scholarly journals Physico-mechanical properties of thermally modified Eucalyptus nitens wood for decking applications

2019 ◽  
Vol 70 (3) ◽  
pp. 235-245 ◽  
Author(s):  
Maximilian Wentzel ◽  
Óscar González-Prieto ◽  
Christian Brischke ◽  
Holger Militz
Keyword(s):  
Brinell Hardness ◽  
Good Alternative ◽  
Solid Wood ◽  
Thermal Modification ◽  
Wood Products ◽  
Added Value ◽  
Eucalyptus Nitens ◽  
Plantation Species ◽  
The Moment ◽  
Quality Material

Eucalyptus nitens is a fast growing plantation species that has a good acclimation in Spain and Chile. At the moment it is mainly used for pulp and paper production, but there is a growing market for solid wood products made from this species. Thermal modification offers a good alternative to produce high quality material to manufacture products with high added value. This study used unmodified and thermally modified E. nitens wood from Spanish and Chilean plantations to elaborate external decking and examine if it complies with the necessary properties to be a competitive product. A process similar to ThermoWood® was applied at the following temperatures: 185 °C, 200 °C and 215 °C. For each modification and for an unmodified specimen mass loss, volumetric swelling, anti-swelling efficiency (ASE) and equilibrium moisture content (EMC) were determined. Brinell hardness, dynamic hardness, screw and nail withdrawal resistance, and abrasion resistance according to the Shaker method and the Taber Abraser method were also determined. According to this study, thermally modified E. nitens from both countries showed high potential to be used as decking material, particularly when modified at 200 °C.

Stem eccentricity, crown dry mass distribution, and longitudinal growth strain of plantation-grown Eucalyptus nitens after thinning

2011 ◽  
Vol 41 (11) ◽  
pp. 2209-2218 ◽  
Author(s):  
Jane Medhurst ◽  
Maria Ottenschlaeger ◽  
Matthew Wood ◽  
Chris Harwood ◽  
Chris Beadle ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Dry Mass ◽  
Solid Wood ◽  
Wood Products ◽  
Eucalyptus Nitens ◽  
Cross Sectional ◽  
The North ◽  
Silvicultural Treatments ◽  
Wind Exposure ◽  
Pith Eccentricity

Silvicultural treatments that aim to improve tree growth rates also have the potential to alter physical characteristics of the tree stem and thus affect the recovery of solid-wood products. We tested the hypothesis that manifest crown asymmetry in thinned Eucalyptus nitens (Deane & Maiden) Maiden plantations was affecting the development of stem shape. The crown and stem characteristics of 15 E. nitens trees from a 22-year-old thinning trial in northeastern Tasmania were examined. The trial had been thinned 16 years previously. Lowering the intensity of local intraspecific competition through thinning increased the crown dry mass in the north-facing aspect. No direct link was found between crown dry mass distribution and stem eccentricity. The direction of pith eccentricity at 3.0 m height was confined to the northwest and southeast sectors and averaged 11%; the degree of noncircularity in stems at 3.0 m height was strongly related to the ratio of stem diameter to total height squared. These results suggest that the dynamic loading from wind exposure plays a greater role in determining the extent and direction of pith eccentricity and stem cross-sectional circularity in E. nitens than does the static load from asymmetrical crown dry mass distribution.

Radio frequency vacuum drying of Eucalyptus nitens juvenile wood

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 4886-4897
Author(s):  
Rubén A. Ananías ◽  
Víctor Sepúlveda-Villarroel ◽  
Natalia Pérez-Peña ◽  
José Torres-Mella ◽  
Linette Salvo-Sepúlveda ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Juvenile Wood ◽  
Wood Quality ◽  
Solid Wood ◽  
Wood Products ◽  
Eucalyptus Nitens ◽  
Drying Time ◽  
Innovative Products ◽  
Conventional Kiln Drying ◽  
Vacuum Method

Wood drying is an important process for adding value and manufacturing innovative products. Eucalyptus nitens wood is inherently difficult to dry because of its natural propensity for checking as well as collapse and shrinkage. Lumber recovery after industrial drying of eucalypts is also very low. This study measured the wood quality of E. nitens juvenile wood (13 mm thickness) after radio-frequency vacuum (RFV) drying and wood dried in a conventional kiln dryer (KD). Drying cycles were performed using a radio frequency vacuum dryer with a 3 m3 of capacity and convective kiln-dryer equipment with a 3.5 m3 of capacity. The results showed that the drying time using the radio frequency vacuum method was reduced by 47% when compared to conventional kiln drying. The shrinkage was significantly lower in the RFV than in the conventional KD. The volumetric collapse decreased by approximately 60% in the RFV drying. RFV drying of E. nitens juvenile wood improves the wood quality for solid wood products because the intensity of surface checking and collapse are reduced.

scholarly journals Durable protection of the surface of wood used outdoors: material constraints, problems and approaches to solutions

