Physical properties of earlywood and latewood of Pinus radiata D. Don: Anisotropic shrinkage, equilibrium moisture content and fibre saturation point

Holzforschung ◽  
2005 ◽  
Vol 59 (6) ◽  
pp. 654-661 ◽  
Author(s):  
Shusheng Pang ◽  
Alfred Herritsch
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Pinus Radiata ◽  
Growth Ring ◽  
Fibre Saturation Point ◽  
Longitudinal Shrinkage ◽  
Saturation Point ◽  
Breast Height ◽  
Second Growth ◽  
Tangential Shrinkage

Abstract Anisotropic shrinkage (tangential and longitudinal), equilibrium moisture content (EMC) and fibre saturation point (FSP) were measured for separated earlywood (EW) and latewood (LW) of a 0.75-m-long log of 20-year old Pinus radiata that was cut at breast height from a selected tree in the forest of Central North Island, New Zealand. The experimental results have shown that at 12% moisture content (MC), tangential shrinkage was 3.23% for EW and 3.90% for LW, with an overall average of 3.56%. Longitudinal shrinkage was 0.23% for EW and 0.21% for LW with an overall average of 0.22%. Shrinkage for the oven dry (OD) state showed similar trends to those at 12% MC in terms of the differences between EW and LW. The tangential and longitudinal shrinkage varied significantly along the radius from pith to bark. The EW tangential shrinkage increased from pith to the seventh growth ring and then remained relatively constant until the last ring adjacent to the bark. The LW tangential shrinkage also increased from the pith outwards until the seventh growth ring, but beyond that was more variable than the EW shrinkage. Both EW and LW showed similar longitudinal shrinkage, with the highest values in the second growth ring, from which the shrinkage decreased exponentially towards the bark. LW had a slightly higher EMC than EW at a relative humidity (RH) below 80%, but the trend was reversed for RH above 80%. The EMC differences between EW and LW were less than 0.6%. The overall average FSP for Pinus radiata was 29.1%, with actual values varying from 25% to 32.8%. The earlywood FSP (28.9%) was slightly lower than that of the latewood (29.4%).

scholarly journals Basic physical properties of spruce wood (Picea abies Karst) from plantations

2007 ◽  
pp. 97-110
Author(s):  
Borislav Soskic ◽  
Zoran Govedar ◽  
Nebojsa Todorovic ◽  
Danijela Petrovic
Keyword(s):  
Physical Properties ◽  
Growth Ring ◽  
Fibre Saturation Point ◽  
Surface Anisotropy ◽  
Saturation Point ◽  
Average Value ◽  
Breast Height ◽  
Spruce Wood ◽  
Volume Porosity ◽  
Ring Diameter

The basic physical properties of spruce wood from plantations in the surroundings of Banja Luka were researched. The dependence of growth ring diameter and wood density, density, volume porosity, shrinkage, fibre saturation point and absorption of moisture were analysed on three trees average age about 16 years. The data for breast height and for all specimens from breast height to 9.3 m were statistically processed. The research and analysis of the basic physical properties of plantation-grown spruce wood shows that the effect of growth ring diameter on the density is negative and that the dependence is logarithmic, which confirms the previous results. Average value of wood density is lower than the usual value reported in references. Average value of radial shrinkage is 3.90%, and tangential 8.10%. This research confirms the linear dependence between the nominal density and volumetric shrinkage of spruce wood and that density has a negative effect on the coefficient of surface anisotropy. At breast height, average value of the coefficient of surface anisotropy is 2.16, volume porosity 72%, and fibre saturation point 32.6%. Average rate of absorption is 3.42% per day, for the first 7 days, and 0.12% per day for the last 30 days. The study results were compared to the results reported by other authors.

scholarly journals Moisture state variety in poplar lumber with moisture content above fibre saturation point during hot-press drying

2018 ◽  
Vol 64 (6) ◽  
pp. 730-737
Author(s):  
Junfeng Hou ◽  
Songlin Yi ◽  
Yongdong Zhou ◽  
Bin Pan
Keyword(s):  
Moisture Content ◽  
Fibre Saturation Point ◽  
Hot Press ◽  
Saturation Point ◽  
Moisture State

Measurement, modelling and prediction of equilibrium moisture content in Pinus radiata heartwood and sapwood

2001 ◽  
Vol 59 (6) ◽  
pp. 457-462 ◽  
Author(s):  
R. D. Ball ◽  
I. G. Simpson ◽  
S. Pang
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Pinus Radiata

scholarly journals SIFAT FISIK BATANG DAN CABANG KAYU MAKADAMIA

PERENNIAL ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 16
Author(s):  
Andi Detti Yunianti
Keyword(s):  
Specific Gravity ◽  
Moisture Content ◽  
Physical Properties ◽  
Quality Indicators ◽  
Basic Density ◽  
Raw Material ◽  
Longitudinal Shrinkage ◽  
Wood Production ◽  
Efficient Utilization ◽  
Tangential Shrinkage

