Timuçin Bardak

Experimental investigation and prediction of bonding strength of Oriental beech (Fagus orientalis Lipsky) bonded with polyvinyl acetate adhesive

Adhesive bond strength of solid wood plays a key role in the efficient use of wood in a large number of engineering applications. In this study, the effects of amount of adhesive, pressing pressure, and pressing time on bonding strength of beech wood bonded with polyvinyl acetate adhesive were investigated and predicted by developing an artificial neural network (ANN) model. Experimental results have showed that bonding strength of wood samples increased generally by increasing amount of adhesive, pressing pressure, and pressing time. Besides, ANN analysis has yielded highly satisfactory results. The designed neural network model allows predicting the bonding strength of wood samples with mean absolute percentage error of 2.454% and correlation coefficient of 97.8% for testing phase. It is clear from the results that the model has a good learning and generalization ability. This model therefore can be used to predict bonding strength of beech samples bonded with polyvinyl acetate adhesive under given conditions. Consequently, this study provides beneficial insights for practitioners in terms of the safe and efficient use of wood as an engineering material in applications related to the strength of the bond between wood and adhesive.

Predictive Performance of Artificial Neural Network and Multiple Linear Regression Models in Predicting Adhesive Bonding Strength of Wood

The purpose of this study was to develop artificial neural network (ANN) and multiple linear regression (MLR) models that are capable of predicting the bonding strength of wood based on moisture content, open assembly time and closed assembly time of the joints prior to pressing process. For this purpose, the experimental studies were conducted and the models based on the experimental results were set up. As a result of the experiments conducted, it was observed that bonding strength first increased and then decreased with increasing the wood moisture content and adhesive open assembly time. In addition, the increased closed assembly time caused a decrease in bonding strength of wood. The ANN results were compared with the results obtained from the MLR model to evaluate the models’ predictive performance. It was found that the ANN model with the R2 value of 97.7% and the mean absolute percentage error of 3.587% in test phase exhibits higher prediction accuracy than the MLR model. The comparison results confirm the feasibility of ANN model in terms of predictive performance. Consequently, it can be said that ANN is an effective tool in predicting wood bonding strength, and quite useful instead of costly and time-consuming experimental investigations.

POLİVİNİLASETAT TUTKALI İLE YAPIŞTIRILMIŞ DOĞU KAYINI (Fagus orientalis Lipsky) VE DOĞU LADİNİ (Picea orientalis (L.) Link.) ODUNLARININ YAPIŞMA PERFORMANSI ÜZERİNE SUDA BEKLETME FAKTÖRLERİNİN ETKİLERİNİN ARAŞTIRILMASI

Odunun yapistirici bagi odun kaynaklarinin etkili kullaniminda anahtar bir faktordur. Bu nedenle, bir yapistirici ile birlestirilen odun urunlerinin performansinin farkli sartlar altinda degerlendirilmesi oldukca onemlidir. Bu calismada, PVAc ile yapistirilan odun ornekleri farkli sicakliktaki suya (20, 40, 60 ve 80oC) farkli sureler (10, 20, 30 ve 40 dakika) icin maruz birakilmistir. Deneysel sonuclar incelendiginde, PVAc ile yapistirilmis odun orneklerinin suya maruz birakilmasi ile orneklerin yapisma direncinde onemli derecede bir dusus oldugu gozlemlenmistir. Direnc degerlerinde gozlemlenen bu dususler ozellikle 60 °C ve uzerindeki sicakliktaki su ile muamelede daha ciddi oranlara ulasmistir. Ayrica, direnc degerlerindeki dususler maruz birakilan surenin artisi ile genellikle artmistir.

The bending and tension strength of furniture joints bonded with polyvinyl acetate nanocomposites

Furniture is the general name given for the portable equipment used in various human activities such as seating, working and relaxing. They can be a product of design and is considered a form of decorative art. They can widely be manufactured with different adhesives. Biodegradable and biobased adhesives which have no toxic compounds and non-dangerous elements have been selected since the furniture is generally benefited in interior locations. Meanwhile, polyvinyl acetate (PVAc) is a thermoplastic polymer which is widely used in the furniture industry. In this study, tension and bending strength of the furniture joints bonded with polyvinyl acetate adhesives filled with nano-TiO2 and nano-SiO2 were investigated. Three materials; oak (Quercus robur) wood, beech (Fagus orientalis) wood and plywood made with beech veneers were selected, and the joints were prepared by mortise and tenon joints. The results showed that the maximum value for the tension strength and bending strength were obtained to beech wood and oak wood in 2% addition of nano-SiO2 fillers. The minimum values for the tension and bending strength nano-SiO2 were found to plywood and 4% loading.