate. It was 1.75 mm, or 6-13% lower, for trees showing a low growth rate than for all other trees. Tensile index was already high before refining, 85-95 Nm g-1, and the increase due to beating was similar for all shelterwood densities and growth rate classes. At 2000 beating revolutions, there was a strong negative correlation between tear index and the proportion of fibres shorter than 0.20 mm. The volume of wood required to produce 1 t of kraft pulp was almost identical, 5.4 ± 0.1 m3 t-1, for sheltered and unsheltered spruce. Norway spruce growing without shelter produced more pulp per hectare in all fibre length classes, but the difference was greatest, 56-59% compared with sheltered spruce, for the longest fibres (i.e., longer than 3 mm).

Differences in wood decay by Heterobasidion parviporum in cloned Norway spruce (Picea abies)

2009 ◽  
Vol 39 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Y. Puentes Rodriguez ◽  
A. Zubizarreta Gerendiain ◽  
A. Pappinen ◽  
H. Peltola ◽  
P. Pulkkinen
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Wood Density ◽  
Fibre Length ◽  
Wood Decay ◽  
Wood Properties ◽  
Average Growth ◽  
Fibre Properties ◽  
The Difference ◽  
Average Wood

In forest breeding, growth has been used as the main selection trait in Norway spruce (Picea abies L. Karst.), whereas wood properties or resistance to pathogens have been taken as secondary traits. We aimed to investigate, in laboratory conditions, the rate of wood decay caused by Heterobasidion parviporum (Fr.) Niemelä & Korhonen (strains 5 and 7) in 20 Norway spruce clones. We also studied if, on average, growth, wood density, and fibre properties differed in the most and least decayed clones as well as from pith to bark. After 6 months of incubation, strain 7 effected significantly higher wood decay than strain 5 (mean 16.9% and 1.7%, respectively). The difference between the five most decayed and five least decayed clones by strain 7 was also statistically significant (P < 0.05). Moreover, regardless of clone or strain, the wood decay was highest near the pith and lowest near the bark, which is the opposite for wood density and fibre length and width. However, neither wood density nor fibre properties explained, statistically, the differences in average wood decay and decay from pith to bark. On the other hand, we could identify clones that simultaneously provided high wood quantity and relatively high wood density and low decay rate.

Enhancement of eucalypt pulp yield through extended impregnation cooking

2018 ◽  
Vol 33 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Gustavo B. de Souza ◽  
Jorge Luiz Colodette ◽  
Fernando José Borges Gomes ◽  
Danila Morais de Carvalho
Keyword(s):  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield

AbstractThe improvement caused by eucalypt chip impregnation on kraft pulping performance was assessed for terminating the cook at kappa in the range of 15–27 and at controlled residual effective alkali (REA) of 6–8 g/L NaOH. Extended impregnation cooking of eucalypt chips (EIC) increased about 1 %lignin- and HexA-freescreen yield gains in relation to conventional cooking (CC), regardless of kappa number in the range of 15–27. The EIC technology allows for cooking eucalypt wood to kappa number up to 27, without rejects production, but without significant improvement inlignin- and HexA-freescreen yield and with larger chlorine dioxide (ClO2) consume during bleaching. The optimum kappa number for both CC and EIC cooking was about 19 with similar refinability and strength properties for both technologies, CC and EIC. It was concluded that extended impregnation cooking is an attractive technique for enhancing bleached eucalypt Kraft pulp yield.

Wood-density variation of Norway spruce in relation to nutrient optimization and fibre dimensions

2002 ◽  
Vol 32 (2) ◽  
pp. 185-194 ◽  
Author(s):  
Harri Mäkinen ◽  
Pekka Saranpää ◽  
Sune Linder
Keyword(s):  
Cell Wall ◽  
Norway Spruce ◽  
Wood Density ◽  
Wall Thickness ◽  
Annual Ring ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Cell Wall Thickness ◽  
Fibre Properties ◽  
The Absolute

The effect of fertilization on wood density, fibre length, fibre diameter, lumen diameter, proportion of cell wall area, and cell wall thickness of Norway spruce (Picea abies (L.) Karst.) were studied in a nutrient optimization experiment in northern Sweden. On the fertilized plots, all essential macronutrients and micronutrients were supplied in irrigation water every second day during the growing season. After 12 years' treatment, data were collected from 24 trees (40 years old) on the fertilized and control plots. Fertilization increased radial growth more than threefold, especially earlywood width, and decreased wood density by over 20% at 1.3 and 4 m height. The decrease in wood density was closely related to the proportion of latewood. The absolute wood density also decreased across the whole annual ring but proportionately more in latewood than in earlywood. A close relationship was found between the wood density and fibre properties, especially with the proportion of cell wall in a cross section of each annual ring, as well as with fibre and lumen width. The absolute cell wall thickness was clearly less related to wood density. However, rather large variations were found between individual trees in the relationship between wood density and fibre properties.

