Acoustic and Strength Characterization of Particleboard and Micronized Rubber Powder Composites

Waste rubber is abundant worldwide and threatens to be an environmental hazard for decades to come. This has led to an interest in the use of recycled rubber materials in value-added products. One such possible use is in the wood products industry. The research analyzed the strength and acoustic properties of composite pine particleboard that contained 10, 20, 30, and 40 percent micronized rubber powder, a dry powdered elastomeric crumb rubber, by weight. Methylene diphenyl diisocyanate was used as the bonding adhesive to produce five particleboard samples, including a control board. Test samples were cut from the five parent boards for use in strength and acoustic testing. Measured displacement values for a simply loaded and simply supported load scenario were used to calculate the modulus of rupture and apparent modulus of elasticity for each composite particleboard. Acoustic measurement by impedance tube provided comparisons of the sound absorption coefficient for frequencies ranging from 60 to 6,300 Hz. Results revealed that the addition of micronized rubber powder led to a decrease in modulus of elasticity and no significant difference in modulus of rupture values as compared with the control. Statistical analysis indicated a decrease in sound absorption in particleboard that contained micronized rubber powder when compared with the control.