Color Stability of Heat-Treated Okan Sapwood during Artificial Weathering

This study describes experiments of testing the color stability of heat-treated okan sapwood samples. Heat-treatment was done at 160°C,180°C,200°C,220°C during 4 hours, under steam. series of experiments were carried out to investigate the color stability of heat-treated okan sapwood compared to untreated wood during 100 hours xenon light irradiation. Color measurements during accelerated weathering were made at intervals throughout the test period. The results are presented in △E* and L* a* b*coordinates according to the CIE(1976)L*a*b* parameters color system. Better photo-stability in terms of color changes was recorded for heat-treated wood compared to the untreated one. The properties of heat treated wood are involved in the heat-treated wood resistanceagainst xenon light under experimental conditions.

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Accelerated weathering and decay resistance of heat-treated wood reinforced polypropylene composites

Drvna industrija ◽

10.5552/drvind.2019.1851 ◽

2019 ◽

Vol 70 (3) ◽

pp. 279-285 ◽

Cited By ~ 1

Author(s):

Deniz Aydemir ◽

Mizgin Alsan ◽

Ahmet Can ◽

Ertugrul Altuntas ◽

Huseyin Sivrikaya

Keyword(s):

Treated Wood ◽

Decay Resistance ◽

Treatment Temperature ◽

Accelerated Weathering ◽

Sem Images ◽

Polypropylene Composites ◽

Color Changes ◽

Heat Treated ◽

Twin Screw ◽

Antifungal Efficiency

The aim of this study was to determine the accelerated weathering and decay resistance of the heattreated wood reinforced polypropylene composites (HT-WPC). Polypropylene (PP) was used as a matrix and the heat-treated wood treated at 180 °C and 220 °C as reinforcement filler. The effect of three filler type, such as 40, 60 and 100 mesh, on the outdoor performance of composites was also investigated. The composites were prepared with twin screw extruder, and the test samples were obtained with compression molding. Lightness index (L*), color changes (ΔE*) and physical changes on the surface of the composites after the accelerated weathering, and decay resistance of the composites were investigated. According to the results, the effects of heat-treated wood on color changes were found to be more than its filler size, and while the filler loadings were increased from 5 % to 20 %, it was determined to increase the color changes of the composites. In scanning electron microscopy (SEM) images, crack formation and deterioration on the surface of the composites were determined. In FTIR spectra, no difference was determined between the composites, and all peaks were similar to each one. The addition of heattreated wood improved the antifungal efficiency of the composite, and the mass losses decreased with the increasing of heat treatment temperature. As a result, adding heat-treated wood to PP was found to improve the outdoor performance of the HT-WPCs.

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Comparison of the color and weight change in Paulownia tomentosa and Pinus koraiensis wood heat-treated in hot oil and hot air

BioResources ◽

10.15376/biores.16.3.5574-5585 ◽

2021 ◽

Vol 16 (3) ◽

pp. 5574-5585

Author(s):

Intan Fajar Suri ◽

Jong Ho Kim ◽

Byantara Darsan Purusatama ◽

Go Un Yang ◽

Denni Prasetia ◽

...

Keyword(s):

Heat Treatment ◽

Color Change ◽

Treated Wood ◽

Pinus Koraiensis ◽

Weight Changes ◽

Paulownia Tomentosa ◽

Wood Color ◽

Color Changes ◽

Hot Air ◽

Heat Treated

Color changes were tested and compared for heat-treated Paulownia tomentosa and Pinus koraiensis wood treated with hot oil or hot air for further utilization of these species. Hot oil and hot air treatments were conducted at 180, 200, and 220 °C for 1, 2, and 3 h. Heat-treated wood color changes were determined using the CIE-Lab color system. Weight changes of the wood before and after heat treatment were also determined. The weight of the oil heat-treated wood increased considerably but it decreased in air heat-treated wood. The oil heat-treated samples showed a greater decrease in lightness (L*) than air heat-treated samples. A significant change in L* was observed in Paulownia tomentosa. The red/green chromaticity (a*) of both wood samples increased at 180 and 200 °C and slightly decreased at 220 °C. The yellow/blue chromaticity (b*) in both wood samples increased at 180 °C, but it rapidly decreased with increasing treatment durations at 200 and 220 °C. The overall color change (ΔE*) in both heat treatments increased with increasing temperature, being higher in Paulownia tomentosa than in Pinus koraiensis. In conclusion, oil heat treatment reduced treatment duration and was a more effective method than air heat treatment in improving wood color.

