scholarly journals Impact of heat treatment on the quality of tree-of-heaven wood

2019 ◽  
Vol 70 (4) ◽  
pp. 351-358
Author(s):  
Ioannis Barboutis ◽  
Vasiliki Kamperidou
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Bending Strength ◽  
Untreated Wood ◽  
Climatic Conditions ◽  
Treatment Temperature ◽  
Modulus Of Rupture ◽  
Tree Of Heaven ◽  
Structural Applications ◽  
Hygroscopic Nature

Ailanthus altissima (Miller) Swingle is a deciduous, fast-growing species that can tolerate extreme climatic conditions and is particularly invasive. In the framework of climate change, and the imperative need for carbon greenhouse gases sequestration, this species could acquire increasing importance through its utilization in the construction of wood based products and structures, due to its satisfying properties combined with its fast growth. This study determines for the first time the influence of thermal treatment, under different conditions (190 ºC, 210 ºC, 230 ºC for 2 hours), on some crucial physical, hygroscopic and mechanical properties of wood, in an attempt to improve its intense hygroscopic nature and not so desirable colour. Thermal treatment affected the dimensional stability and water absorbing capacity of wood in a positive way, decreasing EMC, swelling (tangential–radial) and adsorption percent, compared to untreated wood. The anisotropy of wood was decreased only to a small extent. The total surface colour differences (ΔΕ*), prior and after treatment, ranged between 0.48 and 54.57, and appeared to be well correlated with treatment temperature. Only the most intensive treatment influenced negatively the modulus of rupture and impact bending strength of wood, while the elasticity and compression strength of treated wood were proved to be similar to those of untreated wood. Tree-of-heaven could benefit from a mild or medium intensity heat treatment process, in order to be modified to an aesthetically pleasing wood with enhanced hygroscopic nature and properties, facilitating its use in cabinetry and in variable indoor and outdoor non-structural applications.

scholarly journals Influence of Site Conditions and Quality of Birch Wood on Its Properties and Utilization after Heat Treatment. Part I—Elastic and Strength Properties, Relationship to Water and Dimensional Stability

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 189 ◽  
Author(s):  
Vlastimil Borůvka ◽  
Roman Dudík ◽  
Aleš Zeidler ◽  
Tomáš Holeček
Keyword(s):  
Heat Treatment ◽  
Dimensional Stability ◽  
Bending Strength ◽  
Color Change ◽  
Untreated Wood ◽  
Strength Properties ◽  
Treatment Temperature ◽  
Impact Bending ◽  
The Impact

This work deals with the quality of birch (Betula pendula) wood from different sites and the impact of heat treatment on it. Two degrees of heat treatment were used, 170 °C and 190 °C. The resulting property values were compared with reference to untreated wood samples. These values were wood density, compressive strength, modulus of elasticity (MOE), bending strength (MOR), impact bending strength (toughness), hardness, swelling, limit of hygroscopicity, moisture content and color change. It was supposed that an increase in heat-treatment temperature could reduce strength properties and, adversely, lead to better shape and dimensional stability, which was confirmed by experiments. It was also shown that the properties of the wood before treatment affected their condition after heat treatment, and that the characteristic values and variability of birch properties from 4 sites, 8 stems totally, were reflected in the properties of the heat-treated wood. Values of static MOR were the exception, where the quality of the input wood was less significant at a higher temperature, and this was even more significant in impact bending strength, where it manifested at a lower temperature degree. Impact bending strength also proved to be significantly negatively affected by heat treatment, about 48% at 170 °C, and up to 67% at 190 °C. On the contrary, the most positive results were the MOE and hardness increases at 170 °C by about 30% and about 21%, respectively, with a decrease in swelling at 190 °C by about 31%. On the basis of color change and other ascertained properties, there is a possibility that, after suitable heat treatment, birch could replace other woods (e.g., beech) for certain specific purposes, particularly in the furniture industry.

scholarly journals Influence of wood properties and technological parameters of processing on cutting power in milling of thermally modified beechwood

2011 ◽  
pp. 109-124
Author(s):  
Marija Mandic ◽  
Nebojsa Todorovic ◽  
Ranko Popadic ◽  
Gradimir Danon
Keyword(s):  
Beech Wood ◽  
Untreated Wood ◽  
Treatment Temperature ◽  
Modulus Of Rupture ◽  
Dry Density ◽  
Technological Parameters ◽  
Cross Sectional ◽  
Measuring Device ◽  
Cutting Power ◽  
Wood Processing

