Hygrothermal recovery of compression wood in relation to DMSO swelling and drying shrinkage

Holzforschung ◽  
2020 ◽  
Vol 74 (8) ◽  
pp. 789-797
Author(s):  
Shuoye Chen ◽  
Miyuki Matsuo-Ueda ◽  
Masato Yoshida ◽  
Hiroyuki Yamamoto
Keyword(s):  
Compression Wood ◽  
Wood Specimen ◽  
Microfibril Angle ◽  
Drying Shrinkage ◽  
Growth Stress ◽  
Normal Wood ◽  
Dimensional Changes ◽  
The Matrix ◽  
Dmso Treatment ◽  
Hygrothermal Treatment

AbstractTo understand the irreversible dimensional changes caused by hygrothermal treatment of green wood, i.e. hygrothermal recovery (HTR), green hinoki compression wood (CW) and normal wood (NW) were hygrothermally (HT) treated in water at 100°C for 120 min and their HTR strains were determined. The specimens were then swollen using dimethyl sulfoxide (DMSO) and then completely dried after solvent exchange with water at room temperature. Their HTR strains were then compared with their DMSO swelling and drying shrinkage strains. The volumetric HTR strains in the CW were about twice as large as those in the NW. Moreover, the microfibril angle (MFA) was found to be an important factor for controlling the HTR intensity. A clear commonality between the HTR behavior and both DMSO swelling and drying shrinkage behavior was identified, which indicates that HTR is caused by volumetric changes in the matrix substances. HTR has been defined as a phenomenon due to the release of locked-in growth stress when a wood specimen is HT treated. To determine whether DMSO treatment has a similar effect as hygrothermal treatment, both HT-untreated and HT-treated specimens were swollen using DMSO, and their dimensional changes during and after DMSO treatment were compared. The results showed that DMSO treatment is a possible alternative for releasing the locked-in growth stress.

MICROFIBRIL ANGLE OF THE S1 CELL WALL LAYER OF NORWAY SPRUCE COMPRESSION WOOD TRACHEIDS

IAWA Journal ◽  
2004 ◽  
Vol 25 (4) ◽  
pp. 415-423 ◽  
Author(s):  
Jonas Brändström
Keyword(s):  
Norway Spruce ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Soft Rot ◽  
Wall Layer ◽  
Thermomechanical Pulp ◽  
Ultrastructural Organization ◽  
Normal Wood ◽  
Cell Wall Layer ◽  
Fracture Characteristics

The ultrastructural organization of the outer layer of the secondary wall (i.e. S1 layer) of Norway spruce (Picea abies (L.) Karst.) compression wood tracheids was investigated with emphasis on the microfibril angle. Light microscopy was used to study the orientation of soft rot cavities (viz. microfibril angle) in compression wood tracheids from macerated soft rot degraded wood blocks. In addition, surface and fracture characteristics of compression wood tracheids selected from a thermomechanical pulp were investigated using scanning electron microscopy (SEM). Results showed that the orientation of soft rot cavities varied little between tracheids and the angles were also consistent along the length of individual tracheids. The average S1 microfibril angle in two selected annual rings was 90.0° ± 2.7° and 88.9° ± 2.4° respectively. SEM observations of the compression wood tracheids from the pulp showed distinct fractures between S1 and S2 or within S1 and these fractures were oriented perpendicular to the tracheid axis. It was concluded that the microfibril angle of the S1 layer of compression wood tracheids is higher and less variable than normal wood tracheids. This is considered an adaptation for restraining the compressive forces that act on leaning conifer stems or branches.

Contribution of lignin to the stress transfer in compression wood viewed by tensile FTIR loading

Holzforschung ◽  
2020 ◽  
Vol 74 (5) ◽  
pp. 459-467 ◽  
Author(s):  
Hui Peng ◽  
Lennart Salmén ◽  
Jiali Jiang ◽  
Jianxiong Lu
Keyword(s):  
Compression Wood ◽  
Microfibril Angle ◽  
Stress Transfer ◽  
Direct Coupling ◽  
Normal Wood ◽  
Static Tensile Loading ◽  
Static Tensile ◽  
Lower Load ◽  
Dynamic Loading Conditions ◽  
Molecular Deformation

