WOOD RESEARCH Volume 63, Number 1, 2018
Abdelraheem Ahmad, Abdelrahman Elserogy, Zeidoun Al-Muheisen, François Villeneuve, and Ahmad El-Oqlah

The conservation of a wooden nabataean coffin box from jordan – application of non-destructive ultrasonic technique

In this study, a wooden Nabataean coffin box from Jordan was examined and investigated for its conservation. The previously neglected coffin box was subject to various problems such as fragility, structural disintegration, and biological degradation. Microscopic examination using transmitted light microscope and scanning electron microscope showed the coffin box to be constructed of Lebanon cedar wood. Microbiological investigations allowed the isolation and identification of the fungal and bacterial species that have contributed to the biological degradation of the object. Non-destructive ultrasonic velocity measurements were carried out on the coffin wood to evaluate its deterioration level and to assess the effectiveness of consolidation treatments. Based on these analyses, several conservation processes were carried out on the object. These include cleaning, sterilization, consolidation, and reconstruction. For the consolidation of the coffin box, four different consolidation products were tested. Using ultrasonic technique, Paraloid B72 proved to be the most effective consolidation material for application on the coffin.

WOOD RESEARCH Volume 63, Number 1, 2018
Małgorzata Kajda-Szcześniak and Tomasz J. Jaworski

Characteristics of the combustion process of woodwork waste in the installation of thermal treatment of municipal solid waste (tpok)

The article presents tests concerning efficiency of combustion process in a layer by defining quantitative evaluation indicators (localization of reaction (flame) front, ignition rate, mass loss rate, thermal load of the grate). Wood wastes of various grain size were subject of tests. Obtained results for pure wood and paper have also been presented for comparison. Experimental tests were carried out on laboratory scale. The advantage of such tests is large saving of costs which would have to be incurred for tests performed on a real object. Received values of the quantitative indexes may be used by shifting them from the devices in laboratory scale into industrial devices. They help in selecting technical parameters for the systems. Furthermore, they help to avoid errors of input data at the stage of realization of the new or modernized project of the incineration plant. The results show that the tested wood waste were similar regarding their physicochemical properties. The differences can be observed in heating values (14.30-19.91 MJ∙kg-1). The rate of ignition for all investigated materials is high (0.021-0.063 kg∙(m-2s-1)). Values of SZ and SUM are similar which suggests that the probability of unburned fraction of waste remaining at the end of grate of TPOK installation is low. The ratio SZ/SUM is between 0.79 and 1.49, higher than 1.0, which means that SZ > SUM. It seems to be right as the rate of mass decrement is lower than the rate of ignition.

WOOD RESEARCH Volume 63, Number 1, 2018
Xiaojun Ma and Xiaojun Zhang

Nano-Fe3O4/ NMMO-cellulose composite membrane prepared by the in-situ co-precipitation method

Using NMMO-cellulose membrane as a matrix, Fe3O4/ cellulose composite membrane were prepared by the in-situ co-precipitation method. The effects of Fe2+ and Fe3+ salts concentration on the structure and properties of composite membranes were studied by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared spectrometer(FTIR) and vibrating sample magnetometer(VSM). Results showed that the spherical magnetic Fe3O4 nanoparticleswere dispersed uniformly and immobilized in the cellulose membranes, and there were good interactions between cellulose and Fe3O4 in the membranes. With increased iron ion content, the thermal stability of Fe3O4-CMgradually increases, and the complex membrane has a second significant weightlessness peak within 620–700 °C. In addition, it is also found that Fe3O4/cellulose composite membranes showed good superparamagnetic property.

WOOD RESEARCH Volume 63, Number 1, 2018
Balberčák Jozef, Boháček Štefan, Pažitný Andrej, VLADIMÍR IHNÁT, and HENRICH LÜBKE

Chemical processing of waste wood based agglomerates Part II: Evaluation of properties of fluting liners made of semichemical pulp obtained by an alkaline cooking process

The article describes the method of evaluation and preparation of fluting liners produced from semichemical pulp obtained from waste wood particle boards (PB) and oriented strand boards (OSB). The semichemical pulp was obtained using an alkaline cooking process from a sorted fraction of the 4-8 mm chips. Properties as thickness, bulk density, air resistance of paper sheet, tensile strength, tensile index, breaking length, burst index, CMT30 and SCT were monitored on lab sheets 127 g. m-2 and 170 g. m-2. Values of pH and residual NaOH were determined in the batch leachate.

