Development and Research of Recyclable Composite Metamaterial Structures Made of Plastic and Rubber Waste to Reduce Indoor Noise and Reverberation

According to the Waste Management Policy of the European Union, the recycling and reuse of various wastes is considered the most ecological and advanced waste disposal technology with the lowest impact on the environment. By applying circular economy principles, plastic waste will extend its life cycle and be used as secondary raw materials to create structures with good sound insulation and absorption properties. Structures created from metamaterial with plastic were studied for their sound-absorbing properties in an impedance tube. A combined 100 mm long resonator design with a 2.0 mm perforation, 20 mm thick plate, regardless of whether it is an “X”- or “O”-shaped resonator, achieved a good sound absorption peak at 315 Hz of 0.94. When the combined structures of 50 mm long “X”- and “O”-shaped designs were compared, different sound absorption peaks at high frequencies were achieved. A slightly better sound absorption peak of 0.95 was achieved at 500 Hz with the “O”-shaped resonator and 0.93 at 630 Hz with the “X”-shaped resonator. The results show that the combined plastic and rubber structures can be integrated into building structures and be used as an alternative to improve building acoustics and reduce noise and reverberation