Effect of adding rubber powder to poplar particles on composite properties

The effect of adding rubber powder derived from waste tires to poplar wood particles on mechanical and water-resistant properties of particleboards was examined. Sixty panels were made with rubber contents of 0–40% at hot-pressing temperatures of 140–180 °C, methylene diphenyl diisocyanate resin contents of 2–6% and panel densities of 0.6 to 1 g cm−3. Although the modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB) strength were reduced by adding rubber powder, the thickness swelling (TS) was reduced by 7.3–61% when 10–40% rubber powder was added. Four regression equations (rubber content, pressing temperature, resin content and target panel density as functions of MOR, MOE, IB and TS) were developed and a nonlinear programing model was derived with operation research theory to obtain the most desirable panel properties under some production constraints.