WOOD RESEARCH Volume 63, Number 1, 2018
Wu Zhigang, Xi Xuedong, Liping Yu, Li Su, Hong Lei, Guanben Du, and Zhiwei Yin

An eco-friendly urea-formaldehyde resin: preparation structure and properties

The preparation, structures and properties of UF resin prepared with concentrated formaldehyde at a low molar ratio F/U=1.1 were studied in this paper. According to the results obtained from 13C-NMR, FT-IR and DMA, UF resin prepared with concentrated formaldehyde showed better mechanical properties and heat resistance and lower formaldehyde emission responsible for its high degree of polycondensation and crosslinking than that of UF prepared with common formaldehyde, but its stability was so bad due to its high content of ether bridges. However, it was stated that adding hydrolyzed soy protein to this UF resin at the first alkali preparation stage of “alkali-acid-alkali”, its stability got improved due to the increase of methylene bridges, which was the key contribution to polycondensation.

WOOD RESEARCH Volume 63, Number 1, 2018
Monika Ziemiańska and Robert Kalbarczyk

Biometrics of tree-ring widths of (populus x canadensis moench) and their dependence on precipitation and air temperature in south-western poland

The aim of this study was to explore the structure of the basic biometric characteristics of Canadian poplar (Populus x canadensis Moench) growing on former farmland, and the influence of meteorological elements on the variability of tree-ring widths (TRW). The test was performed on stem discs. Measurements of TRW were made with the use of LINTABTM 6. The impact of meteorological conditions on the TRW of the examined poplars was determined using correlation analysis for the dependent variable – residual chronology and independent variables – rainfall and air temperature in the current year and the year preceding the formation of rings. The average TRW of the Canadian poplar was 6.70 mm, with a coefficient of variation of 45.6%. The average TRW in sapwood was 5.37 mm, 2.11 mm less than in heartwood. The site chronology represented the period 1967-2014 (48 years). Our study demonstrated a significant correlation between rainfall and temperature on TRW in Populus x canadensis. The greatest demand for water by the Canadian poplar was observed in April and September of the current year. In contrast, the effect of air temperature most negatively affected TRW in June-July of the previous year (especially July) and April-May of the current year. In the designated chronology we established 13 pointer years, 7 positive and 6 negative. Negative years were determined in the years in which the shortage of rainfall was up to 50% of the norm, and positive indicator years where precipitation was higher than in the multi-annual period, even >150%. Both the correlation analysis and the analysis of indicator years indicated rainfall as a factor determining the size of the tree-ring width in Canadian poplars. In recent years, Poland has seen a resurging interest in planting poplars, following a long-term global trend in forestry and the paper industry which requires fast-growing tree plantations. The authors of this study attempted to address the gap in knowledge about the impact of meteorological elements on the tree-ring widths of Populus x canadensis in the conditions of south-west Poland.

WOOD RESEARCH Volume 63, Number 1, 2018
Ayhan Ozcifci, Mehmet Erdal Kara, and Alperen Kaymakci

Impact of pf and muf adhesives modified with TiO2 and SiO2 on the adhesion strength

The purpose of this study was to evaluate adhesion strength of phenol formaldehyde (PF) and melamine urea formaldehyde (MUF) adhesives modified with nano-technological products on the adhesion strength of different wood species. For this purpose, the effect of nano-TiO2 and nano-SiO2 on bonding performance and structural properties of PF and MUF were researced. And also, TiO2 and SiO2 chemicals were chosen as a rate of 2%, 4%, 6%, 8% within the adhesives. The bonding strength tests of the acquired Uludag fir and aspen boards were measured with a Universal Zwick Roell brand testing device in accordance with TS EN 205 standards. The obtained results showed that the highest bonding strength for Uludag fir wood was 8.27 N. mm-2 with PF adhesive mixed as 8% of SiO2 and the lowest was 5.91 N. mm-2 with MUF adhesive mixed as 2% TiO2, respectively. For aspen wood, the highest value was determined as 7.32 N. mm-2 with PF adhesive into which 8% of TiO2 had been added and the lowest was as 5.55 N. mm-2 with MUF adhesive into which % 6 TiO2 had been added. In conclusion it was determined that compared to the control samples the bonding strength of wood materials manufactured with the addition of nanoproduct into the PF adhesive enhanced the bonding strength by approximately 30% and 40% within MUF adhesive.

WOOD RESEARCH Volume 63, Number 1, 2018
ŽIKICA TEKIĆ, Aleksandra Nenadović, Saša Đorđević, and SNJEŽAN LUKIĆ

Nail metal connector plate – load-bearing capacity of connector in function of nail-to-plate connection rigidity

This paper deals with the results of experimental determination of load-bearing capacity of structural timber connections realized by nail metal connector plates, in the function of nail to steel plate connection rigidity. In the first group of test samples, the nails are embedded in pre-drilled holes in the steel plate. In the second group, the nails are embedded in pre-drilled holes and then the head of nail is welded to steel plate by its circumference. The main originality of the study is reflected in the achievement of rigidity of the connection of nails and the sleet plate, that is, in provision of rotation resistance, which leads to the plastic hinge formation at the surface of the steel plate, and thus to the increase of connection ductility. The study showed to what extent the degree of nail-to-plate connection rigidity affects the load-bearing capacity of structural timber member connections. Experimental testing was conducted in accordance with the provisions of Eurocode 5.

