Acoustic Properties of Loose and Consolidated Nonmetal Particles from Waste Printed Circuit Boards

摘要

The aim of this study was to present a new method for resource utilization of nonmetal particles from waste printed circuit boards. Acoustic properties of loose particle mixes and their consolidated composites were investigated. Scanning electron microscopy (SEM) observation shows that the nonmetal particles exhibit high irregular shapes and forms an extensive network of micro-pores in the consolidated composites. The acoustic absorbers made from the nonmetal particles exhibit excellent sound absorption ability in broadband frequency ranges. When the particle size is larger than 0.3 mm, the average absorption coefficients are 0.79 and 0.74 for the loose and consolidated materials in the frequency range from 100 to 6,400 Hz. It was found that the consolidation process did not significantly affect the absorption performance when the particle size is larger than 0.15 mm. All the results show that the reuse of nonmetal particles from WPCB as sound absorbing materials represents a promising way for waste recycling and can also resolve both the environment pollution and the noise pollution problems.