Sound Absorbing Panels from Poly(lactic acid) Non-woven Fabric and Natural Fibers

This research studied the utilization of biodegradable polymer for nonwoven fabric production and applied to fabricate a sound absorbing panel by corporate with natural fiber nonwoven fabric. PLA was used as a biodegradable polymer and hemp nonwoven was used as a natural fiber nonwoven fabric. PLA nonwoven fabric was prepared using a melt jet spinning process. The spinning process was carried out at 250 and 260°C with screw speed of 10 rpm and air blown pressure of 0.3 and 0.5 MPa. The die-to-collector of fabric production was studied at 30 and 60 cm to compare the nonwoven fabric product property. It was found that the process temperature, air pressure and die-to-collector distance have significant effects on the nonwoven fabric thickness, GSM, and fabric density. Air permeability decreased with high fabric thickness as well as fine fibers which supported the property of sound absorbing panels. Therefore, the suitable conditions for sound absorbing panel fabrication were processed at temperature of 260°C, air pressure 0.5 MPa and die-to-collector distance of 60 cm. Sound absorbing coefficient measurement revealed that GSM fabric thickness had an effect on increasing sound absorption. The effect of nonwoven sheet order and arrangement of PLA nonwoven and hemp nonwoven of 3 layers sandwich indicated that the layers order of PLA/PLA/Hemp had high sound absorbing coefficient that was comparable with PLA/PLA/PLA due to fiber size and arrangement.