The paper presents results of influence of thermal modification on cutting power required for milling wood processing. The experiment was conducted for the different treatment temperatures (170?C, 190?C and 210?C) and different technological parameters of processing (feed and cutting depth). Cutting powers during milling were measured on four groups of beech wood samples, dimensions 35?16?400 mm, separately for heartwood and sapwood. The following mechanical and physical properties of the processed samples were tested: bending properties (modulus of rupture and modulus of elasticity), cross-sectional and tangential hardness, and air-dry density. The measuring device used for measuring, monitoring and displaying cutting power was developed at the Wood Machining Centre at the Faculty of Forestry in Belgrade. The results point out the differences in the powers required for processing heat-treated wood compared to untreated wood. The analysis shows that with the increase in treatment temperature, the required cutting powers decrease.

Effects of Heat-Treatment Temperature on the Properties of Negative CTE Eucryptite Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 123-125 ◽  
Author(s):  
Yong Li ◽  
Qi Hong Wei ◽  
Ling Li ◽  
Chong Hai Wang ◽  
Xiao Li Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Heat Treatment Temperature ◽  
Bending Strength ◽  
Sol Gel ◽  
Negative Thermal Expansion ◽  
Treatment Temperature ◽  
Heat Treated

In this paper, negative thermal expansion coefficient eucryptite powders were prepared by sol-gel method using silica-sol as starting material. The raw blocks were obtained by dry pressing process after the powder was synthesized, and then the raw blocks were heat-treated at 600º, 1150º, 1280º, 1380º, 1420º and 1450°C, respectively. Variations of density, porosity and thermal expansion coefficient at different heat treatment temperatures were investigated. Phase transformation and fracture surface morphology of eucryptite heat-treated at different temperatures, respectively, were observed by XRD and SEM. The results indicate that, with the increasing heat- treatment temperature, the grain size and the bending strength increased, porosity decreased, thermal expansion coefficient decreased continuously. Negative thermal expansion coefficient of -5.3162×10-6~-7.4413×10-6 (0~800°C) was obtained. But when the heat-treatment temperature was more than 1420°C, porosity began to increase, bending strength began to decrease, which were the symbols of over-burning, while the main crystal phase didn’t change.

Prediction of Heating Processing-Properties of Ti2AlC/TiAl Compound Materials Based on BP Neural Network

2011 ◽  
Vol 306-307 ◽  
pp. 823-826
Author(s):  
Ming Wen ◽  
Yun Long Yue ◽  
Hai Tao Zhang ◽  
Yang Li
Keyword(s):  
Neural Network ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Bp Neural Network ◽  
Bending Strength ◽  
Treatment Temperature ◽  
Preparation Technology ◽  
Bp Artificial Neural Network ◽  
Processing Properties ◽  
Compound Materials

Parameters of processing (heat treatment temperature, holding time) and properties (Bending strength and Microhardness) of Ti2AlC/TiAl compound materials were obtained through mechanical properties examination, the network model was built by BP artificial neural network. The results show that the built model can reflect the relationships between processing and properties very well and has certain accuracy. It can be used for the prediction of the properties of Ti2AlC/TiAl compound materials after heating processing under different experiment conditions. Meanwhile, the model can also serve as a guide for the preparation technology of Ti2AlC/TiAl compound materials.

scholarly journals The Effect of Short Time Thermal Treatment on Swelling of Field Maple (Acer campestre L.) and Fir (Abies alba Mill.)

2020 ◽  
Vol 68 (3) ◽  
pp. 483-490
Author(s):  
Holta Çota ◽  
Leonidha Peri ◽  
Entela Lato ◽  
Hektor Thoma ◽  
Doklea Quku ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Mass Loss ◽  
Abies Alba ◽  
Untreated Wood ◽  
Wood Industry ◽  
Time Duration ◽  
Acer Campestre ◽  
Different Temperatures ◽  
Short Time

From the immemorial time wood is highly abundant and well-performing material. Further one due to practical use the wood heat treatment, as a process for improving its properties has been enhanced in the recent tim. Abies alba Mill and Acer campestre L. are among the most wide spread species in Albanian forest and among the most useful types of wood in Albanian wood industry. The objective of this study is to investigate the influence of short time heat treatment on dimensional stability and the mass loss of these two species. Wood samples are treated in three different temperatures (180 ℃, 200 ℃, 220 ℃) and two different time durations of 15 and 30 minutes. After the heat treatment, the mass loss is determined for treated samples. Treated and untreated samples are immersed in water and the swelling is determined. According to the results obtained, wood swelling undergoes a considerable reduction in the case of wood treatment at a temperature of 220 ℃ for the longest time duration of 30 minutes. The higher percentage of weight loss after the thermal treatment (9.66% for the maple and 10.77% for the fir) was measured in the samples treated in a 220 ℃ for 30 minutes. The results of both treated and untreated wood were given for comparative purposes.

