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 61, Number 5, 2016
Adam Krajewski, Paweł Kozakiewicz, and Piotr Witomski

Shear strength of Scots pine (Pinus sylvestris L.) from the historical buildings

Comparative research was conducted on shear strength parallel to grain of heartwood of Scots pine (Pinus sylvestris L.) from the 16-18th century from Central Poland and of modern wood. Tests were performed on 150 samples of aged wood from 13 construction elements of 4 historic buildings and on 100 samples from 10 modern constructional elements. Aged wood revealed a better technical quality. The difference of average shear strength parallel to grain values equaled 0.09 MPa and the translation of correlation line was about 0.35 MPa in favour of aged wood.

WOOD RESEARCH Volume 62, Number 6, 2017
Mustafa Kucuktuvek, Ergun Baysal, Turkay Turkoglu, Huseyin Peker, Ahmet Gunduz, and Hilmi Toker

Surface characteristics of scots pine wood heated at high temperatures after weathering

This study was conducted to investigate some surface properties of wood specimens of heat treated Scots pine (Pinus sylvestris L.) after weathering such as surface hardness, surface roughness, gloss, and color changes. Heat treatment of Scots pine wood was carried out by hot air in an oven for 1, 2, and 3 hours at 210, 220, and 230°C. The results showed that generally surface hardness losses of heat treated Scots pine wood were lower than that of un-heated Scots pine wood after weathering. Heat treated Scots pine wood gave smooth surface after weathering. Except for heat treatment at 230°C for 1 and 2 hours, heat treatment resulted in better glossiness compared to un-heated Scots pine wood after weathering. According to the test results, while heat treated Scots pine wood become lighter after weathering, un-heated wood become darken after weathering. In general, heat treated wood surface to become reddish and yellowish 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
Donata Krutul, Tomasz Zielenkiewicz, Andrzej Radomski, Janusz Zawadzki, Andrzej Antczak, Michał Drożdżek, and Tomasz Makowski

Metals accumulation in scots pine (Pinus sylvestris L.) wood and bark affected with environmental pollution

Studies on the content and distribution of mineral substances including calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), iron (Fe), sodium (Na), zinc (Zn), aluminum (Al), lead (Pb) and strontium (Sr) were performed. Samples of Scots pine were gained from stems with Ist degradation degree of tree (considered to grow in the area with weak environmental pollution), IInd degradation degree (strong pollution) and IIIrd degradation degree (very strong pollution). Nitrogen industrial plant was acknowledged as the source of pollution. Samples were collected from butt-end, middle- and top sections of the stem in following zones: sapwood, heartwood adjacent sapwood, heartwood and bark. Results indicate that nitrogen industrial plant causes the decrease of mineral substances content in bark from butt-end section of stems with IInd and IIIrd degradation degree in relation to stems with Ist degradation degree. Calcium content is the highest in heartwood and decreases in the direction to stem perimeter, regardless of stem section and environmental pollution degree. Very strong pollution decreases potassium content in wood in comparison to samples collected in areas with strong and weak pollution. Environmental pollution also decreases sodium content in wood, and increases content of manganese, aluminum, lead and strontium.

WOOD RESEARCH Volume 62, Number 3, 2017
Hüseyin Sivrikaya, Ahmet Can, Ibrahim Tümen, and Deniz Aydemir

Weathering performance of wood treated with copper azole and water repellents

Water borne wood preservatives have been widely used for a long time in the protection of wood either in ground contact or above ground. Copper is still major biocide component used today in treatment plant for wood protection despite the environmental concerns over copper-rich preservative systems. On the other hand, water repellents are considered to be potential additives for biocides, resulting in the decreased moisture content, reduced biocide leaching and increased dimensional stabilization. In the present study, copper azole (CA) was used as wood preservatives to the natural weathering for 6, 12 and 24 months respectively. In addition, semitransparent wood stain was used as post treatment with CA, and paraffin and silicon additives were incorporated in to biocide to be water repellent. Paraffin additives reduced the retention values as compared to other formulations. The highest color change and gloss loss were obtained with Scots pine control samples within the six months. CA pretreatment before wood stain was promising by indicating the lowest color change. Color change was reduced by the increasing ratio in paraffin and silicone additives. Combination of CA with wood stain and silicon additive could reduce the copper leaching to some extent.