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Application of Waterborne Acrylic and Solvent-Borne Polyester Coatings on Plasma-Treated Fir (Abies alba M.) Wood

Materials ◽

10.3390/ma15010370 ◽

2022 ◽

Vol 15 (1) ◽

pp. 370

Author(s):

Hadi Gholamiyan ◽

Behnam Gholampoor ◽

Reza Hosseinpourpia

Keyword(s):

Plasma Treatment ◽

Treated Wood ◽

Abies Alba ◽

Untreated Wood ◽

Contact Angle Measurement ◽

Angle Measurement ◽

Accelerated Weathering ◽

Water Contact ◽

Before And After ◽

Carbon Dioxide Co2

This research investigates the effect of plasma treatment with air, nitrogen (N2), and carbon dioxide (CO2) gases on the performance of waterborne (acrylic) and solvent-borne (polyester) coated fir (Abies alba M.) wood samples. The properties of the plasma-coated samples were analyzed before and after exposure to accelerated weathering and compared with those of untreated and solely treated ones. According to pull-off testing, the coating adhesion of the wood samples was considerably improved by plasma treatment, and obvious differences were observed between different plasma gases. The effect was more pronounced after the weathering test. Similar results were obtained for the abrasion resistance of the samples. The water contact angle measurement illustrated more hydrophilic character in the solely plasma-treated wood in comparison with the untreated wood. The application of coatings, however, strongly improved its hydrophobic character. The performances of waterborne and solvent-borne coatings on plasma-treated wood were comparable, although slightly better values were obtained by the waterborne system. Our results exhibit the positive effect of plasma treatment on coating performances and the increased weather resistance of the waterborne and solvent-borne coating systems on plasma-treated wood.

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COLOR CHANGE — MASS LOSS CORRELATION FOR HEAT-TREATED WOOD

CBU International Conference Proceedings ◽

10.12955/cbup.v2.483 ◽

2014 ◽

Vol 2 ◽

pp. 345-352 ◽

Cited By ~ 2

Author(s):

Cristina Marinela Olarescu ◽

Mihaela Campean

Keyword(s):

Heat Treatment ◽

Mass Loss ◽

Color Change ◽

Treated Wood ◽

Untreated Wood ◽

Cost Effective ◽

Assessment Procedure ◽

Mathematical Correlation ◽

Heat Treated ◽

Two Parameters

Heat treatment is renowned as the most environmentally friendly process of dimensional stabilization that can be applied to wood, in order to make it suitable for outdoor uses. It also darkens wood color and improves wood durability. The intensity of heat treatment can be appreciated by means of two parameters: the color change occured in wood due to the high temperature, and the mass loss, which is a measure of the degree of thermal degradation. In order to find a mathematical correlation between these two parameters, an experimental study was conducted with four European wood species, which were heat-treated at 180°C and 200ºC, for 1-3 hours, under atmosheric pressure.The paper presents the results concerning the color changes and mass losses recorded for the heat-treated wood samples compared to untreated wood. For all four species, the dependency between the color change and the mass loss was found to be best described by a logarithmic regression equation with R2 of 0.93 to 0.99 for the soft species (spruce, pine and lime), and R2 of 0.77 for beech. The results of this study envisage to simplify the assessment procedure of the heat treatment efficiency, by only measuring the color – a feature that is both convenient and cost-effective.

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Calorific Power Improvement of Wood by Heat Treatment and Its Relation to Chemical Composition

Energies ◽

10.3390/en13205322 ◽

2020 ◽

Vol 13 (20) ◽

pp. 5322

Author(s):

Idalina Domingos ◽

Umit Ayata ◽

José Ferreira ◽

Luisa Cruz-Lopes ◽

Ali Sen ◽

...

