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PEER-REVIEWED ARTICLE
Properties of Oriented Strand Boards with External Layers made of Non-Strand Chips Radosław Mirski,* Dorota Dziurka, and Adam Derkowski This study evaluated the possibility of producing oriented strand boards (OSB) from non-strand chips. Properties of the produced boards were compared with commercially available OSB/3. Research has shown that replacing the strand chips of external layers with smaller chips allowed for the manufacturing of OSB/3 using chips up to four times shorter than standard strand chips. Oriented strand board manufacturers should consider preparing a new standard and introducing the market to a new type of OSB with very good mechanical properties and made of selected strand chips comprising one of the fractions obtained during screening. Keywords: OSB; MFP; Strand; Fine chips; Mechanical properties Contact information: Pozna ń University of Life Sciences, Department of Wood -Based Materials, ul. Wojska Polskiego 28, 60- 637 Pozna ń , Poland; *Corresponding author: rmirski@up.poznan. INTRODUCTION The feature distinguishing oriented strand boards (OSB) from other wood-based boards is mainly the size of chips used for their production. In general, the chips used for this purpose should be 75 mm to 150 mm long, 5 mm to 30 mm wide, and 0.4 mm to 0.8 mm thick (Barnes 2000, 2001; Chen et al. 2008). These linear dimensions make it possible to achieve the second essential property of these boards, i . e ., chip orientation within the individual layers. Perpendicular orientation of the chips within individual layers provides very good mechanical properties along one axis of the board. Chips of this type are usually obtained from aspen, poplar, or pine. The wood used for the manufacturing of these boards should be characterized by low brittleness. Obtaining chips of these dimensions requires raw materials of considerable size, and preferably in the round form directly from the forest. This, however, significantly affects the price of the final product. Attempts at reducing the price of wood include introducing new species or using wood from fire- impacted trees (Zhang et al. 1998; Shupe et al. 2001; Hermawan et al. 2007; Moya et al. 2009; Cheng et al. 2012). The final price may be also lowered by reducing the board density or using smaller chips in the core layer (Fakhri et al. 2006a, b; Han et al. 2006, 2007; Chen et al. 2008; Mirski and Dziurka 2011a,b; Mirski and Dziurka 2015). On the other hand, research conducted by Lee and Tahir (2003) and Sackey et al . (2011) has shown that using smaller chips on the outer layers of OSB smoothes their surface and reduces the linear expansion compared to particleboard. An important alternative to OSB on the European market is multifunctional panel (MFP) construction board (Type P5, EN 312 2010), made of fine chips with geometric structures resembling the structure of chips used in the core layer of standard furniture particle boards (P2, EN 312) (Pfleiderer 2016). The modulus of rigidity in these boards is over 20 MPa, and their modulus of elasticity is greater than 3500 MPa, regardless of the direction of the sample collection. Therefore, they meet the requirements for OSB/3 boards
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Mirski et al . (2016). “Non - strand chips OSB,” B io R esources 11(4), 8344-8354.
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