Mass loss kinetics of thermally modified wood species as a time–temperature function

2021 ◽  
Author(s):  
Petr Čermák ◽  
Dominik Hess ◽  
Pavlína Suchomelová
Keyword(s):  
Mass Loss ◽  
Wood Species ◽  
Temperature Function ◽  
Thermally Modified Wood ◽  
Kinetics Of ◽  
Modified Wood

scholarly journals Leachates of Thermally Modified Pine (Pinus sylvestris L.) Wood

2015 ◽  
Vol 34 (329) ◽  
pp. 26-31 ◽  
Author(s):  
Anete Meija-Feldmane
Keyword(s):  
Pinus Sylvestris ◽  
Mass Loss ◽  
Tannic Acid ◽  
Environmentally Friendly ◽  
Hazardous Substances ◽  
Environmental Aspects ◽  
Treatment Technology ◽  
Thermally Modified Wood ◽  
Main Components ◽  
Modified Wood

Abstract During the last decades, thermally modified wood has become an object of interest among the wood scientists as an environmentally friendly material, because nowadays environmental aspects of materials have become more and more significant. Leaching is one of the processes that occurs in outdoor use. The aim of this study was to evaluate concentration of potentially hazardous substances in leachates of thermally modified pine wood. Scots pine (Pinus sylvestris L.) wood was thermally modified using Wood Treatment Technology (WTT) company device at 170 °C for 1 hour (TMP170/1) and at 160 °C for 3 hours (TMP160/3) and the mass loss was calculated. Material preparation and leaching procedure was made according to standard LVS EN 84:2000. In obtained leachates, the content of sugars, acetic acid, furfural and tannic acid were determined. Results showed that the total wood mass loss was 7.1 ± 1.4% (n=20) for TMP170/1 and 4.0 ± 1.6% (n=20) for TMP160/3. The initial leaching velocity differs between both modes and is higher for TMP160/3. The velocity decreases exponentially with immersion time and reaches plateau after 7th (5 days) immersion, but leaching still continues after the 9th immersion (14 days). The main components in leachates were tannic acid and pentoses. Among all studied compounds furfural is the hardest leachable one. Thermally modified wood treated at TMP170/1 is more environmentally friendly due to less water leachable substances. It is worth looking forward by investigating volatile organic compounds emissions in the air as it also could give high impact on human health.

scholarly journals Properties of some thermally modified wood species

2013 ◽  
Vol 43 ◽  
pp. 348-355 ◽  
Author(s):  
Balkis Fatomer A. Bakar ◽  
Salim Hiziroglu ◽  
Paridah Md Tahir
Keyword(s):  
Wood Species ◽  
Thermally Modified Wood ◽  
Modified Wood

scholarly journals Influence of natural surface ageing on bonding quality of thermally modified oak and beech wood

2019 ◽  
Vol 70 (3) ◽  
pp. 273-278
Author(s):  
Vjekoslav Živković ◽  
Gustav Gabrek ◽  
Goran Mihulja
Keyword(s):  
Contact Angle ◽  
Shear Strength ◽  
Wood Species ◽  
Contact Angles ◽  
Bonding Quality ◽  
Natural Surface ◽  
Lamination Process ◽  
Thermally Modified Wood ◽  
Modified Wood

This paper presents the influence of natural surface ageing in indoor conditions on bonding quality of thermally modified wood used in structural laminated products. Two unmodified and thermally modified wood species were used for the experiment: oak and beech. Samples were planed and glued with MUF adhesive 2 hours, 1, 2, 6, 10, and 18 days after planing. Properties of laminated beech and oak beams, namely shear strength, delamination and contact angle, were measured in order to detect 1) suitability of wood species for lamination process and 2) influence of extended storage time after planing on properties of laminated wood. Generally, both native and thermally modified beech exhibited better results of shear strength and delamination and had lower contact angles compared to oak and thermally modified oak. Results of the delamination test (total delamination) indicate time dependence of surface ageing. Both unmodified and thermally modified beech may be successfully laminated at least up to 2 days after planing, whereas neither oak nor thermally modified oak are suitable for lamination process due to excessive delamination. Results of delamination may be related to contact angle measurements. Shear strength of glue lines did not show any influence on natural surface ageing. However, whereas beech and thermally modified beech samples exhibited almost the same values of the shear strength regardless of the duration of surface ageing, there is an obvious difference in shear strength of oak and thermally modified oak samples.

scholarly journals Measuring and Analysis Colour of Birch Wood in Digital Picture

2020 ◽  
Vol 28 (3) ◽  
pp. 162-167
Author(s):  
Mária Hrčková ◽  
Pavol Koleda ◽  
Peter Koleda
Keyword(s):  
Wood Species ◽  
Colour Measurement ◽  
Birch Wood ◽  
Colour Space ◽  
Water Steam ◽  
Matlab Program ◽  
Saturated Water ◽  
Heat Treated ◽  
Thermally Modified Wood ◽  
Modified Wood

