High quality sugarcane bagasse-citric acid particleboards

The productivity of Indonesian sugarcane plantation, especially in East Java province reached 1.186.515 tonnes in 2017. Sugarcane liquid is extracted as sugar raw material and set aside sugarcane bagasse as waste of about 30% from total sugarcane weight. Usually sugarcane bagasse is burned to operate boiler in sugarcane mill. Meanwhile, the utilization of sugarcane bagasse, combine with citric acid for high quality particleboards production would be highly recommended. In this study, effect of citric acid content and pressing temperature on sugarcane particleboards properties were analysed. The size and target density of particleboards were 300 x 300 x 9 mm and 0.8 g/cm3, respectively. Citric acid liquid (59%) were sprayed onto sugarcane particles, with varied citric acid content (10, 15, 20 % of sugarcane particle weight). To evaporate water, sugarcane particles which already contain citric acid were pre-dried in oven of 80°C for 6h until the moisture content in sugarcane particles-citric acid was less than 3%. Subsequently, the boards were produced under pressing temperature of 180°C and 200°C, for 10 min. The physical properties of boards produced using 25% citric acid and pressed at 200°C (thickness swelling 4.43%; water absorption 29.48%) were superior than the others boards. The infrared (IR) spectra analysis showed the presence of ester linkage, representing that the carboxyl groups of citric acid had reacted with the hydroxyl groups of the sugarcane particles, providing the boards good physical properties. The boards mechanical properties were fulfilled the requirement of the JIS A 5908:2003 for particleboards type 18 (modulus of rupture 21.88 N/mm2, modulus of elasticity 3944 N/mm2, internal bond 1.03 N/mm2, screw withdrawal 393 N).