AbstractTo achieve efficient utilization of compression wood (CW), a deeper insight into the molecular interactions is necessary. In particular, the role of lignin in the wood needs to be better understood, especially concerning how lignin contributes to its mechanical properties. For this reason, the properties of CW and normal wood (NW) from Chinese fir (Cunninghamia lanceolata) have been studied on a molecular scale by means of polarized Fourier transform infrared (FTIR) spectroscopy, under both static and dynamic loading conditions. Under static tensile loading, only molecular deformations of cellulose were observed in both CW and NW. No participation of lignin could be detected. In relation to the macroscopic strain, the molecular deformation of the cellulose C-O-C bond was greater in NW than in CW as a reflection of the higher microfibril angle and the lower load taken up by CW. Under dynamic deformation, a larger contribution of the lignin to stress transfer was detected in CW; the molecular deformation of the lignin being highly related to the amplitude of the applied stress. Correlation analysis indicated that there was a direct coupling between lignin and cellulose in CW, but there was no evidence of such a direct coupling in NW.

WITHIN-TREE VARIATION IN ANATOMICAL PROPERTIES OF COMPRESSION WOOD IN RADIATA PINE

IAWA Journal ◽  
2004 ◽  
Vol 25 (3) ◽  
pp. 253-271 ◽  
Author(s):  
Lloyd A. Donaldson ◽  
Jenny Grace ◽  
Geoff M. Downes
Keyword(s):  
Wall Thickness ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Basic Density ◽  
Radiata Pine ◽  
Lumen Diameter ◽  
Normal Wood ◽  
Lignin Distribution ◽  
Opposite Wood ◽  
Anatomical Properties

Two trees of radiata pine, one showing severe lean, the other growing almost vertically, were assessed for the presence and anatomical properties of compression wood, including anatomy, lignin distribution, microfibril angle, basic density, radial and tangential lumen diameter and cell wall thickness. Both trees contained significant amounts of compression wood although the severity and amount of compression wood was greater in the leaning tree. Changes in lignin distribution seem to be characteristic of the mildest forms of compression wood with reduced lignification of the middle lamella representing the earliest change observed from normal wood. An increase in microfibril angle was associated with both mild and severe compression wood although examples of severe compression wood with the same or smaller microfibril angles than opposite wood, or with very small microfibril angles, were found. When segregated into mild and severe compression wood the average difference in microfibril angle was 4° and 8° respectively compared with opposite wood. Within-ring distribution of microfibril angle was different in severe compression wood compared to opposite wood with higher angles in the latewood.Severe compression wood showed a 22% increase in basic density compared to mild compression wood and opposite wood. The increased density was accounted for in terms of a 26% increase in tracheid wall thickness throughout the growth ring, offset by a 9% increase in radial lumen diameter, slightly greater in the latewood. There were no significant changes in density or cell dimensions in mild compression wood compared with opposite wood.

scholarly journals Changes in viscoelastic vibrational properties between compression and normal wood: roles of microfibril angle and of lignin

Holzforschung ◽  
2013 ◽  
Vol 67 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Iris Brémaud ◽  
Julien Ruelle ◽  
Anne Thibaut ◽  
Bernard Thibaut
Keyword(s):  
Cell Wall ◽  
Dynamic Modulus ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Axial Direction ◽  
Vibrational Properties ◽  
Normal Wood ◽  
Time Frequency ◽  
Damping Characteristics ◽  
Frequency Domains

Abstract This study aims at better understanding the respective influences of specific gravity (γ), microfibril angle (MFA), and cell wall matrix polymers on viscoelastic vibrational properties of wood in the axial direction. The wide variations of properties between normal wood (NW) and compression wood (CW) are in focus. Three young bent trees (Picea abies, Pinus sylvestris and Pinus pinaster), which recovered verticality, were sampled. Several observed differences between NW and CW were highly significant in terms of anatomical, physical (γ, shrinkage, CIELab colorimetry), mechanical (compressive strength), and vibrational properties. The specific dynamic modulus of elasticity (E′/γ) decreases with increasing MFA, and Young’s modulus (E′) can be satisfactorily explained by γ and MFA. Apparently, the type of the cell wall polymer matrix is not influential in this regard. The damping coefficient (tanδ) does not depend solely on the MFA of NW and CW. The tanδ – E′/γ relationship evidences that, at equivalent E′/γ, the tanδ of CW is approximately 34% lower than that of NW. This observation is ascribed to the more condensed nature of CW lignins, and this is discussed in the context of previous findings in other hygrothermal and time/frequency domains. It is proposed that the lignin structure and the amount and type of extractives, which are both different in various species, are partly responsible for taxonomy-related damping characteristics.

