scholarly journals Wood Properties Characterisation of Thermo-Hydro Mechanical Treated Plantation and Native Tasmanian Timber Species

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1189
Author(s):  
Michelle Balasso ◽  
Andreja Kutnar ◽  
Eva Prelovšek Niemelä ◽  
Marica Mikuljan ◽  
Gregory Nolan ◽  
...  
Keyword(s):  
Mass Loss ◽  
Wood Properties ◽  
High Water ◽  
Radiata Pine ◽  
Wood Products ◽  
Timber Species ◽  
Final Thickness ◽  
Dimensional Changes ◽  
Commercially Important ◽  
Shining Gum

Thermo-hydro mechanical (THM) treatments and thermo-treatments are used to improve the properties of wood species and enhance their uses without the application of chemicals. This work investigates and compares the effects of THM treatments on three timber species from Tasmania, Australia; plantation fibre-grown shining gum (Eucalyptus nitens H. Deane and Maiden), plantation saw-log radiata pine (Pinus radiata D. Don) and native-grown saw-log timber of the common name Tasmanian oak (which can be any of E. regnans F. Muell, E. obliqua L’Hér and E. delegatensis L’Hér). Thin lamellae were compressed by means of THM treatment from 8 mm to a target final thickness of 5 mm to investigate the suitability for using THM-treated lamellas in engineered wood products. The springback, mass loss, set-recovery after soaking, dimensional changes, mechanical properties, and Brinell hardness were used to evaluate the effects of the treatment on the properties of the species. The results show a marked increase in density for all three species, with the largest increase presented by E. nitens (+53%) and the smallest by Tasmanian oak (+41%). E. nitens displayed improvements both in stiffness and strength, while stiffness decreased in P. radiata samples and strength in Tasmanian oak samples. E. nitens also displayed the largest improvement in hardness (+94%) with respect to untreated samples. P. radiata presented the largest springback whilst having the least mass loss. E. nitens and Tasmanian oak showed similar dimensional changes, whilst P. radiata timber had the largest thickness swelling and set-recovery due to the high water absorption (99%). This study reported the effects of THM treatments in less-known and commercially important timber species, demonstrating that the wood properties of a fibre-grown timber can be improved through the treatments, potentially increasing the utilisation of E. nitens for structural and higher quality timber applications.

scholarly journals Hybrid Approach for Wood Modification: Characterization and Evaluation of Weathering Resistance of Coatings on Acetylated Wood

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 658
Author(s):  
Anna Sandak ◽  
Edit Földvári-Nagy ◽  
Faksawat Poohphajai ◽  
Rene Herrera Diaz ◽  
Oihana Gordobil ◽  
...  
Keyword(s):  
Service Life ◽  
Hybrid Approach ◽  
Wood Properties ◽  
Wood Products ◽  
Superior Performance ◽  
Surface Erosion ◽  
Coating Film ◽  
Chemical Treatments ◽  
Cellular Wall ◽  
Bulk Substrate

Wood, as a biological material, is sensitive to environmental conditions and microorganisms; therefore, wood products require protective measures to extend their service life in outdoor applications. Several modification processes are available for the improvement of wood properties, including commercially available solutions. Among the chemical treatments, acetylation by acetic anhydride is one of the most effective methods to induce chemical changes in the constitutive polymers at the cellular wall level. Acetylation reduces wood shrinkage-swelling, increases its durability against biotic agents, improves UV resistance and reduces surface erosion. However, even if the expected service life for external cladding of acetylated wood is estimated to be 60 years, the aesthetics change rapidly during the first years of exposure. Hybrid, or fusion, modification includes processes where the positive effect of a single treatment can be multiplied by merging with additional follow-up modifications. This report presents results of the performance tests of wood samples that, besides the modification by means of acetylation, were additionally protected with seven commercially available coatings. Natural weathering was conducted in Northern Italy for 15 months. Samples were characterized with numerous instruments by measuring samples collected from the stand every three months. Superior performance was observed on samples that merged both treatments. It is due to the combined effect of the wood acetylation and surface coating. Limited shrinkage/swelling of the bulk substrate due to chemical treatment substantially reduced stresses of the coating film. Hybrid process, compared to sole acetylation of wood, assured superior visual performance of the wood surface by preserving its original appearance.

