Effect of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst.

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Nasko Terziev ◽  
Geoffrey Daniel ◽  
Ann Marklund
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Cell Walls ◽  
Compression Wood ◽  
Morphological Changes ◽  
Mechanical Processing ◽  
Opposite Wood ◽  
Tear Index ◽  
Control Samples

Abstract The aim of the present study was to determine the effect of a variety of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst. Fibres representing abnormality were obtained from trees treated by irrigation and fertilisation. Moreover, fibres from compression wood and its accompanying opposite wood were isolated. The effect of dislocations on paper quality was studied on four mixtures (20, 40, 60 and 80% fibres with induced dislocations) of untreated/compressed fibres. Two more groups consisting of control untreated samples and samples with 100%-induced dislocations were also included in the test. The mechanical properties of the paper were tested and the results were compared to those of control samples. Abnormal fibres reduced the desired mechanical properties of the final paper concerning tensile strength, modulus of elasticity and tear-tensile index. Irrespective of the type of treatment, all morphological changes introduced in fibre cell walls appear to directly affect changes in the mechanical properties of the paper. Control samples had a tear index of 25 compared to 10 mN m2 g-1 of samples containing 100% dislocations. It is obvious that 20% of dislocations, an amount that is expected to be induced in pulp under mechanical processing and transport, will contribute to a decrease in tear index with an average of 3 mN m2 g-1, i.e., 10% of the total value.

scholarly journals Inter-Tracheid and Cross-Field Pitting in Compression Wood and Opposite Wood of Norway Spruce (Picea abies L.)

2011 ◽  
Vol 3 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Asghar TARMIAN ◽  
Mohammad AZADFALLAH ◽  
Hadi GHOLAMIYAN ◽  
Mahdi SHAHVERDI
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Air Permeability ◽  
Sem Images ◽  
Aperture Diameter ◽  
Opposite Wood ◽  
Bordered Pits ◽  
S2 Layer

Inter-tracheid and cross-filed pit specifications in compression wood and opposite wood of Norway spruce (Picea abies) were determined. Fewer pits of a smaller size and a smaller aperture diameter were observed in compression wood. In contrast to the uniseriate arrangement of bordered pit pairs in compression wood, both uniseriate and biseriate pits were observed in opposite wood. In contrast to the circular view of the pit aperture in opposite wood, a slit-like pit aperture was often observed in compression wood. SEM images showed a number of helical fissures on the tracheid walls and bordered pits of compression wood along the microfibril angle in the S2 layer. The cross-field pits in compression wood were dominantly piceoid but sometimes cupressoid and occasionally taxodioid, whereas they were mostly piceoid and occasionally cupressoid in opposite wood. Overall, some significant differences in the inter-tracheid and cross-field pitting between the compression wood and opposite wood can give some explanations for their different air permeability and drying kinetics found in the previous studies.

Grade yields and wood properties of Norway spruce [Picea abies (L.) Karst.] from the Maritimes

1995 ◽  
Vol 71 (4) ◽  
pp. 473-478
Author(s):  
Y. H. Chui
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Wood Quality ◽  
Wood Properties ◽  
Bending Properties ◽  
Clear Wood ◽  
Comparative Information ◽  
Grade Yield

Norway spruce [Picea abies (L.) Karst.] is one of the major non-native softwood species in the Maritimes. A project was undertaken to evaluate the grade yields and mechanical properties of Norway spruce. The project also provided comparative information on the wood quality of two Norway spruce provenances from Germany and Poland. Four plantations were selected for the study with two of these plantations containing trees of known provenances. One plantation was mature and the other three were juvenile. In total, 530 pieces of lumber and the same number of matched small clear specimens were tested for bending properties. Prior to testing, the lumber was visually graded according to both British and Canadian specifications. Quality of lumber varied significantly between sites. Lumber from the Polish provenance had slightly better mechanical properties than that from trees of the German provenance. Compared with published information, the plantation-grown Norway spruce had lower clear wood bending properties and specific gravity than primary eastern Canadian spruce species and balsam fir, and natural Norway spruce grown in Europe. Key words: Norway spruce [Picea abies (L.) Karst.], wood quality, bending properties, grade yield

