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PEER-REVIEWED ARTICLE
Today, recycling waste products by utilizing them in manufacturing processes is very attractive because it can prevent environmental pollution and lower production costs (Ayr ı lmi s et al. 2009). Polyethylene is a material that is not able to biodegrade rapidly in the environment. In order to recycle such materials, different kinds of waste products have been increasingly used (Prideaux 2007). Yilgor et al . (2014) manufactured wood based panels using waste Tetra Pak material and evaluated some chemical and physical properties as well as biological, weathering, and fire performance. In their study, Ozdemir and Mengeloglu (2008) showed that thickness swelling and water absorption properties of recycled high density polyethylene (HDPE) based wood plastic composites decreased. In the literature, there is no information related to the effects of waste polyethylene on the physical and mechanical properties of OSBs. Therefore, this study offers a solution to the waste polyethylene problem by investigating the effects of WPE on some physical (density, humidity, dimensional changes, thickness swelling, and water absorption) and mechanical properties (internal bond, modulus of elasticity, modulus of rupture, and screw withdrawal) of OSB panels produced by adding WPE in different ratios. In this study, Scots pine wood ( Pinus sylvestris L.) was used in the manufacture of the OSBs. The strand dimensions were approximately 80 mm long, 20 mm wide, and 0.7 mm thick. Resin, containing 47% liquid phenol-formaldehyde (pH 10.5), was applied at a 6% ratio, based on the weight of the oven-dry wood strands for all boards produced. WPE granules between 0.7 mm and 1.3 mm in thickness were chosen from industrial waste polyethylene. Low-density polyethylene typically has a density value ranging from 0.91 to 0.925 g/cm 3 and Scots pine wood has a density of 0.56 g/cm 3 . Panel Manufacture Six panels, including one control panel (non-WPE) and five panels manufactured with different ratios of WPE (10/90, 20/80, 30/70, 40/60, 50/50) by weight, were tested for physical and mechanical properties. Two boards for each combination of variables and total of 12 boards were produced. Dimensions of the boards were 500 mm x 500 mm x 12 mm. OSB panels were aimed to manufacture with a density of 0.65 g/cm 3 . The panels were manufactured with three layers and particle weight ratios of 25:50:25 (face, core, and face, respectively). The core layer was spread perpendicular to the face layers. The waste polyethylene was used in all layers homogeneously. Polyethylene capped the pores among strands when it melted. The wood strands were dried to 3% moisture content, and then the resin was sprayed straight away once the wood strands got out from the dryer for 3 min. The OSBs were manufactured in the Laboratory of Forestry Faculty, Karabuk University. All mats were pressed in a hot press at a temperature of 180 °C and a pressure of 3.92 N/mm 2 for 9 min to 12 mm- the target thickness. Evaluation of Physical and Mechanical Properties After the pressing process, the boards were conditioned at 65 ± 5% relative humidity and at a temperature of 20 ± 2 °C until their weight was stable (ISO 554 (1976)). The moisture content and density, thickness swelling, water absorption, modulus of rupture EXPERIMENTAL Materials
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Yorur (2016 ). “Waste PE and effects on OSB,” B io R esources 11(1), 2483-2491.
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