Recycling Polyester and Polypropylene Nonwoven Selvages to Produce Functional Sound Absorption Composites

The consumption of polypropylene and polyester makes up over 50% by weight in the nonwoven industry and consequently the waste generated from them increases gradually every year. In this study, the polyester and polypropylene nonwoven selvages were recycled to produce functional composites. First, the two kinds of selvages were shredded and mixed in the proportion1:1, and then stirred well. The functional sound absorption composites were produced by a compress molding technique with proper parameters. Sawdust was also added in the composites to investigate the influence of processing parameters and materials on the sound absorption efficiency of the composites. The sound absorption coefficients were measured according to ASTM E 1050 by an impedance tube. The results revealed that the average of the sound absorption coefficients increased with the thickness of the composites, but decreased with the density. The effect of adding sawdust to the sound absorption efficiency of the composites was not obvious from this work.