Maderas. Ciencia y Tecnología <p>&nbsp;</p> <p>&nbsp;</p> <table style="margin-top: -250px; width: 1025px; height: 672px;"> <tbody> <tr> <td style="width: 30%;"><strong><span style="color: #ffffff; text-align: center;"><img src="/public/site/images/visepul/Portada_21(2)-2019-3D.png"></span></strong></td> <td style="width: 30%;"> <p><img style="width: 30px;" src="" alt=""> <a href="">Full Text PDF</a><br> <img style="width: 30px;" src="" alt=""> e-book version<br> <a href=""><img style="width: 30px;" src="" alt=""></a> mobile version</p> </td> <td style="width: 30%;"> <p>Editor-in-Chief: <a href="" target="_self">Rubén A. Ananias</a><span id="result_box" class="short_text" lang="en"><br>Technical Editor</span>: <a href="">Linette Salvo S.<br></a>Digital Manager: <a href="">Victor Sepúlveda V.</a><br>E-mail :<a href=""></a><br>E-mail :<a href=""></a><br><br>2017 Journal Impact Factors:<br> 2-years: 1.0<br>5-years: 1.1<br> Frequency: 4 issues by year.<br>January, April, July, October<br>ISSN 0718-221X online version.<br>ISSN 0717-3644 printed version.</p> </td> </tr> </tbody> </table> en-US (Ruben A. Ananias.) (Victor Sepulveda Villarroel) Mon, 27 May 2019 00:00:00 -0400 OJS 60 Evaluation of dimensional stability, surface roughness, colour, flexural properties and decay resistance of thermally modified Acacia auriculiformis <p>This paper presents the effect of thermal modification of 14-15 year-old plantation grown <em>Acacia auriculiformis </em>wood in the 150-240ºC temperature range under vacuum condition. Important techno-mechanical parameters of thermally modified wood such as density, dimensional stability, colour, surface roughness, decay resistance against brown and white rot fungi and flexural properties were evaluated and compared with control. Depending on severity of heat treatment, colour of modified sapwood was turned from light to dark brownish. Moreover, the change in colour was found to be uniform throughout the thickness of wood blocks. Amount of shrinkage of <em>Acacia auriculiformis </em>wood was observed to be decreased with increasing treatment temperatures. Maximum dimensional stability of wood thermally modified at 240ºC was in the range of 60-65%. The surface roughness parameters (R<sub>a</sub> and R<sub>z</sub>) were reduced significantly after the treatment. The flexural strength (modulus of rupture-MOR) was observed to be reduced with increasing treatment temperatures. However, flexural stiffness (modulus of elasticity-MOE) was not found to be affected significantly up to 210ºC temperature. The lower amount of weight loss of thermally modified wood compared to untreated control showed improved decay resistance against white and brown rot fungi. With desirable improvements in various esthetic and technologically important quality parameters such as enhanced dimensional stability, biological durability against fungi and certain other properties, thermally modified wood from short-rotation <em>Acacia auriculiformis </em>may be considered as viable alternative to scarcely available timber resource for different value-added applications.</p> S.R. Shukla ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400 Crystallinity of cellulose microfibers derived from Cistus ladanifer and Erica arborea shrubs <p>The effectiveness of the use of cellulose fibers as particulates/composite reinforcers involves the assessment of the crystallinity of such fibers. The aim of the present work is to provide information on the degree of crystallinity of the cellulose microfibers obtained from the stems of <em>Cistus ladanifer</em> and <em>Erica arborea</em> shrubs through two different methods, namely an alkaline treatment and a microwave-assisted deep eutectic solvent (DES) method. The crystallinity indexes (CrI) obtained from X-ray powder diffraction patterns indicated that higher CrI were attained for cellulose obtained from the DES treatment. Complementary information on the degree of crystallinity was also retrieved from attenuated total reflection- Fourier transform infrared spectroscopy (ATR-FTIR) vibrational spectra, scanning electron microscopy (SEM) micrographs, and accessibility data for the DES-treated celluloses from the two species. The crystallinity results for the fibers derived from these two Mediterranean shrubs were within the range of the results for those derived from wood pulp, opening the door to their valorization for cellulose-derived packing applications or for their use as reinforcers in composite materials in combination with other biopolymers.