Utilization of waste tire rubber in manufacture of oriented strandboard Nadir Ayrilmis * , Umit Buyuksari 1 , Erkan Avci 2 Istanbul University, Forestry Faculty, Department of Wood Mechanics and Technology, Bahcekoy, Sariyer, 34473 Istanbul, Turkey article info Article history: Accepted 28 May 2009 Available online 23 June 2009 abstract Some physical and mechanical properties of oriented strandboards (OSBs) containing waste tire rubber at various addition levels based on the oven-dry strand weight, using the same method as that used in the manufacture of OSB. Two resin types, phenol–formaldehyde (PF) and polyisocyanate, were used in the experiments. The manufacturing parameters were: a specific gravity of 0.65 and waste tire rubber con- tent (10/90, 20/80 and 30/70 by wt.% of waste tire rubber/wood strand). Average internal bond values of PF-bonded OSB panels with rubber chips were between 17.6% and 48.5% lower than the average of the control samples while polyisocyanate bonded OSBs were 16.5–50.6%. However, water resistance and mechanical properties of OSBs made using polyisocyanate resin were found to comply with general-pur- pose OSB minimum property requirements of EN 300 Type 1 (1997) values for use in dry conditions at the lowest tire rubber loading level (10%) based on the oven-dry panel weight. The tire rubber improved water resistance of the OSB panel due to its almost hydrophobic property. Based on the findings obtained from this study, we concluded that waste tire rubber could be used for general-purpose OSB manufactur- ing up to 10% ratio based on the oven-dry panel weight. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Oriented strandboard (OSB) is a structural panel made of wood strands that are arranged in cross-oriented layers, similar to ply- wood. OSB is equivalent to other structural panels such as plywood and fiberboard in its strength and rigidity, panel size and thickness, fastener performance and paintability. Since its debut in 1978, OSB has been gaining rapid acceptance as a structural panel. OSB is widely used in residential and commercial construction. OSB has virtually replaced plywood in new residential construction in many areas of Turkey. In the recent years, there has been widespread interest in the manufacture of products from recycled materials. The advantages of doing this is that material recycling makes the technology more economically and environmentally attractive (Song and Hwang, 1997). Waste tires are a major concern because the amount of waste tires is increasing more and more due to the increasing de- mand for tires and because of their short lifetime. Therefore, it is necessary to develop methods for recycling waste tires. European Tyre Recycling Association (ETRA) Conference 2007 in Brussels, Belgium estimated that the equivalent of 300 million or more scrap tires reach their end-of-life each year in the 27 member states of the European Union. It also estimated that similar amounts are found in North America, Latin America, Asia and the Middle East and that the global contamination total is probably over 1 billion passenger car tire equivalents per year (Anonymous, 2007). The disposal of used automotive tires has caused many environ- mental and economical problems to most countries. A typical scrap tire (passenger car) weighs approximately 9 kg and will provide approximately 60 wt.% rubber, 20 wt.% steel and 20 wt.% fiber and other waste products (Amirkhanian and Arnold, 1993). One of the main characteristics of rubber tires is their high volatile and fixed carbon contents with heating value greater than that of coal. But some environmental concerns rose during the last years regarding the incineration of tire rubber (Stefani et al., 2005). Therefore, some efforts in the recycling of tires after its service per- iod were recently carried out. Effectively recycling waste tires such as manufacturing wood– rubber based composites could be one of the solutions (Jun et al., 2008). Song and Hwang (2001) examined the wood waste tires composites and found that the ratio of wood fiber to rubber parti- cles and amount of diphenylmethane diisocyanate (MDI) were the significant factors that influenced board mechanical properties. MDI could excellently bond the wood fiber and waste rubber par- ticles together. The use of rice husk as filler for this purpose has been recently proposed (Yu et al., 2001; Hua, 2001; Yang and Zhang, 2004). In these previous studies, agricultural lignocellulosic fiber (rice straw)-waste tire particle composite boards were able to be used as a substitute for insulation boards and constructional panels in construction were reported. In addition, rice straw and waste tires composites also had better sound insulation, durability, heat insulation, and energy absorption. 0956-053X/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.wasman.2009.05.017 * Corresponding author. Tel.: +90 212 226 1100/25083; fax: +90 212 226 1113. E-mail addresses: nadiray@istanbul.edu.tr (N. Ayrilmis), buyuku@istanbul.edu.tr (U. Buyuksari), avci@istanbul.edu.tr (E. Avci). 1 Tel.: +90 212 226 1100/25356; fax: +90 212 226 1113. 2 Tel.: +90 212 226-1100/25362; fax: +90 212 226 1113. Waste Management 29 (2009) 2553–2557 Contents lists available at ScienceDirect Waste Management journal homepage: www.elsevier.com/locate/wasman