Dislocations in Norway spruce fibres and their effect on properties of pulp and paper

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Nasko Terziev ◽  
Geoffrey Daniel ◽  
Ann Marklund
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Norway Spruce ◽  
Juvenile Wood ◽  
Practical Importance ◽  
Pulp And Paper ◽  
Worst Case ◽  
Machine Failure ◽  
Wood Fibres ◽  
Control Samples

Abstract Wood “cell-wall deformation” is a comprehensive term describing any physical dislocation in the wall caused by mechanical forces. The development and effect of fibre dislocations on wood fibres, and their ultimate impact on the mechanical properties of paper remain rather obscure and controversial. Dislocations are difficult to quantify through a lack of defined measurable features, and research is aggravated by the inherent difficulties of applying statistical tools. A direct approach for studying the effect of dislocations on the mechanical properties of paper was used in this study. Dislocations in fibre cell walls were introduced by exposing whole wood fibres in mature and juvenile wood samples to compression stress. Sapwood samples of Norway spruce (Picea abies Karst.) were loaded by compression to their ultimate strength using an Alwetron-50 universal testing machine. Failure of samples conditioned to a moisture content of 9–15% always occurred in an oblique (relative to the fibre axis) plane and all fibres in the plane were deformed. When samples were loaded in a wet condition (i.e., moisture content close to the fibre saturation point), failure occurred at one end of the samples, resulting in highly disorganised fibres. Pulp and paper from the compressed fibres were produced and the mechanical properties of the paper were tested. Results of the mechanical tests were compared statistically to results derived from paper made from matched non-compressed control samples. Morphological features of fibres and dislocations after compression failure were characterised using microscopy (scanning electron microscopy, polarised light) on the whole wood and macerated fibres before and after paper testing. The above experimental approach showed that paper made from control samples had significantly better mechanical properties than paper made from samples loaded by compression under dry or wet conditions. At a tensile index of 90 N m/g, the tear index was measured as 23.6 mN m2/g for controls, while the corresponding values for compressed wet wood samples was 12.6 and 16.3 mN m2/g for samples at 9–15% moisture content. Paper made from juvenile wood also showed lower mechanical properties compared to controls. The results prove the negative effect of dislocations on the mechanical properties of paper in the worst case scenario and are of practical importance.

Interactions between Norway spruce (Picea abies) and Heterobasidion annosum. I. Infection of nonsuberized and young suberized roots

1994 ◽  
Vol 72 (6) ◽  
pp. 872-883 ◽  
Author(s):  
W. K. Heneen ◽  
M. Gustafsson ◽  
G. Karlsson ◽  
K. Brismar
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Cell Walls ◽  
Heterobasidion Annosum ◽  
Root Infection ◽  
Host Reaction ◽  
Outer Cortex ◽  
Fungal Enzymes ◽  
Transmission Electron ◽  
Inner Cortex

Nonsuberized and young suberized roots of Norway spruce (Picea abies) were inoculated with an S-strain of Heterobasidion annosum for 2–20 days. The roots were sectioned for light microscopy and transmission electron microscopy. They were susceptible to infection at both stages of development. The host reaction to delimit the infection was the formation of a necrotic ring barrier in the outer cortex. In cases where the inner cortex also became infected, fungal hyphae accumulated just before the endodermis, which acted as a new barrier. Only in nonsuberized roots did the hyphae succeed in penetrating the stele, and within 3 days after inoculation the stele was almost completely digested. Other resistance reactions included accumulation of phenolic deposits, secondary thickening of cell walls, and formation of papillae. The hyphae were able to grow within and across cell walls. The presence of translucent areas around penetrating hyphae possibly reflected the digestive action of fungal enzymes. The hyphae showed signs of degeneration when entrapped in encompassing cellular deposits. Key words: Norway spruce, Heterobasidion annosum, root infection, nonsuberized roots, young suberized roots, microscopy.

