Puncture-resisting, sound-absorbing and thermal-insulating properties of polypropylene-selvages reinforced composite nonwovens

In order to realize recycling of polypropylene selvages, polypropylene nonwoven selvages with different plied orientation were inserted between Kevlar/Nylon/low-melting polyester nonwoven fabrics forming composite nonwoven. Low-melting polyester content of nonwoven fabric and hot-pressing temperature of composite nonwoven were both optimized after static and dynamic puncture resistances. Moreover, effects of hot-pressing and plied orientation on static and dynamic puncture resistances, sound absorbing and thermal insulating properties of composite nonwoven were discussed respectively. Result shows that, optimal low-melting polyester fiber content was 30%, and best hot-pressing temperature for composite nonwoven was 180°C. Polypropylene nonwoven selvages improved static puncture resistance, sound absorbing and thermal insulating properties. Hot-pressing slightly increased puncture resistance and obviously improved thermal insulation, but decreased sound absorption coefficient significantly. Plied orientation affected static and dynamic puncture resistance insignificantly, but influenced on sound-absorbing and thermal-insulating properties significantly. When composite nonwoven was plied with 90°/90° polypropylene selvages and hot-pressed at 180°C, the static and dynamic puncture resistances reached 120 N and 80 N, respectively, and thermal conductivity was 0.047 W/mK. Five layers of composite nonwoven before hot-pressing had sound absorption coefficient of above 0.94 at frequency of higher than 1890 Hz.