Non-destructive estimation of fibre morphological parameters and chemical constituents of Tectona grandis L.f. wood by near infrared spectroscopy

2021 ◽  
pp. 096703352199911
Author(s):  
SR Shukla ◽  
S Shashikala ◽  
M Sujatha
Keyword(s):  
Near Infrared ◽  
Cross Validation ◽  
Chemical Constituents ◽  
Fibre Diameter ◽  
Tectona Grandis ◽  
Cost Effective ◽  
Wood Products ◽  
Timber Species ◽  
Morphological Parameters ◽  
Mean Square Errors

Near infrared (NIR) spectroscopy is developing as an advanced and non-invasive tool in the wood, wood products and forestry sectors. It may be applied as a rapid and cost effective technique for assessment of different wood quality parameters of timber species. In the present study, NIR spectra of heartwood samples of Tectona grandis (teak) were collected before measuring fibre morphological parameters (fibre length, fibre diameter and fibre lumen diameter)and main chemical constituents (cellulose, hemicellulose, lignin and extractives) using maceration and wet chemistry methods respectively. Multivariate partial least squares (PLS) regression was applied to develop the calibration models between measured values of wood parameters and NIR spectral data. Pre-processing of NIR spectra demonstrated better predictions based on higher values of correlation coefficient for estimation (R2), validation (Rcv 2 ), ratio of performance to deviation (RPD), and lower values of root mean square errors of estimation (RMSEE), cross-validation (RMSECV) and number of latent variable (rank). Internal cross-validation was used to find the optimum rank. Robust calibrations models with high R2 (>0.87), low errors and high RPD values (> 2.93) were observed from PLS analysis for fibre morphological parameters and main chemical constituents of teak. These linear models may be applied for rapid and cost effective estimation of different fibre parameters and chemical constituents in routine testing and evaluation procedures for teak.

Comparative Performance of Modified Solid and Composite Wood Samples in Standard Tests

2019 ◽  
Vol 69 (4) ◽  
pp. 305-312
Author(s):  
Robert Rose ◽  
Scott Leavengood ◽  
Jeffrey J. Morrell
Keyword(s):  
Medium Density Fiberboard ◽  
Radiata Pine ◽  
Wood Products ◽  
Fungal Decay ◽  
Comparative Performance ◽  
Resistant Medium ◽  
Composite Wood ◽  
Moisture Resistant ◽  
Standard Tests ◽  
Modified Wood

Abstract The properties of several modified wood products were evaluated using North American standards to provide comparative data for architects seeking to use these materials. In general, modified wood products had lower moisture uptakes and less shrinkage than unmodified products. Acetylated materials were highly resistant to fungal decay, whereas thermally modified and furfurylated materials were classified as decay resistant. All materials were susceptible to mold, although the nonacetylated moisture-resistant medium-density fiberboard was most susceptible. Thermally modified and furfurylated materials were similar in mold susceptibility to untreated radiata pine sapwood, whereas acetylated materials appeared to be more mold resistant.

Implications of selection history on genetic architecture of growth, form, and wood-quality traits in Pinus radiata

2008 ◽  
Vol 38 (9) ◽  
pp. 2372-2381 ◽  
Author(s):  
S. Kumar ◽  
R. D. Burdon ◽  
G. T. Stovold ◽  
L. D. Gea
Keyword(s):  
Wood Density ◽  
Pinus Radiata ◽  
Wood Quality ◽  
Genetic Correlations ◽  
Wood Properties ◽  
Radiata Pine ◽  
Single Pair ◽  
Narrow Sense Heritability ◽  
Tree Form ◽  
Selection History

