WOOD RESEARCH Volume 69, Number 3, 2024
MERYEM KACMAZ UNVER, MUSTAFA ALTUNOK, and SEKIP SADIYE YASAR

THE INVESTIGATION OF NATURAL AGING BEHAVIOR OF SOME WOOD SPECIES MODIFIED WITH NATURAL PRESERVATIVES

This study evaluates the effects of 12-month outdoor weathering on Scots pine (Pinus sylvestris L.) and sessile oak (Quercus petraea L.) woods modified with tannins. Wood specimens were divided into four groups: Group A (control, natural aging (NA)), Group B (NA + 100% walnut tannin (WT)), Group C1 (NA + 50% WT and 50% pine tannin), and Group C2 (NA + 50% WT and 50% oak tannin). Group A showed density decreases of 4.3% for Scots pine and 4.7% for sessile oak, while Group B samples exhibited density increases of 2.6% and 1.6%, respectively. Group A specimens had hardness losses of 36.3% for Scots pine and 28.7% for Sessile oak, compared to reduced losses of 8.8% and 11.2% in Group B. Bending strength and modulus of elasticity also decreased significantly in Group A but were minimally affected in Group B. These results indicate that tannin treatments, particularly walnut tannin, improve wood durability and mechanical performance, offering an eco-friendly alternative to conventional treatments

WOOD RESEARCH Volume 68, Number 3, 2023
Sarah Augustina, Wahyu Dwianto, Muhammad Adly Rahandi Lubis, Ratih Damayanti, Danang Sudarwoko Adi, Jamaludin Malik, Imam Wahyudi, WAYAN DARMAWAN, Philippe Gerardin, Sari Delviana Marbun, and Hiroshi Isoda

Effect of Anatomical Structure on Dimensional Stability of Low Molecular Weight Phenol-Formaldehyde Impregnated Wood

This research deals with low molecular weight-phenol formaldehyde (LMW–PF) impregnation on sepetir (Sindora spp), nyatoh (Palaquium spp.), and pisang putih (Mezzettia spp.) woods to determine the effect of different anatomical structure on weight percent gain and dimensional stability improvement. The wood samples were impregnated using LMW–PF solutions with 7, 8, 9, 10, and 11% of concentrations (w/w), vacuum-pressured (–98 kPa, 15 min, 350 kPa, 4 h), and re-immersed in 80°C for 3 h. According to the findings, LMW–PF impregnation reduced coefficient of swelling by 9.64–29.95%, and increased anti-swelling efficiency by 12.24–29.91%. Additionally, the water absorption and thickness swelling reduced by 2.43–38.75% and 15.94–34.21%, respectively, indicating the improvement of dimensional stability. Microscopy and NIR analysis revealed the presence and reaction of LMW–PF within porous wood matrix. The effect of diverse anatomical structures caused complexity on LMW–PF impregnation. Sepetir-treated wood with fewer anatomical barriers resulted in better dimensional stability improvement than others.

WOOD RESEARCH Volume 67, Number 6, 2022
Jamaludin Malik, Erlina Nurul Aini, Deazy Rachmi Trisatya, Sona Suhartana, Imam Wahyudi, and Sarah Augustina

Dimensional stability and durability of hybrid sandwich panel made from oil palm lumber, sengon and gmelina with boron-alum impregnation

In this study, sandwich panels made from oil palm lumber, sengon, and gmelina wood were impregnated with a boron-alum solution to improve their water and termite resistance. Water resistance testing was evaluated using a thickness swelling test following the method in SNI 03-2105. The sandwich panel was also tested for its durability against dry wood termites, according to SNI 01-7207. The weight loss, mortality, and attack degree were used as the parameters for evaluating termite durability. The results showed that the treatment with a boron-alum solution can increase the stability, water resistance, and weight loss properties up to 73%, 41%, and 100%, respectively. The best properties of the sandwich panel were obtained by the sengon-isocyanate panel with 8% boric acid-borax and 5% alum treatment which has thickness swelling of 2.37%, water absorption of 49.04%, weight loss of 0.0124%, termite mortality of 100%, and attack degree of 0.