Since there have been a big difference between wood production and industrial need, wood diversification plays an important role in handling wood deficiencies. Wood raw material diversification could developed and increased throughout the use of whole parts of the tree including branch. The current study was aimed at understanding stem and branch physical properties (basic density, air-dry specific gravity, air-dry moisture content and shrinkage) of macadamia wood as quality indicators for efficient utilization in the future. For the purpose of the study, parts of stem and branch of the tree were taken from a macadamia tree. Test specimens of stem were cut 50 cm from the ground while that of branch were selected from the largest diameter at 10 cm distance from the main stem of the tree. All samples were tested for their physical properties according to ISO standards, 1975. Results showed that the basic density, air dry specific gravity and longitudinal shrinkage of the branchwood of macadamia were higher than those of the stem. The air-dry moisture content, radial and tangential shrinkage were low on the branchwood. Keywords : Wood Physical Properties, Branchwood , Macadamia Wood

Estimating relative error in growth ring analyses of second-growth coast redwood (Sequoia sempervirens)

2006 ◽  
Vol 36 (9) ◽  
pp. 2216-2222 ◽  
Author(s):  
Kristen M Waring ◽  
Kevin L O'Hara
Keyword(s):  
Cross Sections ◽  
Growth Ring ◽  
Ring Width ◽  
Sequoia Sempervirens ◽  
North Central ◽  
Coast Redwood ◽  
Central California ◽  
Breast Height ◽  
Second Growth ◽  
Annual Growth Rings

Coast redwood (Sequoia sempervirens (D. Don) Endl.) grows in the coastal zone of north-central California and southern Oregon in pure and mixed-species forests. Redwood has long been recognized to exhibit unusual patterns within the annual growth rings typical of temperate forest trees, including partial and missing rings and ring-width anomalies. However, these patterns have not been quantified beyond a few suppressed trees. This study quantified the variation in ring counts occurring in 22 second-growth redwood trees from different canopy classes. Ring counts from cross sections taken at sample points along each tree bole revealed missing or incomplete rings in all sample trees and 70% of the cross sections. Ring counts along multiple radii were used to calculate probability of obtaining a maximum ring count along one radius. This probability was lowest at the tree base (0.25) and breast height (0.30) and highest near the top of the tree (0.90). Because of the high amount of variation present in ring counts at breast height, care should be taken when drawing conclusions regarding stand ages from increment cores. Increment cores should be taken from the longest axis of the tree and coring at tree base can be abandoned as cores are not likely to have higher ring counts than breast height cores.

Testing of the fatigue strength along wood fibres at different moisture contents

2021 ◽  
Vol 115 ◽  
pp. 45-54
Author(s):  
Ewa Dobrowolska ◽  
Mateusz Niedbała ◽  
Daniel Tabaczyński
Keyword(s):  
Fatigue Strength ◽  
Moisture Content ◽  
Maximum Stress ◽  
Fibre Saturation Point ◽  
Pedunculate Oak ◽  
Saturation Point ◽  
Moisture Contents ◽  
Wood Fibres ◽  
Short Term Strength ◽  
Limited Usefulness

Testing of the fatigue strength along wood fibres at different moisture contents. The paper determines the effect of wood moisture content on the fatigue strength in compression along fibres. The method of determining the maximum stress at the proportional limit was used for the measurements. Fatigue strength was investigated for three wood species: pedunculate oak (Quercus robur L.), bearded birch (Betula pendula Roth.) and Norway spruce (Picea abies L.), with two moisture contents: close to the absolutely dry state and above the fibre saturation point. The ratio of fatigue strength to short term strength depends on moisture content and is similar for birch (70.3% in the dry state and 72.1% in the wet state), for oak (67.4% and 69.5% in both states) and for spruce (66.6% in the dry state and 68.1% in the wet state). The moisture content of the wood clearly influences the fatigue strength of the wood. On average, the fatigue strength of wood with moisture contents above the fibre saturation point constitutes about 0.20 of the fatigue strength of wood with moisture contents close to 0%. This tendency was found regardless of the tested species. The simplified method for testing fatigue strength at the limit of proportionality has shown its limited usefulness, requiring further analysis and comparison with other methods in order to be thoroughly tested and possibly improved.

