Abstract: In order to investigate the sound insulation performance of multilayer composite meltblown nonwovens, thirteen 6-layers composite meltblown nonwovens were prepared using the calendering method.The corresponding single-layer meltblown nonwovens were produced by combining metering pump frequency, mesh belt frequency and the distance from die to collector in different ways. The sound insulation performance is characterized by transmission loss, and the above composite meltblown nonwovens were tested in this way. The results show that the transmission loss is the function of audio frequency.

Transmission loss decreases with the increase of frequency in the low-frequency band. In addition, it fluctuates acutely in the middle-frequency band and reaches its lowest point as the frequency approaches 630 Hz. Furthermore, transmission loss grows with the increase of frequency in the high-frequency band and reaches its highest point when the frequency is about 10000 Hz. When the metering pump frequency  changes, the transmission loss does not show a significant increase or decrease trend. The increase in mesh belt frequency makes the transmission loss decline significantly. With the increase of the distance from die to collector, the transmission loss shows a slightly downward trend.

Key words: composite meltblown nonwoven; calendering; transmission loss; process parameter