THE EFFECT OF TIME AND EDGE BANDING TYPE AND THICKNESS ON THE BENDING AND TENSILE STRENGTH OF MELAMINE COATED PARTICLEBOARD Cevdet SAÇLI Department of Materials and Material Processing Technologies, Technical Sciences College, Selcuk University, 42003 Konya, Turkey Key words Abstract Bending strength, Edge banding is used to surround the exposed sides of wood composite Heat threatment, such as particleboard, melamine coated particleboard (Mcp), and low, Tensile strength, medium and high density fiberboard. Day and night air temperatures in Wood composite. various regions in Turkey ranging from -5 to +35°C on average have been adopted. In this study, the results of the effect of aging at 12 hour intervals werw monitored. The transition times involved +35 to -5 and -5 to +35°C temperature. This study was carried out to determine the effects of the time and edge banding material which are melamine thickness of 0.4 mm, and polyvinylchloride (PVC) thickness of (0.4, 0.8, 1.0 and 2.0mm), and wood composite panel type on bending and tensile strength properties of (Mcp). Edge band type, thickness, and the effect of heat treatment of the application for bendig strength increases totally 99% and tensile strength increases totally 139%. Corresponding author: [email protected]. Saclı C. Department of Materials and Material Processing Technologies, Technical Sciences College, Selcuk University, 42003 Konya, Turkey 1. INTRODUCTION Over the past several decades, industrial grade composite wood based panel (CWP) have been recognized through the furniture industry as an ideal substrate for Mcp constructions, utilizing various types of overlay surfacing and edge banding materials. Edge banding is perceived as the most important accessory and protective in furniture making. There are various types of edge banding materials such as polyvinylchloride (PVC), acrylic, acrylonitrile butadiene styrene (ABS), melamine, solid wood or wood veneer comprise the types of edge banding materials. During the past decades, there has been successful work accomplished in the (CWP) industry. Lee and Kim [1] found out that there was a significant increase in the modulus of elasticity of wood based composite panels due to coatings. Nemli [2] examined the effects of melamine-impregnated papers coating on the properties of particleboard and stated that surface coating improved the physical, mechanical properties and decreased the formaldehyde emission of particleboard. The purpose of edge banding will be to suppress the absorption of water and humidity and providing a contrasting finish for all decorative surfaces [3]. Interior fitment and furniture manufacturers are applying widespread ratios of decorative composite edge banding materials for (CWP). CWPs are mostly used in construction of home, Saçlı (2015). “The effect of time and edge banding type and thickness on the bending and tensile strength of melamine coated particleboard” Proceedings of the 27th International Conference Research for Furniture Industry September 2015, Turkey office and school furniture. The purpose of edge coating of CWPs is to suppress the absorption of water and humidity, and esthetic [4]. The performance of the coated panels is depended on quality of CWP and the type of coating materials [5]. While particleboard and medium-density fiberboard make ideal substrates, the manufacturer must pay attention to the many factors that will affect surface quality in virtually every step of manufacturing process [6]. Page | 469 Özçifçi [7] studied some corner joints obtained from particleboard, and covered their edges for case furniture with massive wood. Then, ‘‘L” test samples manufactured and jointed with dowel, rebated, tonque-and-rebated joint types by using polyvinyl acetate (Pvac) (Vinyl Acetate Homopolymer) adhesive. In the test, compression and tension strength tests were applied on the bonding area. As a result, the highest compression and tension strength were obtained in dowel joint. Uysal [8] investigated the effects of the thickness of solid wood edge banding strips and the dowel diameter on the withdrawal strength of beech dowels in particleboard. Withdrawal strengths were measured for the prepared test samples and the highest withdrawal strength was obtained in particleboards with12.0 mm edge banding thickness and with 6.0 mm diameter dowel. With the start of production of MCP and PVC edge bands bleating technical, aesthetic and economic reasons, has gained a very high demand. Pvc edge bands used intensively on furniture industry. Studies in the literature examining the effects of time and temperature based on the mechanics worked on this issue due to insufficient. This study time limits 20, 30, 40 and 50 days, teperature limits +35°C to -5°C Unaged IB and aged IB