Development of fibre properties in mill scale high- and low consistency refining of thermomechanical pulp (Part 1)

2020 ◽  
Vol 35 (4) ◽  
pp. 589-599
Author(s):  
Rita Ferritsius ◽  
Christer Sandberg ◽  
Olof Ferritsius ◽  
Mats Rundlöf ◽  
Geoffrey Daniel ◽  
...  
Keyword(s):  
Light Scattering ◽  
Norway Spruce ◽  
Specific Energy ◽  
Mass Fraction ◽  
Fibre Length ◽  
Thermomechanical Pulp ◽  
Fibre Property ◽  
Fibre Properties ◽  
Tensile Index ◽  
Lower Light

AbstractThe aim of this study was to evaluate changes in fibre properties with high (HC)- and low consistency (LC) refining of TMP and determine how these contribute to tensile index. Two process configurations, one with only HC refining and another with HC refining followed by LC refining were evaluated in three TMP mainline processes in two mills using Norway spruce. An increase in tensile index for a given applied specific energy was similar for all LC refiners in the three lines, despite differences in the fibre property profiles of the feed pulps. Compared with only HC refined pulps at a given tensile index, HC+LC refined pulps had greater fibre wall thickness, similar fibre length, strain at break and freeness, but lower light scattering coefficient, fibre curl and external fibrillation. The degree of internal fibrillation, determined by Simons’ stain measurements, was similar for both configurations at a given tensile index. The results indicate that the increase in tensile index in LC refining is largely influenced by a decrease in fibre curl and in HC refining by peeling of the fibre walls. Compared at a given tensile index, the shive content (Somerville mass fraction) was similar for both HC+LC and HC refining.

The effects of initial tree spacing on the fibre properties of plantation-grown coastal western hemlock

2003 ◽  
Vol 33 (12) ◽  
pp. 2460-2468 ◽  
Author(s):  
Paul Watson ◽  
Cameron Garner ◽  
Robin Robertson ◽  
Sandy Reath ◽  
Wai Gee ◽  
...  
Keyword(s):  
Wood Density ◽  
Kraft Pulp ◽  
Fibre Length ◽  
Small Diameter ◽  
Stocking Density ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Economic Implications ◽  
Fibre Properties ◽  
Cell Wall Properties

Fundamental wood and fibre properties determine end product quality potential. They are affected by silvicultural practices. Initial stand stocking density has significant economic implications for both forest managers and industrial end users. An evaluation of the wood density and fibre properties of 38-year-old coastal western hemlock (Tsuga heterophylla (Raf.) Sarg.) planted at five different spacings was completed. We determined that the wood density was not affected by spacing. At the widest spacing, the outer wood fibre length was significantly shorter than at the four tighter spacings. Fibre coarseness and cell wall properties were similar at all spacings. This implies that wood chips prepared from a range of small-diameter thinnings material will not adversely affect kraft pulp fibre properties.

Comparison between Green Liquor Pretreatment-Kraft Pulping and Conventional Kraft Pulping

2013 ◽  
Vol 781-784 ◽  
pp. 2650-2653
Author(s):  
Zhang Hong Xie ◽  
Jing Hui Zhou ◽  
Hai Ming Li ◽  
Guang Wei Sun
Keyword(s):  
Kraft Pulp ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Green Liquor ◽  
Pulp Strength

This paper studied the differences of pulping performances, beating characteristics and strength properties between green liquor pretreatment-Kraft pulping and conventional Kraft pulping based on previous optimized pulping conditions. The green liquor pretreatment-Kraft pulping has higher yield, lower Kappa number, reduced residual effective alkali and decreased viscosity. Green liquor pretreatment improves pulp strength properties although green liquor pretreatment-Kraft pulp has beating characteristics similar to conventional Kraft pulp.

