Physical and mechanical properties of wood plastic composite particle boards produced from the combination of Gmelina arborea and Khaya senegalensis sawdust and polyethylene terephthalate

Abstract

The study investigated the properties of wood-plastic composite (WPC) boards produced from a combination of G. arborea and K.  senegalensis sawdust with Polyethylene Terephthalate (PET). G. aborea and K. Senegalensis sawdust and PET were collected and  prepared. The experiment design was 2 x 2 x 10 (2 types of plastic, 2 types of sawdust and 10 types of composite mixture) factorial in Completely Randomized Design (CRD). A composite board was produced using a rectangular mould size of 2x17x16 cm. Sample mixtures  were in the ratio of 100%, 50:50, 70:30, 60:40, 30:70 mixed thoroughly with a thermo setting adhesive and poured in a flat mould of 2 cm  and pressed using pressing machine for 5 minutes to allow proper curing of the adhesive. Data was collected on density, shattered index,  shattered resistance, compressive strength parallel to grain modulus of elasticity, and modulus of rapture and analyzed using  analysis of variance (ANOVA) with Multiple Range Test as follow up test. The results showed that the density of boards ranged from 0.34  to 0.55 g/cm³ , with the highest density observed in the treatment containing PET and G. arborea (30:70). Shattered index ranged from  5.00% to 6.99%, with the lowest index observed in the treatment containing G. arborea and K. senegalensis (60:40) and the highest index  in the treatment containing 100% PET. The shattered resistance ranged from 93.01% to 95.00%, with the highest resistance observed in  the treatment containing G. arborea and K. senegalensis (60:40). Modulus of Elasticity (MOE) ranged from 1.88 N/mm2 to 8.16 N/mm² ,  with the highest value in the treatment containing 100% G. arborea. Similarly, the Modulus of Rupture (MOR) ranged from 2.68 N/mm² to  10.43 N/mm² , with the highest value in the treatment containing 100% G. arborea. Compressive strength ranged from 135.63 N/mm² to 153.19 N/mm² , highest value in the treatment containing PET and G. arborea (70:30). There were no significantly different among  WPC boards treatments. It was concluded that the combination of G. arborea and K. senegalensis sawdust with PET produced composites  with higher MOE, MOR, and compressive strength compared to the treatment containing only PET.