Oriented Strand Board (Glenn Bailey)
Orientated Strand Board (OSB)
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This document is a student production providing detailed information on OSB for the Forest Products unit, Department of Forestry, Australian National University.
Examples of OSB panels (Norbord)
An Introduction to Orientated Strand Board (OSB)
History of OSB
Particle boards were first made around the time of World War Two as there was a shortage of timber in Europe. They were widely used because the process enabled wood particles from relatively useless small and/or low grade timber to be transformed into useful large wooden panels (Kubler 1980). Armin Elmendorf was the inventor of OSB, which he first described in 1949 (Elmendorf 1949). He later patent his invention in 1965 (Elmendorf 1965). A product called waferboard appeared on the market in the 1970's. It consisted of a random array of thin flakes about 50mm both in length and width (Maloney 1977). The OSB industry evolved from the waferboard industry in the late 1970's as technology and investors caught up with the concept of it. From the time of its invention, research has been conducted into the effect of chip size, the raw material used, the three layer structure, the different methods of strand alignment and the effects of the alignment itself on the strength of OSB (Avramidis 1989).The result has been the development of the commercial OSB produced by industry today.
Why is OSB so special? OSB is three times as strong as particle boards of the same density and resin content. Its three ply form has been described as comparable with Douglas fir plywood (Elmendorf 1949). It is an improvement on wafer board as it has its flakes, or strands, aligned. This alignment can take place because the strands are not dimensionally uniform (Maloney 1977), being only a third to a half of the width of those of waferboard though approximately the same length. The core flakes are aligned at right angles to surface layers. This is intended to mimic the structure, and consequently the strength properties, of plywood. In other words OSB was introduced as an attempt to compete with plywood as a structural material while using a low quality resource (Illston 1994).
Avramidis, S. and Smith, L.(1989). The effect of resin content and face-to-core ratio on some properties of oriented strand board. Holzforschung, 43(2), 131-133.
Elmendorf, A. (1965). Wood fibres from veneer waste. Proc. Forest Prod. Res. Soc. 3, 53-57.
Elmendorf, A. (1965). Oriented strand board. Patent 3, 164, 511.
Illston, J. (ed) (1994). Construction materials Their nature and behaviour. E and FN Spon, London.
Kubler, H.(1980). Wood as a building and hobby material. Wiley and sons, Inc., Canada.
Maloney, T.(1977) Modern particleboard and dry-process fibreboard manufacturing. Miller Freeman Publications, Inc., California, USA.
Norbord. Promotional brochure for Norbord Sterling OSB panel, St Bartholomews, Lewins Mead, Bristol, England, BS1 2NH.
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For further enquiries about this document, please email Peter Beutel
phone +61 6 2494412 ... fax +61 6 2490746
Department of Forestry
Australian National University
Canberra ACT 0200
Last Modified- 20/10/1996