The radial variation of the selected physical and mechanical properties of Norway spruce (Picea abies (L.) H. Karst) wood from the provenance area in Głuchów

2019 ◽  
Vol 105 ◽  
pp. 133-143
Author(s):  
KAROLINA ZAWADZKA ◽  
PAWEŁ KOZAKIEWICZ
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Research Area ◽  
Radial Variation ◽  
Static Modulus ◽  
Spruce Wood ◽  
Static Modulus Of Elasticity

The radial variation of the selected physical and mechanical properties of Norway spruce (Picea abies (L.) H. Karst) wood from the provenance area in Głuchów. Spruce wood (Picea abies (L.) H. Karst) is one of the main species used in building constructions. Due to the wide occurrence, it is important to test various origins and in this way select those with the best material properties. Wood was obtained from one habitat from a provenance experimental area in Głuchów from 40-year-old trees. For the study, trees from three different origins were selected: Nowe Ramuki, Bliżyn and Rycerka Praszywka II (origin from respectively northern, central and southern Poland - seedlings came from these places). Spruce wood from Bliżyn, which is the closest to the proven research area in Głuchów, reached the highest average values in all studied traits (density, ultrasonic wave velocity, dynamic and static modulus of elasticity and static bending strength) and was characterized by the highest variability of these features. Regardless of the origin, the above-mentioned features of the wood showed a clear upward trend going from the pith to the to the side of the trunk.

Comparing Mechanical Properties of Normal and Compression Wood in Norway Spruce: The Role of Lignin in Compression Parallel to the Grain

Holzforschung ◽  
2002 ◽  
Vol 56 (4) ◽  
pp. 395-401 ◽  
Author(s):  
W. Gindl
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cell Wall ◽  
Mechanical Testing ◽  
Cell Walls ◽  
Compression Wood ◽  
Lignin Content ◽  
Microfibril Angle ◽  
Compression Failure

Summary Cell-wall lignin content and composition, as well as microfibril angle of normal and compression wood samples were determined prior to mechanical testing in compression parallel to the grain. No effect of increased lignin content on the Young's modulus in compression wood was discernible because of the dominating influence of microfibril angle. In contrast, compressive strength of compression wood was not negatively affected by the high microfibril angle. It is proposed that the observed high lignification in compression wood increases the resistance of the cell walls to compression failure. An increased percentage of p-hydroxyphenylpropane units observed in compression wood lignin may also contribute to the comparably high compressive strength of compression wood.

Infection of Picea abies clones with a homokaryotic isolate of Heterobasidion parviporum under field conditions

2015 ◽  
Vol 45 (3) ◽  
pp. 227-235 ◽  
Author(s):  
S. Keriö ◽  
S.M. Niemi ◽  
M. Haapanen ◽  
G. Daniel ◽  
F.O. Asiegbu
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Cell Walls ◽  
Necrotic Lesion ◽  
Field Conditions ◽  
Economic Losses ◽  
Northern Europe ◽  
Infection Frequency ◽  
Factors Affecting ◽  
Starting Point

Heterobasidion parviporum Niemelä & Korhonen is responsible for the majority of decay in conifers in northern Europe, which causes severe economic losses. In nature, heterokaryotic isolates of H. parviporum cause infection in Norway spruce (Picea abies (L.) Karst.). However, little is known on whether homokaryons of H. parviporum can infect trees under field conditions. In this study, 40-year-old clonal Norway spruce stems and roots were inoculated with a homokaryotic isolate of H. parviporum under field conditions. After four months, the infection frequency and necrotic lesion lengths were recorded. The homokaryon caused infection and provoked the development of necrotic lesions. Necrotic lesions were larger in roots than in stems. Among the studied Norway spruce genotypes, a Russian clone had the smallest necrotic lesions, whereas a Finnish clone developed the largest necrotic lesions. Clones with higher growth rates were more sensitive to fungal infection and wound damage. Under microscopic observation, H. parviporum grew adpressed to lumen cell walls, colonized tracheids next to rays, and induced lignification in cell walls close to the point of inoculation. This study provides a starting point for further studies on the ability of homokaryons to cause infection under field conditions and for discussions on factors affecting the resistance of Norway spruce against H. parviporum.

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