WOOD RESEARCH Volume 62, Number 1, 2017
Tomasz Jelonek, Witold Pazdrowski, and Magdalena Arasimowicz-Jelonek

Correlation between the stem hydraulic conductivity rates in scots pine (Pinus sylvestris L.) and the lignin content in tracheid walls

This paper is an attempt to evaluate the lignin formation in tracheid walls within the stem circumferential area in mature Scots pine (Pinus sylvestris L.), and establish the correlation between lignin content, and diameter at breast height and hydraulic conductivity in mature pine. The independent variables included lignin content (Lc) in tracheid walls within the stem circumferential area, and pine diameter at breast height (DBH), and the dependent variable was the relative conducting surface of stems (Sa/Nmass, Eas/Nmass). Research material came from the 89-91 year old pine stand in the north of Poland. Chemical analysis included mature wood area, i.e. last ten annual rings at 1.30 m (DBH). The results show clear interdependence between the relative conductive surface (stem hydraulic conductivity), and tree diameter at breast height and lignin content in tracheid walls within the stem circumferential area. Biometric features of pines grown in fresh coniferous forest (FC) and in fresh mixed coniferous forest (FMC) conditions were functionally linked. The link between these values was clear, although it varied, and could be approximated using the linear function.

WOOD RESEARCH Volume 63, Number 5, 2018
Saban Kart, Ergun Baysal, Turkay Turkoglu, Mustafa Kucuktuvek, Huseyin Peker, Caglar Altay, Ahmet Gunduz, and Hilmi Toker

The effect of natural weathering on change in the color of heat treated and varnished scots pine and oriental beech woods

This study was designed to investigate color changes of heat treated and varnished Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis L.) after 3 months of weathering. Heat treatment of Oriental beech and Scots pine wood was carried out by hot air in an oven for 1, 2, and 3 hours at 205, 215, and 225°C. After heat treatment, wood specimens were varnished using a polyurethane varnish (PV) and cellulosic varnish (CV). The results of study showed that heat treatment generally caused decrease of lightness of both wood specimens before weathering. In general, while heated and PV coated Scots pine and Oriental beech wood surfaces turned to reddish and yellowish, heated and CV coated Scots pine and Oriental beech wood surfaces turned to reddish and bluish after weathering. The total color changes of heated and varnished both wood specimens were lower than only varnished both wood specimens after weathering.

WOOD RESEARCH Volume 64, Number 6, 2019
Ahmet Gunduz, Ergun Baysal, Turkay Turkoglu, Mustafa Kucuktuvek, Caglar Altay, Huseyin Peker, and Hilmi Toker

Accelerated weathering performance of Scots pine preimpregnated with copper based chemicals before varnish coating. Part II: Coated with water based varnish

This study was designed to investigate some surface characteristics such as gloss, color, and surface hardness changes of Scots pine wood preimpregnated with some copper-based chemicals before varnish coating after accelerated weathering. While Adolit KD-5 (AD-KD 5), Wolmanit CX-8 (WCX-8), and Celcure AC-500 (CAC-500) were used as copper-based impregnation chemicals, water-based varnish (WBV) was used as a coating material. Results showed that surface hardness and gloss values of Scots pine were increased after accelerated weathering. Impregnated and WBV coated Scots pine gave better surface characteristics compared to only WBV coated Scots pine. In impregnation chemicals, while AD-KD 5 showed the most appropriate chemical, in terms of surface hardness and total color changes, CAC-500 was found the most valuable chemical in terms of gloss changes after 1000 h accelerated weathering exposure.

WOOD RESEARCH Volume 64, Number 5, 2019
Ondřej Schönfelder, Aleš Zeidler, Vlastimil Borůvka, and Lukáš Bílek

Impact of silvicultural measures on the quality of scots pine wood Part II. Effect of site

This study deals with the variability of wood density, compression strength and the impact bending strength within the trunk of Scots pine (Pinus sylvestris L.). The impact of the site on the examined properties was also evaluated. The tree samplers come from four different sites that are representative for Scots pine growth in the Czech Republic. From the samplers the sections representing a basal part of the trunk and a middle part of the tree were cut. The most significant influence of the site was confirmed for wood density; on the other hand, the influence of the site is ambiguous in terms of the examined strength characteristics. A decrease in the wood properties with increasing trunk height was proven for all tested properties. The highest impact of the position was observed for wood density, while the results of vertical variability in mechanical properties are not always significant (compression strength: basal 47.1 MPa and middle 45.8 MPa). A close correlation between mechanical properties and wood density was also proven.