WOOD RESEARCH Volume 67, Number 5, 2022
Renyuan Liu, Zhuliang Zeng, Quan Li, and Cenlong Hu

The effects of ACQ and water glass on the color change and decay resistance of carbonized bamboo

In this study, samples of bamboo and carbonized bamboo were impregnated with alkaline copper quaternary (ACQ) and water glass, the resulting differences in color and resistance to decay by Gloeophyllum trabeum were evaluated. The results showed that the impregnated bamboo and carbonized bamboo greatly reduced their lightness (L*). The red-green color index (a*) first decreased and then increased, while the yellow-blue color index (b*) first increased and then decreased. The total chromatic aberration (ΔE) was largest for bamboo and carbonized bamboo impregnated with ACQ and allowed to decay. Carbonized bamboo impregnated with ACQ and water glass and bamboo impregnated with ACQ reached level I (strong decay resistance). The decay resistance of bamboo and carbonized bamboo was as follows: ACQ impregnated > water glass impregnated > CK. Scanning electron microscopy further confirmed that the bamboo and carbonized bamboo were impregnated with ACQ had fewer hyphae, the maintained intact structure, and good decay resistance.

WOOD RESEARCH Volume 61, Number 6, 2016
Suleyman Ustun, Ergun Baysal, Turkay Turkoglu, Hilmi Toker, Cevdet Sacli, and Huseyin Peker

Surface characteristics of scots pine treated with chemicals containing some copper compounds after weathering

In this study, it was aimed to investigate surface hardness, gloss, and color changes of Scots pine treated with chemicals containing some copper compounds after six months weathering. Adolit KD-5 (AD KD-5), celcure AC-500 (CAC-500), and wolmanit CX-8 (WCX-8) were used as impregnation chemicals containing copper compounds. Scots pine wood specimens were treated with 2 % aqueous solution of chemicals according to ASTM D1413-07e1 (2007) standard. Results showed that while surface hardness and gloss values of untreated Scots pine wood specimens were decreased after weathering, they increased treated Scots pine wood specimens after weathering. The decrease in L* of untreated and treated wood indicates that the specimens became darker after weathering. While weathering caused less green and less yellow for untreated control specimen, it caused less red and less yellow for treated wood. Treated Scots pine wood specimens showed better color stability compared to untreated Scots pine after weathering. In terms of surface hardness, gloss, and color stability values CAC-500 treated Scots pine gave the best results after weathering.

WOOD RESEARCH Volume 62, Number 5, 2017
Ergun Baysal, Turkay Turkoglu, Erdogan Gavcar, Hilmi Toker, Ahmet Gunduz, Mustafa Kucuktuvek, Huseyin Peker, and Dursun Kemal Bayraktar

Weathering properties of Scots pine treated with some chemicals

This study was aimed to investigate the gloss, surface hardness, surface roughness, and color changes of Scots pine that was treated with some chemicals after six months of weathering exposure. Chromated copper boron (CCB), vacsol aqua, and imersol aqua were used as the impregnation chemicals. Scots pine wood specimens were impregnated with 3% aqueous solutions of the chemicals according to ASTM standards.The results showed that while chemical treatment caused a decrease in surface hardness, gloss, and lightness of wood specimens, it increased the surface roughness of the wood before weathering. While the gloss values of all treated Scots pine specimens increased after weathering, the gloss loss was observed for the untreated specimen after weathering. All of the treated and untreated Scots pine wood surfaces were softened after weathering. The chemical treatment caused a decrease of surface roughness of wood after weathering. While in terms of the gloss, surface hardness, and surface roughness changes, the vacsol aqua-treated pine specimens gave the best results. The CCB-treated Scots pine showed the best color stability after weathering.

