Effects of sawdust and adhesive type on the properties of rice husk particleboards

Abstract

This study set out to investigate the effects of adhesive type, rice husk and sawdust proportions on the properties of composite particleboards. Specimens of 200 × 200 × 24 mm were made by blending 500 g of rice husks with each adhesive type at a mass ratio of 1:1. The rest of the specimens of similar dimensions were prepared with addition of sawdust in the range of 10–40 wt%, while maintaining the ratio of biomass particles to adhesive at 1:1. Three commercial synthetic adhesives Fevicol (FV), Ponal (PA) and woodfix (WF) were used. The particle adhesive mixtures were molded into a mat which was subsequently cold pressed at 10 MPa and left to dry in air. Density, water absorption (WA), linear expansion (LE), thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR) and screw holding capacity of the specimens were evaluated. Adhesives were found to have over 42% solid content, with similar liquid constituents but in varying proportions. FTIR library search for the spectra of FV, PA, and WF revealed correlations of 82.5%, 78.6%, and 50.2%, respectively with polyvinyl acetate. The developed boards had a density of 510–610 kg/m3, MOE 13–26 MPa, TS 9–31%, and LE 3–7%. These properties suit them for furniture boards and soundproofing. The properties improved with the increasing proportion of sawdust. FV and PA-bonded particleboards exhibited higher stability and strengths than WF-bonded particleboards due to higher concentrations of polyvinyl-acetate in the latter. Blending 40 wt% sawdust, 10 wt% rice husk with 50 wt% of either FV or PA showed better prospects.

Description

Keywords

Adhesives, Particleboards, Properties, Rice husks, Sawdust

Citation