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Öğe ANALYSIS OF VOLUMETRIC SWELLING AND SHRINKAGE OF HEAT TREATED WOODS: EXPERIMENTAL AND ARTIFICIAL NEURAL NETWORK MODELING APPROACH(Univ Bio-Bio, 2016) Tiryaki, Sebahattin; Bardak, Selahattin; Aydin, Aytac; Nemli, GokayShrinkage and swelling characteristics of wood as a hygroscopic material affect negatively its effective utilization for a variety of applications. Heat treatment is widely used for minimizing the negative effects of volumetric swelling and shrinkage of wood. The present study aims to develop artificial neural network (ANN) models for predicting volumetric swelling and shrinkage of heat treated woods. For this purpose, wood samples were subjected to heat treatment at varying temperatures (130, 150, 170 and 190 degrees C) for varying durations (2, 4, 6 and 8 h). Experimental results have showed that volumetric swelling and shrinkage of wood decreased by heat treatment. Then, neural networks models capable of predicting the swelling and shrinkage of the treated woods were developed based on the resulting data. It was seen that ANN models allowed volumetric swelling and shrinkage of such woods to predict successfully with a limited set of experimental data. This approach was able to predict volumetric swelling and shrinkage of wood with a mean absolute percentage error equal to 2,599% and 2,647% in test phase, respectively. The developed models might thus serve as a robust tool to predict volumetric swelling and shrinkage with less number of experiments.Öğe INFLUENCE OF RESIDUE TYPE ON QUALITY PROPERTIES OF PARTICLEBOARD MANUFACTURED FROM FAST-GROWN TREE OF HEAVEN (AILANTHUS ALTISSIMA (MILL.) SWINGLE)(Inst Technol Drewna, 2019) Bardak, Selahattin; Nemli, Gokay; Tiryaki, SebahattinIn this study, the effect of residue types (soundwood, branchwood and bark) on the quality properties of particleboards made from the tree of heaven (Ailanthus altissima (Mill.) Swingle) was investigated. For this purpose, the soundwood, branchwood and bark mixed at different ratios were used in the production of particleboards. Modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength (IB), thickness swelling (TS) and formaldehyde emission (FE) of the specimens were then tested. The chemical and anatomical properties of the residue types were also determined. Residue type was found to have an impact on the properties of particleboards. The addition of bark and branchwood improved the thickness swelling (2 h immersion) and formaldehyde emission. However, use of branchwood negatively affected the thickness swelling for 24 h immersion. Based on the findings of this study, it can be concluded that different parts of Ailanthus altissima (Mill.) Swingle can be used to manufacture particleboard panels. The branchwood and bark contents significantly affected the quality properties of the manufactured particleboards. The chemical and anatomical properties of the branchwood and bark were also found to be parameters influencing the quality properties of the particleboards. The results indicate that the contents of added bark and branchwood should not exceed 10% and 20% respectively.Öğe Investigation and neural network prediction of wood bonding quality based on pressing conditions(Elsevier Sci Ltd, 2016) Bardak, Selahattin; Tiryaki, Sebahattin; Nemli, Gokay; Aydin, AytacThis paper presents an application of artificial neural network (ANN) to predict the bonding strength of the wood joints pressed under different conditions. An experimental investigation firstly was carried out and then an ANN model was developed based on the experimental data. In the experimental investigation, Oriental beech (Fagus orientalis L) and Oriental spruce (Picea orientalis (L.) Link.) samples bonded with polyvinyl acetate (PVAc) adhesive were pressed at four different temperatures (20, 40, 60 and 80 degrees C) for four different durations (2, 8, 14 and 20 min). The experimental results showed that higher values of bonding strength were obtained when high temperatures were combined with short pressing duration. Similar findings could be also obtained with longer pressing time for lower temperatures. The first case may be recommended to increase the efficiency of the production process, allowing a greater quantity of production per unit time. The ANN results showed a good agreement with the experimental results. It was shown that prediction error was within acceptable limits. The results revealed that the developed ANN model is capable of giving adequate prediction for bonding strength with an acceptable accuracy level. The desired outputs of bonding strength can be thus obtained by conducting less number of time-consuming and costly experimental investigations using the proposed model. (C) 2016 Elsevier Ltd. All rights reserved.Öğe THE INFLUENCE OF RAW MATERIAL GROWTH REGION, ANATOMICAL STRUCTURE AND CHEMICAL COMPOSITION OF WOOD ON THE QUALITY PROPERTIES OF PARTICLEBOARDS(Univ Bio-Bio, 2017) Bardak, Selahattin; Nemli, Gokay; Tiryaki, SebahattinIn the present study, the impact of raw material grown region on the physical, mechanical, surface properties and formaldehyde emission of the particleboard was investigated. Ailanthus altissima wood grown in Trabzon had longer fiber length and thicker fiber and trachea cell wall than those of the wood grown in Artvin. The highest amounts of lignin, ash, condensed tannin and solubility values were found in wood grown in Artvin. Ailanthus altissima wood grown in Trabzon had higher amounts of cellulose and hemicellulose than those of the wood grown in Artvin. Particleboards made from wood grown in Artvin had worse surface quality and mechanical strength properties than those of panels made from wood grown in Trabzon. On the other hand, the results showed that particleboards produced from wood grown in Artvin had lower thickness swelling and formaldehyde emision values than those of the panels produced from wood grown in Trabzon.Öğe THE QUALITY COMPARISON OF PARTICLEBOARDS PRODUCED FROM HEARTWOOD AND SAPWOOD OF EUROPEAN LARCH(Univ Bio-Bio, 2019) Bardak, Selahattin; Nemli, Gokay; Bardak, TimucinIn this paper, the impacts of heartwood and sapwood usage on the physical, mechanical, and surface properties and formaldehyde emission of particleboard are investigated. European Larch (Larix decidua) trees are chosen as a raw material. The logs are divided into three segments: sapwood, heartwood and total wood. The highest amounts of cellulose (51,54%), and hemicelluloses (22,24%) in the sapwood, followed by total wood, and the heartwood, respectively. However, the highest amount of lignin (30,54%) was found in the heartwood. The highest extractives values are obtained from heartwood, followed by total wood, and the sapwood, respectively. While the lowest pH value (3,03) is found in heartwood, the sapwood samples provide the highest values (4,95). The highest ash (0,49%) content and amount of condensed tannin (13,89%) are extracted from heartwood, followed by total wood, and sapwood, respectively. The test panels manufactured from sapwood have the smoothest surface (7,49 mu m (R-a), 48,86 mu m (R-y), and 35,12 mu m (R-z)) and the lowest contact angles (67,8 degrees), while the roughest surface (14,20 mu m (R-a), 68,05 mu m (R-y), and 50,02 mu m (R-z)) and highest contact angle (96,9 degrees) are obtained from the panels of heartwood. The thickness swelling (19,88%) and formaldehyde emission (7,28%) values of the panels manufactured from heartwood are significantly lower than the panels manufactured from the total wood and sapwood. The highest modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond (IB) values are observed on sapwood, respectively, 15,60 MPa (MOR), 2201 MPa (MOE), and 0,523 MPa (IB). These mechanical strength values (MOR, MOE, and IB) are followed by total wood, and the heartwood, respectively. Surface smoothness and wettability of the particleboards manufactured from sapwood are better than those of total wood and heartwood.