WOOD RESEARCH Volume 63, Number 1, 2018
Nadir Ayrilmis, Ali Gürel, Mehmet Özdemir, and Tolga Kapti

Bond performance of formaldehyde-based resins synthesized with condensate generated during kiln-drying step of wood

This research investigated the potential use of condensate generated during vacuum drying with high frequency of wood in the synthesis of urea-formaldehde (UF) and melamineformaldehyde (MUF) resins. The liquid condensate (5 wt%) of total resin composition) of walnut, beech or oak was replaced with deionized water used in the synthesis of UF and MUF resins. The condensate did not affect the properties of the UF and MUF resins in terms of density, solid content, viscosity, pH, and gel time as compared with the control resins. The control UF and MUF resins did not show a significant difference with the bond strength of UF and MUF resins at dry and wet conditions, except for the oak-UF resin. As for the dry condition, the control resin had the highest bond strength with a value of 12.9 N. mm-2, followed by beech-UF resin (12.6 N. mm-2), walnut-UF resin (12.1 N. mm-2), and oak-UF resin (11.8 N. mm-2), respectively. A similar trend was observed for the wet condition. All the modified UF and MUF resins complied with the minimum requirements of EN 12765 standard at dry and wet conditions. The results of this research can be useful for environmentally friend solution of the waste condensate discarded to the ground water.

WOOD RESEARCH Volume 63, Number 1, 2018
Yo-Jin Song and Soon-Il Hong

Performance evaluation of the bending strength of larch cross-laminated timber

A bending strength test was carried out on the strip-type cross-laminated timber (3 layers) that was combined differently by the cross-sectional annual ring orientation of the laminae under the same modulus of elasticity combination. In addition, the bending modulus of elasticity and the maximum bending moment predicted using the gamma method were compared with the results of the actual test. The result of the bending strength test showed no significant difference in bending strength among the specimens combined according to the annual ring orientation. Furthermore, when the outer tension layer of the cross-laminated timber was strengthened with a glass-fiber-reinforced plastic plate (volume ratio: 1.2%), the modulus of elasticity and the modulus of rupture increased by 4.2% and 16.3%, respectively. The ratios of the prediction results for the bending modulus of elasticity and the maximum bending moment by the gamma method to the actual test values were 1.01 and 0.96 on average, respectively, indicating that the two values were almost identical.

WOOD RESEARCH Volume 63, Number 1, 2018
Minmin Li, Yu Cao, Zheng Wang, and Yunlu Wang

Optimization and analysis of processing parameters of wooden crafts based on ultra-high pressure water jet method

The investigation and application of computer-numeric-control (CNC)-based ultra-high pressure water jet technology used in the field of wood processing have been paid increasing attention. In order to further optimize the technique of processing parameters in wooden crafts processing, medium density fiberboard (MDF) and solid wood of Italian poplar (Populus euramericana cv.) were taken as he experimental materials. The orthogonal experiment method was applied and the influence of several processing parameters including sand regulating speed, air-dry density, water jet pressure, feeding speed and target distance was considered to analyze the surface roughness. The water jet experiments were conducted based on the patterns designed by AutoCAD software with aid of numerical control working system. By the measurement of surface roughness and calculations, the influence of each processing parameter was investigated and the optimal scheme was then proposed. This work could provide optimization of processing parameters to the manufacturing of wooden crafts including fancy wood floors, indoor decorative boards of timber structure and mahogany furniture et al., which has high application value and practical significance.

WOOD RESEARCH Volume 63, Number 1, 2018
Lukáš Kaplan, Monika Sarvašová Kvietková, Adam Sikor, and Miroslav Sedlecký

Evaluation of the effect of individual paramaters of oak wood machining and their impact on the values of waviness measured by a laser profilometer

This article deals with determining the effect of different degrees of thermal modification, different cutting speeds (20, 30, 40 m. s-1), different feed rates (4, 8, 11 m. min-1) and different rake angles (15, 20 and 25°) with a 1 mm layer of removed material, on the quality of the surface of the workpiece using the mean arithmetic variation of the waviness profile „Wa“. The release was secured by setting the ruler and firmly holding it in the desired position. The ruler so configured was all the time to milling all the setting options.The article evaluates the process of planar milling of natural and thermally modified oak wood (Quercus cerris). For the evaluation, the samples were thermally modified by the Thermowood process at a temperature range of 160-210°C. The quality of the treated surface was evaluated after the planar milling process. The results obtained from this research show that by increasing the cutting speed during the machining of thermally modified and natural oak wood, we achieve better values of the mean arithmetic deviation of the waviness profile. The values of the monitored characteristic can also be improved by lowering the feed rate and selecting an appropriate rake angle. Thermal modification always lowers the values of the monitored characteristic.

