Effect of Pretreatment and Production Variable on the Sorption and Strength Properties of Cement Bonded Board

Abstract

This study was carried out to investigate the effect of pretreatment on the sorption and strength properties of board manufactured from Gliricidia sepium sawdust. Twenty four (24) experimental boards were produced at three pretreatment levels of hot water (1 h), cold water (2 weeks and 4 weeks), three mixing ratios (1:1, 2:1 and 1:2), and one board density 700 g/m³. and test for their bonding strength by physical (water absorption-WA and thickness swelling-Th.S) and mechanical properties (modulus of elasticity-MOE, modulus of rupture-MOR). Data obtained was analyzed using analysis of variance at α = 0.05. The result showed that board produced from mixing ratio 1:2 (sawdust to cement) of hot water for 1 h pretreatment is more dimensionally stable since it has the least mean values 44.10 and 50.23 % for water absorption and 1.17 and 2.76 % for thickness swelling in 1 and 6 h immersion and highest mean values of 68.94 and 0.33 N/mm² for modulus of rupture and elasticity respectively. However, the analysis of variance shows that pretreatment levels and production variables have a significant effect on the physical and mechanical properties examined thus increase in pretreatment and mixing ratio resulted in the improvement of dimensional stability and increase in the strength properties of the board produced.

Keywords: sawdust, pretreatment, particleboard, strength properties

DOI: 10.7176/JNSR/11-20-03

Publication date:October 31^st 2020