Comparison of Anatomy and Composition Distribution between Normal and Compression Wood of Pinus Bungeana Zucc. Revealed by Microscopic Imaging Techniques

2012 ◽  
Vol 18 (6) ◽  
pp. 1459-1466 ◽  
Author(s):  
Zhiheng Zhang ◽  
Jianfeng Ma ◽  
Zhe Ji ◽  
Feng Xu
Keyword(s):  
Fluorescence Microscopy ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Middle Lamella ◽  
Chemical Imaging ◽  
Raman Microscopy ◽  
Normal Wood ◽  
Confocal Raman Microscopy ◽  
Pinus Bungeana ◽  
Confocal Raman

AbstractThe anatomy and topochemistry in normal and compression wood tracheid cell wall of Pinus bungeana Zucc. were investigated by fluorescence microscopy and confocal Raman microscopy. Using fluorescence microscopy, the severity of compression wood was classed as a mild type for the reason that it did not contain all compression wood features. Chemical imaging by confocal Raman microscopy was used for analyzing the distribution of lignin and cellulose, as well as the functional groups of lignin in tracheid cell walls. By comparison with normal wood, highly lignified outer S2 layer [S2(L)], thicker S1 layer, and obviously reduced lignification in the middle lamella were characteristic of compression wood. In addition, smaller microfibril angle was observed in the S2(L) region. The distribution of coniferyl alcohol and coniferyl aldehyde in normal and compression wood was enriched in S1 and S2 layers but lack in cell corner and/or S2L regions, which showed an opposite pattern to lignin distribution. Confocal Raman microscopy with high spatial resolution contributes to a further understanding of the differences between normal and compression wood in polymers distribution and molecules orientation in situ.

Comparison of the TL-Shear Strength of Normal and Compression Wood of European Larch

Holzforschung ◽  
2003 ◽  
Vol 57 (4) ◽  
pp. 421-426 ◽  
Author(s):  
W. Gindl ◽  
A. A.Teischinger
Keyword(s):  
Shear Strength ◽  
Compression Wood ◽  
Fracture Behaviour ◽  
Microfibril Angle ◽  
Middle Lamella ◽  
Longitudinal Shear ◽  
Normal Wood ◽  
European Larch ◽  
The Difference ◽  
Scanning Electron

Summary The strength of larch compression wood specimens in longitudinal shear in the radial plane was determined and compared to normal wood. Fracture surfaces were examined with a scanning electron microscope. Compression wood showed higher shear strength than normal wood. The difference persisted after correction of the strength values for density. Scanning electron microscopy revealed clear differences in the pattern of failure in normal wood compared to compression wood. While transwall and intrawall fracture predominate in normal wood, intercell fracture at the middle lamella occurs in compression wood. An explanation of this change in fracture behaviour is proposed in terms of microfibril angle and lignification of the cell wall.

Reaction Wood Anatomy in a Vessel-Less Angiosperm Sarcandra Glabra

IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 116-126 ◽  
Author(s):  
Haruna Aiso ◽  
Futoshi Ishiguri ◽  
Yuya Takashima ◽  
Kazuya Iizuka ◽  
Shinso Yokota
Keyword(s):  
Cell Walls ◽  
Compression Wood ◽  
Wood Anatomy ◽  
Microfibril Angle ◽  
Normal Wood ◽  
Reaction Wood ◽  
Lower Side ◽  
Single Tree ◽  
Angiosperm Species ◽  
Guaiacyl Lignin

Anatomy and lignin distribution in artificially inclined stems of Sarcandra glabra were investigated to clarify the characteristics of reaction wood (RW) in a vessel-less angiosperm species. Of the five coppiced stems studied from a single tree, two stems were fixed straight and classified as normal wood (NW) and the remaining three stems were inclined at 50 degrees from the vertical to induce the formation of the RW. Compared with NW, the lower side of the inclined samples had a relatively high compressive surface-released strain and an increase in the microfibril angle of the S2 layer of tracheids. However, no significant change was observed in the length or cell wall thickness of the tracheids. The results of Wiesner and Mäule colour reactions indicated that the amount of guaiacyl lignin in the cell walls of tracheids was increased in RW. It appears that RW in Sarcandra is formed on the lower side of inclined stems, and its anatomical characteristics and chemical composition are similar to those of the compression wood (CW) found in gymnosperm species (the so-called “CW-like RW” type).