Clonal trials of Pinus radiata D. Don (radiata pine), representing two populations (or breeds), one selected for growth and form (GF) and the other selected for high wood density as well as growth and form (HD), were replicated on two low-altitude New Zealand sites: Tarawera (pumice soil, 38°08′S) and Woodhill (coastal dune, 36°42′S). The GF material comprised 33 pair-crosses (19 parents) × 10 clones, and the HD material comprised 19 single-pair crosses (35 parents) × 10 clones, with six ramets per clone per site. Diameter (DBH), two tree-form variables, and needle retention (NRA) were assessed 8 years after planting, and wood density (DEN), acoustic velocity, and collapse were assessed 9 years after planting. The site differences were generally expressed more strongly in the GF population. Estimated genetic parameters were mostly similar for the two breeds, except that genotypic correlation between DBH and DEN was apparently zero in the HD population. Estimated broad-sense heritabilities (H2) were generally markedly higher than narrow-sense heritability estimates (h2), except with DEN. Estimated between-site type-B clonal genotypic correlations were generally high (>0.8) for wood properties. Overall, DBH showed adverse genetic correlations with wood properties. The Elite/Breed strategy appeared to be helpful in combating adverse genetic correlations.

Determining the main and interactive effect of age and clone on wood density, microfibril angle, and modulus of elasticity for Pinus radiata

2010 ◽  
Vol 40 (8) ◽  
pp. 1550-1557 ◽  
Author(s):  
Michael S. Watt ◽  
Charles Sorensson ◽  
Dave J. Cown ◽  
Heidi S. Dungey ◽  
Robert Evans
Keyword(s):  
Pinus Radiata ◽  
Modulus Of Elasticity ◽  
Interactive Effect ◽  
Microfibril Angle ◽  
Wood Properties ◽  
Radiata Pine ◽  
Linear Increase ◽  
Interactive Effects ◽  
Tree Age ◽  
Clonal Variation

Detailed radial measurements of wood properties, taken at breast height, were obtained from control pollinated seedlings and a selection of 13 year old radiata pine ( Pinus radiata D. Don) clones. Using these data the key objectives of this study were to determine (i) the magnitude of mean clonal variation in modulus of elasticity (MOE) and properties affecting MOE (density and microfibril angle (MFA)) and (ii) whether there is a significant age × clone interaction for these traits. All wood properties were significantly affected by the main and interactive effects of age and clone. There was a relatively linear increase in both MOE and density with tree age, while MFA declined linearly with tree age. Values of density and MOE diverged between the clonal extremes from age 3 to age 12. After diverging markedly up to age 6, differences in MFA between clonal extremes remained relatively constant to age 12. At age 12, values for density, MFA, and MOE varied between clonal extremes by, respectively, 194 kg·m–3 (465–659 kg·m–3), 11.3° (9.6–20.9°), and 11.2 GPa (10.4–21.6 GPa). The seedling material had a relatively intermediate ranking, across the age range, for all traits considered.

scholarly journals Tree species identification via 1H NMR fingerprinting of supercritical carbon dioxide wood extractives

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2371-2384
Author(s):  
Laura G. Raymond ◽  
David Sandquist ◽  
Stefan J. Hill ◽  
Roger Meder ◽  
Volker C. Behr
Keyword(s):  
1H Nmr ◽  
Tree Species ◽  
Principal Component ◽  
Radiata Pine ◽  
Picea Sitchensis ◽  
Eucalyptus Species ◽  
Hardwood Species ◽  
Mountain Ash ◽  
Water Redistribution ◽  
Shining Gum

Six tree species were examined using 1H NMR spectroscopy of sap extracted by supercritical CO2. A metabolomic approach was developed to evaluate the sap extracted from sapwood of Norway spruce (Picea abies), Sitka spruce (Picea sitchensis), radiata pine (Pinus radiata), macrocarpa (Cupressus macrocarpa), and two Eucalyptus species—shining gum and mountain ash (Eucalyptus nitens and Eucalyptus regnans. The sap extraction patterns in the different species were visualised using 1H magnetic resonance imaging. In softwoods with distinct annual rings, water was first removed from the latewood bands, and then gradually from the earlywood bands. In the case of the hardwood species an almost random water redistribution, rather than water expulsion, was observed. Analysis of the principal component analysis loading plots showed that the significant differences in the sap between each species were due to the carbohydrate region. Key discriminators were identified as pinitol, sucrose, glucose, and fructose.

