Manufacturing Process and Property Analysis of Sound Absorption Sandwich Board

Typical fabric sound absorbing materials have excellent absorbing property in high frequency, but in low frequency the absorbing performance is bad. In this study the flame retarded hollow 3D crimp PET fiber and low melting point PET fiber were used to manufacture sound absorption sandwich board (SASB). By changing the skin material of sandwich structure that the low frequency of sound absorbed will improve. The SASB was combined with two skin materials and one core material. The skin materials were manufactured into the nonwoven fabrics by needle punched and thermal compressing process. The skin materials have two different thickness (0.02 mm and 0.5mm).The core material was combined five layers of loose nonwoven fabrics and bonding by thermal compressing at the same gauge (15 mm). The sound absorbing properties of core material and sandwich board were analyzed. The sound absorbing property was evaluated using two microphone impedance tube according to ASTM E1050-98. When the skin material thickness is 0.02 mm, both of the high frequency and low frequency sound absorption was optimized. When the skin material thickness is 0.5mm, the sound absorbing property is similar to typical fabric material. The high frequency sound absorption is excellent, but the low frequency sound absorption is bad.