WOOD RESEARCH Volume 62, Number 3, 2017
Aytekin Onduran, S. Sadiye Yasar, and MUSTAFA ALTUNOK

Investigation of the effects of some modification process to the mechanical performance and deformation of the woodwork

In this study, wood modification (thermo-processing and impregnation) and outdoor conditions of storage (natural aging) the effects on the mechanical performance of industrial woodwork was investigated. For this purpose, naturally grown in Turkey and the commercial value of high Scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa Mill) wood was used. Experimental examples are specifically woodwork has been applied in actual size. Considering the previously conducted research literature only diagonal L-type samples used, not on the actual size samples of woodwork. In addition, there is no study that the combination of the heat-treatment and impregnation. This reveals the original values of this study. For preparing of samples is used the double tenon-mortise corner joint from constructions method and as glue polyurethane based Desmodur VTKA and Polyvinyl acetate based two-component D4. Diagonal woodwork test samples prepared by Thermo S class (185°C temperature with a thermo-vapor process protections) applying. After application of the heat treatment, the test samples impregnated with a solution of 95 % natural pine cone resin and %5 pine tannin by dip method (2 hours). Then, the untreated samples (control), only heat-treated samples and heat treatment + impregnated samples kept for 1 year with outdoor conditions (aging). At the end of the aging, the samples tested according to the principles stated in TS 2472 and TS 7251 EN 107 standard. As result, the performance of woodwork decreased after aging in untreated and heat treatment pieces, the other side after aging – heat treatment, impregnation materials increased the values. The deformation value of woodwork increased after aging most untreated materials, Heat treatment and heat treatment-impregnated reduced aging effectiveness.

WOOD RESEARCH Volume 63, Number 6, 2018
Selim Sen, M. Said Fidan, Elif Alkan, and S. Sadiye Yasar

Determination of some properties of Scotch pine (Pinus sylvestris L.) wood which is impregnated with boron compounds and quechua

As the industrialisation and technological developments increase; the search for functional material which is environment-friendly, non-toxic, flame resistant, with a broad applicability and with high-temperature endurance also increases. Even though the wood material corresponds most of these features, its possession of an organic structure causes it to be affected negatively by damages occurring under proper conditions in the outdoor environment. Due to this reason, this study is conducted to prevent damages (biotic, abiotic pests, fire, etc.) caused by the environment to the wooden material, and to determine some physical and mechanical properties of wooden material impregnated with quechua, borax and boric acid, which are used to extend the usage life. Those features are needed in an outdoor environment. The Scotch pine (Pinus sylvestris L.) test specimens are prepared with borax, boric acid, borax+boric acid, from borax compounds, which have a great potential in Turkey, and with quechua, one of the natural impregnation substances. Then these samples are impregnated with three different (1%, 3%, 5%) solution concentrations according to ASTM 1413-76 standards and some physical-mechanical property changes are investigated. After impregnation, samples are tested and compared with control samples. According to the test results; the lowest oven dried density change is obtained in borax as 0.46 g.cm-3 in terms of boron compounds and the retention amount is determined to be highest with 3.83 kg.m-3 in the samples impregnated with boric acid. The bending strength and elastic modulus are found to be highest with 83.53 MPa and 10281 MPa in the samples impregnated with boric acid. When examined at the concentration level, it is determined to be highest with 81.89 MPa in samples with 3% concentration. There are statistical discrepancies with 55.77 MPa in the comprehensive strength parallel to grain in boric acid in terms of boron compounds.

WOOD RESEARCH Volume 65, Number 1, 2020
Caglar Altay, Ergun Baysal, Hilmi Toker, Turkay Turkoglu, Mustafa Kucuktuvek, Ahmet Gunduz, and Huseyin Peker

Effects of natural weathering on surface characteristics of scots pine impregnated with wolmanit CX-8 and varnished