</p> Paula Carrión-Prieto, Pablo Martín-Ramos, Salvador Hernández-Navarro, Luis F. Sánchez-Sastre, José Luís Marcos-Robles, Jesús Martín-Gil ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400 Resistance improvement of rubberwood treated with zinc oxide nanoparticles and phenolic resin against white-rot fungi, Pycnoporus sanguineus <p>Phenolic resin or phenol formaldehyde (PF) resin containing different percentage of zinc oxide (ZnO) nanoparticles was prepared and used to treat rubberwood. Three types of treatment solutions were prepared, namely (1) low molecular weight phenol formaldehyde resin (LMwPF), (2) 1.5 wt % nano ZnO dissolved in water (ZnO/H<sub>2</sub>O), and (3) combination of both LMwPF and 1.5 wt % nano ZnO (LMwPF/ZnO). The rubberwood samples were submerged into the treatment solutions for 60, 90, and 120 min, before vacuum impregnation. The untreated rubberwood samples served as the controlled samples. The thermal stability behaviour and resistance against white-rot fungi (<em>Pycnoporus sanguineus</em>) of the treated rubberwood samples were evaluated. The results reveal that the treated rubberwood had slightly better thermal stability compared to the untreated samples. In terms of decay resistance, the rubberwood treated with LMwPF and LMwPF/ZnO possess very high resistance against white-rot fungi. On the other hand, the rubberwood treated with ZnO/H<sub>2</sub>O did not attain similar effectiveness as the other two treatments, except for the samples that were submerged in ZnO/H<sub>2</sub>O for 120 min. The results indicate that 1.5 wt % nano ZnO could be sufficient in imparting superior durability to rubberwood provided that longer submersion time is adopted.</p> Mohd Khairun Anwar Uyup, Tumirah Khadiran, Hamdan Husain, Sabiha Salim, Nordahlia Abdullah Siam, Lee Seng Hua ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400 Evaluation of wood surface coating performance using water based, solvent based and powder coating <p>The objective of this study was to evaluate the surface coating performance using water base, solvent base and powder coating on medium density fiberboard. Samples were coated using water-base, solvent-base and powder coating. Coating performance was performed by using adhesion strength, surface coating hardness, layer thickness and rapid deformation test. The results were analyzed with two different statistical methods. Adhesion strength, layer thickness and surface hardness were determined by using ANOVA analysis, while results of rapid deformation test were analyzed by using Kruskal-Wallis method. According to these results, coating type was effective factor on the adhesion strength, surface coating hardness, layer thickness and rapid deformation test. Water-based painting application for adhesion strength and impact deformation resistance was higher than solvent-based coating. In the powder coating application, although surface coating hardness was higher than solvent and water base coating application, rapid deformation results were lower than solvent and water base coating applications. Adequacy of models was performed <em>R</em>-square (<em>R</em>²) and Adjusted <em>R</em>-square (Adj-<em>R<sup>2</sup></em>) values. <em>R<sup>2</sup></em> values of adhesion strength, layer hardness and film layer thickness were 93.60 %, 95.33 % and 73.90 %, respectively. Adj-<em>R<sup>2</sup></em> values of adhesion strength, layer hardness and film layer thickness were 93.45 %, 95.23 % and 73.30 %, respectively.</p> Ender Hazir, Kücük Huseyin Koc ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400 Energy efficiency performance enhancement of industrial conventional wood drying kiln by adding forced ventilation and waste heat recovery system: a comparative study <p>Conventional kilns dominate the wood drying industry. However, energy consumption during the process of ventilation remains a significant challenge. In this study, we designed a device to recover waste heat from exhausted wet air during kiln drying. To determine energy conservation, the device was installed in a 50 m<sup>3</sup> kiln used for drying sawn timber in two different Chinese cities, and a traditional kiln with identical size was chosen to enable comparison. Two kinds of hardwood (<em>Betula costata Trautv</em> and <em>Quercus mongolica</em>) swan timbers were dried using conventional technology to investigate the energy saving effect of rainy seasons as well as seasonally different temperature. The results revealed that drying time and energy consumption decreased with the use of this energy-conserving device. Electrical and energy consumption were reduced by 18.9% and 38.5%, respectively. Waste heat recovery efficiencies ranged from 20.32% to 28.15%. Energy-conservation efficiency can be predicted to range from 12.23% to 22.74% annually. Equipment costs can be recovered within 3.5 years.