Keyword(s):

Heat Treatment ◽

Chemical Composition ◽

Lignin Content ◽

Treated Wood ◽

Untreated Wood ◽

High Heating Value ◽

Heat Treated ◽

Positive Linear Correlation ◽

Total Extractives ◽

Calorific Power

Chemical composition influences the calorific power of wood, mainly due to the calorific power of structural compounds and extractives. Heat treatment changes the chemical composition of treated wood. This work studies the relationship between chemical composition and calorific power improvement by heat treatment. Samples were heat-treated by the ThermoWood process ® for 1 h and 2 h. High heating value (HHV) and chemical composition; lignin, cellulose, hemicelluloses and extractives in dichloromethane, ethanol, and water were determined. The HHV of untreated wood ranged between 18.54–19.92 MJ/kg and increased with heat treatment for all the tested species. A positive linear correlation was found between HHV and Klason lignin (R2 = 0.60). A negative trend was observed for holocellulose, cellulose, and hemicelluloses content against HHV, but with low determination coefficients for linear regression. The best adjust for polysaccharides was found for hemicelluloses content. A positive correlation could be found for dichloromethane extractives (R2 = 0.04). The same was obtained in relation to ethanol extractives with R2 = 0.20. For water and total extractives, no clear positive or negative trends could be achieved. The results showed that the HHV of wood increased with heat treatment and that this increase was mainly due to the increase in lignin content.

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Wettability of Heat-Treated Wood

Holzforschung ◽

10.1515/hf.2003.045 ◽

2003 ◽

Vol 57 (3) ◽

pp. 301-307 ◽

Cited By ~ 117

Author(s):

M. Pétrissans ◽

P. Gérardin ◽

I. El bakali ◽

M. Serraj

Keyword(s):

Heat Treatment ◽

Water Drop ◽

Chemical Change ◽

Treated Wood ◽

Untreated Wood ◽

Adsorbed Water ◽

Inert Atmosphere ◽

Contact Angles ◽

Heat Treated ◽

Before And After

Summary The aim of this work was to study the wettability and chemical composition of heat-treated wood. Heat treatment was performed at 240°C under inert atmosphere on four European wood species (pine, spruce, beech and poplar). Contact angle measurements before and after treatment indicated a significant increase in wood hydrophobicity. Advancing contact angles of a water drop were in all cases systematically higher for heat-treated than for untreated wood. Chemical modifications of wood after heat treatment were investigated using FTIR and 13C NMR analysis. FTIR spectra indicated little structural change which could be attributed either to carbon-carbon double bond formation or to adsorbed water. NMR spectra also revealed little chemical change except for the degree of cellulose crystallinity which was considerably higher in heat-treated wood and could explain the higher contact angles.

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Heat treatments of dormant scion wood killed the European canker pathogen in planta, while chemical treatments did not

New Zealand Plant Protection ◽

10.30843/nzpp.2019.72.329 ◽

2019 ◽

Vol 72 ◽

pp. 282

Author(s):

Brent M. Fisher ◽

Reiny W.A. Scheper

Keyword(s):

Room Temperature ◽

Treated Wood ◽

Untreated Wood ◽

Heat Treatments ◽

Causal Agent ◽

In Planta ◽

Chemical Treatments ◽

Canker Pathogen ◽

Heat Treated ◽

Nursery Trees

Neonectria ditissima, the causal agent of European canker, can be present in symptomless scion wood. Sanitation treatments could minimise this risk to nursery trees. In this trial, six heat treatments and five chemical treatments were tested for their effectiveness in removing this pathogen from dormant ‘Royal Gala’ wood. In July 2018, 120 symptomless inoculated shoots (three inoculations/shoot) were harvested and stored at 1oC for 3 months. Bundles of five inoculated shoots (45 cm) were placed in the centre of 24 bundles, each consisting of 25 wood pieces. Heat-treated bundles were submerged in water (45oC for 45 min or 50oC for 15 min), or wrapped in moist cloth, vacuum sealed inside plastic then submerged for 3–6 h at the same temperatures. Chemical-treated bundles were submerged for 16 h at room temperature. Treatments were compared with untreated wood. After surface sterilising, isolation of N. ditissima from inoculated wounds was attempted on apple-sap amended water agar. All wounds from the untreated wood and from the chemical-treated wood yielded the pathogen. However, N. ditissima was not isolated from wounds that had been heat treated. Therefore, heat treatments that do not affect scion wood viability may prove an effective tool to remove European canker from nursery material.