The effect of thermal exposure on precipitation of Ti3Al(C,N) in Ti-48Al-IV-0.2C

1992 ◽  
Vol 50 (1) ◽  
pp. 22-23
Author(s):  
W.T. Donlon ◽  
W.E. Dowling ◽  
C.E. Cambell ◽  
J.E. Allison
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Titanium Aluminides ◽  
Elevated Temperatures ◽  
Volume Fraction ◽  
Weight Ratio ◽  
Thermal Exposure ◽  
Treatment Temperature ◽  
Field Samples ◽  
Structural Applications

Titanium aluminides are attractive candidates for high temperature structural applications because of their high strength to weight ratio at elevated temperatures. The microstructure of these alloys consists of γ-TiAl (distorted L10 structure) , plus α2-Ti3Al (ordered DO19 structure). Varying the heat treatment temperature and cooling rate of these alloys alters the volume fraction and distribution of the γ and α2 phases. This has significant effects on the room temperature ductility. In addition, precipitation of carbides has been observed during high temperature exposure. The effect of these precipitates on the mechanical properties has yet to be determined.Figure 1 shows the general microstructure that was used for this investigation. TEM foils were prepared by electropolishing using 5% perchloric, 35% 1-butanol, 60% methanol at -40°C. No precipitates were found following heat treatment in the γ+α phase field. Samples approximately 20 mm square were thermally exposed to temperatures between 625° and 1000°C for times between 1 and 2000 hours.

Influence of Thermal Treatment Temperature on Phase Formation and Bioactivity of Glass-Ceramics Based on the SiO2-Na2O-CaO-P2O5 System

2019 ◽  
Vol 798 ◽  
pp. 229-234 ◽  
Author(s):  
Puripat Kantha ◽  
Naris Barnthip ◽  
Kamonpan Pengpat ◽  
Tawee Tunkasiri ◽  
Nuttapon Pisitpipathsin
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Phase Formation ◽  
Raw Materials ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Thermal Treatment Temperature ◽  
45S5 Glass

In this work, the thermal treatment temperature effect on phase formation and bioactivity of glass-ceramics based on the SiO2-Na2O-CaO-P2O5 system has been studied. The chemical composition of the system is 45 wt.% SiO2, 24.5 wt.% Na2O, 24.5 wt.% CaO and 6 wt.% P2O5 (45S5). The rice husk ash is used as the natural raw materials instead of commercial SiO2. All of the investigated compositions were prepared by melting the glass mixtures at 1350°C for 3 h. The resulting glass samples were heated at different thermal treatment temperatures ranging from 750 to 1050°C with fixed dwell-time for 4 h for crystallization. Phase identification of the 45S5 glass ceramics was carried out by X-Ray diffraction (XRD). Moreover, the physical properties such as density, porosity and mechanical properties were systematically investigated. It was found that, the increasing of heat treatment temperature led to the increasing of the Na2Ca2Si3O9 phase and obtaining better bioactive behavior after incubation of glass-ceramics in simulated body fluid (SBF) for 7 days. The maximum hardness value of 4.02 GPa was achieved after heating at 1050°C for 4 h. However, the density value has slightly changed with various heat treatment temperatures.

scholarly journals The effect of oil heat treatment on biological, mechanical and physical properties of bamboo

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Xiaomeng Hao ◽  
Qiuyi Wang ◽  
Yihua Wang ◽  
Xin Han ◽  
Chenglong Yuan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Heat Treatment Temperature ◽  
Bending Strength ◽  
Parenchymal Cell ◽  
Decay Resistance ◽  
Treatment Temperature ◽  
Surface Wettability ◽  
High Yield ◽  
Methyl Silicone