WOOD RESEARCH Volume 64, Number 4, 2019
Ondřej Schönfelder, Aleš Zeidler, Vlastimil Borůvka, and Lukáš Bílek

Impact of silvicultural measures on the quality of Scots pine wood. Part I. effect of regeneration method

This study deals with the influence of the silvicultural measures on selected mechanical properties of Scots pine (Pinus sylvestris L.) wood in the Czech Republic. Sample trees were selected at two different localities that are characteristic of Scots pine growth, and they represent two different Scots pine regeneration methods, namely the clear-cutting and shelterwood regeneration method. We tested compressive strength and impact bending strength. The density of the wood was also evaluated as a factor influencing strength characteristics. The shelterwood regeneration method shows higher values in most of the investigated characteristics (49.3 MPa for the shelterwood method and 44.6 MPa for the clear-cutting method in the case of compressive strength); however, these differences are not significant for the processing industry. Another positive effect of the shelterwood regeneration method is the even distribution of the properties within the trunk in radial direction in contrast to clear-cutting method.

WOOD RESEARCH Volume 64, Number 2, 2019
Ergun Baysal, Caglar Altay, Turkay Turkoglu, Hilmi Toker, and Huseyin Peker

Impact of UV irradiance on selected parameters of Scots pine impregnated with some commonly used fire-retardants

This study was designed to determine some selected parameters such as gloss, surface roughness, and color changes of Scots pine wood impregnated with commonly used fireretardant (FR) chemicals after UV irradiance. Sodium acetate (SA), ammonium chlorite (AC), zinc chlorite (ZC), ammoniumsulphate (AS), and di ammonium phosphate (DAP) were used as fire retardants. Wood specimens were prepared from Scots pine (Pinus sylvestris L.). Before test, wood specimens were impregnated with 5 % aqueous solution of chemicals according to ASTM D 1413-76 standard. Results showed that UV irradiance caused gloss loss and increase surface roughness of FR impregnated and un-treated (control) Scots pine specimen. DAP was the most effective chemical in terms of reducing gloss loss and surface roughness of Scots pine after 750 h UV irradiance exposure. UV irradiance caused a dark, reddish, and yellowish color of impregnated and un-treated (control) Scots pine specimen after all UV irradiance periods. Total color changes in color (∆E*) exhibited a systematic trend to higher values with increasing UV irradiance time. Total color changes of ZC impregnated Scots pine were the lowest after 750 h UV irradiance exposure.

WOOD RESEARCH Volume 64, Number 1, 2019
Saban Kart, Ergun Baysal, Mustafa Kucuktuvek, Turkay Turkoglu, Hilmi Toker, Caglar Altay, Cihan Cibo, and Huseyin Peker

Some surface characteristics of varnished thermowood after weathering

This study was designed to investigate some surface characteristics such as glossiness and surface roughness changes of varnished thermowood after six months of weathering. Thermal modification of Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis L.) wood were carried out by hot air in an oven for 1, 2, and 3 hours at 205, 215, and 225°C. After the modification process, wood specimens were varnished using a polyurethane varnish (PV) and cellulosic varnish (CV). The natural weathering process caused an increase in the surface roughness of the test specimens according to the test results. The Scots pine and Oriental beech test specimens which were heat treated and varnished gave more favorable results compared to only varnish test specimens after natural weathering in terms of surface characteristics such as surface roughness and glossiness. Generally, as the heat treatment time and temperature increase, it is observed that the surface characteristics of the Scots pine and Oriental beech wood specimens improve positively. According to the results of the tests, the samples varnished with polyurethane varnish gave better results in terms of surface roughness at the end of the natural weathering process, whereas the samples varnished with cellulosic varnish gave better results in terms of glossiness values.