AbstractThe aim of the research was to verify a new method of measuring the colour of wood. The method was designed to automate wood colour measurement. In the experiments birch wood was used, which was heat treated with saturated water steam. Nikon D3200 camera was used in conjunction with the MATLAB program to implement the method. The assessments were conducted in the colour space of CIE L* a* b*. The measured values confirmed the decrease in lightness from natural to thermally modified wood. The trends of the colour values a* and b* were the same as those reported by the authors who conducted experiments with birch wood. Differences were found in the magnitude of the measured chromatic component a* values. It will be necessary to verify the above facts and determine the reasons for these differences by measuring the colour of other wood species.

scholarly journals Increasing the Strength of the Glue Line in the Production of Thermally Modified Wood Paneling

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 253
Author(s):  
Ruslan Rushanovich Safin ◽  
Aigul Ravilevna Shaikhutdinova ◽  
Ruslan Khasanshin ◽  
Shamil Mukhametzyanov ◽  
Albina Safina
Keyword(s):  
Wood Products ◽  
Ultraviolet Rays ◽  
Surface Activation ◽  
Wood Block ◽  
Two Stage ◽  
Adhesion Properties ◽  
Wood Processing ◽  
Ultraviolet Treatment ◽  
Thermally Modified Wood ◽  
Modified Wood

This work is devoted to the study of the effect of ultraviolet rays for the surface activation of pine wood thermally modified at temperatures of 180−240 °C in order to increase the surface roughness, enhance the wettability of thermal wood and the adhesive strength of the glue in the production of wood block furniture panels. Studies were carried out to measure the contact angle of wettability of thermally modified wood samples of pine, as a result of which it was determined that the ultraviolet treatment process contributes to an increase in the adhesion properties of the surface layer of thermally modified wood by more than 13% due to the reactivity of ultraviolet rays to oxidize and degrade ligno-containing wood products. At the same time, the most active process of surface activation takes place during 60 min of ultraviolet irradiation of wood with a total irradiation of at least 125 W/cm2. It was revealed that the combined effect of two-stage wood processing, including preliminary volumetric thermal modification followed by surface ultraviolet treatment, causes an increase in the moisture resistance of glued wood products by 24%. So, if the strength of the glue seam when gluing natural wood samples after boiling decreased by 46%, then the samples that underwent two-stage processing showed a decrease only by 22%. In connection with the results obtained, an improved technology for the production of furniture boards for the manufacture of moisture-resistant wood products is proposed.

scholarly journals Flammability Characteristics of Thermally Modified Meranti Wood Treated with Natural and Synthetic Fire Retardants

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2160
Author(s):  
Milan Gaff ◽  
Hana Čekovská ◽  
Jiří Bouček ◽  
Danica Kačíková ◽  
Ivan Kubovský ◽  
...  
Keyword(s):  
Burning Rate ◽  
Flame Retardants ◽  
Thermal Modification ◽  
Positive Contribution ◽  
Spearman Correlation ◽  
Chemical Changes ◽  
Combustion Properties ◽  
Flammability Characteristics ◽  
Thermally Modified Wood ◽  
Modified Wood

This paper deals with the effect of synthetic and natural flame retardants on flammability characteristics and chemical changes in thermally treated meranti wood (Shorea spp.). The basic chemical composition (extractives, lignin, holocellulose, cellulose, and hemicelluloses) was evaluated to clarify the relationships of temperature modifications (160 °C, 180 °C, and 210 °C) and incineration for 600 s. Weight loss, burning speed, the maximum burning rate, and the time to reach the maximum burning rate were evaluated. Relationships between flammable properties and chemical changes in thermally modified wood were evaluated with the Spearman correlation. The thermal modification did not confirm a positive contribution to the flammability and combustion properties of meranti wood. The effect of the synthetic retardant on all combustion properties was significantly higher compared to that of the natural retardant.

A model to predict the kinetics of mass loss in wood during thermo-vacuum modification

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ottaviano Allegretti ◽  
Ignazia Cuccui ◽  
Nasko Terziev ◽  
Laerte Sorini
Keyword(s):  
Mass Loss ◽  
Treatment Process ◽  
Linear Trend ◽  
Thermal Modification ◽  
Thermal Treatments ◽  
Temperature Profiles ◽  
Relative Area ◽  
Heat Power ◽  
Kinetics Of

AbstractMass loss (ML) of wood caused by thermal degradation is one of the most important features of the thermal treatments and referred to as an indicator of intensity and quality of the process. The ML is proportional to the quantity of the effective heat power exchanged during the treatment process, represented by the area of the temperature profile versus time during the process. In this paper a model for the ML prediction based on the relative area was discussed. The model proposed an analytical solution to take into account the non-linear trend of ML when plotted versus temperature and time as observed in isothermal experiments. The model was validated comparing calculated and measured final ML of samples treated during thermal modification tests with different temperature profiles. The results showed that the relative area calculated in a transformed time-temperature space improves the correlation with the measured ML.

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