Effect of pre-drying time and citric acid content on Imperata cylindrica particleboards properties

The utilization of natural fibers for eco-friendly particleboards production has become very important due to the decreased of wood resources and the human health concern. In this study, Imperata cylindrica particles and citric acid were used as the raw material and natural adhesive, respectively, for the particleboards production. Since citric acid solution was sprayed onto Imperata particles during particleboards production, the pre-drying treatment was needed to eliminate moisture from particles before hot pressing. The effect of pre-drying time and citric acid content on the physical and mechanical properties of the particleboards was investigated. The boards were produced under pressing conditions of 200°C for 10 min. The citric acid content was varied of 10, 15, 20 wt%. The pre-drying time was for 0, 6, 12 h. The size and target density of boards were 300 x 300 x 9 mm and 0.8 g/cm3, respectively. The physical properties of boards produced using particles after 12 h pre drying time were superior to those of the boards produced using particles after 0 and 6 h pre drying time. The thickness swelling of particleboards with 20 wt% citric acid and pre drying time of 0, 6, 12 h were 5.31%, 3.69%, 2.04%, respectively, fulfilled the requirement of the JIS A 5908:2003. The infrared (IR) spectral analysis showed the presence of ester linkage, representing that the carboxyl groups of citric acid had reacted with the hydroxyl groups of the Imperata particles, providing the boards good physical properties.