Preparation and evaluation of particleboard from insect rearing residue and rice husks using starch/citric acid mixture as a natural binder

This study evaluated the feasibility of manufacturing particleboard from the combinations of insect (black soldier fly larvae) rearing residue and rice husks at different ratios using citric acid/tapioca starch as a natural binder. Physical and mechanical properties of particleboards including density, moisture content, water absorption, thickness swelling, modulus of rupture, modulus of elasticity, internal bond strength, and screw withdrawal resistance were investigated. The results showed that the increase of insect rearing residue significantly increased the water absorption and thickness swelling and decrease the modulus of rupture. The modulus of elasticity, internal bond strength, and screw withdrawal resistance was slightly enhanced when the ratio of insect rearing residue was increased from 10 to 30 wt% with a corresponding reduced ratio of rice husk in the particleboards. Nevertheless, the modulus of elasticity, internal bond strength, and screw withdrawal resistance remarkably decreased when the ratio of insect rearing residue in the boards was over 30 wt%. Among all prepared particleboards, only particleboard B which was composed of 20 wt% insect rearing residue, 50 wt% rice husk, and 30 wt% binder met all the JIS A 5908 requirements for basic particleboard type 8. Based on the results, although further improvements are required, using insect rearing residue combined with agroindustrial wastes for particleboard manufacturing is feasible and possesses the patentability to mitigate the issues associated with deforestation and shortage of raw materials.