Effect of UF and MUF resins on the practical properties of particleboard produced from rice straw and aspen particles

The effect of using UF and MUF resins on physical and mechanical properties of particleboards made of rice straw and aspen particles was investigated. The aim of the study was to determine physical and mechanical properties of rice straw particleboard. Single-layer particleboard was produced with 11% MUF and 11% UF. In order to use UF and MUF, 2% hardener was added to adhesives. The Press condition for MUF was: 1750C for 4 minutes and for UF application was 1750C for 6 minutes. Another variable factor was the rice straw content in three levels (15%, 30% and 45%). Other factors such as board density (0/7gr/cm3) and mat moisture (12%) were the constants. The results indicate that increasing rice straw to wood particles cause some reduction in modulus of rupture, and internal bonding, and to some extent increase in thickness, swelling and water absorption of manufactured boards. But comparing and grouping means by duncan test showed that when up to 30% rice straw was added to wood particle these effects remained mostly insignificant. Particleboard bonded with 11% MUF had the highest bending strength. Particleboards bonded with MUF had better bending strength, shear strength, thickness swelling and water absorption after 2 and 24 hours immersion. Grouping the experimental data while using Duncan method was indicated the fact that an optimum condition for manufacturing particleboard while using a mixture of rice straw and wood particles is to add 30% rice straw to the mixture, use 11% melamine urea formaldehyde resin and employ a pressing time of 4 minutes.