</p> Yang Meng, Guangyuan Chen, Gonghua Hong, Mingjie Wang, Jianmin Gao, Yao Chen ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400 Mechanical characteristics of impregnated white jabon wood (Anthocephalus cadamba) using merbau extractives and selected polymerised merbau extractives <p>This paper presents results of a study on the mechanical characteristics of impregnated Jabon wood (Anthocephalus cadamba) using Merbau extractives (ME) and two types of polymerised Merbau extractives (PME), i.e PME22 and PME33. A set of tests on hardness,&nbsp; shear, modulus of elasticity (MOE) and modulus of rupture (MOR) was conducted according to the relevant standards. Two types qualitative analysis by means of FTIR spectra and XRD analysis were carried out to explore relationship between the mechanical characteristics alteration with physico-chemical characteristics. The results indicated that a positive improvement in mechanical characteristics was obtained for Jabon wood impregnated with PME22 and PME33. Surface hardness of modified wood samples exhibited higher values compared to the non-impregnated samples for end and side hardness, by 20.04 and 30.54 % (PME22), and 32.73 and 39.89 (PME33), respectively. Shear strength increased by 41.87 and 49.58 % (PME22) and 74.02 and 79.10 % (PME) for radial (T) and tangential (T) sections, respectively. MOE increased by 23.52% (PME22) and by 40.12% (PME33), MOR values also increased by 28.50 and 41.19 % after impregnation with PME22 and PME33, respectively. The increment of mechanical properties<br>of treated Jabon wood after impregnation treatment using polymerised Merbau extractives were confirmed by FTIR spectra and crystallinity (XRD) analysis.</p> Jamaludin Malik, Barbara Ozarska ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400 Influence of combined heat treatment and densification on mechanical properties of poplar wood <p>In this study, influence of combined heat treatment and densification on mechanical properties of poplar wood (<em>Populus usbekistanica</em>) such as density, EMC, compression strength, modulus of elasticy, modulus of rupture and static bending strength were investigated. Poplar samples were subjected to a temperature of 120<sup>o</sup>C, 160<sup>o</sup>C and 200<sup>o</sup>C for 1 and 3h. After the heat treatment, the heat treated samples were compressed in a hot press at a temperature of 120<sup>o</sup>C, press pressure of 50 bar and press time of 30 minutes for densification. The results showed that the heat treatment affected the densification with increasing density. Additionally, the heat treatment decreased modulus of rupture (MOR), modulus of elasticity (MOE) and impact bending strength (IBS) with increasing temperature for undensified poplar wood. In conclusion, densification process has improved all the mechanical tested properties.</p> Gonca Düzkale Sözbir, İbrahim Bektaş, Ayşenur Kılıç Ak ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400 Optimization of wood machining parameters in cnc routers: Taguchi orthogonal array based simulated angling algorithm <p>In the present study, two mathematical models were developed to optimize the surface roughness for machining condition of Cedar of Lebanon pine (<em>Cedrus libani</em>). Taguchi approach was applied to examine the effect of CNC processing variables. Quality characteristics parameters were selected as arithmetic average roughness (<em>R</em><sub>a</sub>) and average maximum height of the profile (<em>R<sub>z</sub></em>) for wood material. Analysis of variance (ANOVA) was used to determine effective machining parameters. Developed mathematical models using response surface methodology (RSM) were optimized by a combined approach of the Taguchi’s <em>L<sub>27</sub></em> orthogonal array based simulated angling algorithm (SA). Optimum machining levels for determining the minimum surface roughness values were carried out three stages. Firstly, the desirability function wasused to optimize the mathematical models. Secondly, the results obtained from the desirability function were selected as the initial point for the simulated angling algorithm. Finally, the optimum parameter values were obtained by using simulated angling algorithm. Minimum<em> R<sub>a</sub></em> value was obtained spindle speed of 17377 rpm, feed rate of 2.012 m/min, tool radius of 8 mm and depth of cut of 2.009 mm by using desirability function based simulated angling algorithm. For <em>R<sub>z </sub></em>these results were found as 16980 rpm, 2.004 m/min, 8.001mm and 2.003 mm. The <em>R</em>-square values of the <em>R<sub>a</sub></em> and <em>R<sub>z</sub></em> were 95.91 % and 96.12 %, respectively. The proposed models obtained the minimum surface roughness values and provided better results than the observed values.</p> Ender Hazir, Kücük Hüseyin Koc ##submission.copyrightStatement## Mon, 27 May 2019 00:00:00 -0400