Some physical and strength properties of plywood manufactured from Nigerian timbers
Some physical and strength properties of plywood manufactured from Nigerian timbers
Ioryisa Verinumbe
ABSTRACT
Tests were conducted on five sheets of plywood made from Nigerian-grown species, to determine some physical and mechanical properties. The plywood contains 3 plies: 1mm thick Antiaries Africana facings and 4mm thick Terminalia superba as core. Static binding strength, impact strength, density, moisture content, and glue bond quality were determined as specified in B.S. 4512 (1969) and B.S.1445 (1972). modulus of rupture (MOR), modulus of elasticity (MOE), impact strength, density, moisture content and glue bond quality of samples from each of 5 boards were determined. The mean value for MOR was 47.38 N/mm2 and 31.76 N/mm2 (perpendicular and parallel to grain of face veneer respectively. MOE parallel to grain was 19209.44 N/mm2 and MOE perpendicular to grain was 3498.29 N/mm2. Mean density and moisture content as received was 597.65 kg/m3 and 9.84% respectively. At the testing conditions of 65% relative humidity and 200 C, mean density was 589.85 kg/m3 while moisture content was 8.37%. Impact strength had the mean value of 198.80 mm while the glue bond quality was 5.0(50%). These properties suggest high acquisition by structures made of the plywood. Except for the between board glue bond quality, there was no significant variation between the ply-woods tested (p>0.05).
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March 1985
Vol. 35, Iss. 1
