Application of 3D printed structured materials as the sound absorption panels

Abstract

The human living standard has been increasing day-by-day. Not only the building energy performance has to meet a high expectation, but the noise quality of a building has to be par with it. Sound absorption is one of the key elements in determining the quality of the acoustics performance in a room. A room with high background noise and high reverberant time will affect the comfort level of the occupants in the room. Hence, a well-designed room with acoustics treatment is required. The sound absorptive materials play an important role in reducing the overall sound pressure level in the room. Conventionally sound absorber materials are porous and resonator. With the advancement of the addictive technology, the sound insulation materials can be further improved and optimized with 3D printed structured materials. Two 3D printed structured designs have been developed in this study and were printed out by using fused deposited modelling in 3D printing technology. The two designs are micro perforated design (MPP) and porous design. The structured materials have been tested for its sound absorption ability using the sound impedance tube. The frequency range tested is between 100 Hz to 6400 Hz. In conclusion, micro perforated design (MPP) model has a very good sound absorptive behavior at the low frequency at 4000Hz and below, whereas the porous model is effective at high frequency at the 2500Hz and above. Through the study, the perforation ratio is found to be closely related to the peak sound absorption coefficient frequency. The peak frequency is reduced with the increase of the perforation ratio. The gap between the 3D printed structured materials and end wall also play the important role. The larger the gap, the lower the peak absorptive frequency.