2018 ◽  
Vol 149 ◽  
pp. 01016
Author(s):  
A. Merlin ◽  
B. George ◽  
L. Malassenet ◽  
L. Podgorski
Keyword(s):  
Solid Wood ◽  
Wood Products ◽  
Premature Aging ◽  
Added Value ◽  
Aesthetic Perception ◽  
Surface Appearance ◽  
Protective Function ◽  
Surface Protection ◽  
Wood Processing ◽  
Wooden Structures

The aesthetic durability of wooden structures is a major challenge for the use of this material in construction. Wood is used for its technical performances but also for its architectural qualities and its aesthetic perception. The premature aging of the wooden structures is detrimental because these disorders, even if they do not affect the strength of the structures, are mostly irremediable. The surface protection of wood is generally ensured by the use of a finish, whose essential role is to protect wood from climatic aggressions (water, solar radiation, oxygen, ...). The secondary wood processing industry consists of a series of manufacturing and processing activities, each containing a portion of the added value of the product. The application of a finish on a wood-based work is usually the last and most visible step in this value chain.In outdoor use, the protection of the wood surface with transparent finishes is not yet sufficiently durable to be able to compete with materials used in industrial carpentry such as PVC or aluminum. Opaque finishes generally provide more durable protection but they mask the appearance of the wood sought by users.With the aim of positioning wood in this construction sector, research on transparent finishes has focused on the efficiency and improvement of the durability of the protection of the surface appearance of structures. Faced with climatic aggressions, the optimum conservation of a structure is not only linked to the performance of the finish but also to the characteristics of the wood material. In particular, in order to fulfill its protective function, the finish film must be able to follow the dimensional variations of the wood it covers without breaking and without detachment. In addition to the criteria for the effectiveness of finishes in the protection of structures, the environmental impact must be considered with increasing attention. Currently, more than 80% of composite or solid wood products are still protected with solvent-based liquid products, which are an important source of VOC emissions. Does the solution come from photo-polymerizable systems that can be formulated with 100% dry matter either in liquid phase in reactive diluents or powdered?

scholarly journals The effect of time and site on incidence and spread of pruning-related decay in plantation-grown Eucalyptus nitens

2005 ◽  
Vol 35 (3) ◽  
pp. 495-502 ◽  
Author(s):  
Karen M Barry ◽  
Malcolm F Hall ◽  
Caroline L Mohammed
Keyword(s):  
Quantitative Information ◽  
Solid Wood ◽  
Fungal Species ◽  
Wood Products ◽  
Eucalyptus Nitens ◽  
Ongoing Research ◽  
Yield And Quality ◽  
Eucalypt Plantations ◽  
The Future ◽  
Over Time

Quantitative information on stem decay in eucalypt plantations grown for solid wood products, with consideration of the effect of site, pruning, and spread of decay with time, is required for the prediction of harvest yield and quality. A trial at three Eucalyptus nitens (Dean & Maiden) Maiden plantations in Tasmania revealed that the effect of time on the number and size of decay columns was substantially greater than the effect of site or of whether trees were pruned or not. Length of decay columns was 3.4-fold greater on average for the trees assessed 5.5 years after pruning than at 1 year. All decay columns in pruned trees were restricted to the knotty core, and the amount of decay-free clearwood increased over time. A controlled wounding trial showed that decay in sapwood was not significantly different in length with site but was mainly determined by the fungal species used. Ongoing research to monitor the spread of decay in pruned plantation-grown E. nitens will be important to enable prediction of the future impact of decay on harvest yields of solid wood products.

scholarly journals Thinning Influences Wood Properties of Plantation-Grown Eucalyptus nitens at Three Sites in Tasmania

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1304
Author(s):  
Vilius Gendvilas ◽  
Geoffrey M. Downes ◽  
Mark Neyland ◽  
Mark Hunt ◽  
Peter A. Harrison ◽  
...  
Keyword(s):  
Basic Density ◽  
Wood Properties ◽  
Solid Wood ◽  
Eucalyptus Nitens ◽  
Commercial Thinning ◽  
Standing Trees ◽  
Plantation Species ◽  
Key Indicators ◽  
Forestry Plantations ◽  
The Impact

Thinning of forestry plantations is a common silviculture practice to increase growth rates and to produce larger dimension logs. The wood properties, basic density and stiffness, are key indicators of the suitability of timber for particular purposes and ultimately determine timber value. The impact of thinning operations on wood properties is, therefore, of considerable interest to forest growers and timber producers. To date, studies examining the impact of thinning on wood properties have produced variable results and understanding of the consistency of the effects of thinning treatments across various sites for important plantation species is limited. Two non-destructive assessment techniques, drilling resistance and acoustic wave velocity, were used to examine the impact of thinning on basic density and stiffness in 19–21-year-old plantation grown Eucalyptus nitens across three sites. Commercial thinning to 300 trees ha−1 decreased the stiffness of standing trees and this effect was consistent across the sites. Reduction in stiffness due to thinning ranged from 3.5% to 11.5%. There was no difference in wood properties between commercially and non-commercially thinned trees to 300 trees ha−1 and no difference in wood properties when thinned to 500 trees ha−1. Basic density was not affected by thinning. The site had significant effects on both basic density and stiffness, which were lowest at the highest precipitation and highest elevation site. The results indicate that wood properties are influenced both by silviculture and site environmental differences. This knowledge can be used for the better management of E. nitens resources for solid wood production.