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Coating Performance on Exterior Oil-Heat Treated Wood

Coatings ◽

10.3390/coatings9040225 ◽

2019 ◽

Vol 9 (4) ◽

pp. 225 ◽

Cited By ~ 2

Author(s):

Mojgan Nejad ◽

Mahdi Dadbin ◽

Paul Cooper

Keyword(s):

Moisture Content ◽

Wood Species ◽

Color Change ◽

Treated Wood ◽

Untreated Wood ◽

Average Moisture Content ◽

Southern Pine ◽

Coating Performance ◽

Spruce Wood ◽

Heat Treated

Thermal modification and the degree of improved properties from the treatment depend on wood species and treatment parameters. Southern yellow pine and spruce are two wood species commonly used for decking, fences, and siding in North America. This study evaluated coating performance when applied on oil-heat-treated Southern pine and spruce wood samples. Moisture content, color, and gloss changes of samples were analyzed before weathering and then after each month for the first three months and then every six months during 18 months of natural weathering exposure in Toronto, Canada. The results showed that coated heat-treated woods had lower moisture uptake, lower color change, and overall better appearance ranking than coated-untreated wood samples. Coated-spruce wood samples had lower checking and splitting, and in general, much better performance than coated-Southern pine treated samples. Notably, the average moisture content of treated spruce wood samples was significantly lower than that of Southern pine, which explains lower checking and improved coatings’ appearance.

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Water absorption behavior of heat-treated and untreated red balau saw dust/LDPE composites: Its kinetics and effects on mechanical properties

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705718799823 ◽

2018 ◽

Vol 32 (10) ◽

pp. 1408-1426 ◽

Cited By ~ 2

Author(s):

Ruth A Lafia-Araga ◽

Aziz Hassan ◽

R Yahya ◽

N Abd Rahman ◽

Fauzani Md Salleh

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Water Absorption ◽

Water Immersion ◽

Treated Wood ◽

Untreated Wood ◽

Thermoplastic Composites ◽

Wood Composites ◽

Saw Dust ◽

Heat Treated

The hygroscopic nature of wood limits the use of wood thermoplastic composites (WTC) in outdoor industrial and domestic applications. To reduce this tendency, red balau saw dust was heat treated at 180 and 200°C for 1 h and compounded with Low Density Poly(ethylene) (LDPE) into 20 and 37 wt% and then molded into test specimens by injection molding. Samples were immersed in distilled water at room temperature for 4 months. Heat-treated wood composites showed remarkable water resistance relative to untreated ones. Wood composites made from wood treated at 180 and 200°C exhibited almost similar water absorption pattern. Reduced water absorption of heat-treated wood composites relative to untreated ones indicates that heat treatment has resulted in a degree of modification of the wood. Most of the composites displayed the Fickian mode of water absorption with n values close to 0.5. Also, the diffusion coefficient reduced with wood content in untreated wood composites due to interaction of water with the polar groups in wood through hydrogen bonding. Untreated wood composites exhibited poorer mechanical properties with water immersion as a result of degradation due to moisture. The mechanical properties of the heat-treated wood composites were not adversely affected with water absorption. Therefore, heat treatment can reduce the proneness to water absorption in WTCs and alleviate the detrimental effects on mechanical properties.

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Artificial weathering of heat-treated pines from the Iberian peninsula

BioResources ◽

10.15376/biores.15.4.9642-9655 ◽

2020 ◽

Vol 15 (4) ◽

pp. 9642-9655

Author(s):

Bruno M. Esteves ◽

René Herrera ◽

Jorge Santos ◽

Luísa Carvalho ◽

Lina Nunes ◽

...

Keyword(s):

Treated Wood ◽

Untreated Wood ◽

Industrial Facilities ◽

Artificial Weathering ◽

Class D ◽

Heat Treated ◽

Pinus Pinaster Ait ◽

In The Beginning ◽

Weathering Process

Samples from the two most common pines grown in Portugal (Pinus pinaster Ait) and Spain (Pinus radiata, D. Don) were heat-treated in industrial facilities in accordance with ThermoWood ® class D. For both species, the variation in surface properties, of untreated and heat-treated wood after artificial weathering from 75 to 750 h, is presented. The analysis included the determination of color, roughness, gloss, and wettability before exposure and after each artificial weathering period. Untreated woods became darker faster, while in heat-treated woods, lightness remained approximately constant until 750 h of artificial weathering. Both untreated and heat-treated wood became more reddish in the beginning of the weathering process, turning greener for longer exposure times. Untreated woods became yellower in the beginning, turning into blueish tones later. Heat-treated wood turned slightly yellower until 750 h of weathering. Gloss decreased for untreated wood with no significant changes in heat-treated wood. Despite the changes, the gloss of both untreated and heat-treated wood converged to similar values. Roughness increased for both untreated and heat-treated woods. Artificial weathering increased the wettability of heat-treated wood.

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