WOOD RESEARCH Volume 63, Number 1, 2018
Xuehao Wang, Zhongjia Chen, Guosehng Yu, and Xiangyue Yuan

Effects of poplar f ibres as solid bridge on the physical characteristics of biomass briquette made from sawdust and bamboo powder

At room temperature, on condition that the die be within temperatures of 200 – 300°C biomass briquette production made from sawdust (S) and bamboo powder (B) was conducted by a briquette extruder using post-heating method, fibre with steam explosion poplar fibres used as additive. As observed through the microscope, fibres as additive has the micro-mechanism of promoting mechanical properties of biomass briquette during densification. For verifying the feasibility and effect of fibre as additive, BBD experimental design was macroscopically adopted to compare the indicators of surface quality, relaxation density, maximum radial compression pressure, and hydrophobicity. Response surface model was used to deduce the reasonable heating temperature range for exploring the suitable condition of fibre as additive. The result showed that fibre as additive has apparent effect on briquette densification of sawdust and bamboo powder within a given temperature range. Through microscopic observation, it was found that fibres acted as solid bridges which played a positive role in densification in the heating temperature of 200∼250°C. At the temperature of 240°C, the fibres started to be carbonized. And within the temperature range of 250-300°C, the carbonized fibre mainly acts as lubricant between the briquette and the channel surface of the die.

WOOD RESEARCH Volume 63, Number 1, 2018
Soňa Křivánková, Andrea Nasswettrová, and Pavel Šmíra

Comparison of image quality between a medical and an industrial ct scanner for use in non-destructive testing of tree-ring widths in an oak (Quercus robur) historical sculpture of Madonna

The aim of this paper was to compare the tree-ring width measurement results obtained using standard medical CT scanner Light Speed VCT 64 with the results obtained from industrial CT scanner GE phoenix v|tome|x 240 during dendrochronological dating of a historical wooden sculpture. The examined object was a polychrome wooden sculpture of Madonna, which was of historical value – that is why equipment enabling non-destructive measurement of tree-ring width for dendrochronological dating had to be used. The sculpture was made of ring porous English oak wood (Quercus robur), which is very easy to measure. There are also standard chronologies available for this material for the area of the Czech Republic to be used for absolute dendrochronological dating. During the first stage of the research, an available CT scanner designed for medical examination of human tissue was used; then the object was measured again using an industrial CT scanner where better results could be expected thanks to higher image resolution. This paper compares the quality of images from both scanners and the results of tree-ring width measurement from the output of the two CT scanners. The re-sults successfully document the possibility of obtaining images of sufficient quality to measure the grow ring widths of oak wood using computed tomography, proving that wooden objects can be subject to dendrochronological dating even if strict non-destructivity is required.

WOOD RESEARCH Volume 63, Number 1, 2018
Qian Wan, Sha Sha Song, Xiao He Li, Qi Zhang, Xiao Yang, Ya Chi Zhang, Ben Hua Fei, and Li Hong Yao

The visual perception of the cardboard porduct using eye-tracking technology

Consumers’ visual perception towards the product’s appearance can largely affect their preference and purchase intention of the product. Recently, the cardboard product, as a kind of environmentally friendly product, is becoming more and more popular in the market. Therefore, understanding the perception of consumers’ visual evaluation toward different cardboard products is crucial for cardboard product design. This study used eye-tracking technology and subjective evaluation together to investigate people’s visual perception evoked by different cardboard products. Nine different cardboard products’ pictures chosen from the internet were divided into three different types and three different assembly structures. Participants were then asked to observe those pictures when their eye movement behaviors were recorded by an eye tracker. Additionally, a questionnaire about the participant’s fondness and purchase of those cardboard products were filled out after the eye-tracking test. Consumers spent less average fixation duration on the cardboard product with more usability and more familiar form to evaluate their appearances. And stronger fondness and purchase intention of those kinds of cardboard products were showed in consumers’ visual perception. The exploring of the eye movement measurement on the visual perception can provide an accurate method for designers to better understanding the consumer’s fondness and purchase intention of the cardboard product. Taking consumers’ eye tracking metrics into account may help the product design meet their real needs in the cardboard product market.