Pinus elliottii (slash pine).

2021 ◽  
Author(s):  
Andrew Praciak
Keyword(s):  
Pinus Elliottii ◽  
Site Index ◽  
Solid Wood ◽  
Slash Pine ◽  
South Florida ◽  
Wood Products ◽  
Dendroctonus Frontalis ◽  
Small Range ◽  
Timber Species ◽  
Tree Form

Abstract P. elliottii var. elliottii is an important timber species native to the lower coastal plain within the southeastern USA. Because of its rapid early growth and its production of highly valuable wood products, it has been widely introduced into other countries. As an exotic, it is used in Africa, especially in southern Africa, and in Australia and South America for various products ranging from lumber to pulpwood. In Brazil, it makes an important contribution to the resin production industry. The preferred method of regenerating P. elliottii is by clearcutting followed by chemical or mechanical site preparation, then direct seeding or planting of nursery stock. Although natural regeneration by seedtree, shelterwood, or group selection is an option, availability of genetically superior stock usually makes planting the favoured method of regeneration. Rotation lengths vary according to product objective. The optimum pulpwood rotation is about 25 years. In unthinned plantations, this age increases to 30 from 23 years as density increases and site index declines. South Florida slash pine (P. elliottii var. densa) is characterized by a grasslike, almost stemless stage, that lasts for 2 to 6 years. Variety densa has a small range, a less desirable tree form than var. elliottii, and is more difficult to regenerate. P. elliottii is particularly susceptible to fusiform rust (caused by Cronartium fusiforme) and is frequently attacked by the southern pine bark beetle (Dendroctonus frontalis). The best protection against insect attack is to maintain vigorous, healthy stands through good forest management. The wood is used for a wide variety of products. Markets and size and quality of the material determine whether it is used for sawlogs, veneer logs, poles, pilings, posts, pulpwood, particle board, or chip-n-saw logs. The straightness of the bole makes P. elliottii particularly suited for poles, pilings, and solid-wood products. Although it may often grow more slowly than P. patula and P. taeda, it can produce higher pulpwood yields due to its higher wood density. P. elliottii yields the best quality and highest quantity of commercial turpentine of all American pitch pines (Streets, 1962). However, this use has declined significantly as other sources of resins have become more readily available.

Metabolite profiling reveals complex relationship between developing xylem metabolism and intra-ring checking in Pinus radiata

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Andrew Robinson ◽  
Peter Beets ◽  
Shawn D. Mansfield
Keyword(s):  
Pinus Radiata ◽  
Metabolic Profiling ◽  
Unit Area ◽  
Statistical Tests ◽  
Radiata Pine ◽  
Wood Products ◽  
Common Site ◽  
Strong Indicator ◽  
Ray Cells ◽  
Affect Processing

Abstract Globally, there has been an increasing amount of wood harvested from younger, fast-growing trees derived from plantation forests. As a consequence, producers and industrial consumers of wood products are becoming increasingly concerned with not only growth rates, but specific wood attributes that affect processing efficiencies and final product quality. Intra-ring checking is a problem that down-grades an unacceptably high proportion of radiata pine clearwood. Methods of identifying trees prone to this undesirable behaviour have been relatively destructive and time consuming, and from a breeding perspective, to date, there is no reliable method of predicting which selected progeny will later show a propensity to check. Using 120, 7-year-old Pinus radiata clones sampled from a common site, displaying difference in the propensity to form intra-ring checks, a GC/MS-based global metabolic profiling technique was employed to demonstrate that metabolomics can be used to accurately identify the checking phenotype. Metabolic profiling coupled with statistical tests was then used to develop models with greater than 90% efficiency to predict the intra-ring checking phenotype. Moreover, an inspection of unique metabolites contributing to the models indicated that coniferin, which is often found as a storage compound in rays, is a strong indicator of intra-ring checking, and indeed those genotypes that displayed the propensity to check inherently had a greater number of ray cells per unit area.

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