scholarly journals Managing Australia’s eucalypt gene pools: assessing the risk of exotic gene flow

2016 ◽  
Vol 128 (1) ◽  
pp. 25 ◽  
Author(s):  
Matthew J. Larcombe ◽  
Brad M. Potts ◽  
Rebecca C. Jones ◽  
Dorothy A. Steane ◽  
João Costa E. Silva ◽  
...  
Keyword(s):  
Gene Flow ◽  
Solid Wood ◽  
Biological Data ◽  
Wood Products ◽  
Gene Pools ◽  
Centre Of Origin ◽  
Eucalypt Species ◽  
Eucalypt Plantations ◽  
Plantation Species ◽  
The Many

Most eucalypts are endemic to Australia but they have been introduced into more than 100 countries and there are now over 20 million hectares of eucalypt plantations globally. These plantations are grown mainly for pulpwood but there is expanding interest in their use as a renewable source of solid wood products and energy. In Australia, the eucalypt plantation estate is nearing one million hectares, located mainly in temperate regions and dominated by Eucalyptus globulus and E. nitens (subgenus Symphyomyrtus), which are grown mainly outside their natural ranges. While eucalypt species from different major subgenera do not hybridise, hybrids within subgenera are often reported, including hybrids with plantation species. Concerns were raised in the late 1990s that pollen-mediated gene flow from locally exotic plantation eucalypts may affect the integrity of adjacent native eucalypt gene pools. As Australia is the centre-of-origin of most eucalypt species used in plantations around the world, exotic gene flow is one of the many issues that require management for industry sustainability and certification purposes. We here summarise over a decade of research aimed at providing the framework and biological data to help assess and manage the risk of gene flow from these plantations into native gene pools in Australia.

scholarly journals Genetic variation of microfibril angle and its relationship with solid wood and pulpwood traits in two progeny trials of Eucalyptus nitens in Tasmania

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Manuel F. Rocha-Sepúlveda ◽  
Dean Williams ◽  
Mario Vega ◽  
Peter A. Harrison ◽  
René E. Vaillancourt ◽  
...  
Keyword(s):  
Genetic Correlations ◽  
Microfibril Angle ◽  
Basic Density ◽  
Genotype By Environment Interaction ◽  
Solid Wood ◽  
Wood Products ◽  
Pulp Yield ◽  
Environment Interaction ◽  
Eucalyptus Nitens ◽  
Genotype By Environment

Abstract Microfibril angle (MFA) is a key biological trait contributing to wood stiffness, which is a common breeding objective for solid wood products in many tree species. To explore its genetic architecture, area-weighted MFA was measured in two Eucalyptus nitens progeny trials in Tasmania, Australia, with common open-pollinated families. Radial strips were extracted from 823 trees in 131 families and MFA assessed using SilviScan-2®. Heritability, genotype-by-environment interaction and inter-trait genetic correlations were evaluated to examine the genetic variability and stability of MFA and its relationships with other solid wood and pulpwood selection traits. Significant family variation was found for MFA in both trials. There was no significant genotype-by-environment interaction and the across-site narrow-sense heritability was 0.27. MFA was genetically independent of basic density, growth, and tree form. However, MFA was strongly and favourable genetically correlated to acoustic wave velocity in standing trees, modulus of elasticity and kraft pulp yield (KPY). The present study has shown that genetic improvement of E. nitens for pulpwood selection traits is unlikely to have adversely affected MFA, and thus timber stiffness. Rather these results suggest the possibility that selection for increased KPY may have indirectly improved MFA favourably for solid wood products.

Drying of Eucalyptus nitens for solid wood products

Impact ◽  
2018 ◽  
Vol 2018 (6) ◽  
pp. 43-44
Author(s):  
Rub,n A. ANANIAS
Keyword(s):  
Solid Wood ◽  
Wood Products ◽  
Eucalyptus Nitens

A review on life cycle assessments of thermally modified wood

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kévin Candelier ◽  
Janka Dibdiakova
Keyword(s):  
Life Cycle ◽  
Environmental Impacts ◽  
Treated Wood ◽  
Single Step ◽  
Thermal Modification ◽  
Wood Products ◽  
Wood Preservation ◽  
Cumulative Energy ◽  
Thermally Modified Wood ◽  
Cumulative Energy Intake

AbstractThis review compiles various literature studies on the environmental impacts associated with the processes of thermal modification of wood. In wood preservation field, the wood modification by heat is considered as an ecofriendly process due to the absence of any additional chemicals. However, it is challenging to find proper scientific and industrial data that support this aspect. There are still very few complete studies on the life cycle assessment (LCA) and even less studies on the environmental impacts related to wood heat treatment processes whether on a laboratory or on an industrial scales. This comprehensive review on environmental impact assessment emphasizes environmental categories such as dwindling of natural resources, cumulative energy intake, gaseous, solid and liquid emissions occurred by the thermal-treated wood industry. All literature-based data were collected for every single step of the process of wood thermal modification like resources, treatment process, transport and distribution, uses and end of life of treated wood products.

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