In this study, it was aimed to investigate the effects of weathering on some surface characteristics such as color and surface roughness changes of Scots pine impregnated with copper-containing chemical such as Wolmanit CX-8 (WCX-8) and varnished with synthetic varnish (SV), cellulosic varnish (CV), and polyurethane varnish (PV) were investigated. Results showed that while the WCX-8 impregnated and PV coated Scots pine specimens showed better color stability than other treatment groups after weathering, only CV coated Scots pine gave the most negative effect on color stability. While, the untreated (control) wood surface turned from red to green and yellow to blue respectively, after weathering, other all treatment groups gave reddish and yellowish tone after weathering. Weathering conditions increased the surface roughness of control (untreated) and other all treatment groups. The control group gave a rougher surface than other treatment groups after weathering. Surface roughness increases were the lower for CV coated Scots pine wood than other treatment groups. The results showed that while WCX-8 impregnation before varnishing gave better color characteristics, generally it caused to increase the surface roughness of Scots pine after weathering.

WOOD RESEARCH Volume 64, Number 3, 2019
Ilker Akyüz, Nadir Ersen, Sebahattin Tiryaki, Bahadir Çağri Bayram, Kadri Cemil Akyüz, and Huseyin Peker

Modeling and comparison of bonding strength of impregnated wood material by using different methods: Artificial neural network and multiple linear regression

In this study, the effects of vacuum time, diffusion time and pressing time on the bonding strength of Larix decidua wood impregnated with Immersol-Aqua and bonded with Klebit-303 were investigated. The vacuum time, diffusion time, and pressing time were predicted by using the artificial neural network (ANN) model and multiple linear regression (MLR) methods and the results of ANN and MLR methods were compared. The highest bonding strength (7.664 N. mm-2) was achieved when the vacuum time, the diffusion time and the pressing time were 20, 60 and 60 minutes, respectively, while the lowest value (4.62 N. mm-2) was achieved when the vacuum time, the diffusion time and the pressing time were 80, 120 and 20 minutes, respectively. The model results are as follows: The MAPE value for testing phase in the ANN was 7.266 and R2 value was 0.751 whereas the MAPE value of the MLR was 9.365 and R2 value was 0.558. The ANN model has been found to have better prediction performance than the MLR model.

WOOD RESEARCH Volume 64, Number 1, 2019
S. Sadiye Yasar

Effects of wood preservatives on the combustion process and combustion quality of wood

This study examines the combustion properties of Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis L.) in 3 stages (CWF, SC and EC) according to ASTM E 160-50 (1975). Wood samples were impregnated with Tanalith-E (T) and Wolmanit-CB (WC) and then were varnished with Synthetic (St) and water based (wb) varnishes. When the combustion was completed, the weight loss, combustion temperatures, illuminance values, total time of combustion, and demolition time were measured. As the result, illuminance value of Oriental beech wood decreased, while the smoke density increased. Scots pine was later destroyed in the combustion process. Areas with a risk of fire are advised to use pine wood instead of beech. Wolmanit-CB and synthetic varnish reduced the temperature and illuminance values. Oriental beech, Tanalith-E, and synthetic varnish resulted in the highest temperatures for all combustion stages. This triple interaction increased total combustion time values by more than 90% when compared with the control samples.

WOOD RESEARCH Volume 64, Number 1, 2019
Liu Ming-Li, Li Chun-Feng, and Liu Yan-Long

Physical and mechanical properties of modified poplar wood by heat treatment and impregnation of sodium silicate solution

The objective of this study was to improve physical and mechanical properties of fast-growing Chinese white poplar wood (Populus tomentosa Carrière). To this purpose, the heat treatment and impregnation by sodium silicate solution were investigated. In experiments, four processes under four different conditions were applied on poplar wood samples: temperature treatment (T), solution treatment (J), first solution and then temperature treatment (J-T) and first temperature and then solution treatment (T-J). The results showed that all measured mechanical properties were improved under conditions of J process. The hardness, impact toughness, bending strength and modulus of elasticity were improved by 8.4%, 29.2%, 12.0% and 16.1%, respectively. Additionally, tested wood samples exhibited significant increasing of values some mechanical properties such as hardness (70.1%) and modulus of elasticity (80.4%) in comparison with values for untreated samples if treatment was conducted under J-T process conditions. Treated wood by this technology could be utilized as solid wood composite or material for flooring substrate.