AbstractBamboo is now widely used in construction, papermaking, textile, furniture and other fields because of its renewable, fast-growing, high-strength, high-yield and easy processing. However, compared with wood, bamboo and bamboo products are more vulnerable to damage by fungi and pests. An effective and eco-friendly method is urgently needed to improve their physical and chemical properties, decay resistance and anti-mildew properties, and hydrophobic properties. Here, bamboo was heated with methyl silicone oil. The effect of different temperatures (140 °C–200 °C) and different times (2 h–6 h) on the properties of bamboo was studied systematically, including chemical composition, physical and mechanical properties, surface wettability, decay resistance and anti-mildew property. No starch granules were observed inside the parenchymal cell lumen of bamboo specimen heat treated at 200 °C for 6 h. And with the increase of heat treatment temperature and time, the content of cellulose and hemicellulose decreases gradually while relative content of lignin increases due to its better thermal stability. Accordingly, the surface wettability decreases due to the changes of the surface functional groups and micro-morphologies. Under the condition of oil heat treatment at 160 °C for 2 h, the compressive strength parallel to grain of bamboo samples reach the maximum of 109.52 MPa. With further increase of heating temperature, the corresponding compressive strength decreases. The resulted bending strength and MOE both display similar changing trend. However, the optimal parameter is at 180 °C for 2 h, with the highest bending strength and MOE values of 142.42 MPa and 12,373.00 MPa, respectively. Finally, the decay resistance and anti-mildew property are dramatically enhanced with increased heat treatment temperature and time. All the corresponding changing mechanisms are investigated in depth and in detail. Our results provide comprehensive process parameters and micro-mechanism for the performance of oil heat treatment of bamboo, which can be used to guide the actual production.

scholarly journals INFLUENCE OF COMMERCIAL THERMAL TREATMENT ON Eucalyptus grandis Hill ex Maiden WOOD PROPERTIES

2021 ◽  
Vol 45 ◽  
Author(s):  
Carolina Aparecida Barros Oliveira ◽  
Karina Aparecida de Oliveira ◽  
Julio Cesar Molina ◽  
Vinicius Borges de Moura Aquino ◽  
André Luis Christoforo
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Thermal Treatment ◽  
Eucalyptus Grandis ◽  
Treated Wood ◽  
Wood Properties ◽  
Treatment Temperature ◽  
Saturated Steam ◽  
Physical Chemical ◽  
Different Temperatures

ABSTRACT This study aimed to evaluate the influence of commercial thermal treatment on Eucalyptus grandis considering its physical, chemical, and mechanical properties. The wood samples were heat-treated in an autoclave with saturated steam and pressure application at four different temperatures: 155, 165, 175, and 185 ºC. The physical, chemical, and mechanical properties were altered due to the heat treatment. The extractives content varied between 6.06% and 28.75%; lignin between 28.93% and 37.96%; holocellulose between 65.01% and 38.12%. The mechanical properties reduced significantly with the increase of the heat treatment temperature. Through the set of data obtained, it was possible to generate significant and high precision regression models capable of estimating such properties for heat treatment temperatures not studied experimentally, enabling the determination of the most suitable temperature of heat treatment to achieve a certain property value of the treated wood.

Effects of Heat Treatment on some Physical Properties of Douglas Fir (Pseudotsuga Menziesii) Wood

2011 ◽  
Vol 197-198 ◽  
pp. 90-95 ◽  
Author(s):  
Xian Jun Li ◽  
Zhi Yong Cai ◽  
Qun Ying Mou ◽  
Yi Qiang Wu ◽  
Yuan Liu
Keyword(s):  
Heat Treatment ◽  
Physical Properties ◽  
Pseudotsuga Menziesii ◽  
Treatment Time ◽  
Treated Wood ◽  
Untreated Wood ◽  
Douglas Fir ◽  
Treatment Temperature ◽  
Color Changes ◽  
Moisture Performance

In this study the effect of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) was investigated. Wood specimens were subjected to heat treatment at 160, 180, 200 and 220°C for 1, 2, 3 and 4h. The results show that heat treatment resulted in a darkened color, decreased moisture performance and increased dimensional stability of wood. Compared with untreated wood, equilibrium moisture content (EMC), water absorption (WA) and volume swelling (VS) for treated wood decrease up to 42.63%, 34.93% and 67.47%. The higher the treatment temperature and the longer the treatment time, the lower EMC, WA and VS. The VS of treated specimens has a more significant reduction than EMC and WA when the heat treatment temperature is above 180°C. The visual color changes were more distinct after heat treatment above 180°C. Temperature has a greater influence than time on these properties of specimens.

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