Properties of young Araucaria heterophylla (Norfolk Island pine) reaction and normal wood

Holzforschung ◽  
2014 ◽  
Vol 68 (7) ◽  
pp. 817-821 ◽  
Author(s):  
Monika Sharma ◽  
Clemens Michael Altaner
Keyword(s):  
Pinus Radiata ◽  
Modulus Of Elasticity ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Normal Wood ◽  
Opposite Wood ◽  
Araucaria Heterophylla ◽  
Norfolk Island ◽  
Anatomical Properties

Abstract Young Araucaria heterophylla (Salisb.) Franco seedlings have been grown tilted to obtain compression wood (CW), opposite wood (OW), and normal wood (NW). Mechanical and anatomical properties of these wood tissues have been assessed. CW had characteristics associated with low severity. OW and NW did not differ significantly in their properties and were found to have a considerably lower microfibril angle and higher modulus of elasticity than those of juvenile corewood of Pinus radiata D. Don.

scholarly journals Ultrastructural evaluation of compression wood-like properties of common juniper (Juniperus communis L.)

Holzforschung ◽  
2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Tuomas Hänninen ◽  
Pekka Tukiainen ◽  
Kirsi Svedström ◽  
Ritva Serimaa ◽  
Pekka Saranpää ◽  
...  
Keyword(s):  
Compression Wood ◽  
Microfibril Angle ◽  
Fiber Axis ◽  
Normal Wood ◽  
X Ray Diffraction ◽  
Bending Tests ◽  
Juniperus Communis ◽  
Fiber Cell Wall ◽  
Helical Grooves ◽  
Common Juniper

Abstract To date, very little is known about the ultrastructure of common juniper, Juniperus communis L (juniper). In this study, the mechanical properties of juniper, its chemistry and ultrastructure has been analyzed. The data are presented in comparison to the normal wood (NW) and compression wood (CW) of spruce. Helical grooves, which are a characteristic of CW, were clearly visible in micrographs of juniper. The angle of the grooves with respect to the fiber axis was ca. 40°, which correlates with the microfibril angle determined by X-ray diffraction. Data from 4-point bending tests show that juniper and spruce CW exhibited similar behavior. The elastic moduli of both species were only ca. half from that of NW spruce. The composition of juniper fibers resembled that of CW fiber with respect to high lignin and hemicelluloses contents. However, the galactose content in CW of juniper was low and in CW of spruce was high. Raman imaging clearly revealed that the lignin/cellulose ratio in the fiber cell wall of juniper was similar to that of NW spruce.

ANATOMY AND LIGNIN DISTRIBUTION OF “COMPRESSION-WOOD-LIKE REACTION WOOD” IN GARDENIA JASMINOIDES

IAWA Journal ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Haruna Aiso ◽  
Tokiko Hiraiwa ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
...  
Keyword(s):  
Compression Wood ◽  
Lignin Content ◽  
Microfibril Angle ◽  
Normal Wood ◽  
Reaction Wood ◽  
Anatomical Characteristics ◽  
Lignin Distribution ◽  
Gardenia Jasminoides ◽  
S2 Layer ◽  
Secondary Fibre

Anatomical characteristics and lignin distribution of ‘compression-wood-like reaction wood’ in Gardenia jasminoides Ellis were investigated. Two coppiced stems of a tree were artificially inclined to form reaction wood (RW). One stem of the same tree was fixed straight as a control, and referred to as normal wood (NW). Excessive positive values of surface-released strain were measured on the underside of RW stems. Anatomical characteristics of xylem formed on the underside of RW and in NW stems were also observed. The xylem formed on the underside exhibited a lack of S3 layer in the secondary fibre walls, an increase of pit aperture angle in the S2 layer, and an increase in lignin content. Some of the anatomical characteristics observed in the underside xylem resembled compression wood in gymnosperms. These results suggest that the increase of microfibril angle in the secondary wall and an increase in lignin content in angiosperms might be common phenomena resembling compression wood of gymnosperms.

Sign in / Sign up

Export Citation Format

Share Document