Acoustic properties of a porous polycarbonate material produced by additive manufacturing

This paper aims to investigate the acoustic properties of porous polycarbonate material (PPM) fabricated by additive manufacturing, and the feasibility to tailor artificial porous sound absorbing material is studied. Four PPM samples with different perforation angles were printed by using a 3D printer. Poly carbonate material was used, and the samples were printed with 25.4 micrometre layer resolution. Their sound absorption coefficient was experimentally measured using the two-microphone impedance tube method. It was found that with increased the perforation angle and constant porosity, the sound absorption was decreased. The results indicated that by adjusting the perforation angle and the airgap behind the sample, significant sound absorption can be achieved in the low frequencies where conventional porous materials may not be that effective. The results obtained in this paper provide a new approach for the fabrication of new porous sound absorbing materials. (C) 2016 Elsevier B.V. All rights reserved.