Full-field tracking and analysis of shrinkage strain during moisture content loss in wood

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Zongying Fu ◽  
Xiang Weng ◽  
Yufa Gao ◽  
Yongdong Zhou
Keyword(s):  
Moisture Content ◽  
Growth Ring ◽  
Shrinkage Strain ◽  
Tangential Direction ◽  
Saturation Point ◽  
Full Field ◽  
Parabolic Distribution ◽  
Ratio Curve ◽  
Radial Shrinkage ◽  
A Minor

AbstractAnisotropic shrinkage is a typically feature in wood, which is of critical importance in wood drying. In this study, the shrinkage strains over each growth ring were determined by a full-field strain measurement system during moisture content (MC) loss. Color maps were used to visualize the full-field distribution of displacement and shrinkage strain under different MC conditions. The variation of tangential and radial shrinkage strain from pith to bark, as well as the anisotropic shrinkage in heartwood and sapwood were studied. Both of the displacement and strain values increased as the MC decreased. From pith to bark, the tangential strains were higher at two poles as compared to the center, showing a parabolic distribution below fiber saturation point. While for radial shrinkage strain, a minor difference was observed except for the MC of 10%. An intersection between tangential and radial shrinkage ratio curve was observed at the MC of 28%. Both expansion and shrinkage in tangential direction were larger than radial counterparts, and the transformation from expansion to shrinkage occurred at the MC region of 32–28%. In addition, the shrinkage in heartwood was larger than sapwood, whereas anisotropic shrinkage in sapwood was more pronounced as compared to heartwood.

Efficiency of early selection for rotation-aged growth and wood density traits in Pinus radiata

2005 ◽  
Vol 35 (8) ◽  
pp. 2019-2029 ◽  
Author(s):  
Li Li ◽  
Harry X Wu
Keyword(s):  
Pinus Radiata ◽  
Growth Traits ◽  
Growth Ring ◽  
Genetic Correlations ◽  
Ring Width ◽  
Early Selection ◽  
Breast Height ◽  
Growth Ring Width ◽  
Cambial Age ◽  
Heritability Estimates

A total of 1097 cross-sectional wood disks from breast height were sampled from two rotation-aged (27 and 31 years from planting) genetic trials of radiata pine (Pinus radiata D. Don) in Australia to estimate the genetic correlation between early and rotation-aged growth and wood quality traits and the efficiency of early selection. Annual growth-ring width and density, diameter at breast height (DBH), and area-weighted density (AD) from 30 open-pollinated families were measured using X-ray densitometry. Genotype × site interactions were not significant for density and growth traits. Ring density increased steadily from the pith to cambial age 14, and then density had little change in the following years. For AD, the family and individual heritability estimates were about 0.60 and 0.30 after the first 2 years. For DBH, family and individual narrow-sense heritability estimates increased steadily after the first 4 years, and family heritability increased to 0.7 at a cambial age of 11 and had little change thereafter. Individual heritability estimate increased to 0.4 at cambial age 14 and was similar for the later ages. Beyond a cambial age of 5 years, there were strong negative genetic correlations of around –0.80 between AD and DBH. Age–age genetic correlations for AD were high and reached 0.80 and above after cambial age 3. Age–age genetic correlations for DBH were similar to AD, except the first two years. The most efficient early selection year was between ages 4 and 6 years after planting for AD, and between ages 8 and 11 years for DBH.

scholarly journals SENSITIVITY OF SEVERAL SELECTED MECHANICAL PROPERTIES OF MOSO BAMBOO TO MOISTURE CONTENT CHANGE UNDER THE FIBRE SATURATION POINT

BioResources ◽  
2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Zehui Jiang ◽  
Hankun Wang ◽  
Genlin Tian ◽  
Xing'e Liu ◽  
Yan Yu
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Fibre Saturation Point ◽  
Moso Bamboo ◽  
Saturation Point ◽  
Content Change ◽  
Moisture Content Change

Modelling drying processes of fuelbeds of Scots pine needles with initial moisture content above the fibre saturation point by two-phase models

2012 ◽  
Vol 21 (4) ◽  
pp. 418 ◽  
Author(s):  
Sen Jin ◽  
Pengyu Chen
Keyword(s):  
Moisture Content ◽  
Scots Pine ◽  
Initial Moisture Content ◽  
Fibre Saturation Point ◽  
Phase Model ◽  
Fuel Moisture ◽  
Drying Process ◽  
Rating Systems ◽  
Saturation Point ◽  
Two Phase

Modelling the drying process of fuel moisture with initial moisture content above the fibre saturation point can be used to determine when fuel will become sufficiently dry (after precipitation) to burn and provide a more accurate prediction of fire potential. Based on analysis of the mechanism by which the drying process occurs, we propose a model comprising two phases distinguished by a moisture threshold of 0.35 g g–1, the fibre saturation point; one phase is controlled by evaporation and the other by diffusion. Each phase has a distinct equation with a different timelag. We compared our two-phase model with a one-phase model (one-timelag model) and another two-phase model by estimating drying of 15 Scots pine (Pinus sylvestris var. mongolica) needle fuelbeds. The results indicate that the two-timelag model improves moisture modelling, thereby reducing mean absolute error by more than 30%, i.e. from 0.0047 g g–1 (one-phase model) to 0.0030 g g–1. The model yields consistent results, further suggesting its potential for improving fuel moisture prediction of fire danger rating systems. The first timelag of the model is affected by fuelbed properties. Equations based on variables that represent fuelbed properties were established, thus saving time when estimating parameters for stand-specific fuel moisture models.

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