Characterization of bagasse binderless particleboard manufactured in high-temperature range

Abstract

This paper describes the features of binderless particleboard manufactured from sugarcane bagasse, under a high pressing temperature of 200–280 °C. Mechanical properties [i.e., modulus of rupture (MOR) and elasticity (MOE) in dry and wet conditions, internal bonding strength (IB)] and dimensional stability [i.e., thickness swelling (TS)] of the board were evaluated to investigate the effect of high pressing temperature. Recycled chip binderless particleboards were manufactured under the same conditions for comparison, and particleboards bonded with polymeric methylene diphenyl diisocyanate (PMDI) resin were manufactured as reference material. The target density was 0.8 g/cm3 for all of the boards. The results showed that the mechanical properties and dimensional stability of both types of binderless boards were improved by increasing the pressing temperature. Bagasse showed better performance than that of recycled chip as a raw material in all evaluations. Bagasse binderless particleboard manufactured at 260 °C had an MOE value of 3.5 GPa, which was equivalent to the PMDI particleboard, and a lower TS value of 3.7 % than that of PMDI particleboard. The MOR retention ratio under the dry and wet conditions was 87.0 %, while the ratio for the PMDI particleboard was only 54.6 %. The obtained results showed the possibility of manufacturing high-durability binderless particleboard, with good dimensional stability and water resistance, which previously were points of weakness for binderless boards. Manufacturing binderless boards under high temperature was effective even when using particles with poor contact area, and it was possible to express acceptable properties to allow the manufacture of particleboards. Further chemical analysis indicated a contribution of a saccharide in the bagasse to the improvement of the board properties.