Sound absorption application of fiberglass recycled from waste printed circuit boards

Nonmetal materials of waste printed circuit boards (PCBs) contain 50–70 wt% fiberglasses, which are usually abandoned as waste-byproducts during the recycling of waste PCBs. In this paper, we demonstrated a novel reuse of the fiberglasses recovered from waste PCBs for noise reduction application. The sound absorption performance of the recovered fiberglasses (RFG) was investigated by considering the effect of material thickness and bulk density. Also, the influence of covering layers on the absorption ability was studied. Results show that the high porous structure of the RFG leads to an excellent sound absorption ability in a broad-band frequency range. Average sound absorption coefficient of over 0.8 can be achieved in 100–6,400 Hz for 30 mm RFG sample. It is found that when the sample thickness increases the low-frequency absorption of RFG is significantly improved. All the results indicate that the reuse of RFG for noise reduction represents a promising way to realize high value-added utilization of waste PCBs.