values of all the treated specimens at three retention levels significantly decreased when compared to untreated control values. The IB strength and bond durability of all the treated panels decreased with increasing chemical content [9]. Özçifçi investigated the role of geometry on the mechanical performance of scarf joints in laminated veneer lumber (LVL) bonded with phenol formaldehyde and melamine formaldehyde (MF) adhesives. It was observed that the highest bending strength (291.5N/mm2) and modulus of elasticity (28101N/mm2) were obtained in control (solid wood) samples having three layered LVL, jointed with 30° angle and bonded with MF adhesive. As a result of the effects scarf joints on bending strength and modulus elasticity test, if the scarf angle decreases, the properties of LVL increase [10]. Güntekin studied some mechanical and physical properties before and after accelerated aging tests of the cement bonded fiberboard made of using Calabrian pine fibers. Increase of density and percent of accelerators used generally causes an increase in mechanical properties. Percent accelerator also caused an increase in TS and WA. Increase of fiber / cement ratio resulted in an increase in MOR, TS, and WA while a significant decrease was observed for modulus of elasticity [11]. Saçlı (2015). “The effect of time and edge banding type and thickness on the bending and tensile strength of melamine coated particleboard” Proceedings of the 27th International Conference Research for Furniture Industry September 2015, Turkey Yıldız et al. studied the effects of heat treatment on compression strength (CS) of spruce wood (Picea orientalis). This study indicated that the changes in the chemical structure of the treated wood were determined by analyzing contents of cellulose, hemicelluloses and lignin. Heat treatment was applied on the test samples in an oven at four different temperatures (130, 150, 180 and 200 1C) and three different durations (2, 6 and 10 h) under atmospheric pressure. The results indicate that the effects of heat treatment on CS values generally Page | 470 exhibited a decrease with increased duration and temperature. It was observed that hemicelluloses were the wood-cell components most degraded by the heat treatment [12]. The tests of Mirski et al’s showed that PF resin modification with diol esters makes it possible when maintaining identical pressing parameters to manufacture particleboards with improved mechanical properties and enhances water resistance in comparison to the control board resinated with pure PF resin. The application of diol esters as modifiers of phenol resin makes it also possible to produce at reduced temperature or shortened pressing time particleboards with good mechanical properties and high water resistance [13]. Papadapoulos Antonious studied physical properties of conventional particleboard bonded with amounts of UF and PMDI resin and examine the effect of mat moisture content (MC), wax content and platen temperature on their bonding efficiency, as determined by internal bond strength. It was found that PMDI not only gave superior board properties compared with the UF, but the amount required was reduced considerably as well. The MC of the mat and the platen temperature did not significantly affect the bonding efficiency of PMDI bonded boards, but the bonding efficiency of UF bonded boards. The inclusion of 1% wax significantly affected the bonding efficiency of both resins; however the loss in strength was higher in UF than PMDI bonded boards [14]. P. Bekhta et.al. studied on Short-term effect of temperature on bending strength of wood- based panels. Accordig to this study; Bending strength of different wood-based panels such as particleboard, MDF and OSB has been studied at temperatures between +20°C and +140°C. It was found that the temperature for all studied panels significantly affects bending strength. After one-hour effect of the temperature 140°C the bending strength of panels is reduced (in comparison to the temperature of 20°C) [15]. Kakaras and Papadopoulos found that the internal bond strength was significantly increased by increasing the drying temperature. This was attributed to the breakdown of the particles dried at high temperatures [16]. Increasing the resin content definitely improved the performance of the specimens, apparently because the extra binder increased the resistance of the board to springback and differential shrinkage stresses [17]. One year investigation on the ageing effect and long term performance of Cement Bonded Particle Board the results from stage 1 showed that both strength and stiffness of Varco cement bonded particleboard were increasing consistently although the test results showed much better performance than those required in EN