The Importance of Xylan for the Strength Properties of Spruce Kraft Pulp Fibres

Holzforschung ◽  
2001 ◽  
Vol 55 (6) ◽  
pp. 639-644 ◽  
Author(s):  
C. Schönberg ◽  
T. Oksanen ◽  
A. Suurnäkki ◽  
H. Kettunen ◽  
J. Buchert
Keyword(s):  
Tensile Strength ◽  
Chemical Composition ◽  
Fracture Energy ◽  
Kraft Pulp ◽  
Fibre Length ◽  
Strength Properties ◽  
Total Charge ◽  
Pulp Fibres ◽  
Considerable Impact

Summary In this work the role of xylan in spruce kraft pulp fibres was investigated by selectively removing the pulp fibre xylan and also by sorbing xylan onto the pulp fibres. The effects of xylan removal and sorption on fibre properties were measured and the chemical composition of the fibres and also that of the selectively removed xylans was analyzed. According to the results the xylanase could act on both sorbed and native xylan located on accessible fibre surfaces. Xylan was found to affect the strength properties of handsheets. The location and the charge of xylan had a considerable impact on the formation of interfibre bonds. Scott Bond-values correlated with the amount of surface xylan on fibre surfaces, whereas tensile strength was affected by the total amount of xylan and particularly by the total charge of the fibres. The fracture energy was determined by the combined effect of interfibre bonding ability and effective fibre length.

Effect of Growth Rate on Fibre Characteristics in Norway Spruce (Picea abies (L.) Karst.)

Holzforschung ◽  
2002 ◽  
Vol 56 (5) ◽  
pp. 449-460 ◽  
Author(s):  
H. Mäkinen ◽  
P. Saranpää ◽  
S. Linder
Keyword(s):  
Growth Rate ◽  
Cell Wall ◽  
Norway Spruce ◽  
Wall Thickness ◽  
Fibre Length ◽  
Cell Wall Thickness ◽  
Lumen Diameter ◽  
Breast Height ◽  
And Control ◽  
Fibre Characteristics

Summary To study the effect of growth rate on fibre characteristics and their variations in Norway spruce, trees were sampled in a nutrient optimisation experiment in northern Sweden. Data was collected from 24 trees (40 years old) from fertilised and control plots after 12 years of annual nutrient application, as well as from older trees outside the experimental area. Fibre length, fibre diameter, cell wall thickness, lumen diameter and cell wall percentage were measured from every third annual ring at breast height and at a height of 4 m. Fibre properties, as well as their standard deviation, were closely related to ring number and distance from the pith. Intra-ring variation of fibre characteristics was high compared to their variation between trees. Fertilisation reduced fibre length and cell wall thickness, but increased fibre and lumen diameter in rings of the same age. The difference in fibre width, cell wall thickness and lumen diameter between fertilised and control trees was less apparent, but a greater difference in fibre length was found between the treatments with regard to distance from the pith. There was a similar effect of fertilisation on fibre properties in early- and latewood. The effect of enhanced growth rate was less pronounced at a height of 4 m (near the pith) than at breast height (in older rings). It was demonstrated that it is possible to model intra-tree variability of fibre characteristics using ring width and cambial age as independent variables. Models presented are, however, limited by the relatively young age of the sample trees used.

Differences in fibre properties in cloned Norway spruce (Picea abies)

2008 ◽  
Vol 38 (5) ◽  
pp. 1071-1082 ◽  
Author(s):  
A. Zubizarreta Gerendiain ◽  
H. Peltola ◽  
P. Pulkkinen ◽  
R. Jaatinen ◽  
A. Pappinen
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Wood Density ◽  
Growth Traits ◽  
Fibre Length ◽  
Stem Volume ◽  
Fibre Properties ◽  
Phenotypic Correlations ◽  
Fibre Width ◽  
Selection For

In forest breeding programmes, growth has typically been used as a selection trait of prime importance in Norway spruce ( Picea abies (L.) Karst.), whereas less attention has been given to the wood and fibre characteristics. In the above context, we investigated phenotypic relationships between different fibre properties and growth and wood density traits in 20 cloned Norway spruce based on a clonal trial established in the 1970s in southeastern Finland. We found that fibre width showed, on average (2.9%), the lowest phenotypic variation followed by fibre wall thickness (3.4%), coarseness (5.5%), and fibre length (8.1%). All of the phenotypic correlations between the fibre properties were also positive (p < 0.05), ranging from moderate to strong, suggesting that selection for one trait could simultaneously affect the other traits. The phenotypic correlations, on average, were quite weak but positive between growth and fibre properties and slightly negative or weak positive between wood density and different fibre properties (p < 0.05). Individually, some of the clones showed negative correlation between growth traits and fibre length. As a result, selection for fibre properties alone could also reduce overall stem volume (or stem mass) and would not directly indicate wood density traits and vice versa.

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